Filed Pursuant to Rule 424(b)(5)
Registration No. 333-227182

The information in this preliminary prospectus supplement and the accompanying prospectus is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell, nor are they soliciting an offer to buy, the notes in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED SEPTEMBER 4, 2018

PRELIMINARY PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED SEPTEMBER 4, 2018

$200,000,000

    % Convertible Senior Notes due 2025

Offering Price     %

We are offering $200,000,000 aggregate principal amount of our     % convertible senior notes due 2025 (the “notes”). In addition, we have granted the underwriters an option to purchase, for settlement on or before September 28, 2018, up to an additional $30,000,000 aggregate principal amount of notes, solely to cover over-allotments. The notes will mature on September 15, 2025, unless earlier repurchased, redeemed or converted.

We will pay interest on the notes at an annual rate of     %, payable semi-annually in arrears on March 15 and September 15 of each year, beginning on March 15, 2019.

Noteholders may convert their notes at their option only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2018 (and only during such calendar quarter), if the last reported sale price per share of our common stock for each of at least 20 trading days, whether or not consecutive, during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds 130% of the conversion price on the applicable trading day; (2) during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) if the trading price (as defined in this prospectus supplement) per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions on our common stock, as described in this prospectus supplement; (4) if we call the notes for redemption; and (5) at any time from, and including, May 15, 2025 until the close of business on the scheduled trading day immediately before the maturity date. We will settle conversions by paying or delivering, as applicable, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on the applicable conversion rate(s). The initial conversion rate is                  shares per $1,000 principal amount of notes, which represents an initial conversion price of approximately $        per share, and is subject to adjustment as described in this prospectus supplement. If a “make-whole fundamental change” (as defined in this prospectus supplement) occurs, then we will in certain circumstances increase the conversion rate for a specified period of time.

The notes will be redeemable, in whole or in part, at our option at any time, and from time to time, on or after September 15, 2022 and, in the case of any partial redemption, on or before the 40th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice.

If a “fundamental change” (as defined in this prospectus supplement) occurs, then, except as described in this prospectus supplement, noteholders may require us to repurchase their notes at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date.

The notes will be our general unsecured obligations and will: rank senior in right of payment to all of our indebtedness that is expressly subordinated in right of payment to the notes; rank equal in right of payment with all of our indebtedness that is not so subordinated; effectively rank junior to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness; and rank structurally junior to all indebtedness and other liabilities of our subsidiaries (including trade payables, but excluding intercompany obligations and liabilities of a type not required to be reflected on a balance sheet of such subsidiaries in accordance with generally accepted accounting principles, or GAAP).

No public market currently exists for the notes, and we do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Our common stock is listed on the Nasdaq Global Market under the symbol “RTRX.” On August 31, 2018, the last reported sale price of our common stock was $31.69 per share.

Investing in the notes involves risks. See “Risk Factors ” beginning on page S-9.

Neither the Securities and Exchange Commission nor any state or foreign securities commission or regulatory authority has approved or disapproved of the notes or the shares of our common stock, if any, issuable upon the conversion of the notes or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

We expect to deliver the notes in book-entry form through the facilities of The Depository Trust Company on or about                 , 2018.

Joint Book-Running Managers

Prospectus supplement dated                 , 2018.

TABLE OF CONTENTS

In deciding whether to purchase the notes, you should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus and any related pricing term sheet. Neither we nor any of the underwriters has authorized anyone to provide you with additional or different information. If anyone provides you with additional or different information, you should not rely on it.

You should not assume that the information included or incorporated by reference in this prospectus supplement or the accompanying prospectus is accurate as of any date other than the respective dates of the documents in which the information is contained. Our business, financial condition, results of operations and prospects could have changed since those dates.

You should not consider any information included or incorporated by reference in this prospectus supplement or the accompanying prospectus to be legal, tax or investment advice. You should consult your own counsel, accountant and other advisors for legal, tax, business, financial and related advice regarding any purchase of the notes. Neither we nor any of the underwriters makes any representation regarding the legality of an investment in the notes by any person under applicable investment or similar laws.

This prospectus supplement and the accompanying prospectus do not constitute an offer to sell or the solicitation of an offer to purchase any notes in any jurisdiction or to any person where the offer or solicitation is not permitted.

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RISK FACTORS

Investing in the notes involves a high degree of risk. In addition to the other information contained or incorporated by reference in this prospectus supplement or the accompanying prospectus, including the risks discussed under the section captioned “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2017, you should carefully consider the risks described or referred to below before deciding to purchase the notes. The occurrence of any of these risks may materially harm our business, results of operations and financial condition. As a result, the trading price of the notes and our common stock may decline, and you might lose part or all of your investment. As used in this section, “we,” “our” and “us” refer to Retrophin, Inc. and not to its subsidiaries.

Our indebtedness and liabilities could limit the cash flow available for our operations, expose us to risks that could adversely affect our business, financial condition and results of operations and impair our ability to satisfy our obligations under the notes.

As of June 30, 2018, we and our subsidiaries had approximately $46.0 million aggregate principal amount of indebtedness for borrowed money. We will incur $200.0 million (or, if the underwriters fully exercise their over-allotment option, $230.0 million) of additional indebtedness as a result of this offering. We may also incur additional indebtedness to meet future financing needs. Our indebtedness could have significant negative consequences for our security holders and our business, results of operations and financial condition by, among other things:

Our business may not generate sufficient funds, and we may otherwise be unable to maintain sufficient cash reserves, to pay amounts due under our indebtedness, including the notes, and our cash needs may increase in the future. In addition, any future indebtedness that we may incur may contain financial and other restrictive covenants that limit our ability to operate our business, raise capital or make payments under our other indebtedness. If we fail to comply with these covenants or to make payments under our indebtedness when due, then we would be in default under that indebtedness, which could, in turn, result in that and our other indebtedness becoming immediately payable in full. For a description of our outstanding indebtedness, see “Description of Other Indebtedness.”

We may be unable to raise the funds necessary to repurchase the notes for cash following a fundamental change, or to pay any cash amounts due upon conversion, and our future indebtedness may limit our ability to repurchase the notes or pay cash upon their conversion.

Noteholders may require us to repurchase their notes following a fundamental change at a cash repurchase price generally equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes” In addition, upon conversion, we will satisfy part or all of our conversion obligation in cash unless we elect to settle conversions solely in shares of our common stock.

Further, the indenture governing the 2019 notes contains a similar definition of fundamental change, and noteholders of the 2019 notes will likely have the right to require us to repurchase their 2019 notes for cash upon the occurrence of a fundamental change at a repurchase price equal to 100% of the principal amount of the 2019 notes to be repurchased, plus accrued and unpaid interest, if any.

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We may not have enough available cash or be able to obtain financing at the time we are required to repurchase the notes and/or the 2019 notes or pay the cash amounts due upon conversion of the notes. In addition, applicable law, regulatory authorities and the agreements governing our future indebtedness may restrict our ability to repurchase the notes and/or the 2019 notes or pay the cash amounts due upon conversion of the notes. Our failure to repurchase notes and/or the 2019 notes or to pay the cash amounts due upon conversion of the notes when required will constitute a default under the base and supplemental indentures that will govern the notes, which we refer to collectively as the “indenture,” and/or a default under the indenture governing the 2019 notes. A default under the indenture and/or the indenture governing the 2019 notes or the fundamental change itself could also lead to a default under agreements governing our other indebtedness, which may result in that other indebtedness becoming immediately payable in full. We may not have sufficient funds to satisfy all amounts due under the other indebtedness, the 2019 notes and the notes.

Not all dilutive events will result in an adjustment to the conversion rate.

We will adjust the conversion rate of the notes for certain events, including:

See “Description of Notes—Conversion Rights—Conversion Rate Adjustments.” We are not required to adjust the conversion rate for other events, such as an issuance of common stock (or securities exercisable for, or convertible into, common stock) for cash, that may adversely affect the trading price of the notes and our common stock. An event may occur that adversely affects the noteholders and the trading price of the notes and the underlying shares of our common stock but that does not result in an adjustment to the conversion rate.

Redemption may adversely affect your return on the notes.

The notes will be redeemable, in whole or in part, at our option at any time, and from time to time, on a redemption date occurring on or after September 15, 2022 and on or before the 40th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid, if any, but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on each of at least 20 trading days during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice. As a result, we may choose to redeem some or all of the notes, including at times when prevailing interest rates are relatively low. As a result, you may not be able to reinvest the proceeds you receive from the redemption in a comparable security at an effective interest rate as high as the interest rate on your notes being redeemed. In addition, holders who convert in advance of any redemption would not get any compensation for the lost option value of their notes. See “Description of Notes—Optional Redemption.”

Not all significant restructuring transactions will constitute a fundamental change, in which case you will not have the right to require us to repurchase your notes for cash.

If certain corporate events called “fundamental changes” occur, you will have the right to require us to repurchase your notes for cash. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.” However, the definition of “fundamental change” is limited to specific corporate events and does not include all events that may adversely affect our financial condition or the trading price of the notes. For example, a leveraged recapitalization, refinancing, restructuring or acquisition by us may not constitute a fundamental change that would require us to repurchase the notes. Nonetheless, these events could significantly increase the amount of our indebtedness, harm our credit rating or adversely affect our capital structure and the trading price of the notes.

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The increase to the conversion rate resulting from a make-whole fundamental change may not adequately compensate noteholders for the lost option value of their notes. In addition, a variety of transactions that do not constitute a make-whole fundamental change may significantly reduce the option value of the notes without a corresponding increase to the conversion rate.

If certain corporate events that constitute a “make-whole fundamental change” occur, then we will, in certain circumstances, temporarily increase the conversion rate. See “Description of Notes—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” The amount of the increase to the conversion rate will depend on the date on which the make-whole fundamental change becomes effective and the applicable “stock price.” While the increase to the conversion rate is designed to compensate noteholders for the lost option value of their notes resulting from a make-whole fundamental change, the increase is only an approximation and may not adequately compensate noteholders for the loss in option value. In addition, if the applicable “stock price” is greater than $        per share or less than $        per share (in each case, subject to adjustment), then we will not increase the conversion rate for the make-whole fundamental change. Moreover, we will not increase the conversion rate pursuant to these provisions to an amount that exceeds                  shares per $1,000 principal amount of notes, subject to adjustment.

Furthermore, the definition of make-whole fundamental change is limited to certain specific transactions. Accordingly, the make-whole fundamental change provisions of the indenture will not protect noteholders from other transactions that could significantly reduce the option value of the notes. For example, a spin-off or sale of a subsidiary or business division with volatile earnings, or a change in our line of business, could significantly affect the trading characteristics of our common stock and reduce the option value of the notes without constituting a make-whole fundamental change that results in a temporary increase to the conversion rate.

In addition, our obligation to increase the conversion rate in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

There is currently no trading market for the notes. If an active trading market for the notes does not develop, then noteholders may be unable to resell their notes at desired times or prices, or at all.

The notes are a new class of securities for which no market currently exists. We do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Although the underwriters have advised us that they intend to make a market in the notes, they not obligated to do so and may discontinue any market-making activity at any time and without notice. Accordingly, an active market for the notes may never develop, and, even if one develops, it may not be maintained. If an active trading market for the notes does not develop or is not maintained, then the market price and liquidity of the notes will be adversely affected and noteholders may not be able to resell their notes at desired times or prices, or at all.

The liquidity of the trading market, if any, and future trading prices of the notes will depend on many factors, including, among other things, the trading price of our common stock, prevailing interest rates, our dividend yield, financial condition, results of operations, business, prospects and credit quality relative to our competitors, the market for similar securities and the overall securities market. Many of these factors are beyond our control. Historically, the market for convertible debt has been volatile. Market volatility could significantly harm the market for the notes, regardless of our financial condition, results of operations, business, prospects or credit quality.

The notes will be effectively subordinated to our future secured indebtedness and structurally subordinated to the liabilities of our subsidiaries.

The notes will be our general unsecured obligations that will rank senior in right of payment to all of our indebtedness that is expressly subordinated in right of payment to the notes, equal in right of payment with all of our indebtedness that is not so subordinated and effectively rank junior to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness. In addition, because none of our subsidiaries will guarantee the notes, the notes will be structurally junior to all indebtedness and other liabilities of our subsidiaries (including trade payables, but excluding intercompany obligations and liabilities of a type not required to be reflected on a balance sheet of such subsidiaries in accordance with GAAP). The indenture will not prohibit us from incurring

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additional indebtedness, including secured indebtedness, which would be effectively senior to the notes to the extent of the value of the collateral securing that indebtedness, or indebtedness that would rank equal in right of payment with the notes. The indenture will also not prohibit our subsidiaries from incurring any additional indebtedness or other liabilities that would be structurally senior to our obligations under the notes.

In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure any indebtedness will not be available to make payments under the notes unless all of that indebtedness is first paid in full. We advise you that there may not be sufficient assets remaining to pay amounts due on any or all the notes then outstanding. In the event of the bankruptcy, liquidation, reorganization or other winding up of any of our subsidiaries, we, as a common equity holder of that subsidiary, and, therefore, the noteholders, will rank behind that subsidiary’s creditors, including that subsidiary’s trade creditors, and (to the extent we are not a holder thereof) that subsidiary’s preferred equity holders, if any. Even if we were a creditor of any of our subsidiaries, our rights as a creditor would be effectively subordinated to any security interest of others in the assets of that subsidiary, to the extent of the value of the those assets, and would be subordinated to any indebtedness of that subsidiary that is senior in right of payment to that held by us.

Our subsidiaries will have no obligations under the notes. The ability of our subsidiaries to pay dividends or make other payments to us may be restricted by, among other things, corporate and other laws and by agreements to which our subsidiaries may become a party. Accordingly, we may be unable to gain access to the cash flow or assets of our subsidiaries to enable us to make payments on the notes.

As of June 30, 2018, excluding our subsidiaries, we had no secured indebtedness and $46.0 million aggregate principal amount of unsecured indebtedness for borrowed money, all of which was senior indebtedness, and our subsidiaries had approximately $50,000 of liabilities, including trade payables but excluding intercompany liabilities. After giving effect to the issuance of the notes (assuming no exercise of the underwriters’ over-allotment option), our total consolidated indebtedness for borrowed money would have been approximately $246.0 million in principal amount.

The trading price of our common stock and other factors could significantly affect the trading price of the notes.

We expect that the trading price of our common stock will significantly affect the trading price of the notes, which could result in greater volatility in the trading price of the notes than would be expected for non-convertible securities. The trading price of our common stock will likely continue to fluctuate in response to the factors described or referred to elsewhere in this section and under the caption “Cautionary Note Regarding Forward-Looking Statements,” among others, many of which are beyond our control.

The issuance or sale of shares of our common stock, or rights to acquire shares of our common stock, could depress the trading price of our common stock and the notes.

We may conduct future offerings of our common stock, preferred stock or other securities that are convertible into or exercisable for our common stock to finance our operations or fund acquisitions, or for other purposes. In addition, as of June 30, 2018, we had reserved 7,434,388 shares of common stock for issuance upon the exercise of options outstanding, 735,365 shares of common stock for issuance upon the exercise of warrants outstanding, 691,809 shares of common stock reserved for the vesting of restricted stock units outstanding, 2,542,294 shares of common stock for future issuance under our stock incentive programs and 2,642,159 shares of our common stock reserved for issuance upon conversion of our 2019 notes (without giving effect to the repurchase of certain of the 2019 notes that is expected to occur concurrently with this offering). The indenture for the notes will not restrict our ability to issue additional equity securities in the future. If we issue additional shares of our common stock or rights to acquire shares of our common stock, if any of our existing stockholders sells a substantial amount of our common stock, or if the market perceives that such issuances or sales may occur, then the trading price of our common stock, and, accordingly, the notes may significantly decrease. In addition, our issuance of additional shares of common stock will dilute the ownership interests of our existing common stockholders, including noteholders who have received shares of our common stock upon conversion of their notes.

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We will make only very limited covenants in the indenture, and these limited covenants may not protect your investment.

Many debt instruments contain provisions that are designed to restrict the borrower’s activities and operations in a manner that is designed to preserve the borrower’s ability to make payments on the related indebtedness when due. These provisions include financial and operating covenants, and restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by the borrower or any of its subsidiaries. The indenture for the notes will not contain any of these covenants or restrictions or otherwise place any meaningful restrictions on our ability to operate our business as management deems appropriate. As a result, your investment in the notes may not be as protected as an investment in an instrument that contains some or all of these types of covenants and restrictions.

Recent and future regulatory actions and other events may adversely affect the trading price and liquidity of the notes.

We expect that many investors in the notes, including potential purchasers of the notes from investors in this offering, will seek to employ a convertible note arbitrage strategy. Under this strategy, investors typically short sell a certain number of shares of our common stock and adjust their short position over time while they continue to hold the notes. Investors may also implement this type of strategy by entering into swaps on our common stock in lieu of, or in addition to, short selling shares of our common stock.

The SEC and other regulatory authorities have implemented various rules and taken certain actions, and may in the future adopt additional rules and take other actions, that may impact those engaging in short selling activity involving equity securities (including our common stock). These rules and actions include Rule 201 of SEC Regulation SHO, the adoption by the Financial Industry Regulatory Authority, Inc., and the national securities exchanges of a “limit up-limit down” program, the imposition of market-wide circuit breakers that halt trading of securities for certain periods following specific market declines, and the implementation of certain regulatory reforms required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. Any governmental or regulatory action that restricts investors’ ability to effect short sales of our common stock or enter into equity swaps on our common stock could depress the trading price of, and the liquidity of the market for, the notes.

In addition, the liquidity of the market for our common stock may decline, which could reduce the number of shares available for lending in connection with short sale transactions and the number of counterparties willing to enter into an equity swap on our common stock with a note investor. If investors and potential purchasers seeking to employ a convertible note arbitrage strategy are unable to borrow or enter into equity swaps on our common stock on commercially reasonable terms, then the trading price of, and the liquidity of the market for, the notes may significantly decline.

You may be subject to tax if we make or fail to make certain adjustments to the conversion rate of the notes even though you do not receive a corresponding cash distribution.

The conversion rate of the notes is subject to adjustment in certain circumstances, including the payment of cash dividends. If the conversion rate is adjusted as a result of a distribution that is taxable to our common stockholders, such as a cash dividend, you will be deemed to have received a distribution, which may be treated as a dividend subject to U.S. federal income tax, without the receipt of any cash. In addition, a failure to adjust (or to adjust adequately) the conversion rate after an event that increases your proportionate interest in us could be treated as a deemed taxable dividend to you. If a make-whole fundamental change occurs prior to the maturity date, under some circumstances, we will increase the conversion rate for notes converted in connection with the make-whole fundamental change. Such increase may also be treated as a distribution subject to U.S. federal income tax as a dividend. See “Material U.S. Federal Income Tax Considerations.” If you are a non-U.S. holder (as defined under “Material U.S. Federal Income Tax Considerations”), any deemed dividend will generally be subject to U.S. federal withholding tax at a 30% rate, or such lower rate as may be specified by an applicable treaty, which may be set off against subsequent payments on the notes or any shares of our common stock owned by you or from any proceeds of any subsequent sale, exchange or other disposition of the notes (including the retirement of a note) or such common stock or other funds or assets of yours. The Internal Revenue Service has proposed regulations addressing the amount and timing of deemed distributions, obligations of withholding agents and filing and notice obligations of

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issuers, which if adopted could affect the U.S. federal income tax treatment of beneficial owners of notes deemed to receive such a distribution. See “Material U.S. Federal Income Tax Considerations.”

