0001438533-22-000025 | 10-Q | XBRL Viewer

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Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2022	May 03, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-36257
Entity Registrant Name	TRAVERE THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-4842691
Entity Address, Address Line One	3611 Valley Centre Drive
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92130
City Area Code	888
Local Phone Number	969-7879
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	TVTX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		63,514,152
Entity Central Index Key	0001438533
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 256,572	$ 165,753
Marketable debt securities, at fair value	346,818	387,129
Accounts receivable, net	14,675	15,914
Inventory, net	6,521	7,313
Prepaid expenses and other current assets	6,507	6,718
Total current assets	631,093	582,827
Property and equipment, net	10,602	11,106
Operating lease right of use assets	22,557	23,196
Intangible assets, net	153,321	148,435
Other assets	10,832	11,069
Total assets	828,405	776,633
Current liabilities:
Accounts payable	18,434	15,144
Accrued expenses	69,240	75,180
Deferred revenue, current portion	14,229	16,268
Business combination-related contingent consideration	7,500	7,400
Operating lease liabilities, current portion	4,014	3,908
Other current liabilities	6,056	6,188
Total current liabilities	119,473	124,088
Convertible debt	374,333	226,581
Deferred revenue, less current portion	19,669	20,379
Business combination-related contingent consideration, less current portion	66,000	59,700
Operating lease liabilities, less current portion	30,439	31,497
Other non-current liabilities	10,350	12,276
Total liabilities	620,264	474,521
Commitments and Contingencies (See Note 13)
Stockholders' Equity:
Preferred stock $0.0001 par value; 20,000,000 shares authorized; 0 issued and outstanding as of March 31, 2022 and December 31, 2021	0	0
Common stock $0.0001 par value; 200,000,000 shares authorized; 63,510,277 and 62,491,498 issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	6	6
Additional paid-in capital	1,021,542	1,068,634
Accumulated deficit	(811,712)	(765,966)
Accumulated other comprehensive loss	(1,695)	(562)
Total stockholders' equity	208,141	302,112
Total liabilities and stockholders' equity	$ 828,405	$ 776,633

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock shares authorized (in shares)	200,000,000	200,000,000
Common stock shares issued (in shares)	63,510,277	62,491,498
Common stock shares outstanding (in shares)	63,510,277	62,491,498

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total revenue	$ 48,487	$ 47,407
Operating expenses:
Cost of goods sold	2,138	1,645
Research and development	56,611	47,946
Selling, general and administrative	46,788	36,778
Change in fair value of contingent consideration	9,080	8,587
Total operating expenses	114,617	94,956
Operating loss	(66,130)	(47,549)
Other income (expenses), net:
Interest income	278	409
Interest expense	(2,515)	(5,321)
Loss on early extinguishment of debt	(7,578)	0
Other income (expense), net	26	(1,093)
Total other expense, net	(9,789)	(6,005)
Loss before income tax provision	(75,919)	(53,554)
Income tax provision	(52)	(313)
Net loss	$ (75,971)	$ (53,867)
Basic net loss per common share (in dollars per share)	$ (1.20)	$ (0.96)
Diluted net loss per common share (in dollars per share)	$ (1.20)	$ (0.96)
Basic weighted average common shares outstanding (in shares)	63,132,841	56,268,508
Diluted weighted average common shares outstanding (in shares)	63,132,841	56,268,508
Comprehensive loss:
Net loss	$ (75,971)	$ (53,867)
Foreign currency translation gain	71	1,103
Unrealized loss on marketable debt securities	(1,204)	(463)
Comprehensive loss	(77,104)	(53,227)
Net product sales
Total revenue	46,443	47,407
License and collaboration revenue
Total revenue	$ 2,044	$ 0

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows From Operating Activities:
Net loss	$ (75,971)	$ (53,867)
Adjustments to reconcile net loss to net cash used in operating activities:
Share based compensation	8,186	7,908
Depreciation and amortization	7,092	6,074
Change in estimated fair value of contingent consideration	9,080	8,587
Payments from change in fair value of contingent consideration	(2,075)	(1,825)
Amortization of debt discount and issuance costs	338	2,737
Loss on allowance for inventory	949	487
Amortization of premiums (discounts) on investments	673	177
Loss on early extinguishment of debt	7,578	0
Other	152	1,602
Changes in operating assets and liabilities:
Accounts receivable	1,241	2,851
Prepaid expenses and other current and non-current assets	648	(488)
Change in lease assets and liabilities, net	(246)	3,766
Accounts payable	(4,606)	5,043
Accrued expenses	(4,413)	(9,486)
Deferred revenue, current and non-current	(2,146)	0
Other current and non-current liabilities	(1,800)	(40)
Net cash used in operating activities	(55,320)	(26,474)
Cash Flows From Investing Activities:
Purchase of fixed assets	(131)	(4,495)
Purchase of intangible assets	(5,136)	(4,775)
Proceeds from the sale/maturity of marketable debt securities	64,715	152,399
Purchase of marketable debt securities	(26,283)	(248,835)
Net cash provided by (used in) investing activities	33,165	(105,706)
Cash Flows From Financing Activities:
Payment of acquisition-related contingent consideration	(667)	(732)
Payment of guaranteed minimum royalty	(525)	(525)
Proceeds from exercise of stock options	122	2,755
Proceeds from issuances of 2029 convertible senior notes	316,250	0
Payment of debt issuance costs	(9,488)	0
Repurchase of 2025 convertible senior notes including premium	(211,324)	0
Net cash provided by financing activities	113,913	195,753
Effect of exchange rate changes on cash	(939)	(113)
Net increase in cash and cash equivalents	90,819	63,460
Cash and cash equivalents, beginning of year	165,753	84,772
Cash and cash equivalents, end of period	256,572	148,232
At-The-Market Offering
Cash Flows From Financing Activities:
Proceeds from issuance of common stock	19,545	4,878
Underwritten Equity Offering
Cash Flows From Financing Activities:
Proceeds from issuance of common stock	$ 0	$ 189,377

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Underwritten Equity Offering	At-The-Market Offering	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Common Stock Underwritten Equity Offering	Common Stock At-The-Market Offering	Additional Paid in Capital	Additional Paid in Capital Underwritten Equity Offering	Additional Paid in Capital At-The-Market Offering	Additional Paid in Capital Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2020					52,248,431
Beginning balance at Dec. 31, 2020	$ 211,213				$ 5			$ 797,985				$ (902)	$ (585,875)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based compensation	7,479							7,479
Issuance of common stock under the equity incentive plan and proceeds from exercise (in shares)					470,613
Issuance of common stock under the equity incentive plan and proceeds from exercise	2,755							2,755
Issuance of common stock (in shares)						7,532,500	184,186
Issuance of common stock, net of offering costs		$ 189,377	$ 4,878			$ 1	$ 0		$ 189,376	$ 4,878
Unrealized loss on marketable debt securities	(463)											(463)
Foreign currency translation adjustments	1,103											1,103
Employee stock purchase program purchase and expense	214							214
Net loss	(53,867)												(53,867)
Ending balance (in shares) at Mar. 31, 2021					60,435,730
Ending balance at Mar. 31, 2021	$ 362,689				$ 6			1,002,687				(262)	(639,742)
Accounting Standards Update [Extensible List]	Accounting Standards Update 2020-06 Cumulative Effect, Period of Adoption [Member]
Beginning balance (in shares) at Dec. 31, 2020					52,248,431
Beginning balance at Dec. 31, 2020	$ 211,213				$ 5			797,985				(902)	(585,875)
Ending balance (in shares) at Dec. 31, 2021					62,491,498
Ending balance at Dec. 31, 2021	302,112			$ (44,720)	$ 6			1,068,634			$ (74,945)	(562)	(765,966)	$ 30,225
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based compensation	7,935							7,935
Issuance of common stock under the equity incentive plan and proceeds from exercise (in shares)					317,179
Issuance of common stock under the equity incentive plan and proceeds from exercise	122							122
Issuance of common stock (in shares)							701,600
Issuance of common stock, net of offering costs			$ 19,545							$ 19,545
Unrealized loss on marketable debt securities	(1,204)											(1,204)
Foreign currency translation adjustments	71											71
Employee stock purchase program purchase and expense	251							251
Net loss	(75,971)												(75,971)
Ending balance (in shares) at Mar. 31, 2022					63,510,277
Ending balance at Mar. 31, 2022	$ 208,141				$ 6			$ 1,021,542				$ (1,695)	$ (811,712)

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Underwritten Equity Offering
Issuance costs		$ 12.2
At-The-Market Offering
Issuance costs	$ 0.6	$ 0.2

DESCRIPTION OF BUSINESS	3 Months Ended
DESCRIPTION OF BUSINESS	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS	DESCRIPTION OF BUSINESS Organization and Description of Business Travere Therapeutics, Inc. (“we”, “our”, “us”, “Travere” and the “Company”) refers to Travere Therapeutics, Inc., a Delaware corporation, as well as our direct and indirect subsidiaries. Travere is a fully integrated biopharmaceutical company headquartered in San Diego, California focused on identifying, developing and delivering life-changing therapies to people with rare diseases. We regularly evaluate and, where appropriate, act on opportunities to expand our product pipeline through licenses and acquisitions of products in areas that will serve patients with serious or rare diseases and that we believe offer attractive growth characteristics. The ongoing novel coronavirus (COVID-19) pandemic has resulted in travel restrictions, quarantines, “stay-at-home” and “shelter-in-place” orders and extended shutdown of certain businesses around the world. While the impact of the COVID-19 pandemic did not have a material adverse effect on our financial position or results of operations for the three months ended March 31, 2022, these governmental actions and similar actions that may be enacted in the future, and the widespread economic disruption arising from the pandemic, have the potential to materially impact our business and influence our business decisions. The extent and duration of the pandemic is unknown, and the future effects on our business are uncertain and difficult to predict. The Company is continuing to monitor the events and circumstances surrounding the COVID-19 pandemic, which may require adjustments to the Company’s estimates and assumptions in the future. Clinical Programs: Sparsentan is a novel investigational product candidate and has been granted Orphan Drug Designation for the treatment of focal segmental glomerulosclerois (FSGS) and immunoglobulin A nephropathy (IgAN) in the U.S. and Europe. Sparsentan is currently being evaluated in two pivotal Phase 3 clinical studies in rare kidney diseases. Pegtibatinase (TVT-058) is a novel investigational human enzyme replacement candidate being evaluated for the treatment of classical homocystinuria (HCU). Pegtibatinase has been granted Rare Pediatric Disease and Fast Track designations by the U.S. Food and Drug Administration ("FDA"), as well as orphan drug designation in the United States and European Union. Pegtibatinase is currently being evaluated in the Phase 1/2 COMPOSE Study to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and clinical effects in patients with classical HCU. The Company acquired pegtibatinase as part of the November 2020 acquisition of Orphan Technologies Limited. Chenodal (chenodeoxycholic acid or CDCA) is a naturally occurring bile acid that is approved for the treatment of people with radiolucent stones in the gallbladder. In January 2020, we randomized the first patients in our Phase 3 RESTORE Study to evaluate the effects of Chenodal in adult and pediatric patients with cerebrotendinous xanthomatosis (CTX), and the study enrollment remains open. The pivotal study is intended to support an NDA submission for marketing authorization of Chenodal for CTX in the United States. Preclinical Programs: We are a participant in two Cooperative Research and Development Agreements ("CRADAs"), which form a multi-stakeholder approach to pool resources with leading experts, and incorporate the patient perspective early in the therapeutic identification and development process. We have partnered with the National Institutes of Health’s National Center for Advancing Translational Sciences ("NCATS") and leading patient advocacy organizations, CDG Care and Alagille Syndrome Alliance, aimed at the identification of potential small molecule therapeutics for NGLY1 deficiency and Alagille syndrome ("ALGS"), respectively. There are no treatment options currently approved for these diseases. Approved products: •Chenodal (chenodiol tablets) is approved in the United States for the treatment of patients suffering from gallstones in whom surgery poses an unacceptable health risk due to disease or advanced age. •Cholbam® (cholic acid capsules) is approved in the United States for the treatment of bile acid synthesis disorders due to single enzyme defects and is further indicated for adjunctive treatment of patients with peroxisomal disorders. •Thiola® and Thiola EC® (tiopronin tablets) are approved in the United States for the prevention of cystine (kidney) stone formation in patients with severe homozygous cystinuria.

BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on February 24, 2022. The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information, the instructions for Form 10-Q and the rules and regulations of the SEC. Accordingly, since they are interim statements, the accompanying condensed consolidated financial statements do not include all of the information and notes required by GAAP for annual financial statements, but reflect all adjustments consisting of normal, recurring adjustments, that are necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. Interim results are not necessarily indicative of the results that may be expected for any future periods. The December 31, 2021 balance sheet information was derived from the audited financial statements as of that date. Certain reclassifications have been made to the prior period consolidated financial statements to conform to the current period presentation. A summary of the significant accounting policies applied in the preparation of the accompanying condensed consolidated financial statements follows: Principles of Consolidation The unaudited condensed consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with GAAP. All intercompany accounts and transactions have been eliminated in consolidation. Revenue Recognition The Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"), the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect substantially all the consideration it is entitled to in exchange for the goods or services it transfers to the customer. See Note 3 and Note 4 for further discussion. Payments received under collaboration and licensing agreements may include non-refundable fees at the inception of the arrangements, milestone payments for specific achievements and royalties on the sale of products. At the inception of arrangements that include milestone payments, the Company uses judgement to evaluate whether the milestones are probable of being achieved and estimates the amount to include in the transaction price utilizing the most likely amount method. If it is probable that a significant revenue reversal will not occur, the estimated amount is included in the transaction price. Milestone payments that are not within the Company or the licensee’s control, such as regulatory approvals are not included in the transaction price until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of development milestones and any related constraint and adjusts the estimate of the overall transaction price, if necessary. The Company recognizes aggregate sales-based milestones and royalty payments from product sales at the later of when the related sales occur or when the performance obligation to which the sales-based milestone or royalty has been allocated has been satisfied. If it is probable that a significant revenue reversal will not occur, the Company estimates the sales-based milestone and royalty payments using the most likely amount method. The Company utilizes significant judgement to develop estimates of the stand-alone selling price for each distinct performance obligation based upon the relative stand-alone selling price. Variable consideration that relates specifically to the Company’s efforts to satisfy specific performance obligations is allocated entirely to those performance obligations. The stand-alone selling price for license-related performance obligations requires judgement in developing assumptions to project probability-weighted cash flows based upon estimates of forecasted revenues, clinical and regulatory timelines and discount rates. The stand-alone selling price for clinical development performance obligations is based on forecasted expected costs of satisfying a performance obligation plus an appropriate margin. If the licenses to intellectual property are determined to be distinct from the other performance obligations identified in the arrangement and have stand-alone functionality, the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to benefit from the license. For licenses that are not distinct from other promises, the Company applies judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the related revenue recognition accordingly. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided. Revenue is recorded proportionally as costs are incurred. The Company generally utilizes the cost-to-cost method of progress because it best measures the transfer of control to the customer which occurs as the Company incurs costs. Under the cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company uses judgment to estimate the total costs expected to complete the clinical development performance obligations, which include subcontractor costs, labor, materials, other direct costs and an allocation of indirect costs. The Company evaluates these cost estimates and the progress each reporting period and adjusts the measure of progress, if necessary. Research and Development Expenses Research and development includes expenses related to sparsentan, pegtibatinase, and the Company's other pipeline programs. The Company expenses all research and development costs as they are incurred. The Company's research and development costs are comprised of salaries and bonuses, benefits, share-based compensation, license fees, milestones under license agreements, costs paid to third-party contractors to perform research, conduct clinical trials, and develop drug materials and delivery devices, and associated overhead expenses and facilities costs. The Company charges direct internal and external program costs to the respective development programs. The Company also incurs indirect costs that are not allocated to specific programs because such costs benefit multiple development programs and allow us to increase our pharmaceutical development capabilities. These consist of internal shared resources related to the development and maintenance of systems and processes applicable to all of our programs. Clinical Trial Expenses The Company records expenses in connection with clinical trials under contracts with contract research organizations (CROs) that support conducting and managing clinical trials. The financial terms and activities of these agreements vary from contract to contract and may result in uneven expense levels. Generally, these agreements set forth activities that drive the recording of expenses such as start-up and initiation activities, enrollment and treatment of patients, or the completion of other clinical trial activities. Expenses related to clinical trials are accrued based on our estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts we are obligated to pay under our clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), the Company adjusts its accruals accordingly on a prospective basis. Revisions to the Company's contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. The Company currently has three Phase 3 clinical trials in process that are in varying stages of activity, with ongoing non-clinical support trials. As such, clinical trial expenses will vary depending on all the factors set forth above and may fluctuate significantly from quarter to quarter. Intangible Assets with Cost Accumulation Model In 2014, the Company entered into a license agreement with Mission Pharmacal in which the Company obtained the exclusive right to license the trademark of Thiola. The acquisition of the Thiola license qualified as an asset acquisition under the principles of ASC 805, Business Combinations ("ASC 805") in effect at the time of acquisition. The license agreement requires the Company to make royalty payments based on net sales of Thiola. The liability for royalties in excess of the annual contractual minimum is recognized in the period in which the royalties become probable and estimable, which is typically in the period corresponding with the respective sales. The Company records an offsetting increase to the cost basis of the asset under the cost accumulation model. The additional cost basis is subsequently amortized over the remaining life of the license agreement. Consistent with all prior periods since Thiola was acquired, the Company has not accrued any liability for future royalties in excess of the annual contractual minimum at March 31, 2022 as such royalties are not yet probable and estimable. Variable Interest Entity The Company reviews each investment and collaboration agreement to determine if it has a variable interest in the entity. In assessing whether the Company has a variable interest in the entity as a whole, the Company considers and makes judgements regarding the purpose and design of the entity, the value of the licensed assets to the entity, the value of the entity’s total assets and the significant activities of the entity. If the Company has a variable interest in the entity as a whole, the Company assesses whether or not the Company is a primary beneficiary of that variable interest entity (“VIE”), based on a number of factors, including: (i) which party has the power to direct the activities that most significantly affect the VIE’s economic performance, (ii) the parties’ contractual rights and responsibilities pursuant to the collaboration agreement, and (iii) which party has the obligation to absorb losses of or the right to receive benefits from the VIE that could be significant to the VIE. If the Company determines that it is the primary beneficiary of a VIE at the onset of the collaboration, the collaboration is treated as a business combination and the Company consolidates the financial statements of the VIE into the Company’s consolidated financial statements. On a quarterly basis, the Company evaluates whether it continues to be the primary beneficiary of the consolidated VIE. If the Company determines that it is no longer the primary beneficiary of a consolidated VIE, it deconsolidates the VIE in the period in which the determination is made. Assets and liabilities recorded as a result of consolidating the financial results of the VIE into the Company’s consolidated balance sheet do not represent additional assets that could be used to satisfy claims against the Company’s general assets or liabilities for which creditors have recourse to the Company’s general assets. Adoption of New Accounting Standards In August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity's Own Equity. The ASU includes amendments to the guidance on convertible instruments and the derivative scope exception for contracts in an entity's own equity in Subtopic 815-40 and simplifies the accounting for convertible instruments which include beneficial conversion features or cash conversion features by removing certain separation models in Subtopic 470-20. Additionally, the ASU will require entities to use the "if-converted" method when calculating diluted earnings per share for convertible instruments. The ASU is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. The adoption of the new standard impacted the Company's accounting for its Convertible Senior Notes Due 2025 (2025 Notes), discussed in Note 10, which were previously accounted for using the cash conversion model applied under ASC 470-20, Debt with Conversion and Other Options ("ASC 470-20"). The Company adopted ASU 2020-06 on January 1, 2022 using the modified retrospective method. The cumulative effect of the accounting change as of January 1, 2022 increased the carrying amount of the 2025 Notes by $44.7 million, reduced additional paid-in capital by $74.9 million, and reduced accumulated deficit by $30.2 million.

REVENUE RECOGNITION

3 Months Ended

Mar. 31, 2022

Revenue from Contract with Customer [Abstract]

REVENUE RECOGNITION

Product Sales, Net

Product sales consist of Bile Acid products (Chenodal and Cholbam) and Tiopronin products (Thiola and Thiola EC). The Company sells its products through direct-to-patient distributors worldwide, with the Unites States and Canada representing 98% and 2% of net product sales, respectively, and rest of world representing less than 1% of net product sales, based on the product shipment destination.

Revenues from product sales are recognized when the customer obtains control of the Company’s product, which occurs upon delivery to the customer. The Company receives payments from its product sales based on terms that generally are within 30 days of delivery of product to the patient.

Deductions from Revenue

Revenues from product sales are recorded at the net sales price, which includes provisions resulting from discounts, rebates and co-pay assistance that are offered to customers, health care providers, payers and other indirect customers relating to the Company’s sales of its products. These provisions are based on the amounts earned or to be claimed on the related sales and are classified as a reduction of accounts receivable (if the amount is payable to a customer) or as a current liability (if the amount is payable to a party other than a customer). Where appropriate, these reserves take into consideration the Company’s historical experience, current contractual and statutory requirements and specific known market events and trends. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the contract. If actual results in the future vary from the Company’s provisions, the Company will adjust the provision, which would affect net product revenue and earnings in the period such variances become known. Our historical experience is that such adjustments have been immaterial.

Government Rebates: We calculate the rebates that we will be obligated to provide to government programs and deduct these estimated amounts from our gross product sales at the time the revenues are recognized. Allowances for government rebates and discounts are established based on actual payer information, which is reasonably estimated at the time of delivery, and the government-mandated discounts applicable to government-funded programs. Rebate discounts are included in other current liabilities in the accompanying consolidated balance sheets.

Commercial Rebates: We calculate the rebates that we incur due to contracts with certain commercial payers and deduct these amounts from our gross product sales at the time the revenues are recognized. Allowances for commercial rebates are established based on actual payer information, which is reasonably estimated at the time of delivery. Rebate discounts are included in other current liabilities in the accompanying consolidated balance sheets.

Prompt Pay Discounts: We offer discounts to certain customers for prompt payments. We accrue for the calculated prompt pay discount based on the gross amount of each invoice for those customers at the time of sale.

Product Returns: Consistent with industry practice, we offer our customers a limited right to return product purchased directly from the Company, which is principally based upon the product’s expiration date. Generally, shipments are only made upon a patient prescription thus returns are minimal.

Co-pay Assistance: We offer a co-pay assistance program, which is intended to provide financial assistance to qualified commercially insured patients with prescription drug co-payments required by payers. The calculation of the accrual for co-pay assistance is based on an identification of claims and the cost per claim associated with product that has been recognized as revenue.

The following table summarizes net product sales for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Bile acid products	$	25,075	$	21,964
Tiopronin products	21,368		25,443
Total net product sales	$	46,443	$	47,407

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 606
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-Section 50
-Paragraph 10
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

COLLABORATION AND LICENSE AGREEMENTS	3 Months Ended
COLLABORATION AND LICENSE AGREEMENTS	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
COLLABORATION AND LICENSE AGREEMENTS	COLLABORATION AND LICENSE AGREEMENTS On September 15, 2021, the Company entered into a license and collaboration agreement (“License Agreement”) with Vifor (International) Ltd. (“Vifor Pharma”), pursuant to which the Company granted an exclusive license to Vifor Pharma for the commercialization of sparsentan in Europe, Australia and New Zealand ("Licensed Territories"). Vifor Pharma also has first right of negotiation to expand the licensed territories into Canada, China, Brazil and/ or Mexico. Under the terms of the License Agreement, the Company received an upfront payment of $55.0 million and will be eligible for up to $135.0 million in aggregate regulatory and market access related milestone payments and up to $655.0 million in aggregate sales-based milestone payments for a total potential value of up to $845.0 million. The Company is also entitled to receive tiered double-digit royalties of up to 40 percent of annual net sales of sparsentan in the Licensed Territories. Under the License Agreement, Vifor Pharma will be responsible for all commercialization activities in the Licensed Territories. The Company remains responsible for the worldwide clinical development of sparsentan through regulatory approval as defined and will retain all rights to sparsentan in the United States and rest of world outside of the Licensed Territories. Development costs for any post regulatory approval development activities, subject to approval by both parties, will be borne by the Company and Vifor Pharma as defined, respectively. The License Agreement will remain in effect, unless terminated earlier, until the expiration of all royalty terms for sparsentan in the licensed territories. Each party has the right to terminate the License Agreement for the other party’s uncured material breach, insolvency or if the time required for performance under the License Agreement by the other party is extended due to a force majeure event that continues for six months or more. The Company assessed the License Agreement and determined that it meets both criteria to be considered a collaborative agreement within the Scope of ASC 808, Collaborative Arrangements of active participation by both parties and exposures to significant risks and rewards dependent on the commercial success of the activities. Both parties participate on joint steering and other committees overseeing the collaboration activities. Also, both parties are exposed to significant risks and rewards based on the economic outcomes of regulatory approvals and commercialization of sparsentan. The Company determined the transaction price under the License Agreement totaled $55.0 million, consisting of the fixed non-refundable upfront payment. The variable regulatory and access related milestones were excluded from the transaction price given the substantial uncertainty related to their achievement. Sales-based milestone payments and royalties on net sales were excluded from the transaction price and will be recognized at the later of when the related sales occur or when the performance obligation to which the sales-based milestone or royalty has been allocated have been satisfied. The Company concluded that Vifor Pharma represented a customer and applied relevant guidance from ASC 606 to evaluate the accounting under the License Agreement. In accordance with this guidance, the Company concluded that the promise to grant the license is distinct from the promise to provide clinical development services resulting in two performance obligations. As a result, the Company allocated $12.0 million of the transaction price, based on the performance obligations' relative standalone selling prices, to the license, which was recognized in full in 2021. The remaining $43.0 million of the transaction price was allocated to the clinical development activities and recorded as deferred revenue, which will be recognized over the development period based upon the ratio of costs incurred to date to the total estimated costs. The Company recognized $2.0 million in license and collaboration revenue for the three months ended March 31, 2022, based upon the ratio of costs incurred to total estimated costs. Deferred revenue related to the clinical development activities as of March 31, 2022 was $33.9 million. Of this amount, $14.2 million was classified as current as of March 31, 2022, based upon amounts expected to be realized within the next year. In February 2021, the Company entered into a limited co-promotion agreement with Albireo Pharma, Inc. ("Albireo"), whereby the Company's Cholbam dedicated sales representatives will devote a portion of their efforts to promoting Albireo's product, Bylvay (odevixibat), in the United States. The initial term of the arrangement is two years from the July 2021 launch of Bylvay, terminable at will by either party after one year following launch. For the three months ended March 31, 2022, the Company recognized $0.8 million offset against selling, general, and administrative expenses.