A rating agency may not rate the notes or may assign a rating that is lower than expected.

We do not intend to seek to have the notes rated by any rating agency. However, if one or more rating agencies rates the notes and assigns a rating that is lower than the rating that investors expect, or reduces their rating in the future, then the trading price of our common stock and the notes could significantly decline.

In addition, market perceptions of our creditworthiness will directly affect the trading price of the notes. Accordingly, if a ratings agency rates any of our indebtedness in the future or downgrades or withdraws the rating, or puts us on credit watch, then the trading price of the notes will likely decline.

Provisions in the indenture could delay or prevent an otherwise beneficial takeover of us.

Certain provisions in the notes and the indenture could make a third party attempt to acquire us more difficult or expensive. For example, if a takeover constitutes a fundamental change, then noteholders will have the right to require us to repurchase their notes for cash. In addition, if a takeover constitutes a make-whole fundamental change, then we may be required to temporarily increase the conversion rate. In either case, and in other cases, our obligations under the notes and the indenture could increase the cost of acquiring us or otherwise discourage a third party from acquiring us or removing incumbent management, including in a transaction that noteholders or holders of our common stock may view as favorable.

You may be unable to convert your notes before May 15, 2025, and the trading price of the notes could be less than the value of the consideration into which they could otherwise be converted.

Before May 15, 2025, you may convert your notes only if specific conditions are met. If these conditions are not met, then you will not be able to convert your notes and receive the cash, shares of our common stock or combination of cash and shares, as applicable, into which the notes would otherwise be convertible. As a result, the notes may trade at prices that are less than the value of the consideration into which they would otherwise be convertible.

Fluctuations in the trading price of our common stock after you elect to convert your notes may cause you to receive less valuable consideration than expected.

We will generally have the right to settle conversions in cash, shares of our common stock or a combination of cash and shares. If we elect to settle conversions solely in cash or in a combination of cash and shares, then the consideration due upon conversion will be determined based on the volume-weighted average price of our common stock during the related “observation period,” which is defined under the caption “Description of Notes—Definitions” and will consist of 40 “VWAP trading days.” Except in certain circumstances, the observation period will begin after the related conversion date. Accordingly, a considerable amount of time may lapse between the time you elect to convert your notes and the time you receive the consideration due upon conversion, and if the trading price of our common stock declines during this time, then you may receive less consideration, or consideration that is less valuable, than expected.

Our management may spend the proceeds of this offering in ways with which you may disagree or that may not be profitable.

We intend to use a portion of the net proceeds from this offering to repurchase a portion of our outstanding 2019 notes, as described under the caption “The Concurrent Repurchases.” We intend to use the remaining net proceeds from this offering for general corporate purposes, which may include clinical trial and other research and development expenses, commercialization expenses, capital expenditures, working capital and general and administrative expenses, and potential acquisitions of or investments in businesses, products and technologies that complement our business, including, without limitation, our potential exercise of the Option to acquire Censa. However, our management will have broad discretion to apply the net proceeds, and investors will rely on our management’s judgment in spending the net proceeds. Our management may use the proceeds in ways that do not earn a profit or otherwise result in the creation of stockholder value. Pending the use of such proceeds, we intend to

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invest the net proceeds in short- and intermediate-term, interest-bearing, investment grade or direct or guaranteed obligations of the U.S. government. These investments may not yield a favorable return to our stockholders.

The accounting method for the notes could adversely affect our reported financial condition and results.

The accounting method for reflecting the notes on our balance sheet, accruing interest expense for the notes and reflecting the underlying shares of our common stock in our reported diluted earnings per share may adversely affect our reported earnings and financial condition.

We expect that, under applicable accounting principles, the initial liability carrying amount of the notes will be the fair value of a similar debt instrument that does not have a conversion feature, valued using our cost of capital for straight, unconvertible debt. We expect to reflect the difference between the net proceeds from this offering and the initial carrying amount as a debt discount for accounting purposes, which will be amortized into interest expense over the term of the notes. As a result of this amortization, the interest expense that we expect to recognize for the notes for accounting purposes will be greater than the cash interest payments we will pay on the notes, which will result in lower reported net income. The lower reported income resulting from this accounting treatment could depress the trading price of our common stock and the notes.

In addition, because we intend to settle conversions by paying the conversion value in cash up to the principal amount being converted and any excess in shares, we expect to be eligible to use the treasury stock method to reflect the shares underlying the notes in our diluted earnings per share. Under this method, if the conversion value of the notes exceeds their principal amount for a reporting period, then we will calculate our diluted earnings per share assuming that all the notes were converted and that we issued shares of our common stock to settle the excess. However, if reflecting the notes in diluted earnings per share in this manner is anti-dilutive, or if the conversion value of the notes does not exceed their principal amount for a reporting period, then the shares underlying the notes will not be reflected in our diluted earnings per share. In addition, if accounting standards change in the future and we are not permitted to use the treasury stock method, then our diluted earnings per share may decline.

Furthermore, if any of the conditions to the convertibility of the notes is satisfied, then we may be required under applicable accounting standards to reclassify the liability carrying value of the notes as a current, rather than a long-term, liability. This reclassification could be required even if no noteholders convert their notes and could materially reduce our reported working capital.

Because the notes will initially be held in book-entry form, noteholders must rely on DTC’s procedures to receive communications relating to the notes and exercise their rights and remedies.

We will initially issue the notes in the form of one or more “global notes” registered in the name of Cede & Co., as nominee of DTC. Beneficial interests in global notes will be shown on, and transfers of global notes will be effected only through, the records maintained by DTC. Except in limited circumstances, we will not issue certificated notes. See “Description of Notes—Book Entry, Settlement and Clearance.” Accordingly, if you own a beneficial interest in a global note, then you will not be considered an owner or holder of the notes. Instead, DTC or its nominee will be the sole holder of the notes. Payments of principal, interest and other amounts on global notes will be made to the paying agent, who will remit the payments to DTC. We expect that DTC will then credit those payments to the DTC participant accounts that hold book-entry interests in the global notes and that those participants will credit the payments to indirect DTC participants. Unlike persons who have certificated notes registered in their names, owners of beneficial interests in global notes will not have the direct right to act on our solicitations for consents or requests for waivers or other actions from noteholders. Instead, those beneficial owners will be permitted to act only to the extent that they have received appropriate proxies to do so from DTC or, if applicable, a DTC participant. The applicable procedures for the granting of these proxies may not be sufficient to enable owners of beneficial interests in global notes to vote on any requested actions on a timely basis. In addition, notices and other communications relating to the notes (including any notice of redemption) will be sent to DTC. We expect DTC will forward any such communications to DTC participants, which in turn would forward such communications to indirect DTC participants, but we can make no assurances that you will timely receive any such communications.

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Holding notes will not, in itself, confer any rights with respect to our common stock.

Noteholders will generally not be entitled to any rights with respect to our common stock (including voting rights and rights to receive any dividends or other distributions on our common stock). However, noteholders will be subject to all changes affecting our common stock to the extent the trading price of the notes depends on the market price of our common stock and to the extent they receive shares of our common stock upon conversion of their notes. For example, if we propose an amendment to our charter documents that requires stockholder approval, then a noteholder will not, as such, be entitled to vote on the amendment, although the noteholder will be subject to any changes implemented by that amendment in the powers, preferences or special rights of our common stock.

Repurchases of our 2019 notes may affect the value of the notes and our common stock.

Concurrently with this offering, in separate transactions, we expect to repurchase approximately $         million aggregate principal amount of our outstanding 2019 notes for cash, including accrued and unpaid interest, of approximately $        million. See “The Concurrent Repurchases.” We may also exchange or repurchase or induce conversions of additional outstanding 2019 notes following the completion of this offering. Any exchange, repurchase or induced conversion of our outstanding 2019 notes could affect the market price of our common stock and, in the case of exchanges effected concurrently with this offering, the initial conversion price of your notes.

Our search for a new Chief Executive Officer involves risks and our ability to successfully manage this transition could impact our business.

On July 26, 2018, we announced that Stephen Aselage, our Chief Executive Officer, plans to retire. Our board of directors has initiated a global search for his successor that will include both internal and external candidates. Mr. Aselage will remain in his role as Chief Executive Officer until his replacement is appointed. Leadership transitions can be difficult to manage and may cause disruptions to our operations. The search for a new Chief Executive Officer and the related transition may increase the likelihood of turnover among our employees and result in changes in our business strategy, which may create uncertainty and negatively impact our ability to execute our business strategy quickly and effectively. The presence of a new Chief Executive Officer may also impact our relationships with customers and suppliers, and create uncertainty among investors, employees, creditors and others concerning our future direction and performance. Any significant disruption, uncertainty or change in business strategy could adversely affect our business, financial condition and operating results.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein contain forward-looking statements within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act that involve a number of risks and uncertainties. Although our forward-looking statements reflect the good faith judgment of our management, these statements can only be based on facts and factors currently known by us. Consequently, these forward-looking statements are inherently subject to risks and uncertainties, and actual results and outcomes may differ materially from results and outcomes discussed in the forward-looking statements. Such forward-looking statements include statements regarding, among other things:

Forward-looking statements can be identified by the use of forward-looking words such as “believes,” “expects,” “hopes,” “may,” “will,” “plan,” “intends,” “estimates,” “could,” “should,” “would,” “continue,” “seeks,” “pro forma,” or “anticipates,” or other similar words (including their use in the negative), or by discussions of future matters such as the development of new products, technology enhancements, possible collaborations, possible changes in legislation and other statements that are not historical. These statements include but are not limited to statements under the captions “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and in other sections incorporated by reference from our Annual Report on Form 10-K and Quarterly Reports on Form 10-Q, as applicable, as well as our other filings with the SEC. You should be aware that the occurrence of any of the events discussed under the heading “Risk Factors” in this prospectus supplement, the accompanying prospectus and any documents incorporated by reference herein or therein could substantially harm our business, operating results and financial condition and that if any of these events occurs, it could adversely affect the value of an investment in our securities.

The cautionary statements made in this prospectus supplement are intended to be applicable to all related forward-looking statements wherever they may appear in this prospectus supplement, the accompanying prospectus or any documents incorporated by reference herein or therein. We urge you not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. Except as required by law, we assume no obligation to update our forward-looking statements, even if new information becomes available in the future.

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USE OF PROCEEDS

We estimate that the proceeds from this offering will be approximately $        million (or $        million if the initial purchasers exercise their over-allotment option in full), after deducting estimated initial purchasers’ discounts and estimated offering expenses payable by us.

We intend to use a portion of the net proceeds from this offering to repurchase a portion of our outstanding 2019 notes, as described under the caption “The Concurrent Repurchases.” We intend to use the remaining net proceeds from this offering for general corporate purposes, which may include clinical trial and other research and development expenses, commercialization expenses, capital expenditures, working capital and general and administrative expenses, and potential acquisitions of or investments in businesses, products and technologies that complement our business, including, without limitation, our potential exercise of the Option to acquire Censa.

Pending the use of such proceeds, we intend to invest the net proceeds in short- and intermediate-term, interest-bearing, investment grade or direct or guaranteed obligations of the U.S. government.

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CAPITALIZATION

The following table sets forth our cash, cash equivalents and marketable securities and our capitalization as of June 30, 2018:

This table should be read in conjunction with the other information in this prospectus supplement, the accompanying prospectus and the documents that are incorporated by reference, including our consolidated financial statements and related notes.

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PRICE RANGE OF COMMON STOCK

Our common stock is quoted on the Nasdaq Global Market under the symbol “RTRX” and is part of the Nasdaq Biotechnology Index (NASDAQ: RTRX). The following table sets forth for the periods indicated the high and low sale price for our common stock. These prices do not include retail markups, markdowns or commissions.

As of August 31, 2018, the closing price of our common stock as reported on the Nasdaq Global Market was $31.69 per share. The number of beneficial stockholders is substantially greater than the number of holders of record as a large portion of our common stock is held through brokerage firms. As of August 30, 2018, there were 40,859,214 shares of common stock outstanding and there were 191 holders of record of our common stock, based upon information furnished by American Stock Transfer & Trust Company, LLC, the transfer agent for our securities.

DIVIDEND POLICY

Since inception we have not paid any dividends on our common stock. We currently do not anticipate paying any cash dividends in the foreseeable future on our common stock. Although we intend to retain our earnings, if any, to finance the exploration and growth of our business, our Board of Directors will have the discretion to declare and pay dividends in the future. Payment of dividends in the future will depend upon our earnings, capital requirements and other factors which our Board of Directors may deem relevant.

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DESCRIPTION OF NOTES

We will issue the notes under an indenture and a supplemental indenture (together, the “indenture”), each between us and U.S. Bank National Association, as trustee (the “trustee”), and to be dated as of the initial closing date of this offering.

The following is a summary of certain provisions of the notes and the indenture. It is only a summary and is not complete. We qualify this summary by referring you to the indenture and the notes, because they, and not this summary, define your rights as a holder of the notes. We will provide you with a copy of the indenture, which includes the form of the notes, as provided under the caption “Where You Can Find More Information.”

In addition, the indenture and the notes will be deemed to include certain terms that are made a part of the indenture and the notes pursuant to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

Certain terms used in this summary are defined below under the caption “—Definitions.” Certain other terms used in this summary are defined in the indenture.

This “Description of Notes” section supplements and, to the extent inconsistent therewith, supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities.”

References to “we,” “us” and “our” in this section refer to Retrophin, Inc. only and not to any of its subsidiaries. References to any “note” in this section refer to any authorized denomination of a note, unless the context requires otherwise.

Generally

The notes will:

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The indenture will not contain any financial covenants and will not limit us or our subsidiaries from incurring additional indebtedness, paying dividends or issuing or repurchasing any securities. Except to the extent described below under the captions “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change,” “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes” and “—Consolidation, Merger and Asset Sale,” the indenture will not contain any provisions designed to protect noteholders upon a highly leveraged transaction involving us or a decline in our credit rating as a result of a recapitalization, takeover, highly leveraged transaction or other restructuring involving us.

Without the consent of any noteholder, we may issue additional notes under the indenture with the same terms as the notes we are offering (except for certain differences, such as the date as of which interest begins to accrue and the first interest payment date for such additional notes). However, such additional notes must be identified by a separate CUSIP number or by no CUSIP number if they are not fungible, for federal income tax or federal securities laws purposes, with other notes we issue under the indenture.

We do not intend to list the notes on any securities exchange or include them in any automated inter-dealer quotation system.

Absent manifest error, a person in whose name a note is registered on the registrar’s books will be considered to be the holder of that note for all purposes, and only registered noteholders (which, in the case of notes held through DTC, will initially be DTC’s nominee, Cede & Co.) will have rights under the indenture as noteholders.

Subject to applicable law, we or our subsidiaries may directly or indirectly repurchase notes in the open market or otherwise, whether through private or public tender or exchange offers, cash-settled swaps or other cash-settled derivatives. The indenture requires us to promptly deliver to the trustee for cancellation all notes that we or our subsidiaries have purchased or otherwise acquired.

Payments on the Notes

For purposes of the notes, the description below under this section titled “—Payments on the Notes” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Payment and Paying Agents.”

We will pay (or cause the paying agent to pay) the principal of, and interest on, any global note by wire transfer of immediately available funds. We will pay (or cause the paying agent to pay) the principal of, and interest on, any certificated note as follows:

To be timely, a written request referred to in the first bullet point above must be delivered no later than the “close of business” (as defined below under the caption “—Definitions”) on the following date: (i) with respect to the payment of any interest due on an interest payment date, the immediately preceding record date; and (ii) with respect to any other payment, the date that is 15 calendar days immediately before the date such payment is due.

If the due date for a payment on a note is not a “business day” (as defined below under the caption “—Definitions”), then such payment may be made on the immediately following business day and no interest will accrue on such payment as a result of the related delay. Solely for purposes of the immediately preceding sentence, a day on which the applicable place of payment is authorized or required by law or executive order to close or be closed will be deemed not to be a “business day.”

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Registrar, Paying Agent and Conversion Agent

We will maintain one or more offices or agencies in the continental United States where notes may be presented for registration of transfer or for exchange, payment and conversion, which we refer to as the “registrar,” “paying agent” and “conversion agent,” respectively. We have appointed the trustee as the initial registrar, paying agent and conversion agent and its office in the United States as a place where notes may be presented for payment. However, we may change the registrar, paying agent and conversion agent, and we or any of our subsidiaries may choose to act in that capacity as well, without prior notice to the noteholders.

Transfers and Exchanges

For purposes of the notes, the description below under this section titled “—Transfers and Exchanges” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Form, Exchange and Transfer.”

A noteholder may transfer or exchange its notes at the office of the registrar in accordance with the indenture. We, the trustee and the registrar may require the noteholder to, among other things, deliver appropriate endorsements or transfer instruments, and such certificates or other documentation or evidence as we or they may reasonably require to determine that such transfer or exchange complies with applicable securities laws. The notes and any shares issued upon conversion of the notes are subject to transfer restrictions, which are described below under the caption “Transfer Restrictions.” In addition, we, the trustee and the registrar may refuse to register the transfer or exchange of any note that is subject to conversion, redemption or required repurchase.

We have appointed the trustee’s office in the United States as a place where notes may be presented for registration of transfer or for exchange. However, we may change the registrar or act as the registrar ourselves without prior notice to the noteholders.

Interest

The notes will bear cash interest at an annual rate of     %, payable semi-annually in arrears on March 15 and September 15 of each year, beginning on March 15, 2019, to the noteholders of record of the notes as of the close of business on the immediately preceding March 1 and September 1, respectively. Interest will accrue from, and including, the last date to which interest has been paid or duly provided for (or, if no interest has been paid or duly provided for, from, and including, the date the notes are initially issued) to, but excluding, the next interest payment date. Interest will be computed on the basis of a 360-day year comprised of twelve 30-day months.

In addition to the stated interest on the notes referred to above, special interest will accrue on the notes in the circumstances described below under the caption “—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults.” All references in this prospectus supplement to interest on the notes include any special interest payable on the notes, unless the context requires otherwise.

Ranking

The notes will be our general unsecured obligations that will:

The indenture will not prohibit us from incurring additional indebtedness, including secured indebtedness, which would be effectively senior to the notes to the extent of the value of the collateral securing that indebtedness, or indebtedness that would rank equal in right of payment with the notes. The indenture will also not prohibit our subsidiaries from incurring any additional indebtedness or other liabilities that would be structurally senior to our obligations under the notes.

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In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure any indebtedness will not be available to make payments under the notes unless all of that indebtedness is first paid in full. We advise you that there may not be sufficient assets remaining to pay amounts due on any or all the notes then outstanding. In the event of the bankruptcy, liquidation, reorganization or other winding up of any of our subsidiaries, we, as a common equity holder of that subsidiary, and, therefore, the noteholders, will rank behind that subsidiary’s creditors, including that subsidiary’s trade creditors, and (to the extent we are not a holder thereof) that subsidiary’s preferred equity holders. Even if we were a creditor of any of our subsidiaries, our rights as a creditor would be effectively subordinated to any security interest of others in the assets of that subsidiary, to the extent of the value of those assets, and would be subordinated to any indebtedness of that subsidiary that is senior in right of payment to that held by us.

Our subsidiaries will have no obligations under the notes. The ability of our subsidiaries to pay dividends or make other payments to us is restricted by, among other things, corporate and other laws and by agreements to which our subsidiaries may become a party. Accordingly, we may be unable to gain access to the cash flow or assets of our subsidiaries to enable us to make payments on the notes.

As of June 30, 2018, excluding our subsidiaries, we had no secured indebtedness and $46.0 million aggregate principal amount of unsecured indebtedness for borrowed money, all of which was senior indebtedness and our subsidiaries had $50,000 of liabilities, including trade payables, but excluding intercompany liabilities. After giving effect to the issuance of the notes (assuming no exercise of the underwriters’ option to purchase additional notes, solely to cover over-allotments) and prior to the use of proceeds thereof, excluding our subsidiaries, our total indebtedness for borrowed money would have been $246.0 million in principal amount.

Optional Redemption

We may not redeem the notes at our option at any time before September 15, 2022. Subject to the terms of the indenture, we have the right, at our election, to redeem all, or any portion in an authorized denomination, of the notes, at any time and from time to time, on a redemption date occurring on or after September 15, 2022 and, in the case of any partial redemption, on or before the 40th scheduled trading day before the maturity date, for cash, but only if the “last reported sale price” (as defined below under the caption “—Definitions”) per share of common stock exceeds 130% of the “conversion price” (as defined below under the caption “—Definitions”) on each of at least 20 “trading days” (as defined below under the caption “—Definitions”) (whether or not consecutive) during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice.

The redemption date will be a business day of our choosing that is no more than 65, nor less than 45, “scheduled trading days” (as defined below under the caption “—Definitions”) after the date we send the related redemption notice, as described below.

The redemption price for any note called for redemption will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the redemption date. However, if the redemption date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such redemption, to receive, on or before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and (ii) the redemption price will not include accrued and unpaid interest on such note to, but excluding, such redemption date.

We will send to each noteholder notice of the redemption containing certain information set forth in the indenture, including the redemption price and the redemption date.

Notes called for redemption must be delivered to the paying agent (in the case of certificated notes) or the “depositary procedures” (as defined below under the caption “—Definitions”) must be complied with (in the case of global notes) for the holder of those notes to be entitled to receive the redemption price.

If only a portion of a note is subject to redemption and that note is converted in part, then the converted portion of that note will be deemed to be from the portion of that note that was subject to redemption.

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Notwithstanding anything to the contrary above, we may not redeem any notes if the principal amount of the notes has been accelerated (other than as a result of a failure to make the payment of the related redemption price and any related interest described above on the redemption date) and such acceleration has not been rescinded on or before the redemption date.

Conversion Rights

Generally

The notes (or any portion of a note in an authorized denomination) will be convertible in the circumstances described below, at the noteholders’ option, into cash, shares of our common stock or a combination of cash and shares of our common stock (together with cash in lieu of any fractional share, if applicable), at our election, based on an initial conversion rate of              shares per $1,000 principal amount of notes (which represents an initial conversion price of approximately $         per share).

Noteholders may convert their notes only in the circumstances described below under the caption “—When the Notes May Be Converted.”

Treatment of Interest upon Conversion

We will not adjust the conversion rate to account for any accrued and unpaid interest on any note being converted, and, except as described below, our delivery of the consideration due in respect of the conversion will be deemed to fully satisfy and discharge our obligation to pay the principal of, and accrued and unpaid interest, if any, on, such note. As a result, except as described below, any accrued and unpaid interest on a converted note will be deemed to be paid in full rather than cancelled, extinguished or forfeited. In addition, if the consideration due upon conversion consists of both cash and shares of our common stock, then accrued and unpaid interest that is deemed to be paid therewith will be deemed to be paid first out of such cash.

Notwithstanding anything to the contrary above, if the conversion date of a note is after a regular record date and before the next interest payment date, then:

However, such noteholder need not deliver such cash:

Accordingly, for the avoidance of doubt, all noteholders as of the close of business on the regular record date immediately before the maturity date will receive the full interest payment that would have been due on the maturity date regardless of whether their notes have been converted after such regular record date.

When the Notes May Be Converted

Noteholders may convert their notes only in the circumstances set forth below. However, in no event may notes be converted after the close of business on the scheduled trading day immediately before the maturity date.

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Conversion upon Satisfaction of Common Stock Sale Price Condition

Prior to the close of business on the business day immediately preceding May 15, 2025, a noteholder may convert its notes during any calendar quarter commencing after the calendar quarter ending on December 31, 2018 (and only during such calendar quarter), if the last reported sale price per share of our common stock for each of at least 20 trading days, whether or not consecutive, during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter exceeds 130% of the conversion price on the applicable trading day.

Conversion upon Satisfaction of Note Trading Price Condition

Prior to the close of business on the business day immediately preceding May 15, 2025, a noteholder may convert its notes during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) if the “trading price” (as defined below under the caption “—Definitions”) per $1,000 principal amount of notes, as determined following a request by a noteholder in accordance with the procedures described below, for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day. We refer to this condition as the “trading price condition.”

The trading price will be determined by the bid solicitation agent as described below and the definition of “trading price.” The bid solicitation agent (if not us) will have no obligation to determine the trading price of the notes unless we have requested such determination, and we will have no obligation to make such request (or seek bids ourselves) unless a noteholder of at least $5.0 million aggregate principal amount of notes (or such lesser principal amount as may be then outstanding) provides us with reasonable evidence that the trading price per $1,000 principal amount of notes would be less than 98% of the product of the last reported sale price per share of our common stock and the conversion rate. If such a noteholder provides such evidence, then we will instruct the bid solicitation agent to (or, if we are acting as the bid solicitation agent, we will) determine the trading price of the notes beginning on the next trading day and on each successive trading day until the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day. If the trading price condition has been met as described above, then we will notify the noteholders and the trustee of the same, and each of the noteholders and the trustee will be entitled to rely conclusively upon the accuracy of such notice and any calculations therein without independent verification. If, on any trading day after the trading price condition has been met as described above, the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day, then we will notify the noteholders and the trustee of the same, and, thereafter, neither we nor the bid solicitation agent will be required to solicit bids again until another noteholder request is made as described above.

We will act as the initial bid solicitation agent. However, we may change the bid solicitation agent, and any of our subsidiaries may choose to act in that capacity as well, without prior notice to the noteholders.

Conversion upon Specified Corporate Events

Certain Distributions

If, prior to the close of business on the business day immediately preceding May 15, 2025, we elect to:

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then, in either case, we will send notice of such distribution, and of the related right to convert notes, to noteholders and the trustee at least 45 scheduled trading days before the “ex-dividend date” (as defined below under the caption “—Definitions”) for such distribution (or, if later in the case of any such separation of rights issued pursuant to a stockholder rights plan or the occurrence of any such triggering event under a stockholder rights plan, as soon as reasonably practicable after we become aware of that such separation or triggering event has occurred or will occur). Once we have sent such notice, noteholders may convert their notes at any time until the earlier of the close of business on the business day immediately before such ex-dividend date and our announcement that such issuance or distribution will not take place.

Noteholders may not convert their notes pursuant to the provision described in the preceding paragraph on account of any distribution if each noteholder participates, at the same time and upon the same terms as holders of our common stock and solely as a result of holding notes, in such distribution without having to convert its notes as if such noteholder held a number of shares of common stock equal to the conversion rate in effect on the record date for such distribution, multiplied by the principal amount (expressed in thousands) of notes held by such noteholder as of such record date.

Certain Corporate Events

If, prior to the close of business on the business day immediately preceding May 15, 2025, a fundamental change, “make-whole fundamental change” (as defined below under the caption “—Definitions”) or “common stock change event” (as defined below under the caption “—Effect of Common Stock Change Event”) (other than a common stock change event that is solely for the purpose of changing our jurisdiction of incorporation and that (x) does not constitute a fundamental change or a make-whole fundamental change and (y) results in a reclassification, conversion or exchange of outstanding shares of our common stock solely into shares of common stock of the surviving entity and such common stock becomes the “reference property” (as defined below under the caption “—Effect of Common Stock Change Event”) for the notes) occurs, then, in each case, noteholders may convert their notes at any time from, and including, the effective date of such transaction or event to, and including, the 35th trading day after such effective date (or, if such transaction or event also constitutes a fundamental change (other than an “exempted fundamental change,” as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes—No Repurchase Right in Certain Circumstances”), to, but excluding, the related fundamental change repurchase date). No later than the second business day after the effective date of any fundamental change, make-whole fundamental change or common stock change event that occurs before the maturity date, we will send notice to the noteholders and the trustee of such transaction or event, such effective date and, if applicable, the related right to convert notes.

Conversion upon Redemption

If we call any note for redemption, then the holder of such note may convert such note at any time before the close of business on the business day immediately before the related redemption date (or, if we fail to pay the redemption price due on such redemption date in full, at any time until such time as we pay such redemption price in full).

Conversions During Free Convertibility Period

A noteholder may convert its notes at any time from, and including, May 15, 2025 until the close of business on the scheduled trading day immediately before the maturity date.

Conversion Procedures

To convert a beneficial interest in a global note, the owner of the beneficial interest must:

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To convert all or a portion of a physical note, the holder of such note must:

Notes may be surrendered for conversion only after the “open of business” (as defined below under the caption “—Definitions”) and before the close of business on a day that is a business day.

We will pay any documentary, stamp or similar issue or transfer tax or duty due on the issue of any shares of our common stock upon conversion, except any tax or duty that is due because the converting noteholder requests those shares to be registered in a name other than the noteholder’s name.

We refer to the first business day on which the requirements described above to convert a note are satisfied as the “conversion date.”

If a noteholder has validly delivered a “fundamental change repurchase notice” (as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes”) with respect to a note, then such note may not be converted, except to the extent such notice is withdrawn in accordance with the procedures described below.

Settlement upon Conversion

Generally

Upon conversion, we may choose to pay or deliver, as applicable, either cash (“cash settlement”), shares of our common stock (“physical settlement”) or a combination of cash and shares of our common stock (“combination settlement”), as described below. We refer to each of these settlement methods as a “settlement method.” If cash settlement or combination settlement applies to a conversion, then the consideration due will be determined over an “observation period” (as defined below under the caption “—Definitions”) consisting of 40 “VWAP trading days” (as defined below under the caption “—Definitions”).

Settlement Method

We will have the right, as described below, to elect the settlement method applicable to the conversion of any notes. Except as described below, we must use the same settlement method for all conversions with a conversion date that occurs on the same day, but we will not be obligated to use the same settlement method for conversions with conversion dates that occur on different days. All conversions with a conversion date that occurs on or after May 15, 2025 will be settled using the same settlement method, and we will send notice of such settlement method to noteholders and the conversion agent no later than the close of business on the scheduled trading day immediately before May 15, 2025. If we elect a settlement method for a conversion with a conversion date that occurs before May 15, 2025, then we will send notice of such settlement method to the converting noteholder and the conversion agent no later than the close of business on the business day immediately after the conversion date. However, notwithstanding anything to the contrary above, if we call any notes for redemption, then (i) we will specify in the related redemption notice the settlement method that will apply to all conversions with a conversion date that occurs on or after the date we send such redemption notice and before the business day immediately before the related redemption date; and (ii) if the related redemption date is on or after May 15, 2025, then such settlement method must be the same settlement method that applies to all conversions with a conversion date that occurs on or after May 15, 2025.

If we do not timely elect a settlement method with respect to any conversion, then we will be deemed to have elected the “default settlement method” (as defined below). If we timely elect combination settlement with respect to a conversion but do not timely notify the converting noteholder of the applicable “specified dollar amount” (as defined below under the caption “—Definitions”), then the specified dollar amount for such conversion will be

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deemed to be $1,000 per $1,000 principal amount of notes. For the avoidance of doubt, our failure to timely elect a settlement method or specify the applicable specified dollar amount will not constitute a default under the indenture. We currently intend to settle conversions through combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of notes.

The “default settlement method” will initially be combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of notes. However, we may, from time to time, change the default settlement method by sending notice of the new default settlement method to the noteholders.

Consideration Due upon Conversion

The consideration due upon conversion of each $1,000 principal amount of a note will be as follows:

However, in lieu of delivering any fractional share of common stock otherwise due upon conversion, we will pay cash based on (i) the daily VWAP on the applicable conversion date (or, if such conversion date is not a VWAP trading day, the immediately preceding VWAP trading day), in the case of physical settlement; or (ii) the daily VWAP on the last VWAP trading day of the applicable observation period, in the case of combination settlement.

If a noteholder converts more than one note on a conversion date, then the consideration due upon such conversion will (in the case of any global note, to the extent permitted by, and practicable under, the depositary procedures) be computed based on the total principal amount of notes converted on such conversion date by that noteholder.

Delivery of the Conversion Consideration

Except as described below under the captions “—Conversion Rate Adjustments” and “—Effect of Common Stock Change Event,” we will pay or deliver, as applicable, the consideration due upon conversion as follows: (i) if cash settlement or combination settlement applies, on or before the second business day immediately after the last VWAP trading day of such observation period; and (ii) if physical settlement applies, on or before the second business day immediately after such conversion date.

When Converting Noteholders Become Stockholders of Record

The person in whose name any share of common stock is issuable upon conversion of any note will be deemed to become the holder of record of that share as of the close of business on (i) the conversion date for such conversion, in the case of physical settlement; or (ii) the last VWAP trading day of the observation period for such conversion, in the case of combination settlement.

Conversion Rate Adjustments

Generally

The conversion rate will be adjusted for the events described below. However, we are not required to adjust the conversion rate for these events (other than a stock split or combination or a tender or exchange offer) if each noteholder participates, at the same time and on the same terms as holders of our common stock, and solely by virtue of being a holder of notes, in such transaction or event without having to convert such noteholder’s notes and as if such noteholder held a number of shares of our common stock equal to the product of (i) the conversion rate in effect on the related record date; and (ii) the aggregate principal amount (expressed in thousands) of notes held by such noteholder on such date.

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where:

Each adjustment to the conversion rate made pursuant to the preceding sentence will become effective at the time set forth in the definition of CR₁ above. If any dividend, distribution, stock split or stock combination of the type described in this paragraph (1) is declared or announced, but not so paid or made, then the conversion rate will be readjusted, effective as of the date our “board of directors” (as defined below under the caption “—Definitions”) determines not to pay such dividend or distribution or to effect such stock split or stock combination, to the conversion rate that would then be in effect had such dividend, distribution, stock split or stock combination not been declared or announced.

where:

Each adjustment to the conversion rate made pursuant to the preceding sentence will become effective at the time set forth in the definition of CR₁ above. To the extent that shares of our common stock are not delivered after the expiration of such rights, options or warrants (including as a result of such rights, options or warrants not being exercised), the conversion rate will be readjusted to the conversion rate that would then be in effect

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had the increase to the conversion rate for such distribution been made on the basis of delivery of only the number of shares of our common stock actually delivered upon exercise of such rights, option or warrants. To the extent such rights, options or warrants are not so distributed, the conversion rate will be readjusted to the conversion rate that would then be in effect had the ex-dividend date for the distribution of such rights, options or warrants not occurred.

For purposes of this paragraph (2) and the provisions described above under the caption “—When the Notes May Be Converted—Conversion upon Specified Corporate Events—Certain Distributions,” in determining whether any rights, options or warrants entitle holders of our common stock to subscribe for or purchase shares of our common stock at a price per share that is less than the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before the date of the distribution of such rights, options or warrants is announced, and in determining the aggregate price payable to exercise such rights, options or warrants, there will be taken into account any consideration we receive for such rights, options or warrants and any amount payable on exercise thereof, with the value of such consideration, if not cash, to be determined by us in good faith.

then the conversion rate will be increased based on the following formula:

where:

Each adjustment to the conversion rate made pursuant to the preceding sentence will become effective at the time set forth in the definition of CR₁ above. If FMV is equal to or greater than SP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such distribution, at the same time and on the same terms as holders of our common stock, the amount and kind of shares of capital stock, evidences of indebtedness, assets,

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property, rights, options or warrants that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date.

To the extent such distribution is not so paid or made, or such rights, options or warrants are not exercised before their expiration (including as a result of being redeemed or terminated), the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the distribution, if any, actually made or paid or on the basis of the distribution of only such rights, options or warrants, if any, that were actually exercised, if at all.

where:

The adjustment to the conversion rate pursuant to this paragraph (3)(b) will be calculated as of the close of business on the last trading day of the spin-off valuation period but will be given effect immediately after the open of business on the ex-dividend date for the spin-off, with retroactive effect. If a note is converted and the conversion date (in the case of physical settlement) or any VWAP trading day of the applicable observation period (in the case of cash settlement or combination settlement) occurs during the spin-off valuation period, then, notwithstanding anything to the contrary, we will, if necessary, delay the settlement of such conversion until the second business day after the last day of the spin-off valuation period.

To the extent any dividend or distribution of the type described above in this paragraph (3)(b) is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

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where:

Each adjustment to the conversion rate made pursuant to the preceding sentence will become effective at the time set forth in the definition of CR₁ above. If D is equal to or greater than SP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such dividend or distribution, at the same time and on the same terms as holders of our common stock, the amount of cash that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date. To the extent such dividend or distribution is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

where:

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provided, however, that the conversion rate will in no event be adjusted down pursuant to the provisions described in this paragraph (5), except to the extent provided in the immediately following paragraph. The adjustment to the conversion rate pursuant to this paragraph (5) will be calculated as of the close of business on the last trading day of the tender/exchange offer valuation period but will be given effect immediately after the expiration time, with retroactive effect. If a note is converted and the conversion date (in the case of physical settlement) or any VWAP trading day of the applicable observation period (in the case of cash settlement or combination settlement) occurs during the tender/exchange offer valuation period, then, notwithstanding anything to the contrary, we will, if necessary, delay the settlement of such conversion until the second business day after the last day of the tender/exchange offer valuation period.

To the extent such tender or exchange offer is announced but not consummated (including as a result of being precluded from consummating such tender or exchange offer under applicable law), or any purchases or exchanges of shares of common stock in such tender or exchange offer are rescinded, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the purchases or exchanges of shares of common stock, if any, actually made, and not rescinded, in such tender or exchange offer.