MARKETABLE DEBT SECURITIES

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

MARKETABLE DEBT SECURITIES

The Company's marketable debt securities as of March 31, 2022 and December 31, 2021 were comprised of available-for-sale corporate and government debt securities. These securities are carried at fair value, with the unrealized gains and losses reported in accumulated other comprehensive income (loss), unless an impairment is determined to be the result of credit-related factors or the Company intends to sell the security or it is more likely than not that the Company will be required to sell the security before recovery. The amortized cost of marketable debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in interest income. Realized gains and losses and declines in value that are determined to be the result of credit losses, if any, on available-for-sale securities are included in other income or expense. Unrealized losses that are determined to be credit-related are also recorded as an allowance against the amortized cost basis. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in interest income. All available-for-sale securities are classified as current assets, even if the maturity when acquired by the Company is greater than one year due to the ability to liquidate within the next 12 months.

During the three months ended March 31, 2022, investment activity for the Company included $64.7 million in maturities and $26.3 million in purchases, all relating to debt based marketable securities.

Marketable debt securities consisted of the following (in thousands):


	March 31, 2022		December 31, 2021
Marketable debt securities:
Commercial paper	$	115,345	$	127,379
Corporate debt securities	216,010		233,319
Securities of government sponsored entities	15,463		26,431
Total marketable debt securities	$	346,818	$	387,129

The following is a summary of short-term marketable debt securities classified as available-for-sale as of March 31, 2022 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	115,467	$	—	$	(122)	$	115,345
Corporate debt securities	Less than 1	145,227		3		(447)		144,783
Securities of government-sponsored entities	Less than 1	13,005		—		(36)		12,969
Total maturity less than 1 year		273,699		3		(605)		273,097
Corporate debt securities	1 to 2	72,250		—		(1,023)		71,227
Securities of government-sponsored entities	1 to 2	2,543		—		(49)		2,494
Total maturity 1 to 2 years		74,793		—		(1,072)		73,721
Total available-for-sale marketable debt securities		$	348,492	$	3	$	(1,677)	$	346,818

The following is a summary of short-term marketable debt securities classified as available-for-sale as of December 31, 2021 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	127,435	$	—	$	(57)	$	127,378
Corporate debt securities	Less than 1	113,001		—		(97)		112,904
Securities of government-sponsored entities	Less than 1	21,909		—		(5)		21,904
Total maturity less than 1 year		262,345		—		(159)		262,186
Corporate debt securities	1 to 2	120,705		—		(289)		120,416
Securities of government-sponsored entities	1 to 2	4,549		—		(22)		4,527
Total maturity 1 to 2 years		125,254		—		(311)		124,943
Total available-for-sale marketable debt securities		$	387,599	$	—	$	(470)	$	387,129

The primary objective of the Company’s investment portfolio is to preserve capital and liquidity while enhancing overall returns. The Company’s investment policy limits interest-bearing security investments to certain types of instruments issued by institutions with primarily investment grade credit ratings and places restrictions on maturities and concentration by asset class and issuer.

The Company reviews the available-for-sale marketable debt securities for declines in fair value below the cost basis each quarter. For any security whose fair value is below its amortized cost basis, the Company first evaluates whether it intends to sell the impaired security, or will otherwise be more likely than not required to sell the security before recovery. If either are true, the amortized cost basis of the security is written down to its fair value at the reporting date. If neither circumstance holds true, the Company assesses whether any portion of the unrealized loss is a result of a credit loss. Any amount deemed to be attributable to credit loss is recognized in the income statement, with the amount of the loss limited to the difference between fair value and amortized cost and recorded as an allowance for credit losses. The portion of the unrealized loss related to factors other than credit losses is recognized in other comprehensive income (loss).

The following is a summary of available-for-sale marketable debt securities in an unrealized loss position with no credit losses reported as of March 31, 2022 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	115,345	$	122	$	—	$	—	$	115,345	$	122
Corporate debt securities	188,966		1,445		12,033		25		200,999		1,470
Securities of government-sponsored entities	5,462		85		—		—		5,462		85
Total	$	309,773	$	1,652	$	12,033	$	25	$	321,806	$	1,677

The following is a summary of available-for-sale marketable debt securities in an unrealized loss position with no credit losses reported as of December 31, 2021 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	122,380	$	57	$	—	$	—	$	122,380	$	57
Corporate debt securities	231,879		386		—		—		231,879		386
Securities of government-sponsored entities	26,431		27		—		—		26,431		27
Total	$	380,690	$	470	$	—	$	—	$	380,690	$	470

As of March 31, 2022 and December 31, 2021, the amortized cost of the available-for-sale marketable debt securities in an unrealized loss position was $323.5 million and $381.2 million, respectively.

As of March 31, 2022 and December 31, 2021, the Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost basis. The Company does not believe the unrealized losses incurred during the period are due to credit-related factors. The increase in unrealized losses for the three months ending March 31, 2022 was primarily due to increases in short-term interest rates. Liquidity issues that arose from economic circumstances surrounding the COVID-19 pandemic have eased and the credit ratings of the securities held remain of the highest quality. Moreover, the Company continues to receive payments of interest and principal as they become due, and our expectation is that those payments will continue to be received timely. Uncertainty surrounding the COVID-19 pandemic, as well as other factors unknown to us at this time, may cause actual results to differ and require adjustments to the Company’s estimates and assumptions in the future.

VARIABLE INTEREST ENTITIES	3 Months Ended
VARIABLE INTEREST ENTITIES	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES On March 8, 2022, the Company entered into a Collaboration Agreement with PharmaKrysto Limited (“PharmaKrysto”), a privately held pre-clinical stage company related to PharmaKrysto's early-stage cystinuria discovery program, and concurrently therewith entered into a Stock Purchase Agreement with PharmaKrysto (together, the "Agreements"). Pursuant to the terms of the Agreements, the Company paid PharmaKrysto's shareholders $0.6 million in cash to purchase 5% of the outstanding common shares of PharmaKrysto and $0.4 million to PharmaKrysto as a one-time signing fee. Under the Collaboration Agreement, the Company will fund all research and development expenses for the pre-clinical activities associated with the cystinuria program, which are estimated to be approximately $5.0 million. The Agreements require the Company to purchase an additional 5% of the outstanding common shares for $1.0 million upon the occurrence of a specified pre-clinical milestone, and grant an option to the Company to purchase the remaining outstanding shares of PharmaKrysto for $5.0 million upon the occurrence of a subsequent pre-clinical milestone prior to expiration of the option on March 8, 2025. If the Company elects to exercise the option, it would be required to perform commercially reasonable clinical diligence obligations. In addition, it would be required to make cash milestone payments totaling up to an aggregate $16.0 million upon the achievement of certain development and regulatory milestones, plus tiered royalty payments of less than 4% on future net sales of a product, if approved. The Company has the right to terminate the Agreements and return the shares for a nominal price at any time upon 60 days’ notice, subject to survival of contingent obligations, if any. The Company determined that PharmaKrysto is a VIE because it lacks the resources to conduct the cystinuria clinical program and the limitation on the residual returns through the Company's option to purchase the remaining outstanding shares. The Company further concluded that it is the primary beneficiary of the VIE due to the Company's ultimate control over the research and development program, and its obligation, subject to continuation of the collaboration, to fund 100% of research and development costs of the program pursuant to the terms of the Collaboration Agreement. The upfront payments were expensed to research and development and other income (expense), net upon initial consolidation. The Company consolidated cash and cash equivalents and accrued liabilities of $0.4 million as of March 31, 2022. The results of operations were not significant for the three months ended March 31, 2022. The Company is not required to provide additional funding other than the contractually required amounts disclosed above. The creditors and beneficial holders of PharmaKrysto have no recourse to the general credit of the Company.

LEASES

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

LEASES

As of March 31, 2022, the Company had one operating lease with Kilroy Realty, L.P. (the "Landlord") for office space located in San Diego, California, which was entered into in April 2019 and subsequently amended in May 2020. Coinciding with our ability to direct the use of the office space, which occurred in phases over 2020, and utilizing a discount rate equal to our borrowing rate, the Company established ROU assets totaling $34.6 million and lease liabilities totaling $34.5 million. The total ROU asset and lease liability at measurement were each offset by lease incentives associated with tenant improvement allowances totaling $7.9 million.

The initial term of the office lease ends in August 2028, and the Landlord has granted the Company an option to extend the term of the lease by a period of 5 years. At this time, it is not reasonably certain that we will extend the term of the lease and therefore the renewal period has been excluded from the aforementioned ROU asset and lease liability measurements. The measurement of the lease term occurs from the February 2021 occupancy date of the office space delivered in September 2020. The aggregate base rent due over the initial term of the lease is approximately $49.5 million.

Following is a schedule of the future minimum rental commitments for our operating leases reconciled to the lease liability and ROU asset as of March 31, 2022 (in thousands):


	March 31, 2022
2022	$	4,525
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	42,224

Present value discount	(7,771)
Total lease liability	34,453
Unamortized lease incentives	(6,313)
Cash payments in excess of straight-line lease expense	(5,583)
Total ROU asset	$	22,557

For the three months ended March 31, 2022 and 2021, the Company recorded $1.2 million and $1.2 million, respectively, in expense related to operating leases, including amortized tenant improvement allowances.

FAIR VALUE MEASUREMENTS

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

Financial Instruments and Fair Value

The Company accounts for financial instruments in accordance with ASC 820, Fair Value Measurements and Disclosures (“ASC 820”). ASC 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under ASC 820 are described below:

Level 1 – Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

Level 2 – Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly; and

Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.

The valuation techniques used to measure the fair value of the Company’s debt securities and all other financial instruments, all of which have counter-parties with high credit ratings, were valued based on quoted market prices or model driven valuations using significant inputs derived from or corroborated by observable market data. Based on the fair value hierarchy, the Company classified debt securities within Level 2.

The Company acquired two businesses, related to the Cholbam and Chenodal products, whose purchase price included potential future payments that are contingent on the achievement of certain milestones and percentages of future net sales derived from the products acquired. The Company recorded contingent consideration liabilities at their fair value on the acquisition date and revalues them at the end of each reporting period. In estimating the fair value of the Company’s contingent consideration, the Company uses a Monte Carlo Simulation. The determination of the contingent consideration liabilities requires significant judgements including the appropriateness of the valuation model and reasonableness of estimates and assumptions included in the forecasts of future net sales and the discount rates applied to such forecasts. Changes in these estimates and assumptions could have a significant impact on the fair value of the contingent consideration liabilities.

Discount rates used to determine the fair value at March 31, 2022 and December 31, 2021 are as follows:


	Revenue Discount		Payment Discount
	Cholbam	Chenodal
March 31, 2022	6.50%	7.00%	8.24%
December 31, 2021	6.25%	7.25%	6.48%

Based on the fair value hierarchy, the Company classified the fair value measurement of contingent consideration within Level 3 because valuation inputs are based on projected revenues discounted to a present value.

Financial instruments with carrying values approximating fair value include cash and cash equivalents, accounts receivable, and accounts payable, due to their short-term nature. As of March 31, 2022, the fair value of the Company's 2.5% Convertible Senior Notes due 2025 was $69.6 million and the fair value of the Company's 2.25% Convertible Senior Notes due 2029 was $332.3 million, which were estimated utilizing market quotations, and are considered Level 2.