We will not be required to adjust the conversion rate except as described above or below under the caption “—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” Without limiting the foregoing, we will not be required to adjust the conversion rate on account of:

The Deferral Exception

If an adjustment to the conversion rate otherwise required by the provisions described above would result in a change of less than 1% to the conversion rate, then, notwithstanding anything to the contrary described above, we may, at our election, defer and carry forward such adjustment, except that all such deferred adjustments must be given effect immediately upon the earliest to occur of the following: (i) when all such deferred adjustments would result in an aggregate change of at least 1% to the conversion rate; (ii) the conversion date of any note (in the case of physical settlement) or the first VWAP trading day of any observation period of any note (in the case of cash settlement or combination settlement); (iii) the date a fundamental change or make-whole fundamental change occurs; (iv) the date we call any notes for redemption; and (v) May 15, 2025. We refer to our ability to defer adjustments as described above as the “deferral exception.”

Notice of Conversion Rate Adjustments

Upon the effectiveness of any adjustment to the conversion rate pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally,” we will promptly send notice to the noteholders and the trustee containing (i) a brief description of the transaction or other event on account of which such adjustment was made; (ii) the conversion rate in effect immediately after such adjustment; and (iii) the effective time of such adjustment.

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Voluntary Conversion Rate Increases

To the extent permitted by law and applicable stock exchange rules, we, from time to time, may (but are not required to) increase the conversion rate by any amount if (i) our board of directors determines that such increase is in our best interest or that such increase is advisable to avoid or diminish any income tax imposed on holders of our common stock or rights to purchase our common stock as a result of any dividend or distribution of shares (or rights to acquire shares) of our common stock or any similar event; (ii) such increase is in effect for a period of at least 20 business days; and (iii) such increase is irrevocable during such period.

Tax Considerations

A noteholder may, in some circumstances, including a cash distribution or dividend on our common stock, be deemed to have received a distribution that is subject to U.S. federal income tax as a result of an adjustment or the non-occurrence of an adjustment to the conversion rate. Applicable withholding taxes (including backup withholding) may be withheld from interest and payments upon conversion, repurchase, redemption or maturity of the notes. In addition, if any withholding taxes (including backup withholding) are paid on behalf of a noteholder, then those withholding taxes may be set off against payments of cash or the delivery of shares of common stock, if any, in respect of the notes (or, in some circumstances, any payments on our common stock) or sales proceeds received by, or other funds or assets of, that noteholder. For a discussion of the U.S. federal income tax treatment of an adjustment to the conversion rate, see “Material U.S. Federal Income Tax Considerations.”

Special Provisions for Adjustments that Are Not Yet Effective and Where Converting Noteholders Participate in the Relevant Transaction or Event

Notwithstanding anything to the contrary, if:

then, solely for purposes of such conversion, we will, without duplication, give effect to such adjustment on such conversion date (in the case of physical settlement) or such VWAP trading day (in the case of combination settlement), and, for the avoidance of doubt, such shares will not be entitled to participate in such event. In such case, if the date we are otherwise required to deliver the consideration due upon such conversion is before the first date on which the amount of such adjustment can be determined, then we will delay the settlement of such conversion until the second business day after such first date.

Notwithstanding anything to the contrary in the indenture or the notes, if:

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then (x) such conversion rate adjustment will not be given effect for such conversion (in the case of physical settlement) or for such VWAP trading day (in the case of combination settlement); and (y) the shares of common stock, if any, issuable upon such conversion (in the case of physical settlement) or issuable with respect to such VWAP trading day (in the case of combination settlement) based on such unadjusted conversion rate will be entitled to participate in such dividend or distribution.

Stockholder Rights Plans

If any shares of our common stock are to be issued upon conversion of any note and, at the time of such conversion, we have in effect any stockholder rights plan, then the holder of that note will be entitled to receive, in addition to, and concurrently with the delivery of, the consideration otherwise due upon such conversion, the rights set forth in such stockholder rights plan, unless such rights have separated from our common stock at such time, in which case, and only in such case, the conversion rate will be adjusted pursuant to the provisions described above in paragraph (3)(a) under the caption “—Conversion Rate Adjustments—Generally” on account of such separation as if, at the time of such separation, we had made a distribution of the type referred to in such paragraph to all holders of our common stock, subject to readjustment as described above if such rights expire, terminate or are redeemed. We currently do not have a stockholder rights plan in effect.

Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change

Generally

If a make-whole fundamental change occurs and the conversion date for the conversion of a note occurs during the related “make-whole fundamental change conversion period” (as defined below under the caption “—Definitions”), then, subject to the provisions described below, the conversion rate applicable to such conversion will be increased by a number of shares (the “additional shares”) set forth in the table below corresponding (after interpolation as described below) to the effective date and the “stock price” (as defined below under the caption “—Definitions”) of such make-whole fundamental change:

If such effective date or stock price is not set forth in the table above, then:

Notwithstanding anything to the contrary, in no event will the conversion rate be increased to an amount that exceeds                  shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment in the same manner as, and at the same time and for the same events for which, the conversion rate is required to be adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

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Adjustment of Stock Prices and Number of Additional Shares

The stock prices in the first row (i.e., the column headers) of the table above will be adjusted at the same time and for the same events for which, the conversion rate is adjusted as a result of the operation of the provisions described above under the caption “—Conversion Rate Adjustments—Generally.” The adjusted stock prices will equal the stock prices immediately prior to such adjustment, multiplied by a fraction, the numerator of which is the conversion rate immediately prior to the adjustment giving rise to the share price adjustment and the denominator of which is the conversion rate as so adjusted. The numbers of additional shares in the table above will be adjusted in the same manner as, and at the same time and for the same events for which, the conversion rate is adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

Notice of Make-Whole Fundamental Change

We will notify noteholders and the trustee of each make-whole fundamental change no later than the second business day after the effective date of such make-whole fundamental change.

Enforceability

Our obligation to increase the conversion rate as described above in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

Effect of Common Stock Change Event

Generally

If there occurs any:

and, as a result of which, our common stock is converted into, or is exchanged for, or represents solely the right to receive, other securities, cash or other property, or any combination of the foregoing (such an event, a “common stock change event,” and such other securities, cash or property, the “reference property,” and the amount and kind of reference property that a holder of one share of our common stock would be entitled to receive on account of such common stock change event (without giving effect to any arrangement not to issue or deliver a fractional portion of any security or other property), a “reference property unit”), then, notwithstanding anything to the contrary,

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If the reference property consists of more than a single type of consideration to be determined based in part upon any form of stockholder election, then the composition of the reference property unit will be deemed to be the weighted average, per share of our common stock, of the types and amounts of consideration actually received, per share of our common stock, by the holders of common stock. We will notify the noteholders of the weighted average as soon as practicable after such determination is made.

We will not become a party to any common stock change event unless its terms are consistent with the provisions described under this “—Effect of Common Stock Change Event” caption.

Execution of Supplemental Indenture

At or before the effective time of the common stock change event, we and the resulting, surviving or transferee person (if not us) of such common stock change event (the “successor person”) will execute and deliver to the trustee a supplemental indenture that gives effect to the provisions described above and that contains such other provisions as we reasonably determine are appropriate to preserve the economic interests of the holders. If such reference property includes, in whole or in part, any stock or other securities, then such supplemental indenture will, to the extent applicable, provide for subsequent adjustments to the conversion rate in a manner consistent with the provisions described above. In addition, if the reference property includes, in whole or part, shares of stock or other securities or assets (other than cash or cash equivalents) of a person other than the successor person, then such other person will also execute such supplemental indenture and such supplemental indenture will contain such additional provisions we reasonably determine are appropriate to preserve the economic interests of noteholders.

Notice of Common Stock Change Event

No later than the second business day after the effective date of each common stock change event, we will notify the noteholders and the trustee of such common stock change event, including a brief description of the event, its effective date and a brief description of the anticipated change in the conversion right of the notes.

Equitable Adjustments to Prices

Whenever the indenture requires us to calculate the average of the last reported sale prices, or any function thereof, over a span of multiple days (including to calculate the stock price or an adjustment to the conversion rate), we will make proportionate adjustments to those calculations account for any adjustment to the conversion rate pursuant to paragraph (1) above under the caption “—Conversion Rights—Conversion Rate Adjustments—Generally” that becomes effective, or any event requiring such an adjustment to the conversion rate where the ex-dividend date or effective date, as applicable, of such event occurs, at any time during the period over which such average is to be calculated.

Exchange in Lieu of Conversion

When a noteholder surrenders any note for conversion, we may, at our election (an “exchange election”), direct the conversion agent to surrender, on or prior to the business day immediately following the conversion date, such note to one or more financial institutions designated by us for exchange in lieu of conversion. In order to accept any notes surrendered for conversion, the designated financial institution(s) must agree to timely pay or deliver, as the case may be, in exchange for such note, the consideration that would otherwise be due upon conversion as described above under “—Settlement upon Conversion.” To make an exchange election with respect to any note, we must, by the close of business on the business day following the relevant conversion date, notify in writing the trustee, the conversion agent (if other than the trustee) and the holder of such note and we must notify the designated financial institution(s) of the relevant deadline for delivery of the consideration due upon conversion and the type of conversion consideration to be paid or delivered, as the case may be.

Any notes exchanged by the designated financial institution(s) will remain outstanding, subject to the depositary procedures, if applicable. If any financial institution agrees to accept any notes for exchange but does not timely pay or deliver, as the case may be, the related conversion consideration, or if such designated financial institution does not accept the notes for exchange, then we will pay or deliver, as the case may be, the relevant conversion consideration, as, and at the time, required pursuant to the indenture as if we had not made the exchange election.

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Our designation of any financial institution(s) to which the notes may be submitted for exchange does not require such financial institution(s) to accept any notes.

Fundamental Change Permits Noteholders to Require Us to Repurchase Notes

Generally

If a fundamental change occurs, then each noteholder will have the right (the “fundamental change repurchase right”) to require us to repurchase its notes (or any portion thereof in an authorized denomination) for cash on a date (the “fundamental change repurchase date”) of our choosing, which must be a business day that is no more than 35, nor less than 20, business days after the date we send the related fundamental change notice, as described below.

The repurchase price (the “fundamental change repurchase price”) for a note tendered for repurchase will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date. However, if the fundamental change repurchase date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such repurchase, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but not including, such interest payment date; and (ii) the fundamental change repurchase price will not include accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date.

Notwithstanding anything to the contrary above, we may not repurchase any notes if the principal amount of the notes has been accelerated and such acceleration has not been rescinded on or before the fundamental change repurchase date (except in the case of an acceleration resulting solely from a default by us in the payment of the related fundamental change repurchase price and any related interest described above on the fundamental change repurchase date).

Notice of Fundamental Change

On or before the 20th calendar day after the occurrence of a fundamental change, we will send to each noteholder and the trustee notice of such fundamental change containing certain information set forth in the indenture, including the fundamental change repurchase date, the fundamental change repurchase price and the procedures noteholders must follow to tender their notes for repurchase.

Procedures to Exercise the Fundamental Change Repurchase Right

To exercise its fundamental change repurchase right with respect to a note, the holder thereof must deliver a notice (a “fundamental change repurchase notice”) to the paying agent before the close of business on the business day immediately before the related fundamental change repurchase date (or such later time as may be required by law).

The fundamental change repurchase notice must contain certain information set forth in the indenture, including the certificate number of any physical notes to be repurchased, or must otherwise comply with the depositary procedures in the case of a global note.

A noteholder that has delivered a fundamental change repurchase notice with respect to a note may withdraw that notice by delivering a withdrawal notice to the paying agent at any time before the close of business on the business day immediately before the fundamental change repurchase date (or, if we fail to pay the related fundamental change repurchase price for such note when due, at any time before such fundamental change repurchase price is paid in full). The withdrawal notice must contain certain information set forth in the indenture, including the certificate number of any physical notes with respect to which the withdrawal notice is being delivered, or must otherwise comply with the depositary procedures in the case of a global note.

Notes to be repurchased must be delivered to the paying agent (in the case of certificated notes) or the depositary procedures must be complied with (in the case of global notes) for the holder of those notes to be entitled to receive the fundamental change repurchase price.

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Repurchase by Third Party

Notwithstanding anything to the contrary described above, we will be deemed to satisfy our obligations to repurchase notes pursuant to the provisions described above if (i) one or more third parties conduct the repurchase offer and repurchase tendered notes in a manner that would have satisfied our obligations to do the same if conducted directly by us; and (ii) an owner of a beneficial interest in the notes would not receive a lesser amount (as a result of taxes, additional expenses or for any other reason) than such owner would have received had we repurchased the notes.

No Repurchase Right in Certain Circumstances

Notwithstanding anything to the contrary, we will not be required to send a fundamental change notice, or offer to repurchase or repurchase any notes, as described above, in connection with a fundamental change occurring pursuant to clause (ii)(2) (or pursuant to clause (i) that also constitutes a fundamental change occurring pursuant to clause (ii)(2)) of the definition thereof, if:

We refer to any fundamental change with respect to which, in accordance with the provision described above, we do not offer to repurchase any notes as an “exempted fundamental change.”

Compliance with Securities Laws

We will comply in all material respects with all federal and state securities laws in connection with a repurchase following a fundamental change (including complying with the tender offer rules under the Exchange Act and filing any required Schedule TO, to the extent applicable) so as to permit effecting such repurchase in the manner described above. However, to the extent that the provisions of any securities laws or regulations adopted after the date on which the notes are first issued conflict with the provisions of the indenture relating to our obligations to purchase the notes upon a fundamental change, we will comply with such applicable securities laws and regulations and will not be deemed to have breached our obligations under such provisions of the indenture by virtue of such conflict.

Consolidation, Merger and Asset Sale

For purposes of the notes, the description below under this section titled “—Consolidation, Merger and Asset Sale” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Consolidation, Merger or Sale.”

We will not consolidate with or merge with or into, or sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of us and our subsidiaries, taken as a whole, to another person (other than any such sale, lease or transfer to one or more of our “wholly owned subsidiaries” (as defined below under the caption “—Definitions”) not effected by means of a consolidation or merger) (a “business combination event”), unless:

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At the effective time of a business combination event that complies with the provisions described above, the successor corporation (if not us) will succeed to, and may exercise every right and power of, us under the indenture and the notes, and, except in the case of a lease, the predecessor company will be discharged from its obligations under the indenture and the notes.

The definition of “business combination event” includes a reference to “all or substantially all” of our and our subsidiaries’ assets. There is no precise, established definition of the phrase “all or substantially all” under applicable law. Accordingly, there may be uncertainty as to whether the provisions described above would apply to a sale, lease or transfer of less than all of our and our subsidiaries’ assets.

Events of Default

For purposes of the notes, the description below under this section titled “—Events of Default” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Events of Default under the Indenture.”

Generally

An “event of default” means the occurrence of any of the following:

and, in either case, such acceleration has not been rescinded or annulled or such failure to pay or default is not cured or waived, or such indebtedness is not paid or discharged in full, within 60 days after written notice to us by the trustee or to us and the trustee by holders of at least 25% of the aggregate principal amount of notes then outstanding; and

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Acceleration

If an event of default described in paragraph (9) above occurs with respect to us (and not solely with respect to a significant subsidiary of ours), then the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding will immediately become due and payable without any further action or notice by any person. If an event of default (other than an event of default described in paragraph (9) above with respect to us and not solely with respect to a significant subsidiary of ours) occurs and is continuing, then, except as described below under the caption “—Special Interest as Sole Remedy for Certain Reporting Defaults,” the trustee, by notice to us, or noteholders of at least 25% of the aggregate principal amount of notes then outstanding, by notice to us and the trustee, may declare the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding to become due and payable immediately.

Noteholders of a majority in aggregate principal amount of the notes then outstanding, by notice to us and the trustee, may, on behalf of all noteholders, rescind any acceleration of the notes and its consequences if (i) such rescission would not conflict with any judgment or decree of a court of competent jurisdiction; and (ii) all existing events of default (except the non-payment of principal of, or interest on, the notes that has become due solely because of such acceleration) have been cured or waived. No such rescission will affect any subsequent default or impair any right consequent thereto.

If any portion of the amount payable on the notes upon acceleration is considered by a court to be unearned interest (through the allocation of the value of the instrument to the embedded warrant or otherwise), then the court could disallow recovery of any such portion.

Waiver of Past Defaults

An event of default pursuant to paragraph (1), (2), (4) or (6) above (that, in the case of paragraph (6) only, results from a default under any covenant that cannot be amended without the consent of each affected noteholder), and a default that could lead to such an event of default, can be waived only with the consent of each affected noteholder. Each other default or event of default may be waived, on behalf of all noteholders, by noteholders of a majority in aggregate principal amount of the notes then outstanding.

Notice of Defaults

If a default or event of default occurs, then, within 30 days after its occurrence, we will notify the trustee, setting forth what action we are taking or propose to take with respect thereto, except that we are not required to deliver such notice if such default or event of default has been cured. We must also provide the trustee, within 120 days after the end of each fiscal year, a certificate as to whether any defaults or events of default have occurred or are continuing. If a default or event of default occurs and is continuing and is known to the trustee, then the trustee must notify the noteholders of the same within 90 days after it occurs or, if it is not known to the trustee at such time, promptly (and in any event within 10 business days) after it becomes known to a responsible officer of the trustee. However, except in the case of a default or event of default in the payment of the principal of, or interest on, any note, the trustee may withhold such notice if and for so long as it in good faith determines that withholding such notice is in the interests of the noteholders.

Limitation on Suits; Absolute Rights of Noteholders

Except with respect to the rights referred to below, no noteholder may pursue any remedy with respect to the indenture or the notes, unless:

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However, notwithstanding anything to the contrary, the right of each holder of a note to receive payment or delivery, as applicable, of the principal of, or the redemption price or fundamental change repurchase price for, or any interest on, or the consideration due upon conversion of, such note on or after the respective due dates therefor, or to bring suit for the enforcement of any such payment or delivery on or after such respective due dates, will not be impaired or affected without the consent of such holder.

Noteholders of a majority in aggregate principal amount of the notes then outstanding may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee or exercising any trust or power conferred on it. However, the trustee may refuse to follow any direction that conflicts with law, the indenture or the notes, or that, subject to the terms of the indenture, the trustee determines may be unduly prejudicial to the rights of other noteholders or may involve the trustee in liability, unless the trustee is offered security and indemnity satisfactory to the trustee against any loss, liability or expense to the trustee that may result from the trustee’s following such direction.

Special Interest as Sole Remedy for Certain Reporting Defaults

Notwithstanding anything to the contrary described above, we may elect that the sole remedy for any event of default (a “reporting event of default”) pursuant to paragraph (6) above arising from our failure to comply with our obligations described below under the caption “—Exchange Act Reports” (including our obligations under Section 314(a)(1) of the Trust Indenture Act) will, for each of the first 360 calendar days on which a reporting event of default has occurred and is continuing, consist exclusively of the accrual of special interest on the notes. If we have made such an election, then (i) the notes will be subject to acceleration as described above on account of the relevant reporting event of default from, and including, the 361st calendar day on which a reporting event of default has occurred and is continuing or if we fail to pay any accrued and unpaid special interest when due; and (ii) special interest will cease to accrue on any notes from, and including, the earlier of (x) the date such event of default is cured or waived and (y) such 361st calendar day.

Any special interest that accrues on a note will be payable on the same dates and in the same manner as the stated interest on such note and will accrue at a rate per annum equal to 0.25% of the principal amount thereof for the first 180 days on which special interest accrues and, thereafter, at a rate per annum equal to 0.50% of the principal amount thereof from the 181st day to, and including, the 360th day on which special interest accrues. However, in no event will special interest accrue on any day on a note at a rate per annum that exceeds 0.50%, regardless of the number of events or circumstances giving rise to the accrual of special interest. For the avoidance of doubt, any special interest that accrues on a note will be in addition to the stated interest that accrues on such note.

To make the election to pay special interest as described above, we must provide notice of such election to noteholders before the date on which each reporting event of default first occurs. The notice will also, among other things, briefly describe the periods during which and rate at which special interest will accrue and the circumstances under which the notes will be subject to acceleration on account of such reporting event of default.

Modification and Amendment

For purposes of the notes, the description below under this section titled “—Modification and Amendment” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Modification of Indenture; Waiver.”

We and the trustee may, with the consent of holders of a majority in aggregate principal amount of the notes then outstanding, amend or supplement the indenture or the notes or waive compliance with any provision of the

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indenture or the notes. However, without the consent of each affected noteholder, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may:

For the avoidance of doubt, pursuant to the first four bullet points above, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may change the amount or type of consideration due on any note (whether on an interest payment date, redemption date, fundamental change repurchase date or the maturity date or upon conversion, or otherwise), or the date(s) or time(s) such consideration is payable or deliverable, as applicable, without the consent of each affected noteholder.

Notwithstanding anything to the contrary above, we and the trustee may amend or supplement the indenture or the notes without the consent of any noteholder to:

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Exchange Act Reports

We will send to the trustee copies of all annual or quarterly reports (on Form 10-K or Form 10-Q, or any respective successor forms) that we are required to file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act within 15 calendar days after the date that we are required to so file or furnish the same (after giving effect to all applicable grace periods under the Exchange Act). However, we need not send to the trustee any material for which we have received, or are seeking in good faith and have not been denied, confidential treatment by the SEC. Any report that we file with or furnish to the SEC through the EDGAR system (or any successor thereto) will be deemed to be sent to noteholders at the time such report is so filed or furnished via the EDGAR system (or such successor).

We will also comply with our other obligations under Section 314(a)(1) of the Trust Indenture Act.

Discharge

For purposes of the notes, the description below under this section titled “—Discharge” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Discharge.”

Subject to the terms of the indenture, our obligations under the indenture with respect to the notes will be discharged if we deliver all outstanding notes to the trustee for cancellation, or if all outstanding notes have become due and payable (including upon conversion, if the consideration due upon such conversion has been determined) and we have irrevocably deposited with the trustee, or caused to be delivered to noteholders, sufficient cash or other consideration to satisfy all such amounts that have become due and payable.

Calculations

Except as otherwise provided in the indenture, we will be responsible for making all calculations called for under the indenture or the notes, including determinations of the last reported sale price, the daily cash amount, the daily share amount, accrued interest on the notes and the conversion rate. We will make all calculations in good faith, and, absent manifest error, our calculations will be final and binding on all noteholders. We will provide a schedule of our calculations to the trustee, and the trustee will promptly forward a copy of each such schedule to any noteholder upon written request.

Trustee

The trustee under the indenture is U.S. Bank National Association. The trustee assumes no responsibility for the accuracy or completeness of the information contained in this prospectus supplement or the related documents.

Notices

We will send all notices or communications to noteholders pursuant to the indenture in writing by first class mail, certified or registered, return receipt requested, or by overnight air courier guaranteeing next day delivery, to the noteholders’ respective addresses shown on the register for the notes. However, in the case of global notes, we are permitted to send notices or communications to noteholders pursuant to the depositary procedures, and notices and communications that we send in this manner will be deemed to have been properly sent to such noteholders in writing.

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No Personal Liability of Directors, Officers, Employees and Stockholders

No past, present or future director, officer, employee, incorporator or stockholder of ours, as such, will have any liability for any obligations of ours under the indenture or the notes or for any claim based on, in respect of, or by reason of, such obligations or their creation. By accepting any note, each noteholder will be deemed to waive and release all such liability, and such waiver and release are part of the consideration for the issuance of the notes.

Governing Law; Waiver of Jury Trial

The indenture and the notes, and any claim, controversy or dispute arising under or related to the indenture or the notes, will be governed by and construed in accordance with the laws of the state of New York. The indenture will provide that we and the trustee will irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the indenture, the notes or the transactions contemplated by the indenture or the notes.

Submission to Jurisdiction

Any legal suit, action or proceeding arising out of or based upon the indenture or the transactions contemplated by the indenture may be instituted in the federal courts of the United States of America located in the City of New York or the courts of the State of New York, in each case located in the City of New York (collectively, the “specified courts”), and each party will be deemed to irrevocably submit to the non-exclusive jurisdiction of those courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail (to the extent allowed under any applicable statute or rule of court) to any party’s address as provided in the indenture will be effective service of process for any such suit, action or proceeding brought in any such court. Each of us, the trustee and each noteholder (by its acceptance of any note) will be deemed to irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the specified courts and to irrevocably and unconditionally waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum.

Definitions

“Bid solicitation agent” means the person who is required to obtain bids for the trading price in accordance with the provisions described under the caption “—Conversion Rights—When the Notes May Be Converted—Conversion upon Satisfaction of Note Trading Price Condition” and in the definition of “trading price.”

“Board of directors” means our board of directors or a committee of such board duly authorized to act on behalf of such board.

“Business day” means any day other than a Saturday, a Sunday or any day on which the Federal Reserve Bank of New York is authorized or required by law or executive order to close or be closed.

“Capital stock” of any person means any and all shares of, interests in, rights to purchase, warrants or options for, participations in, or other equivalents of, in each case however designated, the equity of such person, but excluding any debt securities convertible into such equity.

“Close of business” means 5:00 p.m., New York City time.

“Conversion price” means, as of any time, an amount equal to (i) $1,000 divided by (ii) the conversion rate in effect at such time.

“Conversion rate” initially means              shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment as described above under the caption “—Conversion Rights.” Whenever in this prospectus supplement we refer to the conversion rate as of a particular date without setting forth a particular time on such date, such reference will be deemed to be to the conversion rate immediately after the close of business on such date.

“Daily cash amount” means, with respect to any VWAP trading day, the lesser of (i) the applicable daily maximum cash amount; and (ii) the daily conversion value for such VWAP trading day.

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“Daily conversion value” means, with respect to any VWAP trading day, one-40th of the product of (i) the conversion rate on such VWAP trading day; and (ii) the daily VWAP per share of our common stock on such VWAP trading day.

“Daily maximum cash amount” means, with respect to a conversion of any note, the quotient obtained by dividing (i) the specified dollar amount applicable to such conversion by (ii) 40.

“Daily share amount” means, with respect to any VWAP trading day, the quotient obtained by dividing (i) the excess, if any, of the daily conversion value for such VWAP trading day over the applicable daily maximum cash amount by (ii) the daily VWAP for such VWAP trading day. For the avoidance of doubt, the daily share amount will be zero for such VWAP trading day if such daily conversion value does not exceed such daily maximum cash amount.

“Daily VWAP” means, for any VWAP trading day, the per share volume-weighted average price of our common stock as displayed under the heading “Bloomberg VWAP” on Bloomberg page “RTRX <EQUITY> AQR” (or, if such page is not available, its equivalent successor page) in respect of the period from the scheduled open of trading until the scheduled close of trading of the primary trading session on such VWAP trading day (or, if such volume-weighted average price is unavailable, the market value of one share of our common stock on such VWAP trading day, determined, using a volume-weighted average price method, by a nationally recognized independent investment banking firm we select, which may include any of the underwriters). The daily VWAP will be determined without regard to after-hours trading or any other trading outside of the regular trading session.

“Depositary procedures” means, with respect to any transfer, exchange or transaction involving a global note or any beneficial interest therein, the rules and procedures of the depositary applicable to such transfer, exchange or transaction.

“DTC” means The Depository Trust Company.

“Ex-dividend date” means, with respect to an issuance, dividend or distribution on our common stock, the first date on which shares of our common stock trade on the applicable exchange or in the applicable market, regular way, without the right to receive such issuance, dividend or distribution (including pursuant to due bills or similar arrangements required by the relevant stock exchange). For the avoidance of doubt, any alternative trading convention on the applicable exchange or market in respect of our common stock under a separate ticker symbol or CUSIP number will not be considered “regular way” for this purpose.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Fundamental change” means any of the following events:

(i) a “person” or “group” (within the meaning of Section 13(d)(3) of the Exchange Act), other than us, any of our wholly owned subsidiaries or any employee benefit plans of ours or any of our wholly owned subsidiaries, has become and files any report with the SEC that discloses that such person or group has become the direct or indirect “beneficial owner” (as defined below) of shares of our common stock representing more than 50% of the voting power of all of our then-outstanding common stock; provided, however, that, for these purposes, no “person” or “group” will be deemed to be the beneficial owner of any securities tendered pursuant to a tender or exchange offer made by or on behalf of such “person” or “group” until such tendered securities are accepted for purchase or exchange under such offer;

(ii) the consummation of: (1) any sale, lease or other transfer, in one transaction or a series of transactions, of all or substantially all of the assets of us and our subsidiaries, taken as a whole, to any person, other than one or more of our wholly owned subsidiaries; or (2) any transaction or series of related transactions in connection with which (whether by means of merger, consolidation, share exchange, combination, reclassification, recapitalization, acquisition, liquidation or otherwise) all of our common stock is exchanged for, converted into, acquired for, or constitutes solely the right to receive, other securities, cash or other property (other than changes resulting solely from a subdivision or combination, or a change in par value, of our common stock); provided, however, that any merger, consolidation, share exchange or combination of us pursuant to which the persons that directly or indirectly “beneficially owned” (as defined below) all classes of our common equity immediately before such transaction directly or indirectly “beneficially own,” immediately after such transaction, more than 50% of all classes of

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common equity of the surviving, continuing or acquiring company or other transferee, as applicable, or the parent thereof, in substantially the same proportions vis-à-vis each other as immediately before such transaction will be deemed not to be a fundamental change pursuant to this clause (ii);

(iii) our stockholders approve any plan or proposal for our liquidation or dissolution; or

(iv) our common stock ceases to be listed or quoted on any of The New York Stock Exchange, The Nasdaq Global Market or The Nasdaq Global Select Market (or any of their respective successors);

provided, however, that a transaction or event described in clause (i) or (ii) above will not constitute a fundamental change if at least 90% of the consideration received or to be received by the holders of our common stock (excluding cash payments for fractional shares or pursuant to dissenters rights), in connection with such transaction or event, consists of shares of common stock listed or quoted (or depositary receipts or shares representing shares of common stock, which depositary receipts or shares are listed or quoted) on any of The New York Stock Exchange, The Nasdaq Global Market or The Nasdaq Global Select Market (or any of their respective successors), or that will be so listed when issued or exchanged in connection with such transaction or event, and such transaction or event constitutes a common stock change event whose reference property consists of such consideration. For purposes of this definition of “fundamental change” above, any transaction that constitutes a fundamental change pursuant to both clauses (i) and (ii) above (without regard to the proviso in clause (ii) above) will be deemed to occur solely pursuant to clause (ii) above (subject to such proviso).

For the purposes of this definition, whether a person is a “beneficial owner” and whether shares are “beneficially owned” will be determined in accordance with Rule 13d-3 under the Exchange Act, subject to the proviso to clause (i) above

“Holder” and “noteholder” mean a person in whose name a note is registered in the register for the notes.

“Last reported sale price” of our common stock for any trading day means the closing sale price per share (or, if no closing sale price is reported, the average of the last bid price and the last ask price per share or, if more than one in either case, the average of the average last bid prices and the average last ask prices per share) of our common stock on such trading day as reported in composite transactions for the principal U.S. national or regional securities exchange on which our common stock is then listed. If our common stock is not listed on a U.S. national or regional securities exchange on such trading day, then the last reported sale price will be the last quoted bid price per share of our common stock on such trading day in the over-the-counter market as reported by OTC Markets Group Inc. or a similar organization. If our common stock is not so quoted on such trading day, then the last reported sale price will be the average of the mid-point of the last bid price and the last ask price per share of our common stock on such trading day from each of at least three nationally recognized independent investment banking firms we select, which may include any of the underwriters. The “last reported sale price” will be determined without regard to after-hours trading or any other trading outside of the regular trading session hours.

“Make-whole fundamental change” means a fundamental change (determined after giving effect to the proviso immediately after clause (iv) of the definition thereof, but without regard to the proviso to clause (ii)(2) of the definition thereof).

“Make-whole fundamental change conversion period” means, with respect to a make-whole fundamental change, the period from, and including, the effective date of such make-whole fundamental change to, and including, the 35th trading day after such effective date (or, if such make-whole fundamental change also constitutes a fundamental change (other than an exempted fundamental change), to, but excluding, the related fundamental change repurchase date).

“Market disruption event” means, with respect to any date, the occurrence or existence, during the one-half hour period ending at the scheduled close of trading on such date on the principal U.S. national or regional securities exchange or other market on which our common stock is listed for trading or trades, of any material suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant exchange or otherwise) in our common stock or in any options, contracts or futures contracts relating to our common stock.

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“Maturity date” means September 15, 2025.

“Observation period” means, with respect to any note to be converted, (i) subject to clause (ii) below, if the conversion date for such note occurs on or before the 45th scheduled trading day immediately before the maturity date, the 40 consecutive VWAP trading days beginning on, and including, the third VWAP trading day immediately after such conversion date; (ii) if such conversion date occurs on or after the date we have sent a redemption notice calling such note for redemption and before the related redemption date, the 40 consecutive VWAP trading days beginning on, and including, the 41st scheduled trading day immediately before such redemption date; and (iii) subject to clause (ii) above, if such conversion date occurs after the 45th scheduled trading day immediately before the maturity date, the 40 consecutive VWAP trading days beginning on, and including, the 41st scheduled trading day immediately before the maturity date.

“Open of business” means 9:00 a.m., New York City time.

“Person” means any individual, corporation, partnership, limited liability company (or series thereof), joint venture, association, joint-stock company, trust, unincorporated organization or government or other agency or political subdivision thereof.

“Scheduled trading day” means any day that is scheduled to be a trading day on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded. If our common stock is not so listed or traded, then “scheduled trading day” means a business day.

“Securities Act” means the U.S. Securities Act of 1933, as amended.

“Significant subsidiary” of any person means any subsidiary of that person that constitutes, or any group of subsidiaries of that person that, in the aggregate, would constitute, a “significant subsidiary” (as defined in Rule 1-02(w) of Regulation S-X under the Exchange Act) of that person; provided, however, that, if a subsidiary meets the criteria of clause (3) of the definition of “significant subsidiary” in Rule 1-02(w) but not clause (1) or (2) thereof, then such subsidiary will not be deemed not to be a significant subsidiary of that person unless such subsidiary’s or group’s income from continuing operations before income taxes, extraordinary items and cumulative effect of a change in accounting principle, exclusive of amounts attributable to any non-controlling interests, for the last completed fiscal year before the date of determination exceeds $20,000,000.

“Specified dollar amount” means, with respect to the conversion of a note to which combination settlement applies, the maximum cash amount per $1,000 principal amount of such note deliverable upon such conversion (excluding cash in lieu of any fractional share of common stock).

“Stock price” has the following meaning for any make-whole fundamental change: (i) if the holders of our common stock receive only cash in consideration for their shares of common stock in such make-whole fundamental change and such make-whole fundamental change is pursuant to clause (ii) of the definition of “fundamental change,” then the stock price is the amount of cash paid per share of our common stock in such make-whole fundamental change; and (ii) in all other cases, the stock price is the average of the last reported sale prices per share of common stock for the five consecutive trading days ending on, and including, the trading day immediately before the effective date of such make-whole fundamental change.

“Subsidiary” means, with respect to any person, (i) any corporation, association or other business entity (other than a partnership or limited liability company) of which more than 50% of the total voting power of the capital stock entitled (without regard to the occurrence of any contingency, but after giving effect to any voting agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of directors, managers or trustees, as applicable, of such corporation, association or other business entity is owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person; and (ii) any partnership or limited liability company where (x) more than 50% of the capital accounts, distribution rights, equity and voting interests, or of the general and limited partnership interests, as applicable, of such partnership or limited liability company are owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person, whether in the form of membership, general, special or limited partnership or limited liability company interests or

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otherwise; and (y) such person or any one or more of the other subsidiaries of such person is a controlling general partner of, or otherwise controls, such partnership or limited liability company.

Trading day” means any day on which (i) trading in our common stock generally occurs on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded; and (ii) there is no “market disruption event” (as defined above in this “—Definitions” section). If our common stock is not so listed or traded, then “trading day” means a business day.

“Trading price” of the notes on any trading day means the average of the secondary market bid quotations, expressed as a cash amount per $1,000 principal amount of notes, obtained by the bid solicitation agent for $1,000,000 in principal amount of notes at approximately 3:30 p.m., New York City time, on such trading day from three nationally recognized independent securities dealers we select, which may include any of the underwriters; provided, however, that, if three such bids cannot reasonably be obtained by the bid solicitation agent but two such bids are obtained, then the average of the two bids will be used, and if only one such bid can reasonably be obtained by the bid solicitation agent, then that one bid will be used. If, on any trading day, (i) the bid solicitation agent cannot reasonably obtain at least one bid for $1,000,000 in principal amount of notes from a nationally recognized independent securities dealer; (ii) we are not acting as the bid solicitation agent and we fail to instruct the bid solicitation agent to obtain bids when required; or (iii) the bid solicitation agent fails to solicit bids when required, then, in each case, the trading price per $1,000 principal amount of notes on such trading day will be deemed to be less than 98% of the product of the last reported sale price per share of our common stock on such trading day and the conversion rate on such trading day.

“VWAP market disruption event” means, with respect to any date, (i) the failure by the principal U.S. national or regional securities exchange on which our common stock is then listed, or, if our common stock is not then listed on a U.S. national or regional securities exchange, the principal other market on which our common stock is then traded, to open for trading during its regular trading session on such date; or (ii) the occurrence or existence, for more than one half hour period in the aggregate, of any suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant exchange or otherwise) in our common stock or in any options, contracts or futures contracts relating to our common stock, and such suspension or limitation occurs or exists at any time before 1:00 p.m., New York City time, on such date.

“VWAP trading day” means a day on which (i) there is no VWAP market disruption event; and (ii) trading in our common stock generally occurs on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded. If our common stock is not so listed or traded, then “VWAP trading day” means a business day.

“Wholly owned subsidiary” of a person means any subsidiary of such person all of the outstanding capital stock or other ownership interests of which (other than directors’ qualifying shares) are owned by such person or one or more wholly owned subsidiaries of such person.

Book Entry, Settlement and Clearance

Global Notes

The notes will be initially issued in the form of one or more notes registered in the name of Cede & Co., as nominee of DTC, without interest coupons (the “global notes”), and will be deposited with the trustee as custodian for DTC.