The following table presents the Company’s assets and liabilities, measured and recognized at fair value on a recurring basis, classified under the appropriate level of the fair value hierarchy as of March 31, 2022 (in thousands):


	As of March 31, 2022
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Cash and Cash Equivalents	$	256,572	$	256,572	$	—	$	—
Debt securities, available-for-sale	346,818		—		346,818		—
Total	$	603,390	$	256,572	$	346,818	$	—
Liabilities:
Business combination-related contingent consideration	$	73,500	$	—	$	—	$	73,500
Total	$	73,500	$	—	$	—	$	73,500


	As of December 31, 2021
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Cash and Cash Equivalents	$	165,753	$	165,753	$	—	$	—
Debt securities, available-for-sale	387,129		—		387,129		—
Total	$	552,882	$	165,753	$	387,129	$	—
Liabilities:
Business combination-related contingent consideration	67,100		—		—		67,100
Total	$	67,100	$	—	$	—	$	67,100

The following table sets forth a summary of changes in the estimated fair value of the Company's Level 3 business combination-related contingent consideration for the three months ended March 31, 2022 (in thousands):


	Fair Value Measurements of Acquisition-Related Contingent Consideration (Level 3)
Balance at January 1, 2022	$	67,100
Changes in the fair value of contingent consideration	9,080
Contractual payments	—
Contractual payments included in accrued liabilities at March 31, 2022	(2,680)

Balance at March 31, 2022	$	73,500

For the three months ended March 31, 2022 and 2021, the Company incurred charges of $9.1 million and $8.6 million, respectively, in operating expenses on the Condensed Consolidated Statements of Operations and Comprehensive Loss for the change in fair value of the contingent consideration liabilities. In both periods, the value changed due to the timing of future payments and changes in market driven discount rates.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

INTANGIBLE ASSETS

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

INTANGIBLE ASSETS

Ligand License Agreement

In 2012, the Company entered into an agreement with Ligand Pharmaceuticals, Inc. ("Ligand") for a worldwide sublicense to develop, manufacture and commercialize a drug technology compound including sparsentan (the “Ligand License Agreement”). The cost of the Ligand License Agreement, which is presented net of amortization in the accompanying Consolidated Balance Sheets in intangible assets, net, is being amortized to research and development on a straight-line basis through September 30, 2023. As consideration for the license, the Company is required to make substantial payments upon the achievement of certain milestones, totaling up to $114.1 million. Through March 31, 2022, the Company has capitalized $15.0 million for contractual milestone payments under the Ligand License Agreement. Should the Company commercialize sparsentan or any products containing related compounds, the Company will be obligated to pay to Ligand an escalating annual royalty between 15% and 17% of net sales of all such products.

As of March 31, 2022, the net book value of amortizable intangible assets was approximately $152.4 million.

The following table sets forth amortizable intangible assets as of March 31, 2022 and December 31, 2021 (in thousands):


	March 31, 2022		December 31, 2021
Finite-lived intangible assets	$	295,175	$	283,557
Less: accumulated amortization	(142,790)		(136,058)
Net carrying value	$	152,385	$	147,499

As of March 31, 2022 and December 31, 2021, the Company had goodwill of $0.9 million.

The following table summarizes amortization expense for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Research and development	$	286	$	286
Selling, general and administrative	6,270		5,666
Total amortization expense	$	6,556	$	5,952

CONVERTIBLE NOTES PAYABLE

3 Months Ended

Mar. 31, 2022

Debt Disclosure [Abstract]

CONVERTIBLE NOTES PAYABLE

The composition of the Company’s convertible senior notes are as follows (in thousands):


	March 31, 2022		December 31, 2021
2.25% convertible senior notes due 2029	$	316,250	$	—
2.50% convertible senior notes due 2025	68,904		276,000
Unamortized debt discount	—		(46,045)
Unamortized debt issuance costs - 2.25% convertible senior notes due 2029	(9,726)		—
Unamortized debt issuance costs - 2.50% convertible senior notes due 2025	(1,095)		(3,374)
Total convertible senior notes, net of unamortized debt discount and debt issuance costs	$	374,333	$	226,581

Convertible Senior Notes Due 2029

On March 11, 2022, the Company completed a registered underwritten public offering of $316.3 million aggregate principal amount of 2.25% Convertible Senior Notes due 2029 (“2029 Notes”), which includes $41.3 million aggregate principal amount of 2029 Notes sold pursuant to the full exercise of the underwriters’ option to purchase additional 2029 Notes. The Company issued the 2029 Notes under an indenture, dated as of September 10, 2018, as supplemented by the second supplemental indenture, dated as of March 11, 2022 (collectively, the “2029 Indenture”). The 2029 Notes will mature on March 1, 2029, unless earlier repurchased, redeemed, or converted. The 2029 Notes are senior unsecured obligations of the Company and bear interest at an annual rate of 2.25%, payable semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2022.

The Company received net proceeds from the issuance of the 2029 Notes of $306.4 million, after deducting commissions and offering expenses of $9.8 million. At March 31, 2022, accrued interest on the 2029 Notes of $0.4 million is included in accrued expenses in the accompanying Condensed Consolidated Balance Sheets. The 2029 Notes comprise the Company’s senior, unsecured obligations and are (i) equal in right of payment with the Company’s existing and future senior, unsecured indebtedness; (ii) senior in right of payment to the Company’s existing and future indebtedness that is expressly subordinated to the 2029 Notes; (iii) effectively subordinated to the Company’s existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness; and (iv) structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables.

Holders may convert their 2029 Notes at their option only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2022 (and only during such calendar quarter), if the last reported sale price per share of the Company’s 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 per $1,000 principal amount of 2029 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 the Company’s common stock on such trading day and the conversion rate on such trading day; (3) upon the occurrence of certain corporate events or distributions of the Company’s common stock; (4) if the Company calls the 2029 Notes for redemption; and (5) at any time from, and including, December 1, 2028 until the close of business on the scheduled trading day immediately before the maturity date. The Company will settle conversions by paying or delivering, as applicable, cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s election, based on the applicable conversion rate. The initial conversion rate for the 2029 Notes is 31.3740 shares of the Company’s common stock per $1,000 principal amount of 2029 Notes, which represents an initial conversion price of approximately $31.87 per share. If a “make-whole fundamental change” (as defined in the 2029 Indenture) occurs, then the Company will, in certain circumstances, increase the conversion rate for a specified period of time.

The 2029 Notes will be redeemable, in whole or in part at the Company’s option at any time, and from time to time, on or after March 2, 2026 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 2029 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 the Company’s common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends the related redemption notice; and (2) the trading day immediately before the date the Company sends such notice. However, the Company may not redeem less than all of the outstanding 2029 Notes unless at least $100.0 million aggregate principal amount of 2029 Notes are outstanding and not called for redemption as of the time the Company sends the related redemption notice. In addition, calling any 2029 Note for redemption will constitute a make-whole fundamental change with respect to that 2029 Note, in which case the conversion rate applicable to the conversion of that 2029 Note will be increased in certain circumstances if it is converted after it is called for redemption. If a fundamental change (as defined in the 2029 Indentures) occurs, then, except as described in the 2029 Indentures, holders may require the Company to repurchase their 2029 Notes at a cash repurchase price equal to the principal amount of the 2029 Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date. In the event of conversion, holders would forgo all future interest payments, any unpaid accrued interest and the possibility of further stock price appreciation. Upon the receipt of conversion requests, the settlement of the 2029 Notes will be paid pursuant to the terms of the 2029 Indenture. In the event that all of the 2029 Notes are converted, the Company would be required to repay the principal amount and any conversion premium in any combination of cash and shares of its common stock at the Company’s option. In addition, calling the 2029 Notes for redemption will constitute a “make-whole fundamental change."

The Company incurred approximately $9.8 million of debt issuance costs relating to the issuance of the 2029 Notes, which were recorded as a reduction to the 2029 Notes on the Condensed Consolidated Balance Sheets. The debt issuance costs are being amortized and recognized as additional interest expense over the expected life of the 2029 Notes using the effective interest method. We determined the expected life of the debt is equal to the seven-year term of the 2029 Notes. The effective interest rate on the 2029 Notes is 2.74%.

Convertible Senior Notes Due 2025

On September 10, 2018, the Company completed a registered underwritten public offering of $276.0 million aggregate principal amount of 2.50% Convertible Senior Notes due 2025 ("2025 Notes"), and entered into a base indenture and supplemental indenture agreement ("2025 Indenture") with respect to the 2025 Notes. The 2025 Notes will mature on September 15, 2025, unless earlier repurchased, redeemed, or converted. The 2025 Notes are senior unsecured obligations of the Company and bear interest at an annual rate of 2.50%, payable semi-annually in arrears on March 15 and September 15 of each year, beginning on March 15, 2019.

The net proceeds from the issuance of the 2025 Notes were approximately $267.2 million, after deducting commissions and the offering expenses of $8.8 million payable by the Company. At March 31, 2022, accrued interest of $0.1 million is included in accrued expenses in the accompany Condensed Consolidated Balance Sheets. The 2025 Notes comprise the Company’s senior, unsecured obligations and are (i) equal in right of payment with the Company’s existing and future senior, unsecured indebtedness; (ii) senior in right of payment to the Company’s existing and future indebtedness that is expressly subordinated to the 2025 Notes; (iii) effectively subordinated to the Company’s existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness; and (iv) structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables.

Holders may convert their 2025 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 the Company’s 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 (“measurement period”) if the trading price per $1,000 principal amount of 2025 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 the Company’s 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 the Company’s common stock; (4) if the Company calls the 2025 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. The Company will settle conversions by paying or delivering, as applicable, cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s election, based on the applicable conversion rate.

The initial conversion rate for the 2025 Notes is 25.7739 shares of the Company’s common stock per $1,000 principal amount of 2025 Notes, which represents an initial conversion price of approximately $38.80 per share. If a “make-whole fundamental change” (as defined in the 2025 Indenture) occurs, then the Company will, in certain circumstances, increase the conversion rate for a specified period of time.

The 2025 Notes will be redeemable, in whole or in part, at the Company’s 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 2025 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 the Company’s 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 the Company sends the related redemption notice. If a fundamental change (as defined in the 2025 Indenture) occurs, then, subject to certain exceptions, holders may require the Company to repurchase their 2025 Notes at a cash repurchase price equal to the principal amount of the 2025 Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date. In the event of conversion, holders would forgo all future interest payments, any unpaid accrued interest and the possibility of further stock price appreciation. Upon the receipt of conversion requests, the settlement of the 2025 Notes will be paid pursuant to the terms of the 2025 Indenture. In the event that all of the 2025 Notes are converted, the Company would be required to repay the principal amount and any conversion premium in any combination of cash and shares of its common stock at the Company’s option. In addition, calling the 2025 Notes for redemption will constitute a “make-whole fundamental change."

The Company incurred approximately $8.8 million of debt issuance costs relating to the issuance of the 2025 Notes, which were recorded as a reduction to the 2025 Notes on the Condensed Consolidated Balance Sheets. The debt issuance costs are being amortized and recognized as additional interest expense over the expected life of the 2025 Notes using the effective interest method. The Company determined the expected life of the debt is equal to the seven-year term of the 2025 Notes. The effective interest rate on the 2025 Notes is 2.98%.

On March 11, 2022, the Company completed its repurchase of $207.1 million aggregate principal amount of 2025 Notes for cash, including accrued and unpaid interest, for a total of $213.8 million. This transaction involved a contemporaneous exchange of cash between the Company and holders of the 2025 Notes participating in the issuance of the 2029 Notes. Accordingly, we evaluated the transaction for modification or extinguishment accounting in accordance with ASC 470-50, Debt – Modifications and Extinguishments on a creditor-by creditor basis depending on whether the exchange was determined to have substantially different terms. The repurchase of the 2025 Notes and issuance of the 2029 Notes were deemed to have substantially different terms based on the present value of the cash flows or significant difference between the value of the conversion option immediately prior to and after the exchange. Therefore, the repurchase of the 2025 Notes was accounted for as a debt extinguishment. The Company recorded a $7.6 million loss on early extinguishment of debt on its Condensed Consolidated Statements of Operations for the three months ending March 31, 2022, which includes the write-off of related deferred financing costs of $3.4 million. After giving effect to the repurchase, the total remaining principal amount outstanding under the 2025 Notes as of March 31, 2022 was $68.9 million.

The 2025 and 2029 Notes are accounted for in accordance with ASC 470-20, Debt with conversion and Other Options (“ASC 470-20”) and ASC 815-40, Contracts in Entity’s Own Equity (“ASC 815-40”). Under ASC 815-40, to qualify for equity classification (or nonbifurcation, if embedded) the instrument (or embedded feature) must be both (1) indexed to the issuer’s stock and (2) meet the requirements of equity classification guidance. Based upon the Company’s analysis, it was determined that the 2025 Notes and the 2029 Notes do not contain embedded features requiring recognition as derivatives and bifurcation, and therefore are measured at amortized cost and recorded as liabilities on the Condensed Consolidated Balance Sheets.

The 2025 and 2029 Notes do not contain any financial or operating covenants or any restrictions on the payment of dividends, the issuance of other indebtedness or the issuance or repurchase of securities by the Company. There were no events of default for the 2025 Notes or 2029 Notes at March 31, 2022.

The 2025 and 2029 Notes are classified on the Company's Condensed Consolidated Balance Sheets at March 31, 2022 as long-tern convertible debt.

The following table sets forth total interest expense recognized related to the 2025 and 2029 Notes (in thousands):


	Three Months Ended March 31,
	2022		2021
Contractual interest expense	$	1,843	$	1,725
Amortization of debt discount	—		2,511
Amortization of debt issuance costs	337		225
Total interest expense for the 2025 and 2029 Notes	$	2,180	$	4,461

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

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-Name Accounting Standards Codification
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+ Details

ACCRUED EXPENSES

3 Months Ended

Mar. 31, 2022

Payables and Accruals [Abstract]

ACCRUED EXPENSES

Accrued expenses at March 31, 2022 and December 31, 2021 consisted of the following (in thousands):


	March 31, 2022		December 31, 2021
Compensation related costs	$	23,408	$	25,998
Research and development	22,058		26,841
Government rebates payable	9,351		7,493
Accrued royalties and contingent consideration	6,694		8,402
Selling, general and administrative	5,349		3,144
Miscellaneous accrued expenses	2,380		3,302

Total accrued expenses	$	69,240	$	75,180

NET LOSS PER COMMON SHARE

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

NET LOSS PER COMMON SHARE

Basic and diluted net loss per common share is calculated by dividing net loss applicable to common stockholders by the weighted-average number of common shares outstanding during the period. The Company’s potentially dilutive shares, which include outstanding stock options, restricted stock units, and shares issuable upon conversion of the 2025 Notes and 2029 Notes, are considered to be common stock equivalents and are not included in the calculation of diluted net loss per share because their effect is anti-dilutive.

Basic and diluted net loss per share is calculated as follows (net loss amounts are stated in thousands):


	Three Months Ended March 31,
	2022					2021
	Shares	Net Loss		Loss per common share		Shares	Net Loss		Loss per common share
Basic and diluted loss per share	63,132,841	$	(75,971)	$	(1.20)	56,268,508	$	(53,867)	$	(0.96)

The following common stock equivalents have been excluded because they were anti-dilutive:


	Three Months Ended March 31,
	2022	2021
Options	9,864,889	9,228,627
Convertible debt	8,336,091	7,113,402
Restricted stock	1,900,016	1,637,072

Total anti-dilutive shares	20,100,996	17,979,101

COMMITMENTS AND CONTINGENCIES	3 Months Ended
COMMITMENTS AND CONTINGENCIES	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Contingencies In October 2021, our Kolbam distributor in France notified us that the French authorities were asking for reimbursement for a portion of Kolbam sales in France during the periods from 2015-2020. During this period, the Company had aggregate revenues from sales of Kolbam in France of approximately $8.0 million. At this time, the Company is not able to estimate the potential liability that may be incurred, if any. Legal Proceedings From time to time in the normal course of business, the Company is subject to various legal matters such as threatened or pending claims or litigation. Although the results of claims and litigation cannot be predicted with certainty, the Company does not believe it is a party to any claim or litigation the outcome of which, if determined adversely to it, would individually or in the aggregate be reasonably expected to have a material adverse effect on its results of operations or financial condition.

SHARE-BASED COMPENSATION

3 Months Ended

Mar. 31, 2022

Equity [Abstract]

SHARE-BASED COMPENSATION

Stock Options

The following table summarizes stock option activity during the three months ended March 31, 2022:


	Shares Underlying Options	Weighted Average Exercise Price	Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2021	8,886,284	$20.26	6.27	$	96,577
Granted	1,447,270	27.65
Exercised	(7,576)	16.11
Forfeited/canceled	(30,932)	24.09
Outstanding at March 31, 2022	10,295,046	$21.29	6.51	$	54,540

At March 31, 2022, unamortized stock compensation for stock options was $44.7 million, with a weighted-average recognition period of 2.9 years.

At March 31, 2022, outstanding options to purchase 6.6 million shares of common stock were exercisable with a weighted-average exercise price per share of $19.76.

Restricted Stock Units

Service Based Restricted Stock Units

The following table summarizes the Company’s service based restricted stock unit activity during the three months ended March 31, 2022:


	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2021	1,473,949	$	21.88
Granted	817,118	27.49
Vested	(292,103)	22.29
Forfeited/canceled	(15,471)	23.11
Unvested March 31, 2022	1,983,493	$	24.12

At March 31, 2022, unamortized stock compensation for service based restricted stock units was $42.1 million, with a weighted-average recognition period of 2.8 years.

Performance Based Restricted Stock Units

The following table summarizes the Company’s performance based restricted stock unit activity during the three months ended March 31, 2022:


	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2021	52,500	$	18.73
Granted	117,208	27.50
Vested	(17,500)	25.26
Forfeited/canceled	—	—
Unvested March 31, 2022	152,208	$	24.73

At March 31, 2022, unamortized stock compensation for performance based restricted stock units was $3.1 million, with a weighted-average recognition period of 1.9 years.

Share-Based Compensation

The following table sets forth total share-based compensation for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Research and development	$	3,168	$	3,002
Selling, general & administrative	5,018		4,692
Total	$	8,186	$	7,694

INCOME TAXES	3 Months Ended
INCOME TAXES	Mar. 31, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXESFor the three months ended March 31, 2022, we recognized an income tax expense of $0.1 million as compared to an income tax expense of $0.3 million for the three months ended March 31, 2021.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

INVENTORY

3 Months Ended

Mar. 31, 2022

Inventory Disclosure [Abstract]

INVENTORY

Inventory, net of reserves, consisted of the following at March 31, 2022 and December 31, 2021 (in thousands):


	March 31, 2022		December 31, 2021
Raw materials	$	4,964	$	5,205
Finished goods	1,557		2,108
Total inventory	$	6,521	$	7,313

The inventory reserve was $4.1 million and $4.1 million at March 31, 2022 and December 31, 2021, respectively.

ACCOUNTS RECEIVABLE	3 Months Ended
ACCOUNTS RECEIVABLE	Mar. 31, 2022
Receivables [Abstract]
ACCOUNTS RECEIVABLE	ACCOUNTS RECEIVABLEAccounts receivable, net of reserves for prompt pay discounts and expected credit losses, was $14.7 million and $15.9 million at March 31, 2022 and December 31, 2021, respectively. The total reserves for both periods were immaterial.The Company's evaluation and application of ASU No. 2016-13, Financial Instruments - Credit Losses for the current period included an assessment of our aged trade receivables balances and their underlying credit risk characteristics. Our evaluation of past events, current conditions, and reasonable and supportable forecasts about the future resulted in an expectation of immaterial credit losses.

EQUITY OFFERINGS	3 Months Ended
EQUITY OFFERINGS	Mar. 31, 2022
Equity [Abstract]
EQUITY OFFERINGS	EQUITY OFFERINGS Underwritten Public Offering of Common Stock In February 2021, the Company sold an aggregate of 7.5 million shares of its common stock in an underwritten public offering, at a price of $26.75 per share. The net proceeds to the Company from the offering, after deducting the underwriting discounts and offering expenses, were $189.3 million. At-the-Market Equity Offering In February 2020, the Company entered into an Open Market Sale Agreement ("ATM Agreement") with Jefferies LLC, as agent (“Jefferies”), pursuant to which the Company may offer and sell, from time to time through Jefferies, shares of its common stock having an aggregate offering price of up to $100.0 million. Of the $100.0 million originally authorized for sale under the ATM Agreement, approximately $28.6 million were sold under the Company’s prior registration statement on Form S-3 (Registration No. 333-227182). An additional $51.9 million were sold under the Company's effective registration statement on Form S-3 (Registration Statement No. 333-259311), which included gross proceeds of $20.1 million from the settlement of 701,600 shares sold under the ATM Agreement in the three months ended March 31, 2022. As of March 31, 2022, an aggregate of $19.5 million remained eligible for sale under the ATM Agreement. Authorized Shares of Common Stock On May 14, 2021, in connection with the Company’s 2021 Annual Meeting of Stockholders, the Company’s stockholders approved, among other matters, a Certificate of Amendment (“Certificate of Amendment”) to the Company’s Certificate of Incorporation to increase the number of shares of common stock authorized for issuance thereunder from 100,000,000 to 200,000,000. Effective May 18, 2021, the Certificate of Amendment was filed with the Secretary of State of the State of Delaware.