Only persons who have accounts with DTC (“DTC participants”) or persons who hold interests through DTC participants may own beneficial interests in a global note. We expect that, under procedures established by DTC:

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Book-Entry Procedures for Global Notes

All interests in a global note will be subject to the operations and procedures of DTC. Accordingly, you must allow for sufficient time in order to comply with those operations and procedures if you wish to exercise any of your rights with respect to the notes. The operations and procedures of DTC are controlled by DTC and may be changed at any time. None of us, the trustee or any of the underwriters will be responsible for those operations or procedures.

DTC has advised us that it is:

DTC was created to hold securities for its participants and to facilitate the clearance and settlement of securities transactions between its participants through electronic book-entry changes to the accounts of its participants. DTC’s participants include securities brokers and dealers (including the underwriters), banks and trust companies, clearing corporations and other organizations. Indirect access to DTC’s book-entry system is also available to other “indirect participants,” such as banks, brokers, dealers and trust companies, who directly or indirectly clear through or maintain a custodial relationship with a DTC participant. Purchasers of notes who are not DTC participants may beneficially own securities held by or on behalf of DTC only through DTC participants or indirect participants in DTC.

So long as DTC or its nominee is the registered owner of a global note, DTC or that nominee will be considered the sole owner or holder of the notes represented by that global note for all purposes under the indenture. Except as provided below, owners of beneficial interests in a global note:

As a result, each investor who owns a beneficial interest in a global note must rely on the procedures of DTC (and, if the investor is not a participant or an indirect participant in DTC, on the procedures of the DTC participant through whom the investor owns its interest) to exercise any rights of a noteholder under the indenture.

Payments on any global notes will be made to DTC’s nominee as the registered holder of the global note. Neither we nor the trustee will have any responsibility or liability for the payment of amounts to owners of beneficial interests in a global note, for any aspect of the records relating to, or payments made on account of, those interests by DTC or for maintaining, supervising or reviewing any records of DTC relating to those interests. Payments by participants and indirect participants in DTC to the owners of beneficial interests in a global note will be governed by standing instructions and customary industry practice and will be the responsibility of those participants or indirect participants and DTC.

Transfers between participants in DTC will be effected under DTC’s procedures and will be settled in same-day funds.

Certificated Notes

A global note will be exchanged, pursuant to customary procedures, for one or more physical notes only if:

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DESCRIPTION OF OTHER INDEBTEDNESS

On May 30, 2014, we issued $46 million aggregate principal amount of 4.50% senior convertible notes due 2019 (the “2019 notes”). The 2019 notes will mature on May 30, 2019, unless earlier repurchased or converted. The notes are our senior unsecured obligations and bear interest at an annual rate of 4.50%, payable semi-annually in arrears on May 15 and November 15 of each year, commencing on November 15, 2014. The 2019 notes are governed by an indenture between us and U.S. Bank, National Association, as trustee.

The 2019 notes have an initial conversion rate of 57.4300 shares of common stock per $1,000 principal amount of 2019 notes, representing an initial conversion price of approximately $17.41 per share of common stock. The conversion rate is subject to adjustment under certain circumstances in accordance with the terms of the indenture governing the 2019 notes. The 2019 notes are convertible at the option of the holders thereof at any time prior to the close of business on the business day immediately preceding the maturity date. Upon conversion, we will satisfy our conversion obligation by delivering shares of our common stock in the manner and subject to the terms and conditions provided in the indenture governing the 2019 notes.

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DESCRIPTION OF CAPITAL STOCK

As of the date of this prospectus supplement, our certificate of incorporation, as amended, authorizes us to issue 100,000,000 shares of common stock, par value $0.0001 per share, and 20,000,000 shares of preferred stock, par value $0.001 per share. As of August 30, 2018, 40,859,214 shares of common stock were outstanding and no shares of preferred stock were outstanding.

The following summary description of our capital stock is based on the provisions of our certificate of incorporation, as amended, as well as our amended and restated bylaws, and the applicable provisions of the Delaware General Corporation Law. This information is qualified entirely by reference to the applicable provisions of our certificate of incorporation, as amended, amended and restated bylaws, and the Delaware General Corporation Law. For information on how to obtain copies of our certificate of incorporation, as amended, and amended and restated bylaws, see “Where You Can Find Additional Information.”

Common Stock

The holders of our common stock are entitled to one vote per share on matters on which our stockholders vote. There are no cumulative voting rights. Subject to any preferential dividend rights of any outstanding shares of preferred stock, holders of our common stock are entitled to receive dividends, if declared by our board of directors, out of funds that we may legally use to pay dividends. Generally, all matters to be voted on by stockholders must be approved by a majority (or, in the case of election of directors, by a plurality) of the votes entitled to be cast by all shares of our common stock that are present in person or represented by proxy.

Holders representing fifty percent (50%) of our common stock issued, outstanding and entitled to vote, represented in person or by proxy, are necessary to constitute a quorum at any meeting of our stockholders. A vote by the holders of a majority of our outstanding shares is required to effectuate certain fundamental corporate changes such as liquidation, merger or an amendment to our certificate of incorporation. If we liquidate or dissolve, holders of our common stock are entitled to share ratably in our assets once our debts and any liquidation preference owed to any then-outstanding preferred stockholders are paid. Our certificate of incorporation does not provide our common stock with any redemption, conversion or preemptive rights.

Preferred Stock

We currently have 20,000,000 shares of authorized capital stock that are designated as preferred stock. 1,000 of such shares of preferred stock are designated as Class A Preferred, par value $0.001 per share. Shares of Class A Preferred are not entitled to interest and have certain liquidation preferences and special voting rights. No preferred stock has been issued to date.

Unless required by law or by any stock exchange on which our common stock is listed in the future, our board of directors has the authority, without further action by our stockholders, to issue the authorized but undesignated shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control of our company or other corporate action.

The issuance of preferred stock could adversely affect, among other things, the voting power of holders of common stock and the likelihood that stockholders will receive dividend payments and payments upon our liquidation, dissolution or winding up. The issuance of preferred stock could also have the effect of delaying, deferring or preventing a change in control of us.

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Anti-Takeover Effects of Provisions of our Certificate of Incorporation, our Bylaws and Delaware Law

Some provisions of Delaware law, our certificate of incorporation, as amended, and our amended and restated bylaws contain provisions that could make the following transactions more difficult: acquisition of us by means of a tender offer; acquisition of us by means of a proxy contest or otherwise; or removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares. These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits persons deemed “interested stockholders” from engaging in a “business combination” with a publicly-held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is, or the transaction in which the person became an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation’s voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors, such as discouraging takeover attempts that might result in a premium over the market price of our common stock.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC. The transfer agent and registrar’s address is 59 Maiden Lane, New York, New York 10038.

Listing on the Nasdaq Global Market

Our common stock is listed on the Nasdaq Global Market under the symbol RTRX.

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MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS

The following is a summary of certain U.S. federal income tax considerations of the purchase, ownership and disposition of notes and the shares of common stock into which the notes may be converted. This summary is based upon provisions of the U.S. Internal Revenue Code (“Code”), applicable Treasury Regulations, administrative rulings and judicial decisions in effect as of the date hereof, any of which may subsequently be changed, possibly retroactively, so as to result in U.S. federal income tax consequences different from those discussed below. This summary does not address tax consequences that may apply to holders whose existing 4.50% senior convertible notes due 2019 are being repurchased in the substantially simultaneous repurchase transactions. Except where noted, this summary deals only with a note or share of common stock held as a capital asset by a beneficial owner who purchased the note on original issuance at its “issue price” (the first price at which a substantial portion of the notes is sold to persons other than bond houses, brokers, or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers). This summary is general in nature and does not address all aspects of U.S. federal income taxes and does not address state, local, estate, gift or non-U.S. consequences, In addition, it does not deal with all tax consequences that may be relevant to holders in light of their personal circumstances or particular situations, such as:

If an entity or arrangement treated as a partnership holds notes or shares of common stock, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner in a partnership holding the notes or shares of common stock, you should consult your tax advisor.

We have not sought, nor will we seek, a ruling from the Internal Revenue Service, or the IRS, with respect to the matters discussed below. There can be no assurance that the IRS will not take a different position concerning the tax consequences of the purchase, ownership or disposition of the notes or common stock or that any such position would not be sustained.

THIS SUMMARY OF CERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONS IS FOR GENERAL INFORMATION ONLY AND IS NOT TAX ADVICE. YOU SHOULD CONSULT YOUR TAX ADVISOR WITH RESPECT TO THE APPLICATION OF U.S. FEDERAL INCOME TAX LAWS TO YOUR PARTICULAR SITUATION AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP, AND DISPOSITION OF THE NOTES OR THE SHARES OF OUR COMMON STOCK INTO WHICH THE NOTES ARE CONVERTIBLE ARISING UNDER U.S. FEDERAL ESTATE OR GIFT TAX RULES OR UNDER THE LAWS OF ANY STATE, LOCAL, NON-U.S. OR ANY OTHER TAXING JURISDICTION OR UNDER ANY APPLICABLE TAX TREATY.

As used herein, the term “U.S. holder” means a beneficial owner of notes or shares of common stock received upon conversion of the notes that is, for U.S. federal income tax purposes:

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A “non-U.S. holder” is a beneficial owner (other than a partnership, or any entity treated as a partnership for U.S. federal income tax purposes) of notes or shares of common stock received upon conversion of the notes that is not a U.S. holder. Special rules may apply to certain non-U.S. holders such as individuals who are U.S. expatriates and certain non-U.S. holders that are subject to the Medicare net investment income tax. Consequently, non-U.S. holders should consult their tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them.

Consequences to U.S. Holders

Interest

It is anticipated, and this discussion assumes, that the notes will be issued with no more than a de minimis amount of original issue discount, if any (as determined under the Code). In such case, interest on a note will generally be taxable to a U.S. holder as ordinary income at the time it is paid or accrued in accordance with the U.S. holder’s usual method of accounting for tax purposes.

Additional Amounts

As described under the heading “Description of Notes—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults,” we may pay additional interest on the notes in certain circumstances. We intend to take the position that the possibility of such payments should not cause the notes to be treated as contingent payment debt instruments. This position is based in part on our assessment that the possibility, as of the date of issuance of the notes, that such additional amounts will be paid, is remote. Assuming such position is respected, any additional interest paid to a U.S. holder as described under “Description of Notes—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults” would be taxable as additional ordinary income when received or accrued, in accordance with such U.S. holder’s method of accounting for U.S. federal income tax purposes.

Our position that the notes are not contingent payment debt instruments is binding on each U.S. holder unless such U.S. holder discloses its contrary position to the IRS in the manner required by applicable Treasury Regulations. Our position that the notes are not contingent payment debt instruments is not, however, binding on the IRS. If the IRS successfully challenged this position, and the notes were treated as contingent payment debt instruments because of the possibility of such payments, U.S. holders would, among other things, be required to accrue interest income at a higher rate than the stated interest rate on the notes and to treat any gain recognized on the sale or other disposition of a note (including any gain realized on the conversion of a note) as ordinary income rather than as capital gain. The remainder of this discussion assumes that the notes are not treated as contingent payment debt instruments.

Sale, Exchange, Redemption, Repurchase, Retirement or Other Taxable Disposition of Notes

Except as provided below under “—Conversion of Notes” a U.S. holder will generally recognize capital gain or loss upon the sale, exchange, redemption, repurchase, retirement or other taxable disposition of a note, equal to the difference between the sum of the cash plus the fair market value of any other property received upon such disposition (excluding any amount attributable to accrued but unpaid interest, which will be treated as described above under “—Interest”) and such U.S. holder’s adjusted tax basis in the note. A U.S. holder’s adjusted tax basis in a note will generally be equal to the amount that the U.S. holder paid for the note, plus the amount, if any, included in income on an adjustment to the conversion rate of the notes, as described in “—Constructive Distributions” below. If, at the time of the sale, exchange, redemption, repurchase, retirement or other taxable disposition of the note, a U.S. holder held the note for more than one year, such gain or loss will be long-term capital gain or loss. Long-term capital gains recognized by certain non-corporate U.S. holders, including individuals, will generally be subject to a reduced rate of U.S. federal income tax. A U.S. holder’s ability to deduct capital losses may be limited.

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Conversion of Notes

If a U.S. holder presents a note for conversion, a U.S. holder may receive solely cash, solely common stock or a combination of cash and common stock in exchange for notes, depending upon our chosen settlement method.

If a U.S. holder receives solely cash in exchange for notes upon conversion, the U.S. holder’s gain or loss will be determined in the same manner as if the U.S. holder disposed of the notes in a taxable disposition (as described above under “–Sale, Exchange, Redemption, Repurchase, Retirement or Other Taxable Disposition of Notes”).

If a U.S. holder receives solely stock in exchange for a note upon conversion, the U.S. holder generally will not recognize any income, gain or loss on the conversion, except with respect to cash received in lieu of a fractional share of common stock and the fair market value of any common stock attributable to accrued and unpaid interest, subject to the discussion under “–Constructive Distributions” regarding the possibility that the adjustment to the conversion rate of notes converted in connection with a make-whole fundamental change may be treated as a deemed distribution. The U.S. holder’s aggregate tax basis in the common stock (including any fractional share for which cash is paid, but excluding shares attributable to accrued interest) will equal the U.S. holder’s tax basis in the note. The U.S. holder’s holding period in the common stock (other than shares attributable to accrued interest) will include the holding period in the note. A U.S. holder’s tax basis in common stock attributable to accrued interest will equal its fair market value on the date of receipt and the holding period for such stock will commence on the day after the date of receipt.

The U.S. federal income tax treatment of the conversion of a note into cash and common stock is uncertain, and U.S. holders should consult their tax advisors regarding the consequences of such a conversion. In general, the income tax treatment will depend on whether the conversion is treated as a recapitalization or alternatively as a conversion of a portion of the note for common stock and a taxable sale of a portion of the note for cash.

The conversion can only be treated as a recapitalization if the notes are treated as “securities” for U.S. federal income tax purposes. An instrument is a “security” for these purposes if, based on all the facts and circumstances, the instrument constitutes a meaningful investment in the issuer of the instrument. Although there are a number of factors that may affect the determination of whether a debt instrument is a “security,” one of the most important factors is the original term of the instrument, or the length of time between the issuance of the instrument and its maturity. In general, instruments with an original term of more than ten years are likely to be treated as “securities,” and instruments with an original term of less than five years are less likely to be treated as “securities.” In addition, the convertibility of a debt instrument into stock of the issuer may argue in favor of “security” treatment because of the holder’s possible equity participation in the issuer. If recapitalization treatment applies, then a U.S. holder will recognize gain, but not loss, in an amount equal to the lesser of (i) the excess of the sum of the cash and the fair market value of the common stock received (other than amounts attributable to accrued interest, which will be treated as described above under “–Interest” over the U.S. holder’s adjusted tax basis in the notes converted and (ii) the amount of cash received (other than cash received in lieu of a fractional share or cash attributable to accrued interest). Any gain recognized on conversion generally will be capital gain and will be long-term capital gain if, at the time of the conversion, the note has been held for more than one year.

Cash received in lieu of a fractional share of our common stock upon a conversion of a note should be treated as a payment in exchange for the fractional share of our common stock. Accordingly, the receipt of cash in lieu of a fractional share of our common stock should generally result in capital gain or loss, if any, measured by the difference between the cash received for the fractional share of our common stock and a U.S. holder’s tax basis allocable to such fractional share of our common stock, as described below.

The tax basis of the shares of common stock received upon a conversion that is treated as a recapitalization (including any fractional share deemed to be received by the U.S. holder but excluding common stock attributable to accrued interest) generally will equal the tax basis of the note that was converted, reduced by the amount of any cash received (other than cash received in lieu of a fractional share or cash attributable to accrued interest), and increased by the amount of gain, if any, recognized (other than with respect to a fractional share). A U.S. holder’s tax basis in a fractional share of our common stock will be determined by allocating such holder’s tax basis in the shares of our common stock, as determined in accordance with the previous sentence, between the shares of our common stock actually received and the fractional share of our common stock deemed received upon conversion, in

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accordance with their respective fair market values. A U.S. holder’s holding period for shares of common stock (other than common stock attributable to accrued interest) will include the period during which the U.S. holder held the notes. A U.S. holder’s tax basis in common stock attributable to accrued interest will equal its fair market value on the date of receipt and the holding period for such stock will commence on the day after the date of receipt.

If the conversion of a note into cash and common stock were not treated as a recapitalization, under an alternative characterization the cash payment received may be treated as proceeds from the sale of a portion of the note taxable in the manner described under “––Sale, Exchange, Redemption, Repurchase, Retirement or Other Taxable Disposition of Notes” above, and the common stock received on such a conversion (other than common stock attributable to accrued interest) may be treated as received upon a conversion of the other portion of the note, which generally would not be taxable to a U.S. holder. In that case, the U.S. holder’s tax basis in the note would generally be allocated pro rata among the common stock received and the portion of the note that is treated as sold for cash, in accordance with their respective fair market values. The holding period for the common stock received in the conversion (other than common stock attributable to accrued interest) would include the holding period for the notes.

As described in “Description of Notes–Conversion Rights–Treatment of Interest upon Conversion,” our delivery of cash, common stock or a combination of cash and shares of common stock will be deemed to satisfy our obligation with respect to accrued and unpaid interest on the notes. We intend to take the position that upon a conversion of notes accrued and unpaid interest is paid first by any cash paid upon such conversion (other than cash paid in lieu of a fractional share) and then by any shares of common stock.

Exchange in Lieu of Conversion

If a U.S. Holder surrenders notes for conversion, we direct the notes to be offered to a financial institution for exchange in lieu of conversion, and the designated institution accepts the notes and delivers cash, common stock or a combination of cash and common stock in exchange for the notes, the holder will be taxed on the transfer as a sale or exchange of the notes, as described above under “–Sale, Exchange, Redemption, Repurchase, Retirement or Other Taxable Disposition of Notes.” In such case, a U.S. holder’s tax basis in the common stock received will equal the fair market value of the stock on the date of the exchange, and the holder’s holding period in the shares of common stock received will begin the day after the date of the exchange.

Possible Effect of the Change in Conversion Consideration after a Change in Control

In the event we undergo certain of the events described under “Description of Notes–Conversion Rights–Effect of Common Stock Change Event,” the conversion rate and the related conversion consideration may be adjusted such that a U.S. holder would be entitled to convert its notes into the shares, property or assets described in such section.

Depending on the facts and circumstances at the time of such event, such adjustment may result in a deemed exchange of the outstanding notes, which may be a taxable event for U.S. federal income tax purposes. Whether or not such an adjustment results in a deemed exchange of the outstanding notes, a subsequent conversion of the notes might be treated as a fully taxable disposition of the notes if the property into which the notes are convertible is no longer stock of the notes’ obligor. Furthermore, depending on the circumstances, the U.S. federal income tax consequences of the exchange or conversion of the notes as well as the ownership of the notes and the shares may be different from the U.S. federal income tax consequences addressed in this disclosure. A U.S. holder should consult its tax advisor regarding the U.S. federal income tax consequences of such an adjustment.