BASIS OF PRESENTATION AND SIGNIFICANT ACCCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The unaudited condensed consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with GAAP. All intercompany accounts and transactions have been eliminated in consolidation.
Revenue Recognition	Revenue RecognitionThe Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"), the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect substantially all the consideration it is entitled to in exchange for the goods or services it transfers to the customer. Deductions from Revenue Revenues from product sales are recorded at the net sales price, which includes provisions resulting from discounts, rebates and co-pay assistance that are offered to customers, health care providers, payers and other indirect customers relating to the Company’s sales of its products. These provisions are based on the amounts earned or to be claimed on the related sales and are classified as a reduction of accounts receivable (if the amount is payable to a customer) or as a current liability (if the amount is payable to a party other than a customer). Where appropriate, these reserves take into consideration the Company’s historical experience, current contractual and statutory requirements and specific known market events and trends. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the contract. If actual results in the future vary from the Company’s provisions, the Company will adjust the provision, which would affect net product revenue and earnings in the period such variances become known. Our historical experience is that such adjustments have been immaterial. Government Rebates: We calculate the rebates that we will be obligated to provide to government programs and deduct these estimated amounts from our gross product sales at the time the revenues are recognized. Allowances for government rebates and discounts are established based on actual payer information, which is reasonably estimated at the time of delivery, and the government-mandated discounts applicable to government-funded programs. Rebate discounts are included in other current liabilities in the accompanying consolidated balance sheets. Commercial Rebates: We calculate the rebates that we incur due to contracts with certain commercial payers and deduct these amounts from our gross product sales at the time the revenues are recognized. Allowances for commercial rebates are established based on actual payer information, which is reasonably estimated at the time of delivery. Rebate discounts are included in other current liabilities in the accompanying consolidated balance sheets. Prompt Pay Discounts: We offer discounts to certain customers for prompt payments. We accrue for the calculated prompt pay discount based on the gross amount of each invoice for those customers at the time of sale. Product Returns: Consistent with industry practice, we offer our customers a limited right to return product purchased directly from the Company, which is principally based upon the product’s expiration date. Generally, shipments are only made upon a patient prescription thus returns are minimal. Co-pay Assistance: We offer a co-pay assistance program, which is intended to provide financial assistance to qualified commercially insured patients with prescription drug co-payments required by payers. The calculation of the accrual for co-pay assistance is based on an identification of claims and the cost per claim associated with product that has been recognized as revenue.
Collaborative Arrangements	Payments received under collaboration and licensing agreements may include non-refundable fees at the inception of the arrangements, milestone payments for specific achievements and royalties on the sale of products. At the inception of arrangements that include milestone payments, the Company uses judgement to evaluate whether the milestones are probable of being achieved and estimates the amount to include in the transaction price utilizing the most likely amount method. If it is probable that a significant revenue reversal will not occur, the estimated amount is included in the transaction price. Milestone payments that are not within the Company or the licensee’s control, such as regulatory approvals are not included in the transaction price until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of development milestones and any related constraint and adjusts the estimate of the overall transaction price, if necessary. The Company recognizes aggregate sales-based milestones and royalty payments from product sales at the later of when the related sales occur or when the performance obligation to which the sales-based milestone or royalty has been allocated has been satisfied. If it is probable that a significant revenue reversal will not occur, the Company estimates the sales-based milestone and royalty payments using the most likely amount method. The Company utilizes significant judgement to develop estimates of the stand-alone selling price for each distinct performance obligation based upon the relative stand-alone selling price. Variable consideration that relates specifically to the Company’s efforts to satisfy specific performance obligations is allocated entirely to those performance obligations. The stand-alone selling price for license-related performance obligations requires judgement in developing assumptions to project probability-weighted cash flows based upon estimates of forecasted revenues, clinical and regulatory timelines and discount rates. The stand-alone selling price for clinical development performance obligations is based on forecasted expected costs of satisfying a performance obligation plus an appropriate margin. If the licenses to intellectual property are determined to be distinct from the other performance obligations identified in the arrangement and have stand-alone functionality, the Company recognizes revenues from non-refundable, upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to benefit from the license. For licenses that are not distinct from other promises, the Company applies judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the related revenue recognition accordingly. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided. Revenue is recorded proportionally as costs are incurred. The Company generally utilizes the cost-to-cost method of progress because it best measures the transfer of control to the customer which occurs as the Company incurs costs. Under the cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. The Company uses judgment to estimate the total costs expected to complete the clinical development performance obligations, which include subcontractor costs, labor, materials, other direct costs and an allocation of indirect costs. The Company evaluates these cost estimates and the progress each reporting period and adjusts the measure of progress, if necessary.
Research and Development Expense	Research and Development Expenses Research and development includes expenses related to sparsentan, pegtibatinase, and the Company's other pipeline programs. The Company expenses all research and development costs as they are incurred. The Company's research and development costs are comprised of salaries and bonuses, benefits, share-based compensation, license fees, milestones under license agreements, costs paid to third-party contractors to perform research, conduct clinical trials, and develop drug materials and delivery devices, and associated overhead expenses and facilities costs. The Company charges direct internal and external program costs to the respective development programs. The Company also incurs indirect costs that are not allocated to specific programs because such costs benefit multiple development programs and allow us to increase our pharmaceutical development capabilities. These consist of internal shared resources related to the development and maintenance of systems and processes applicable to all of our programs.
Clinical Trial Expenses	Clinical Trial Expenses The Company records expenses in connection with clinical trials under contracts with contract research organizations (CROs) that support conducting and managing clinical trials. The financial terms and activities of these agreements vary from contract to contract and may result in uneven expense levels. Generally, these agreements set forth activities that drive the recording of expenses such as start-up and initiation activities, enrollment and treatment of patients, or the completion of other clinical trial activities. Expenses related to clinical trials are accrued based on our estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts we are obligated to pay under our clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), the Company adjusts its accruals accordingly on a prospective basis. Revisions to the Company's contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. The Company currently has three Phase 3 clinical trials in process that are in varying stages of activity, with ongoing non-clinical support trials. As such, clinical trial expenses will vary depending on all the factors set forth above and may fluctuate significantly from quarter to quarter.
Intangible Assets with Cost Accumulation Model	Intangible Assets with Cost Accumulation Model In 2014, the Company entered into a license agreement with Mission Pharmacal in which the Company obtained the exclusive right to license the trademark of Thiola. The acquisition of the Thiola license qualified as an asset acquisition under the principles of ASC 805, Business Combinations ("ASC 805") in effect at the time of acquisition. The license agreement requires the Company to make royalty payments based on net sales of Thiola. The liability for royalties in excess of the annual contractual minimum is recognized in the period in which the royalties become probable and estimable, which is typically in the period corresponding with the respective sales. The Company records an offsetting increase to the cost basis of the asset under the cost accumulation model. The additional cost basis is subsequently amortized over the remaining life of the license agreement. Consistent with all prior periods since Thiola was acquired, the Company has not accrued any liability for future royalties in excess of the annual contractual minimum at March 31, 2022 as such royalties are not yet probable and estimable.
Variable Interest Entity	Variable Interest Entity The Company reviews each investment and collaboration agreement to determine if it has a variable interest in the entity. In assessing whether the Company has a variable interest in the entity as a whole, the Company considers and makes judgements regarding the purpose and design of the entity, the value of the licensed assets to the entity, the value of the entity’s total assets and the significant activities of the entity. If the Company has a variable interest in the entity as a whole, the Company assesses whether or not the Company is a primary beneficiary of that variable interest entity (“VIE”), based on a number of factors, including: (i) which party has the power to direct the activities that most significantly affect the VIE’s economic performance, (ii) the parties’ contractual rights and responsibilities pursuant to the collaboration agreement, and (iii) which party has the obligation to absorb losses of or the right to receive benefits from the VIE that could be significant to the VIE. If the Company determines that it is the primary beneficiary of a VIE at the onset of the collaboration, the collaboration is treated as a business combination and the Company consolidates the financial statements of the VIE into the Company’s consolidated financial statements. On a quarterly basis, the Company evaluates whether it continues to be the primary beneficiary of the consolidated VIE. If the Company determines that it is no longer the primary beneficiary of a consolidated VIE, it deconsolidates the VIE in the period in which the determination is made. Assets and liabilities recorded as a result of consolidating the financial results of the VIE into the Company’s consolidated balance sheet do not represent additional assets that could be used to satisfy claims against the Company’s general assets or liabilities for which creditors have recourse to the Company’s general assets.
Adoption of New Accounting Standards	Adoption of New Accounting StandardsIn August 2020, the FASB issued ASU No. 2020-06, Accounting for Convertible Instruments and Contracts in an Entity's Own Equity. The ASU includes amendments to the guidance on convertible instruments and the derivative scope exception for contracts in an entity's own equity in Subtopic 815-40 and simplifies the accounting for convertible instruments which include beneficial conversion features or cash conversion features by removing certain separation models in Subtopic 470-20. Additionally, the ASU will require entities to use the "if-converted" method when calculating diluted earnings per share for convertible instruments. The ASU is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. The adoption of the new standard impacted the Company's accounting for its Convertible Senior Notes Due 2025 (2025 Notes), discussed in Note 10, which were previously accounted for using the cash conversion model applied under ASC 470-20, Debt with Conversion and Other Options ("ASC 470-20"). The Company adopted ASU 2020-06 on January 1, 2022 using the modified retrospective method. The cumulative effect of the accounting change as of January 1, 2022 increased the carrying amount of the 2025 Notes by $44.7 million, reduced additional paid-in capital by $74.9 million, and reduced accumulated deficit by $30.2 million.
Marketable Securities	The primary objective of the Company’s investment portfolio is to preserve capital and liquidity while enhancing overall returns. The Company’s investment policy limits interest-bearing security investments to certain types of instruments issued by institutions with primarily investment grade credit ratings and places restrictions on maturities and concentration by asset class and issuer.
Fair Value Measurement	Financial Instruments and Fair Value The Company accounts for financial instruments in accordance with ASC 820, Fair Value Measurements and Disclosures (“ASC 820”). ASC 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under ASC 820 are described below: Level 1 – Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 – Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly; and Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. The valuation techniques used to measure the fair value of the Company’s debt securities and all other financial instruments, all of which have counter-parties with high credit ratings, were valued based on quoted market prices or model driven valuations using significant inputs derived from or corroborated by observable market data. Based on the fair value hierarchy, the Company classified debt securities within Level 2. The Company acquired two businesses, related to the Cholbam and Chenodal products, whose purchase price included potential future payments that are contingent on the achievement of certain milestones and percentages of future net sales derived from the products acquired. The Company recorded contingent consideration liabilities at their fair value on the acquisition date and revalues them at the end of each reporting period. In estimating the fair value of the Company’s contingent consideration, the Company uses a Monte Carlo Simulation. The determination of the contingent consideration liabilities requires significant judgements including the appropriateness of the valuation model and reasonableness of estimates and assumptions included in the forecasts of future net sales and the discount rates applied to such forecasts. Changes in these estimates and assumptions could have a significant impact on the fair value of the contingent consideration liabilities.
Income (Loss) Per Share	Basic and diluted net loss per common share is calculated by dividing net loss applicable to common stockholders by the weighted-average number of common shares outstanding during the period. The Company’s potentially dilutive shares, which include outstanding stock options, restricted stock units, and shares issuable upon conversion of the 2025 Notes and 2029 Notes, are considered to be common stock equivalents and are not included in the calculation of diluted net loss per share because their effect is anti-dilutive.

REVENUE RECOGNITION (Tables)

3 Months Ended

Mar. 31, 2022

Revenue from Contract with Customer [Abstract]

Summary of net product revenue

The following table summarizes net product sales for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Bile acid products	$	25,075	$	21,964
Tiopronin products	21,368		25,443
Total net product sales	$	46,443	$	47,407

MARKETABLE DEBT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Schedule of marketable debt securities

Marketable debt securities consisted of the following (in thousands):


	March 31, 2022		December 31, 2021
Marketable debt securities:
Commercial paper	$	115,345	$	127,379
Corporate debt securities	216,010		233,319
Securities of government sponsored entities	15,463		26,431
Total marketable debt securities	$	346,818	$	387,129

Schedule of available for sale securities

The following is a summary of short-term marketable debt securities classified as available-for-sale as of March 31, 2022 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	115,467	$	—	$	(122)	$	115,345
Corporate debt securities	Less than 1	145,227		3		(447)		144,783
Securities of government-sponsored entities	Less than 1	13,005		—		(36)		12,969
Total maturity less than 1 year		273,699		3		(605)		273,097
Corporate debt securities	1 to 2	72,250		—		(1,023)		71,227
Securities of government-sponsored entities	1 to 2	2,543		—		(49)		2,494
Total maturity 1 to 2 years		74,793		—		(1,072)		73,721
Total available-for-sale marketable debt securities		$	348,492	$	3	$	(1,677)	$	346,818

The following is a summary of short-term marketable debt securities classified as available-for-sale as of December 31, 2021 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	127,435	$	—	$	(57)	$	127,378
Corporate debt securities	Less than 1	113,001		—		(97)		112,904
Securities of government-sponsored entities	Less than 1	21,909		—		(5)		21,904
Total maturity less than 1 year		262,345		—		(159)		262,186
Corporate debt securities	1 to 2	120,705		—		(289)		120,416
Securities of government-sponsored entities	1 to 2	4,549		—		(22)		4,527
Total maturity 1 to 2 years		125,254		—		(311)		124,943
Total available-for-sale marketable debt securities		$	387,599	$	—	$	(470)	$	387,129

Schedule of marketable debt securities in an unrealized loss position

The following is a summary of available-for-sale marketable debt securities in an unrealized loss position with no credit losses reported as of March 31, 2022 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	115,345	$	122	$	—	$	—	$	115,345	$	122
Corporate debt securities	188,966		1,445		12,033		25		200,999		1,470
Securities of government-sponsored entities	5,462		85		—		—		5,462		85
Total	$	309,773	$	1,652	$	12,033	$	25	$	321,806	$	1,677

The following is a summary of available-for-sale marketable debt securities in an unrealized loss position with no credit losses reported as of December 31, 2021 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	122,380	$	57	$	—	$	—	$	122,380	$	57
Corporate debt securities	231,879		386		—		—		231,879		386
Securities of government-sponsored entities	26,431		27		—		—		26,431		27
Total	$	380,690	$	470	$	—	$	—	$	380,690	$	470

LEASES (Tables)

3 Months Ended

Mar. 31, 2022

Leases [Abstract]

Schedule of future minimum rent commitments

Following is a schedule of the future minimum rental commitments for our operating leases reconciled to the lease liability and ROU asset as of March 31, 2022 (in thousands):


	March 31, 2022
2022	$	4,525
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	42,224

Present value discount	(7,771)
Total lease liability	34,453
Unamortized lease incentives	(6,313)
Cash payments in excess of straight-line lease expense	(5,583)
Total ROU asset	$	22,557

FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Schedule of discount rates used

Discount rates used to determine the fair value at March 31, 2022 and December 31, 2021 are as follows:


	Revenue Discount		Payment Discount
	Cholbam	Chenodal
March 31, 2022	6.50%	7.00%	8.24%
December 31, 2021	6.25%	7.25%	6.48%

Schedule of fair value on a recurring basis


	As of March 31, 2022
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Cash and Cash Equivalents	$	256,572	$	256,572	$	—	$	—
Debt securities, available-for-sale	346,818		—		346,818		—
Total	$	603,390	$	256,572	$	346,818	$	—
Liabilities:
Business combination-related contingent consideration	$	73,500	$	—	$	—	$	73,500
Total	$	73,500	$	—	$	—	$	73,500


	As of December 31, 2021
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Assets:
Cash and Cash Equivalents	$	165,753	$	165,753	$	—	$	—
Debt securities, available-for-sale	387,129		—		387,129		—
Total	$	552,882	$	165,753	$	387,129	$	—
Liabilities:
Business combination-related contingent consideration	67,100		—		—		67,100
Total	$	67,100	$	—	$	—	$	67,100

Schedule of fair value measurements of acquisition-related contingent consideration


	Fair Value Measurements of Acquisition-Related Contingent Consideration (Level 3)
Balance at January 1, 2022	$	67,100
Changes in the fair value of contingent consideration	9,080
Contractual payments	—
Contractual payments included in accrued liabilities at March 31, 2022	(2,680)

Balance at March 31, 2022	$	73,500

INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of finite-lived amortizable intangible assets

The following table sets forth amortizable intangible assets as of March 31, 2022 and December 31, 2021 (in thousands):


	March 31, 2022		December 31, 2021
Finite-lived intangible assets	$	295,175	$	283,557
Less: accumulated amortization	(142,790)		(136,058)
Net carrying value	$	152,385	$	147,499

Schedule of amortization expense

The following table summarizes amortization expense for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Research and development	$	286	$	286
Selling, general and administrative	6,270		5,666
Total amortization expense	$	6,556	$	5,952

CONVERTIBLE NOTES PAYABLE (Tables)

3 Months Ended

Mar. 31, 2022

Debt Disclosure [Abstract]

Schedule of long-term debt instruments

The composition of the Company’s convertible senior notes are as follows (in thousands):


	March 31, 2022		December 31, 2021
2.25% convertible senior notes due 2029	$	316,250	$	—
2.50% convertible senior notes due 2025	68,904		276,000
Unamortized debt discount	—		(46,045)
Unamortized debt issuance costs - 2.25% convertible senior notes due 2029	(9,726)		—
Unamortized debt issuance costs - 2.50% convertible senior notes due 2025	(1,095)		(3,374)
Total convertible senior notes, net of unamortized debt discount and debt issuance costs	$	374,333	$	226,581

The following table sets forth total interest expense recognized related to the 2025 and 2029 Notes (in thousands):


	Three Months Ended March 31,
	2022		2021
Contractual interest expense	$	1,843	$	1,725
Amortization of debt discount	—		2,511
Amortization of debt issuance costs	337		225
Total interest expense for the 2025 and 2029 Notes	$	2,180	$	4,461

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

ACCRUED EXPENSES (Tables)

3 Months Ended

Mar. 31, 2022

Payables and Accruals [Abstract]

Schedule of accrued expenses

Accrued expenses at March 31, 2022 and December 31, 2021 consisted of the following (in thousands):


	March 31, 2022		December 31, 2021
Compensation related costs	$	23,408	$	25,998
Research and development	22,058		26,841
Government rebates payable	9,351		7,493
Accrued royalties and contingent consideration	6,694		8,402
Selling, general and administrative	5,349		3,144
Miscellaneous accrued expenses	2,380		3,302

Total accrued expenses	$	69,240	$	75,180

NET LOSS PER COMMON SHARE (Tables)

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Schedule of basic and diluted net loss per share

Basic and diluted net loss per share is calculated as follows (net loss amounts are stated in thousands):


	Three Months Ended March 31,
	2022					2021
	Shares	Net Loss		Loss per common share		Shares	Net Loss		Loss per common share
Basic and diluted loss per share	63,132,841	$	(75,971)	$	(1.20)	56,268,508	$	(53,867)	$	(0.96)

Schedule of common stock options, convertible debt and restricted stock units anti-dilutive

The following common stock equivalents have been excluded because they were anti-dilutive:


	Three Months Ended March 31,
	2022	2021
Options	9,864,889	9,228,627
Convertible debt	8,336,091	7,113,402
Restricted stock	1,900,016	1,637,072

Total anti-dilutive shares	20,100,996	17,979,101

SHARE-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2022

Equity [Abstract]

Schedule of stock option issuances and balances outstanding

The following table summarizes stock option activity during the three months ended March 31, 2022:


	Shares Underlying Options	Weighted Average Exercise Price	Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2021	8,886,284	$20.26	6.27	$	96,577
Granted	1,447,270	27.65
Exercised	(7,576)	16.11
Forfeited/canceled	(30,932)	24.09
Outstanding at March 31, 2022	10,295,046	$21.29	6.51	$	54,540

Schedule of service based restricted stock activity

The following table summarizes the Company’s service based restricted stock unit activity during the three months ended March 31, 2022:


	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2021	1,473,949	$	21.88
Granted	817,118	27.49
Vested	(292,103)	22.29
Forfeited/canceled	(15,471)	23.11
Unvested March 31, 2022	1,983,493	$	24.12

Schedule of performance based restricted stock activity

The following table summarizes the Company’s performance based restricted stock unit activity during the three months ended March 31, 2022:


	Number of Restricted Stock Units	Weighted Average Grant Date Fair Value
Unvested December 31, 2021	52,500	$	18.73
Granted	117,208	27.50
Vested	(17,500)	25.26
Forfeited/canceled	—	—
Unvested March 31, 2022	152,208	$	24.73

Schedule of share based compensation expenses

The following table sets forth total share-based compensation for the three months ended March 31, 2022 and 2021 (in thousands):


	Three Months Ended March 31,
	2022		2021
Research and development	$	3,168	$	3,002
Selling, general & administrative	5,018		4,692
Total	$	8,186	$	7,694

INVENTORY (Tables)

3 Months Ended

Mar. 31, 2022

Inventory Disclosure [Abstract]

Schedule of inventory

Inventory, net of reserves, consisted of the following at March 31, 2022 and December 31, 2021 (in thousands):


	March 31, 2022		December 31, 2021
Raw materials	$	4,964	$	5,205
Finished goods	1,557		2,108
Total inventory	$	6,521	$	7,313

BASIS OF PRESENTATION AND SIGNIFICANT ACCCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Jan. 01, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity	$ 208,141		$ 302,112	$ 362,689	$ 211,213
Additional paid-in capital	(1,021,542)		(1,068,634)
Reduction in accumulated deficit	$ (811,712)		(765,966)
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity			$ (44,720)
Cumulative Effect, Period of Adoption, Adjustment \| Accounting Standards Update 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Convertible notes payable		$ 44,700
Additional paid-in capital		74,900
Reduction in accumulated deficit		$ 30,200

- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

+ References + Details

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

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+ Details

REVENUE RECOGNITION - Additional Information (Details) - Geographic Concentration Risk - Revenue Benchmark	3 Months Ended
	Mar. 31, 2022
United States
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	98.00%
Canada
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	2.00%
Rest of World
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	1.00%

REVENUE RECOGNITION - Net Product Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 48,487	$ 47,407
Bile acid products
Disaggregation of Revenue [Line Items]
Total revenue	25,075	21,964
Tiopronin products
Disaggregation of Revenue [Line Items]
Total revenue	21,368	25,443
Net product sales
Disaggregation of Revenue [Line Items]
Total revenue	$ 46,443	$ 47,407

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

COLLABORATION AND LICENSE AGREEMENTS (Details) $ in Thousands		1 Months Ended	3 Months Ended
	Sep. 15, 2021 USD ($) performanceObligation	Feb. 28, 2021	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			$ 48,487	$ 47,407
Deferred revenue, current portion			14,229		$ 16,268
License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			2,044	$ 0
Albireo Pharma, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Co-promotion agreement, term		2 years
Co-promotion agreement, period after which the agreement can be terminated		1 year
Co-promotion agreement, amount recognized			800
Collaborative Arrangement \| Vifor Pharma
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment	$ 55,000
Maximum milestone payments	$ 845,000
Percentage of royalty on net sales receives	40.00%
Revenue	$ 55,000
Number of performance obligations \| performanceObligation	2
Deferred revenue	$ 43,000		33,900
Deferred revenue, current portion			14,200
Collaborative Arrangement \| Vifor Pharma \| Regulatory and Market Access Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments	135,000
Collaborative Arrangement \| Vifor Pharma \| Sales-based Milestone Payments
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments	$ 655,000
Collaborative Arrangement \| Vifor Pharma \| License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			$ 12,000

MARKETABLE DEBT SECURITIES - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Proceeds from sale of debt securities	$ 64,700
Purchase of debt securities	26,300
Available-for-sale marketable debt securities in an unrealized loss position	$ 323,500	$ 381,200

MARKETABLE DEBT SECURITIES - Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	$ 346,818	$ 387,129
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	115,345	127,379
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	216,010	233,319
Securities of government sponsored entities
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	$ 15,463	$ 26,431

MARKETABLE DEBT SECURITIES - Available for Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	$ 273,699	$ 262,345
Marketable debt securities, available for sale, unrealized gain, current	3	0
Marketable debt securities, available for sale, unrealized loss, current	(605)	(159)
Marketable debt securities, available-for-sale, current	273,097	262,186
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	74,793	125,254
Marketable debt securities, available for sale, unrealized gain, noncurrent	0	0
Marketable debt securities, available for sale, unrealized loss, noncurrent	(1,072)	(311)
Marketable debt securities, available-for-sale, noncurrent	73,721	124,943
Marketable debt securities, available-for-sale, amortized cost	348,492	387,599
Marketable debt securities, available for sale, unrealized gains	3	0
Marketable debt securities, available-for-sale, unrealized gain (loss)	(1,677)	(470)
Total available-for-sale marketable debt securities	346,818	387,129
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	115,467	127,435
Marketable debt securities, available for sale, unrealized gain, current	0	0
Marketable debt securities, available for sale, unrealized loss, current	(122)	(57)
Marketable debt securities, available-for-sale, current	115,345	127,378
Total available-for-sale marketable debt securities	115,345	127,379
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	145,227	113,001
Marketable debt securities, available for sale, unrealized gain, current	3	0
Marketable debt securities, available for sale, unrealized loss, current	(447)	(97)
Marketable debt securities, available-for-sale, current	144,783	112,904
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	72,250	120,705
Marketable debt securities, available for sale, unrealized gain, noncurrent	0	0
Marketable debt securities, available for sale, unrealized loss, noncurrent	(1,023)	(289)
Marketable debt securities, available-for-sale, noncurrent	71,227	120,416
Total available-for-sale marketable debt securities	216,010	233,319
Securities of government sponsored entities
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	13,005	21,909
Marketable debt securities, available for sale, unrealized gain, current	0	0
Marketable debt securities, available for sale, unrealized loss, current	(36)	(5)
Marketable debt securities, available-for-sale, current	12,969	21,904
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	2,543	4,549
Marketable debt securities, available for sale, unrealized gain, noncurrent	0	0
Marketable debt securities, available for sale, unrealized loss, noncurrent	(49)	(22)
Marketable debt securities, available-for-sale, noncurrent	2,494	4,527
Total available-for-sale marketable debt securities	$ 15,463	$ 26,431

MARKETABLE DEBT SECURITIES - Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 309,773	$ 380,690
Less than 12 months, unrealized losses	1,652	470
12 months or greater, fair value	12,033	0
12 months or greater, unrealized losses	25	0
Total, fair value	321,806	380,690
Total, unrealized losses	1,677	470
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	115,345	122,380
Less than 12 months, unrealized losses	122	57
12 months or greater, fair value	0	0
12 months or greater, unrealized losses	0	0
Total, fair value	115,345	122,380
Total, unrealized losses	122	57
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	188,966	231,879
Less than 12 months, unrealized losses	1,445	386
12 months or greater, fair value	12,033	0
12 months or greater, unrealized losses	25	0
Total, fair value	200,999	231,879
Total, unrealized losses	1,470	386
Securities of government-sponsored entities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	5,462	26,431
Less than 12 months, unrealized losses	85	27
12 months or greater, fair value	0	0
12 months or greater, unrealized losses	0	0
Total, fair value	5,462	26,431
Total, unrealized losses	$ 85	$ 27

VARIABLE INTEREST ENTITIES (Details) - USD ($) $ in Thousands	Mar. 08, 2022	Mar. 31, 2022	Dec. 31, 2021
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash and cash equivalents		$ 256,572	$ 165,753
Collaborative Arrangement \| PharmaKrysto, LTD
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Colllaboration agreement payment	$ 400
Research and development expenses, estimated	5,000
Collaborative arrangement, option to purchase additional shares of VIE, amount	1,000
Collaborative arrangement, option to purchase remaining shares of VIE, amount	5,000
Milestone payments contingently due	$ 16,000
Royalty payments, percentage (less than)	4.00%
Agreement termination notice period		60 days
Percentage of research and development to be funded by the company	100.00%
PharmaKrysto, LTD
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Payment to purchase interest in VIE	$ 600
Percentage ownership purchased	5.00%
PharmaKrysto, LTD \| Variable Interest Entity, Not Primary Beneficiary
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash and cash equivalents		$ 400
Accrued liabilities		$ 400
PharmaKrysto, LTD \| Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional ownership interest to be purchased upon achievement of certain milestones	5.00%

LEASES - Additional Information (Details) $ in Thousands	3 Months Ended
LEASES - Additional Information (Details) $ in Thousands	Mar. 31, 2022 USD ($) lease	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Apr. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right of use assets	$ 22,557		$ 23,196
Lease liability	34,453
Operating lease extension term					5 years
Aggregate base rent					$ 49,500
Operating lease expense	$ 1,200	$ 1,200
Office Lease 2020
Lessee, Lease, Description [Line Items]
Operating lease right of use assets				$ 34,600
Lease liability				34,500
Lease incentive, tenant improvements				$ 7,900
Kilroy Realty, L.P.
Lessee, Lease, Description [Line Items]
Number of operating leases \| lease	1

LEASES - Future Minimum Rent Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Leases [Abstract]
2022	$ 4,525
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	42,224
Present value discount	(7,771)
Total lease liability	34,453
Unamortized lease incentives	(6,313)
Cash payments in excess of straight-line lease expense	(5,583)
Total ROU asset	$ 22,557	$ 23,196

FAIR VALUE MEASUREMENTS - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) business	Mar. 31, 2021 USD ($)
Business Acquisition [Line Items]
Number of businesses acquired \| business	2
Change in fair value of contingent consideration	$ 9,080	$ 8,587
Senior Notes Due 2025 \| Senior Notes
Business Acquisition [Line Items]
Interest rate percentage	2.50%
Fair value of convertible debt	$ 69,600
Senior Notes Due 2029 \| Senior Notes
Business Acquisition [Line Items]
Interest rate percentage	2.25%
Fair value of convertible debt	$ 332,300

FAIR VALUE MEASUREMENTS - Discount Rates Used (Details)	Mar. 31, 2022	Dec. 31, 2021
Payment Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0824	0.0648
Cholbam \| Revenue Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0650	0.0625
Chenodal \| Revenue Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0700	0.0725