Constructive Distributions

The conversion rate of the notes will be adjusted in certain circumstances. Adjustments (or failures to make adjustments) that have the effect of increasing a U.S. holder’s proportionate interest in our assets or earnings may in some circumstances result in a deemed distribution to a U.S. holder for U.S. federal income tax purposes even though no cash or property is received. Adjustments to the conversion rate made pursuant to a bona fide reasonable adjustment formula that has the effect of preventing the dilution of the interest of the holders of the notes, however, will generally not be considered to result in a deemed distribution to a U.S. holder. Certain of the possible conversion rate adjustments provided in the notes (including, without limitation, adjustments with respect to taxable dividends to holders of our common stock) will not qualify as being pursuant to a bona fide reasonable adjustment formula. If such adjustments are made, a U.S. holder will be deemed to have received a distribution even though the U.S. holder has not received any cash or property as a result of such adjustments. In addition, an adjustment to the

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conversion rate in connection with a make-whole fundamental change may be treated as a deemed distribution. Any deemed distributions will be taxable as a dividend, return of capital, or capital gain as described in “–Distributions” below. However, U.S. holders should consult with their own tax advisors as to whether a constructive dividend deemed paid to a non-corporate U.S. holder would be eligible for the preferential rates of U.S. federal income tax applicable in respect of certain dividends received. It is also unclear whether corporate holders would be entitled to claim the dividends received deduction with respect to any such constructive dividends. Because a constructive dividend deemed received by a U.S. holder would not give rise to any cash from which any applicable withholding could be satisfied, if backup withholding is paid on behalf of a U.S. holder (because such U.S. holder failed to establish an exemption from backup withholding), such backup withholding may be withheld from payments of cash and common stock payable on the notes (or, in certain circumstances, against any payments on the common stock). Generally, a U.S. holder’s adjusted tax basis in a note will be increased to the extent any such constructive distribution is treated as a dividend. U.S. holders should consult their tax advisors on the impact a constructive distribution may have on their holding period in the notes.

We are currently required to report the amount of any deemed distributions on our website or to the IRS and to holders of notes not exempt from reporting. The IRS proposed regulations addressing the amount and timing of deemed distributions, obligations of withholding agents and filing and notice obligations of issuers. If adopted as proposed, the regulations would generally provide that (i) the amount of a deemed distribution is the excess of the fair market value of the right to acquire stock without the adjustment, (ii) the deemed distribution occurs at the earlier of the date the adjustment occurs under the terms of the note and the date of the actual distribution of cash or property that results in the deemed distribution and (iii) we are required to report the amount of any deemed distributions on our website or to the IRS and to all holders of notes (including holders of notes that would otherwise be exempt from reporting). The final regulations will be effective for deemed distributions occurring on or after the date of adoption, but holders of notes and withholding agents may rely on them prior to that date under certain circumstances.

Distributions

Distributions, if any, made on our common stock generally will be included in a U.S. holder’s income as ordinary dividend income to the extent of our current or accumulated earnings and profits as determined for U.S. federal income tax purposes. However, with respect to dividends received by individuals, such dividends are generally taxed at the lower applicable long-term capital gains rates, provided certain holding period and other requirements for treatment of such dividends as “qualified dividend income” are satisfied. Distributions in excess of our current and accumulated earnings and profits will be treated as a return of capital to the extent of a U.S. holder’s tax basis in the common stock and thereafter as capital gain from the sale or exchange of such common stock as described in “—Sale or Other Taxable Disposition of Common Stock,” below. Dividends received by a corporation may be eligible for a dividends received deduction, subject to applicable limitations.

Sale or Other Taxable Disposition of Common Stock

Upon the sale or other taxable disposition of our common stock, a U.S. holder generally will recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of all other property received upon such disposition and (ii) the U.S. holder’s tax basis in the common stock. Such capital gain or loss will be long-term capital gain or loss if a U.S. holder’s holding period in the common stock is more than one year at the time of the taxable disposition. Long-term capital gains recognized by certain non-corporate U.S. holders (including individuals) will generally be subject to reduced rates of U.S. federal income tax. A U.S. holder’s ability to deduct capital losses may be limited.

Medicare Tax on Net Investment Income

Generally, a 3.8 percent Medicare contribution tax is imposed on the net investment income of certain individuals with a modified adjusted gross income of over $200,000 ($250,000 in the case of joint filers) and on the undistributed net investment income of certain estates and trusts. Interest and dividends received (or deemed to be received) by holders of the notes and our common stock and capital gains from the sale or other disposition of notes or common stock generally will constitute net investment income and be subject to the 3.8 percent tax. U.S. holders that are individuals, estates or trusts should consult their tax advisors regarding the applicability of the Medicare tax to them.

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Information Reporting and Backup Withholding

Information reporting requirements generally will apply to payments of interest on the notes (including additional interest that we may pay under circumstances described above under the heading “Description of Notes–Events of Default–Special Interest as Sole Remedy for Certain Reporting Defaults”) and dividends on shares of common stock (including constructive dividends deemed paid) and to the proceeds of a sale of a note or share of common stock paid to a U.S. holder unless the U.S. holder is an exempt recipient (such as a corporation). Backup withholding (currently at a 24% rate) will apply to those payments if the U.S. holder fails to provide its correct taxpayer identification number, or certification of exempt status, or if the U.S. holder is notified by the IRS that it has failed to report in full payments of interest and dividend income. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against a U.S. holder’s U.S. federal income tax liability provided the required information is furnished timely to the IRS.

Consequences to Non-U.S. Holders

Payments of Interest

U.S. federal income tax and the 30% U.S. federal withholding tax will not be applied to any payment of interest on a note to a non-U.S. holder provided that:

Special certification rules apply to non-U.S. holders that are pass-through entities.

If a non-U.S. holder cannot satisfy the requirements described above, payments of interest will generally be subject to the 30% U.S. federal withholding tax, unless the non-U.S. holder provides the applicable withholding agent with a properly executed (1) IRS Form W-8BEN or IRS Form W-8BEN-E (or other applicable form) claiming an exemption from or reduction in withholding under the benefit of an applicable income tax treaty or (2) IRS Form W-8ECI (or other applicable form) stating that interest paid on the notes is not subject to withholding tax because it is effectively connected with the non-U.S. holder’s conduct of a trade or business in the United States and includible in the non-U.S. holder’s gross income. If a non-U.S. holder is engaged in a trade or business in the United States and interest on the notes is effectively connected with the conduct of that trade or business and, if required by an applicable income tax treaty, is attributable to a U.S. permanent establishment or a U.S. fixed base, then (although the non-U.S. holder will be exempt from the 30% withholding tax provided the certification requirements discussed above are satisfied) the non-U.S. holder will be subject to U.S. federal income tax on that interest on a net income basis generally in the same manner as if the non-U.S. holder were a U.S. holder. In addition, if a non-U.S. holder is a foreign corporation, it may be subject to a branch profits tax equal to 30% (or lesser rate under an applicable income tax treaty) of its earnings and profits for the taxable year, subject to adjustments, that are effectively connected with its conduct of a trade or business in the United States.

Dividends and Constructive Distributions

Any dividends paid to a non-U.S. holder with respect to the shares of common stock (and any deemed dividends resulting from certain adjustments, or failure to make adjustments, to the conversion rate, see “Consequences to U.S. Holders–Constructive Distributions” above) will be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. However, dividends that are effectively connected with a non-U.S. holder’s conduct of a trade or business within the United States and, if required by an applicable income tax treaty, are attributable to a U.S. permanent establishment or a U.S. fixed base, are not subject to the withholding

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tax, but instead are subject to U.S. federal income tax on a net income basis at applicable graduated individual or corporate rates. Certain certification requirements and disclosure requirements must be complied with in order for effectively connected income to be exempt from withholding. Any such effectively connected income received by a foreign corporation may, under certain circumstances, be subject to an additional branch profits tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. Because a constructive dividend deemed received by a non-U.S. holder would not give rise to any cash from which any applicable withholding tax could be satisfied, if withholding taxes are paid on behalf of a non-U.S. holder, those withholding taxes may be withheld from payments of cash and common stock payable on the notes (or, in certain circumstances, against any payments on the common stock) or sales proceeds received by or other funds or assets of such holder.

A non-U.S. holder of shares of common stock that wishes to claim the benefit of an applicable income tax treaty rate is required to satisfy applicable certification and other requirements. If a non-U.S. holder is eligible for a reduced rate of U.S. withholding tax pursuant to an income tax treaty, it may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS.

Sale, Exchange, Redemption, Repurchase, Retirement or Conversion of Notes or Shares of Common Stock

Subject to the discussion of backup withholding and withholding on foreign accounts below, any gain realized by a non-U.S. holder on the sale, exchange, redemption, repurchase, retirement or other taxable disposition of a note or common stock, or on the taxable conversion of a note, such as upon the conversion of a note into cash or a combination of cash and stock or an exchange of notes in lieu of conversion, will not be subject to U.S. federal income tax unless:

If a non-U.S. holder’s gain is described in the first bullet point above, such holder will be subject to tax at regular graduated U.S. federal income tax rates on the net gain derived from the sale, exchange, redemption, repurchase, retirement, conversion or other taxable disposition of a note or common stock, generally in the same manner as if such holder were a U.S. holder. If a non-U.S. holder is a foreign corporation that recognizes gain described in the first bullet point above, such holder may also be subject to the branch profits tax equal to 30% (or such lower rate as may be prescribed under an applicable U.S. income tax treaty) of its effectively connected earnings and profits. If a non-U.S. holder is described in the second bullet point above, such holder will be subject to a flat 30% tax on the gain recognized on the sale, exchange, redemption, repurchase, retirement, conversion or other taxable disposition of a note or common stock generally in the same manner as if such holder were a U.S. holder (which gain may be offset by certain U.S.-source capital losses), even though the holder is not considered a resident of the United States. Any amounts (including common stock) which a non-U.S. holder receives on a sale, exchange, redemption, repurchase, retirement, conversion or other taxable disposition of a note which are attributable to accrued interest will be taxable as interest and may be subject to the rules described above under “–Payments of Interest.”

In general, we would be a USRPHC if the fair market value of our U.S. real property interests equals or exceeds 50% of the sum of the fair market value of our worldwide real property interests plus our other assets used or held for use in a trade or business. We believe that we are not, and we do not anticipate becoming, a USRPHC for U.S. federal income tax purposes. However, there can be no assurance that we will not become a USRPHC in the future.

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Information Reporting and Backup Withholding

Generally, we or an applicable withholding agent must report annually to the IRS and to non-U.S. holders the amount of interest (including additional interest that we may be required to pay under circumstances described above under “Description of Notes––Events of Default–Special Interest as Sole Remedy for Certain Reporting Defaults”) and dividends paid to non-U.S. holders (including constructive dividends deemed paid) and the amount of tax, if any, withheld with respect to those payments. Copies of the information returns reporting such interest, dividends and withholding may also be made available to the tax authorities in the country in which a non-U.S. holder resides under the provisions of an applicable income tax treaty. In general, a non-U.S. holder will not be subject to backup withholding with respect to payments of interest or dividends that we make, provided the statement described above in the last bullet point under “–Payments of Interest” has been received (and we or an applicable withholding agent does not have actual knowledge or reason to know that the holder is a U.S. person, as defined under the Code, that is not an exempt recipient). In addition, a non-U.S. holder will be subject to information reporting and, depending on the circumstances, backup withholding with respect to payments of the proceeds of the sale of a note or share of common stock within the United States or conducted through certain U.S.-related financial intermediaries, unless the statement described above has been received (and the payer does not have actual knowledge or reason to know that a holder is a U.S. person, as defined under the Code, that is not an exempt recipient) or the non-U.S. holder otherwise establishes an exemption. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against a non-U.S. holder’s U.S. federal income tax liability provided the required information is furnished timely to the IRS.

Withholding on Foreign Accounts

The Foreign Account Tax Compliance Act (“FATCA”) imposes withholding at a 30% rate on certain types of “withholdable payments” (including interest or constructive dividends paid on, and the gross proceeds from the sale or other disposition of, certain debt instruments, and dividends paid on, and the gross proceeds from the sale or other disposition of, stock in a U.S. corporation) made to a “foreign financial institution” or to a “non-financial foreign entity” (all as defined in the Code) (whether such foreign financial institution or non-financial foreign entity is the beneficial owner or an intermediary), unless (1) the foreign financial institution undertakes certain diligence and reporting obligations, (2) the nonfinancial foreign entity either certifies it does not have any “substantial United States owners” (as defined in the Code) or furnishes identifying information regarding each substantial United States owner or (3) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in (1) above, it must enter into an agreement with the U.S. Department of the Treasury requiring, among other things, that it undertake to identify accounts held by certain U.S. persons or U.S.-owned foreign entities (as defined in applicable Treasury Regulations), annually report certain information about such accounts and withhold 30% on payments to noncompliant foreign financial institutions and certain other account holders. Foreign governments may enter into an agreement with the IRS to implement FATCA in a different manner.

Under recently issued Treasury Regulations and official guidance FATCA withholding currently applies to payments of interest and constructive dividends on the notes and dividends on our shares and will apply to payments of gross proceeds from the sale or other disposition of the notes or our shares on or after January 1, 2019. Prospective investors should consult their tax advisors regarding the application of FATCA to the notes and our common stock.

Withholding on Dividend Equivalents

Section 871(m) of the Code requires withholding (of up to 30%, depending on whether a treaty applies) on certain financial instruments to the extent that the payments or deemed payments on the financial instruments are contingent upon or determined by reference to U.S.-source dividends. Under Treasury Regulations and other guidance issued in connection with Section 871(m), Section 871(m) will generally apply to certain financial instruments issued in 2017 and 2018 only if they are “delta-one.” A “delta one” instrument is one in which the ratio of the change in the fair market value of the instrument to the change in the fair market value of the property referenced by the contract is equal to 1.00. We do not believe that the notes are delta one instruments. Accordingly, in the absence of a material modification that may result in a deemed reissuance on or after January 1, 2019, non-U.S. holders of the notes should not be subject to tax under Section 871(m).

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THE CONCURRENT REPURCHASES

Concurrently with this offering, in separate transactions, we expect to repurchase approximately $        million aggregate principal amount of our outstanding 2019 notes for cash, including accrued and unpaid interest, of approximately $        million. We are negotiating these repurchases through one of the underwriters or its affiliate acting as our agent, for which that underwriter or affiliate may receive a customary commission.

We may also exchange or repurchase or induce conversions of additional outstanding 2019 notes following the completion of this offering. Any exchange, repurchase or induced conversion of our outstanding 2019 notes could affect the market price of our common stock and, in the case of repurchases effected concurrently with this offering, the initial conversion price of your notes.

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UNDERWRITING

Under the terms and subject to the conditions contained in an underwriting agreement, we have agreed to sell to the underwriters named below, for whom Jefferies LLC and Barclays Capital Inc. are acting as representatives, the following respective principal amounts of the notes:

The underwriting agreement provides that the underwriters are obligated to purchase all of the notes, except the notes subject to the over-allotment option referred to below. The underwriting agreement also provides that if an underwriter defaults, the purchase commitments of non-defaulting underwriters may be increased or the offering of notes may be terminated.

In addition, we have granted the underwriters an option to purchase, for settlement on or before September 28, 2018, up to an additional $30,000,000 aggregate principal amount of notes, solely to cover over-allotments.

The underwriters propose to offer the notes initially at the public offering price on the cover page of this prospectus supplement and to selling group members at that price less a selling concession of up to             % of the principal amount of the notes. After the initial public offering, the underwriters may change the public offering price and concession and discount to broker/dealers.

The following table summarizes the compensation we will pay to the underwriters.

We estimate that our out of pocket expenses for this offering will be approximately $450,000. We have agreed to reimburse the underwriters for certain of their expenses incurred in connection with the offering in an amount up to $5,000. The notes are a new issue of securities with no established trading market. The underwriters have advised us that they intend to make a market in the notes. However, they are not obligated to do so and may discontinue any market-making activity at any time and without notice. No assurance can be given as to how liquid the trading market for the notes will be.

The underwriters will not confirm sales to any accounts over which they exercise discretionary authority without first receiving a written consent from those accounts.

We, and our directors and officers, have agreed, subject to specified exceptions, not to directly or indirectly:

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This restriction terminates after the close of trading of the common stock on and including the 90^th day after the date of this prospectus.

The Representatives may, in their sole discretion and at any time or from time to time before the termination of the 90-day period release all or any portion of the securities subject to lock-up agreements. There are no existing agreements between the underwriters and any of directors and officers who have executed a lock-up agreement providing consent to the sale of shares prior to the expiration of the lock-up period.

We have agreed to indemnify the several underwriters and their control persons against liabilities under the Securities Act, or contribute to payments which the underwriters may be required to make in that respect.

In connection with the offering the underwriters, may engage in stabilizing transactions, syndicate covering transactions, and penalty bids in accordance with Regulation M under the Exchange Act.

These stabilizing transactions, syndicate covering transactions and penalty bids may have the effect of raising or maintaining the market price of the notes or preventing or retarding a decline in the market price of the notes. As a result the price of the notes may be higher than the price that might otherwise exist in the open market. These transactions may be effected on the Nasdaq Global Market or otherwise and, if commenced, may be discontinued at any time.

A prospectus supplement and accompanying prospectus in electronic format may be made available on the web sites maintained by one or more of the underwriters participating in this offering and one or more of the underwriters participating in this offering may distribute prospectuses electronically. The representative may agree to allocate securities to underwriters for sale to their online brokerage account holders. Internet distributions will be allocated by the underwriters that will make internet distributions on the same basis as other allocations.

The underwriters and certain of their affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. The underwriters and certain of their affiliates have, from time to time, performed, and may in the future perform, various commercial and investment banking and financial advisory services for us and our affiliates, for which they received or will receive customary fees and expenses.

In the ordinary course of their various business activities, the underwriters and certain of their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve our or our affiliates’ securities or instruments. If the underwriters or their affiliates have a lending relationship with us, they routinely hedge their credit exposure to us consistent with their customary risk management policies. The underwriters and their affiliates may hedge such exposure by entering into transactions that consist of either the purchase of credit default swaps or the creation of short positions in our securities or the securities of our affiliates, including potentially the notes offered hereby. Any such short positions could adversely affect future trading prices of the notes offered hereby or the trading prices of our common stock. The underwriters and certain of their affiliates may also communicate independent investment recommendations,

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market color or trading ideas or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long or short positions in, such securities and instruments.

Notice to Prospective Investors in the European Economic Area

In relation to each member state of the European Economic Area that has implemented the Prospectus Directive (each, a relevant member state) with effect from and including the date on which the Prospectus Directive is implemented in that relevant member state (the relevant implementation date), an offer of securities described in this prospectus supplement or the accompanying prospectus may not be made to the public in that relevant member state other than:

provided that no such offer of securities shall require us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Directive or supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

For purposes of this provision, the expression an “offer of securities to the public” in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and the securities to be offered so as to enable an investor to decide to purchase or subscribe for the securities, as the expression may be varied in that member state by any measure implementing the Prospectus Directive in that member state, and the expression “Prospectus Directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive, to the extent implemented in the relevant member state), and includes any relevant implementing measure in each relevant member state. The expression “2010 PD Amending Directive” means Directive 2010/73/EU.

Notice to Prospective Investors in the United Kingdom

This prospectus supplement and the accompanying prospectus have not been approved by an authorized person for the purposes of section 21 of the Financial Services and Markets Act 2000 (“FSMA”) and are, accordingly, only being distributed in the United Kingdom to, and are only directed at (i) investment professionals falling within the description of persons in Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the “Financial Promotion Order”); or (ii) high net worth companies and other persons falling within Article 49(2)(a) to (d) of the Financial Promotion Order; or (iii) to any other person to whom it may otherwise lawfully be communicated or made in accordance with the Financial Promotion Order (all such persons together being referred to as “relevant persons”).

The notes are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such notes will be engaged in only with, relevant persons. Any person who is not a relevant person should not act or rely on this document or any of its contents.

An invitation or inducement to engage in investment activity (within the meaning of Section 21 of FSMA) in connection with the issue or sale of any notes that are the subject of the offering contemplated by this prospectus supplement and the accompanying prospectus will only be communicated or caused to be communicated in circumstances in which Section 21(1) of FSMA does not apply to the issuer.

Notice to Prospective Investors in Switzerland

The notes may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This document has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of

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Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this document nor any other offering or marketing material relating to the notes or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this document nor any other offering or marketing material relating to the offering, the Company or the notes have been or will be filed with or approved by any Swiss regulatory authority. In particular, this document will not be filed with, and the offer of notes will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA, and the offer of notes has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (“CISA”). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of notes.

Notice to Prospective Investors in the Dubai International Financial Centre

This prospectus supplement and the accompanying prospectus relate to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority (“DFSA”). This prospectus supplement and the accompanying prospectus are intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. They must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement or the accompanying prospectus nor taken steps to verify the information set forth herein or therein and has no responsibility for this prospectus supplement or the accompanying prospectus. The notes to which this prospectus supplement and the accompanying prospectus relate may be illiquid or subject to restrictions on their resale. Prospective purchasers of the notes offered should conduct their own due diligence on the notes. If you do not understand the contents of this prospectus supplement or the accompanying prospectus, you should consult an authorized financial advisor.

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WHERE YOU CAN FIND ADDITIONAL INFORMATION

We file annual, quarterly and special reports, proxy statements and other information with the SEC. Our SEC filings are available to the public through the Internet at the SEC’s website at www.sec.gov. You may also read and copy any document in our files at the SEC’s public reference room in Washington, D.C. Please call the SEC at 1-800-SEC-0330 for further information concerning the public reference room. Our SEC filings are also available to the public through our website at www.retrophin.com. We have included the SEC’s website address and our website address as inactive textual references only. Neither the contents of the SEC’s website nor our website, nor any other website that may be accessed from such websites, is incorporated in or otherwise considered a part of this prospectus supplement or the accompanying prospectus.

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

We “incorporate by reference” into this prospectus supplement and the accompanying prospectus the information we file with the SEC. This means that we disclose important information to you by referring you to those filings. You should read the information incorporated by reference because it is an important part of this prospectus supplement and the accompanying prospectus. Information in this prospectus supplement and the accompanying prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus supplement, while information that we file later with the SEC and prior to the termination of this offering of the notes will automatically update and supersede the information in this prospectus supplement and the accompanying prospectus. We incorporate by reference into this prospectus supplement and the accompanying prospectus the information or documents listed below that we have filed with the SEC (File No. 001-36257):

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, until the termination of this offering of the notes and will become a part of this prospectus supplement and the accompanying prospectus from the date that such documents are filed with the SEC. Information in any such future filings updates and supplements the information provided in this prospectus supplement and the accompanying prospectus. Any information in any such future filings will also automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

We will furnish without charge to you, upon written or oral request, a copy of any or all of the documents incorporated by reference, including exhibits to these documents. You should direct any requests for documents by writing us at 3721 Valley Centre Drive, Suite 200, San Diego, CA 92130 or telephoning us at (760) 260-8600.

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LEGAL MATTERS

Certain legal matters in connection with the offering of the notes will be passed upon for us by Cooley LLP, San Diego, California. The initial purchasers are being represented by Latham & Watkins LLP, San Diego, California.

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EXPERTS

The financial statements as of December 31, 2017 and 2016 and for each of the three years in the period ended December 31, 2017 and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2017 incorporated by reference in this Prospectus have been so incorporated in reliance on the reports of BDO USA, LLP, an independent registered public accounting firm, incorporated herein by reference, given on the authority of said firm as experts in auditing and accounting.

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Prospectus

Common Stock

Preferred Stock

Debt Securities

Warrants

From time to time, we may offer and sell any combination of the securities described in this prospectus, either individually or in combination with other securities. We may also offer common stock or preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock or debt securities upon the exercise of warrants.

Each time we sell securities pursuant to this prospectus, we will provide the specific terms of these offerings and securities in one or more supplements to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference, before buying any of the securities being offered.

Our common stock is listed on the Nasdaq Global Market under the trading symbol “RTRX.” On August 31, 2018, the last reported sale price of our common stock was $31.69 per share. The applicable prospectus supplement will contain information, where applicable, as to other listings, if any, on the Nasdaq Global Market or any other securities exchange of the securities covered by the applicable prospectus supplement.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” on page 8 of this prospectus and contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the documents that are incorporated by reference into this prospectus.

This prospectus may not be used to consummate a sale of securities unless accompanied by a prospectus supplement.

The securities may be sold directly to investors, through agents designated from time to time or to or through underwriters or dealers, on a continuous or delayed basis. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus. If any agents, underwriters or dealers are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such agents, underwriters or dealers and any applicable fees, commissions, discounts and over-allotment options will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is September 4, 2018.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may offer and sell shares of our common stock and preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or in combination with other securities, in one or more offerings. There is no limit on the aggregate amount of the securities that we may offer pursuant to the registration statement of which this prospectus is a part. This prospectus provides you with a general description of the securities we may offer.

Each time we offer securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents that we have incorporated by reference into this prospectus. We urge you to read carefully this prospectus, any applicable prospectus supplement and any free writing prospectuses we have authorized for use in connection with a specific offering, together with the information incorporated herein by reference as described under the heading “Incorporation of Certain Information by Reference,” before buying any of the securities being offered.

This prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

We have not authorized anyone to provide you with any information or to make any representations other than those contained in this prospectus, any applicable prospectus supplement or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so.

The information appearing in this prospectus, any applicable prospectus supplement and any related free writing prospectus is accurate only as of the date on the front of the document and any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, the applicable prospectus supplement or any related free writing prospectus, or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.”

Unless the context indicates otherwise, as used in this prospectus, all references to “Retrophin,” the “Company,” “we,” “us,” “our,” or similar references refer to Retrophin, Inc. as well as its direct and indirect subsidiaries on a consolidated basis, except where the context otherwise requires or as otherwise indicated. “RETROPHIN”, “CHENODAL”, “CHOLBAM” and “THIOLA” are registered trademarks of Retrophin, Inc., and are our property. This prospectus also includes references to trademarks and service marks of other entities, and those trademarks and service marks are the property of their respective owners.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and described under the section entitled “Risk Factors” contained in our most recent Annual Report on Form 10-K and Quarterly Reports on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus, the documents incorporated by reference and any free writing prospectus that we may authorize for use in connection with a specific offering. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our securities to decline, resulting in a loss of all or part of your investment. Please also carefully read the section below entitled “Forward-Looking Statements.”

FORWARD-LOOKING STATEMENTS

This prospectus, each prospectus supplement and the information incorporated by reference in this prospectus and each prospectus supplement contain forward-looking statements within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act that involve a number of risks and uncertainties. Although our forward-looking statements reflect the good faith judgment of our management, these statements can only be based on facts and factors currently known by us. Consequently, these forward-looking statements are inherently subject to risks and uncertainties, and actual results and outcomes may differ materially from results and outcomes discussed in the forward-looking statements. Such forward-looking statements include statements regarding, among other things:

Forward-looking statements can be identified by the use of forward-looking words such as “believes,” “expects,” “hopes,” “may,” “will,” “plan,” “intends,” “estimates,” “could,” “should,” “would,” “continue,” “seeks,” “pro forma,” or “anticipates,” or other similar words (including their use in the negative), or by discussions of future matters such as the development of new products, technology enhancements, possible collaborations, possible changes in legislation and other statements that are not historical. These statements include but are not limited to statements under the captions “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and in other sections incorporated by reference from our Annual

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Report on Form 10-K and Quarterly Reports on Form 10-Q, as applicable, as well as our other filings with the SEC. You should be aware that the occurrence of any of the events discussed under the heading “Risk Factors” in any applicable prospectus supplement and any documents incorporated by reference herein or therein could substantially harm our business, operating results and financial condition and that if any of these events occurs, it could adversely affect the value of an investment in our securities.

The cautionary statements made in this prospectus are intended to be applicable to all related forward-looking statements wherever they may appear in this prospectus or in any prospectus supplement or any documents incorporated by reference herein or therein. We urge you not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. Except as required by law, we assume no obligation to update our forward-looking statements, even if new information becomes available in the future.

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RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our ratio of earnings to fixed charges and the ratio of earnings to combined fixed charges and preference securities dividends for each of the periods indicated. The following table is qualified by the more detailed information appearing in the computation table set forth in Exhibit 12.1 to the registration statement of which this prospectus is part and the historical financial statements, including the notes to those financial statements, incorporated by reference in this prospectus.

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USE OF PROCEEDS

We will retain broad discretion over the use of the net proceeds from the sale of the securities offered hereby. Unless otherwise indicated in any prospectus supplement, we intend to use the net proceeds from the sale of the securities under this prospectus for general corporate purposes, which may include clinical trial and other research and development expenses, commercialization expenses, capital expenditures, working capital and general and administrative expenses, and potential acquisitions of or investments in businesses, products and technologies that complement our business. We will set forth in the applicable prospectus supplement or free writing prospectus our intended use for the net proceeds received from the sale of any securities sold pursuant to the prospectus supplement or free writing prospectus. Pending these uses, we intend to invest the net proceeds in short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

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DESCRIPTION OF CAPITAL STOCK

As of the date of this prospectus, our certificate of incorporation, as amended, authorizes us to issue 100,000,000 shares of common stock, par value $0.0001 per share, and 20,000,000 shares of preferred stock, par value $0.001 per share. As of August 30, 2018, 40,859,214 shares of common stock were outstanding and no shares of preferred stock were outstanding.

The following summary description of our capital stock is based on the provisions of our certificate of incorporation, as amended, as well as our amended and restated bylaws, and the applicable provisions of the Delaware General Corporation Law. This information is qualified entirely by reference to the applicable provisions of our certificate of incorporation, as amended, amended and restated bylaws, and the Delaware General Corporation Law. For information on how to obtain copies of our certificate of incorporation, as amended, and amended and restated bylaws, see “Where You Can Find Additional Information.”

Common Stock

The holders of our common stock are entitled to one vote per share on matters on which our stockholders vote. There are no cumulative voting rights. Subject to any preferential dividend rights of any outstanding shares of preferred stock, holders of our common stock are entitled to receive dividends, if declared by our board of directors, out of funds that we may legally use to pay dividends. Generally, all matters to be voted on by stockholders must be approved by a majority (or, in the case of election of directors, by a plurality) of the votes entitled to be cast by all shares of our common stock that are present in person or represented by proxy.

Holders representing fifty percent (50%) of our common stock issued, outstanding and entitled to vote, represented in person or by proxy, are necessary to constitute a quorum at any meeting of our stockholders. A vote by the holders of a majority of our outstanding shares is required to effectuate certain fundamental corporate changes such as liquidation, merger or an amendment to our certificate of incorporation. If we liquidate or dissolve, holders of our common stock are entitled to share ratably in our assets once our debts and any liquidation preference owed to any then-outstanding preferred stockholders are paid. Our certificate of incorporation does not provide our common stock with any redemption, conversion or preemptive rights.

Preferred Stock

We currently have 20,000,000 shares of authorized capital stock that are designated as preferred stock. 1,000 of such shares of preferred stock are designated as Class A Preferred, par value $0.001 per share. Shares of Class A Preferred are not entitled to interest and have certain liquidation preferences and special voting rights. No preferred stock has been issued to date.

Unless required by law or by any stock exchange on which our common stock is listed in the future, our board of directors has the authority, without further action by our stockholders, to issue the authorized but undesignated shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change of control of our company or other corporate action.

The issuance of preferred stock could adversely affect, among other things, the voting power of holders of common stock and the likelihood that stockholders will receive dividend payments and payments upon our liquidation, dissolution or winding up. The issuance of preferred stock could also have the effect of delaying, deferring or preventing a change in control of us.

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Anti-Takeover Effects of Provisions of our Certificate of Incorporation, our Bylaws and Delaware Law

Some provisions of Delaware law, our certificate of incorporation, as amended, and our amended and restated bylaws contain provisions that could make the following transactions more difficult: acquisition of us by means of a tender offer; acquisition of us by means of a proxy contest or otherwise; or removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares. These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits persons deemed “interested stockholders” from engaging in a “business combination” with a publicly-held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is, or the transaction in which the person became an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation’s voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors, such as discouraging takeover attempts that might result in a premium over the market price of our common stock.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC. The transfer agent and registrar’s address is 59 Maiden Lane, New York, New York 10038.

Listing on the Nasdaq Global Market

Our common stock is listed on the Nasdaq Global Market under the symbol “RTRX.”

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act. We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets and the requirements to maintain an office or agency with respect to each series of securities contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

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Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than a subsidiary of ours) must assume, by supplemental indenture, all of our obligations under the indenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

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If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, unless the principal of all the debt securities of that series shall have already become due and payable, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of(and premium, if any, on) and accrued and unpaid interest, if any, on all the debt securities of that series to be due and payable immediately, and upon any such declaration the same shall become and shall be immediately due and payable. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities of that series then outstanding shall automatically be immediately due and payable without any declaration or other act on the part of the trustee or any holder.

The holders of a majority in aggregate principal amount of the outstanding debt securities of an affected series may on behalf of the holders of all of the debt securities of such series waive any past default in the performance of any of the covenants contained therein or established pursuant therein with respect to the series and its consequences, except a default or events of default regarding payment of the principal of, or premium, if any, or interest on any of the debt securities of that series as and when the same shall become due by the terms of such debt securities otherwise than by acceleration, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default; but no such waiver shall extend to any subsequent or other default or impair any right consequent thereon.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request, order or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee security or indemnity reasonably acceptable to the Trustee against the costs, expenses and liabilities that may be incurred therein or thereby. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

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These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders for one or more of the following purposes:

In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

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Discharge

The indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 or any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company, or DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating to any book-entry securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount, upon payment of a sum sufficient to cover any tax or other governmental charge in relation thereto.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

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If we elect to redeem the debt securities of any series, we will not be required to:

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care and skill in their exercise as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for such interest installment.

We will pay principal of and any premium and interest on the debt securities of a particular series at the time and place and in the manner provided in the indenture, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us on May 31 of each year or upon our request, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplement and free writing prospectus, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectus, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms of the series of warrants being offered, including:

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Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. The warrants may be exercised as set forth in the prospectus supplement relating to the warrants offered. Unless we otherwise specify in the applicable prospectus supplement, warrants may be exercised at any time up to the close of business on the expiration date set forth in the prospectus supplement relating to the warrants offered thereby. After the close of business on the expiration date, unexercised warrants will become void.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and deliver the securities purchasable upon such exercise. If less than all of the warrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Governing Law

Unless we provide otherwise in the applicable prospectus supplement, the warrants and any warrant agreements will be governed by and construed in accordance with the internal laws of the State of New York.

Enforceability of Rights by Holders of Warrants

Each warrant agent, if any, will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

Outstanding Warrants to Purchase Common Stock

As of June 30, 2018, there were warrants to purchase 735,365 shares of common stock outstanding.

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LEGAL OWNERSHIP OF SECURITIES

We may issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a book-entry security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee and of any third parties employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

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For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with depositary participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of the indenture or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the holders contact the indirect holders is up to the holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form or in street name, you should check with your own institution to find out:

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, DTC will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under the section entitled “Special Situations When a Global Security Will Be Terminated” in this prospectus. As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

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Special Considerations for Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, the global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, the global security will terminate when the following special situations occur:

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The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and not we or any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

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PLAN OF DISTRIBUTION

We may sell the securities from time to time pursuant to underwritten public offerings, “at-the-market” offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through one or more underwriters or dealers (acting as principal or agent), through agents, or directly to one or more purchasers. We may distribute securities from time to time in one or more transactions:

A prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you) will describe the terms of the offering of the securities, including, to the extent applicable:

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement, other than securities covered by any over-allotment option. If a dealer is used in the sale of securities, we or an underwriter will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale. To the extent required, we will set forth in the prospectus supplement the name of the dealer and the terms of the transaction. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time.

We may use underwriters, dealers or agents with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, dealer or agent, the nature of any such relationship.

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We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities and we will describe any commissions payable to the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, the agent will act on a best-efforts basis for the period of its appointment.

We may provide agents, underwriters and dealers with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents, underwriters or dealers may make with respect to these liabilities. Agents, underwriters and dealers, or their affiliates, may engage in transactions with, or perform services for, us in the ordinary course of business.

All securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in over-allotment, stabilizing transactions, short-covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Over-allotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate-covering or other short-covering transactions involve purchases of the securities, either through exercise of the over-allotment option or in the open market after the distribution is completed, to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

Any underwriters that are qualified market makers on the Nasdaq Global Market may engage in passive market making transactions in the common stock on the Nasdaq Global Market in accordance with Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the common stock. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

In compliance with guidelines of the Financial Industry Regulatory Authority, or FINRA, the maximum consideration or discount to be received by any FINRA member or independent broker dealer may not exceed 8% of the aggregate amount of the securities offered pursuant to this prospectus and the applicable prospectus supplement.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, certain legal matters in connection with the offering and the validity of the securities offered by this prospectus, and any supplement thereto, will be passed upon by Cooley  LLP, San Diego, California.

EXPERTS

The financial statements as of December 31, 2017 and 2016 and for each of the three years in the period ended December 31, 2017 and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2017 incorporated by reference in this Prospectus have been so incorporated in reliance on the reports of BDO USA, LLP, an independent registered public accounting firm, incorporated herein by reference, given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. You may also read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of the Public Reference Room.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus, while information that we file later with the SEC will automatically update and supersede the information in this prospectus. We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-36257):

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus and will become a part of this prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

We will furnish without charge to each person, including any beneficial owners, to whom a prospectus is delivered, upon written or oral request, a copy of any or all of the documents incorporated by reference, including exhibits to these documents. You should direct any requests for documents by writing us at 3721 Valley Centre Drive, Suite 200, San Diego, CA 92130 or telephoning us at (760) 260-8600.

DISCLOSURE OF COMMISSION POSITION ON INDEMNIFICATION FOR

SECURITIES ACT LIABILITY

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers or persons controlling the registrant pursuant to the foregoing provisions, the registrant has been informed that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

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$200,000,000

    % Convertible Senior Notes due 2025

PROSPECTUS SUPPLEMENT