FAIR VALUE MEASUREMENTS - Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets:
Cash and Cash Equivalents	$ 256,572	$ 165,753
Debt securities, available-for-sale	346,818	387,129
Total	603,390	552,882
Liabilities:
Business combination-related contingent consideration	73,500	67,100
Total	73,500	67,100
Quoted prices in active markets (Level 1)
Assets:
Cash and Cash Equivalents	256,572	165,753
Debt securities, available-for-sale	0	0
Total	256,572	165,753
Liabilities:
Business combination-related contingent consideration	0	0
Total	0	0
Significant other observable inputs (Level 2)
Assets:
Cash and Cash Equivalents	0	0
Debt securities, available-for-sale	346,818	387,129
Total	346,818	387,129
Liabilities:
Business combination-related contingent consideration	0	0
Total	0	0
Significant unobservable inputs (Level 3)
Assets:
Cash and Cash Equivalents	0	0
Debt securities, available-for-sale	0	0
Total	0	0
Liabilities:
Business combination-related contingent consideration	73,500	67,100
Total	$ 73,500	$ 67,100

FAIR VALUE MEASUREMENTS - Acquisition-related Contingent Consideration (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 67,100
Changes in the fair value of contingent consideration	9,080
Contractual payments	0
Contractual payments included in accrued liabilities at March 31, 2022	(2,680)
Ending balance	$ 73,500

INTANGIBLE ASSETS - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Payments to date under terms of licensing agreement	$ 5,136	$ 4,775
Net book value of amortizable intangible assets	152,385		$ 147,499
Goodwill	900		$ 900
Ligand License Agreement
Finite-Lived Intangible Assets [Line Items]
Substantial payments payable upon achievement of milestones	114,100
Payments to date under terms of licensing agreement	$ 15,000
Ligand License Agreement \| Minimum
Finite-Lived Intangible Assets [Line Items]
Annual royalty percentage	15.00%
Ligand License Agreement \| Maximum
Finite-Lived Intangible Assets [Line Items]
Annual royalty percentage	17.00%

INTANGIBLE ASSETS - Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived intangible assets	$ 295,175	$ 283,557
Less: accumulated amortization	(142,790)	(136,058)
Net carrying value	$ 152,385	$ 147,499

INTANGIBLE ASSETS - Amortization (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 6,556	$ 5,952
Research and development
Finite-Lived Intangible Assets [Line Items]
Total amortization expense	286	286
Selling, general and administrative
Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 6,270	$ 5,666

CONVERTIBLE NOTES PAYABLE - Schedule of Carrying Amount of Debt (Details) - Senior Notes - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Unamortized debt discount	$ 0	$ (46,045)
Total convertible senior notes, net of unamortized debt discount and debt issuance costs	$ 374,333	226,581
Senior Notes Due 2029
Debt Instrument [Line Items]
Interest rate percentage	2.25%
Convertible senior notes	$ 316,250	0
Unamortized debt issuance costs	$ (9,726)	0
Senior Notes Due 2025
Debt Instrument [Line Items]
Interest rate percentage	2.50%
Convertible senior notes	$ 68,904	276,000
Unamortized debt issuance costs	$ (1,095)	$ (3,374)

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details

CONVERTIBLE NOTES PAYABLE - Additional Information (Details) $ / shares in Units, $ in Thousands			3 Months Ended
	Mar. 11, 2022 USD ($)	Sep. 10, 2018 USD ($)	Mar. 31, 2022 USD ($) $ / shares	Mar. 31, 2022 USD ($) $ / shares	Mar. 31, 2022 USD ($) business $ / shares	Mar. 31, 2022 USD ($) d $ / shares	Mar. 31, 2022 USD ($) day $ / shares	Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Debt instrument, repurchase amount Including accrued and unpaid interest	$ 213,800
Loss on early extinguishment of debt			$ 7,578					$ 0
Write off of deferred debt financing costs			$ 3,400
Senior Notes \| Senior Notes Due 2029
Debt Instrument [Line Items]
Long-term debt, excluding current maturities	316,300
Interest rate percentage			2.25%	2.25%	2.25%	2.25%	2.25%
Proceeds from issuance of debt	306,400
Debt issuance costs, net	9,800		$ 9,800	$ 9,800	$ 9,800	$ 9,800	$ 9,800
Accrued interest			$ 400	$ 400	$ 400	$ 400	$ 400
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Conversion ratio				0.001374
Conversion price (in dollars per share) \| $ / shares			$ 31.87	$ 31.87	$ 31.87	$ 31.87	$ 31.87
Notes payable			$ 100,000	$ 100,000	$ 100,000	$ 100,000	$ 100,000
Long-term debt, term			7 years	7 years	7 years	7 years	7 years
Effective interest percentage			2.74%	2.74%	2.74%	2.74%	2.74%
Senior Notes \| Senior Notes Due 2029 \| Debt Conversion, Scenario One
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days					20	20
Debt instrument, convertible, threshold consecutive trading days \| d						30
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Senior Notes \| Senior Notes Due 2029 \| Debt Conversion, Scenario Two
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| business					5
Debt instrument, convertible, threshold consecutive trading days \| business					10
Debt instrument, convertible, threshold percentage of stock price trigger				98.00%
Senior Notes \| Senior Notes Due 2029, Issued Pursuant to Underwriters Option
Debt Instrument [Line Items]
Long-term debt, excluding current maturities	41,300
Senior Notes \| Senior Notes Due 2025
Debt Instrument [Line Items]
Long-term debt, excluding current maturities		$ 276,000
Interest rate percentage			2.50%	2.50%	2.50%	2.50%	2.50%
Proceeds from issuance of debt		267,200
Debt issuance costs, net		$ 8,800
Accrued interest			$ 100	$ 100	$ 100	$ 100	$ 100
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Conversion ratio				0.0257739
Conversion price (in dollars per share) \| $ / shares			$ 38.80	$ 38.80	$ 38.80	$ 38.80	$ 38.80
Long-term debt, term			7 years	7 years	7 years	7 years	7 years
Effective interest percentage			2.98%	2.98%	2.98%	2.98%	2.98%
Debt instrument, repurchase amount	$ 207,100
Long-term debt, excluding current maturities, repaid if converted			$ 68,900	$ 68,900	$ 68,900	$ 68,900	$ 68,900
Senior Notes \| Senior Notes Due 2025 \| Debt Conversion, Scenario One
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| d						20
Debt instrument, convertible, threshold consecutive trading days \| d						30
Debt instrument, convertible, threshold percentage of stock price trigger				130.00%
Senior Notes \| Senior Notes Due 2025 \| Debt Conversion, Scenario Two
Debt Instrument [Line Items]
Debt instrument, convertible, threshold trading days \| day							5
Debt instrument, convertible, threshold consecutive trading days \| day							10
Debt instrument, convertible, threshold percentage of stock price trigger				98.00%

CONVERTIBLE NOTES PAYABLE - Schedule of Interest Expense (Details) - Senior Notes - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Senior Notes Due 2025
Debt Instrument [Line Items]
Contractual interest expense	$ 1,843	$ 1,725
Amortization of debt discount	0	2,511
Amortization of debt issuance costs	337	225
Total interest expense for the 2025 and 2029 Notes	2,180	4,461
Senior Notes Due 2029
Debt Instrument [Line Items]
Contractual interest expense	1,843	1,725
Amortization of debt discount	0	2,511
Amortization of debt issuance costs	337	225
Total interest expense for the 2025 and 2029 Notes	$ 2,180	$ 4,461

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Compensation related costs	$ 23,408	$ 25,998
Research and development	22,058	26,841
Government rebates payable	9,351	7,493
Accrued royalties and contingent consideration	6,694	8,402
Selling, general and administrative	5,349	3,144
Miscellaneous accrued expenses	2,380	3,302
Total accrued expenses	$ 69,240	$ 75,180

NET LOSS PER COMMON SHARE - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Basic shares outstanding (in shares)	63,132,841	56,268,508
Diluted shares outstanding (in shares)	63,132,841	56,268,508
Net loss (Basic)	$ (75,971)	$ (53,867)
Net loss (Diluted)	$ (75,971)	$ (53,867)
Basic net loss per common share (in dollars per share)	$ (1.20)	$ (0.96)
Diluted net loss per common share (in dollars per share)	$ (1.20)	$ (0.96)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

+ References + Details

NET LOSS PER COMMON SHARE - Antidilutive Shares (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total anti-dilutive shares
Anti-dilutive shares excluded from the calculation (in shares)	20,100,996	17,979,101
Options
Total anti-dilutive shares
Anti-dilutive shares excluded from the calculation (in shares)	9,864,889	9,228,627
Convertible debt
Total anti-dilutive shares
Anti-dilutive shares excluded from the calculation (in shares)	8,336,091	7,113,402
Restricted stock
Total anti-dilutive shares
Anti-dilutive shares excluded from the calculation (in shares)	1,900,016	1,637,072

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Loss Contingencies [Line Items]
Total revenue	$ 48,487	$ 47,407
Kolbam \| FRANCE
Loss Contingencies [Line Items]
Total revenue	$ 8,000

- Definition

+ References

+ Details

SHARE-BASED COMPENSATION - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Weighted Average Exercise Price
Number of shares exercisable (in shares)	6,600,000
Weighted average exercise price (in dollars per share)	$ 19.76
Stock Options
Shares Underlying Options
Beginning balance (in shares)	8,886,284
Granted (in shares)	1,447,270
Exercised (in shares)	(7,576)
Forfeited/canceled (in shares)	(30,932)
Ending balance (in shares)	10,295,046	8,886,284
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 20.26
Granted (in dollars per share)	27.65
Exercised (in dollars per share)	16.11
Forfeited/canceled (in dollars per share)	24.09
Ending balance (in dollars per share)	$ 21.29	$ 20.26
Weighted Average Remaining Contractual Life (years)	6 years 6 months 3 days	6 years 3 months 7 days
Aggregate Intrinsic Value	$ 54,540	$ 96,577
Unamortized stock compensation expense	$ 44,700
Weighted-average recognition period (in years)	2 years 10 months 24 days

SHARE-BASED COMPENSATION - Service Based Restricted Stock Activity (Details) - Restricted stock units $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) $ / shares shares
Number of Restricted Stock Units
Beginning balance (in shares) \| shares	1,473,949
Granted (in shares) \| shares	817,118
Vested (in shares) \| shares	(292,103)
Forfeited/canceled (in shares) \| shares	(15,471)
Ending balance (in share) \| shares	1,983,493
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share) \| $ / shares	$ 21.88
Granted (in dollars per share) \| $ / shares	27.49
Vested (in dollars per share) \| $ / shares	22.29
Forfeited/canceled (in dollars per share) \| $ / shares	23.11
Ending balance (in dollars per share) \| $ / shares	$ 24.12
Unamortized stock compensation expense \| $	$ 42.1
Weighted-average recognition period (in years)	2 years 9 months 18 days

SHARE-BASED COMPENSATION - Performance Based Restricted Stock Activity (Details) - Performance Shares $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) $ / shares shares
Number of Restricted Stock Units
Beginning balance (in shares) \| shares	52,500
Granted (in shares) \| shares	117,208
Vested (in shares) \| shares	(17,500)
Forfeited/canceled (in shares) \| shares	0
Ending balance (in share) \| shares	152,208
Weighted Average Grant Date Fair Value
Beginning balance (in dollars per share) \| $ / shares	$ 18.73
Granted (in dollars per share) \| $ / shares	27.50
Vested (in dollars per share) \| $ / shares	25.26
Forfeited/canceled (in dollars per share) \| $ / shares	0
Ending balance (in dollars per share) \| $ / shares	$ 24.73
Unamortized stock compensation expense \| $	$ 3.1
Weighted-average recognition period (in years)	1 year 10 months 24 days

SHARE-BASED COMPENSATION - Stock based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 8,186	$ 7,694
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,168	3,002
Selling, general & administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,018	$ 4,692

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended
INCOME TAXES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 52	$ 313

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

INVENTORY - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 4,964	$ 5,205
Finished goods	1,557	2,108
Total inventory	$ 6,521	$ 7,313

INVENTORY - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Inventory reserve	$ 4.1	$ 4.1

ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Receivables [Abstract]
Accounts receivable, net	$ 14,675	$ 15,914

EQUITY OFFERINGS (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2021	Mar. 31, 2022	Dec. 31, 2021	May 18, 2021	May 17, 2021	Feb. 29, 2020
Class of Stock [Line Items]
Common stock shares authorized (in shares)		200,000,000	200,000,000	200,000,000	100,000,000
Underwritten Equity Offering
Class of Stock [Line Items]
Shares authorized in sale (in shares)	7,500,000
Sales price per share (in dollars per share)	$ 26.75
Proceeds from the issuance of common stock, net of issuance costs	$ 189.3
At-The-Market Offering
Class of Stock [Line Items]
Shares authorized in sale (in shares)		701,600
Proceeds from the issuance of common stock, net of issuance costs		$ 20.1
Aggregate offering amount authorized						$ 100.0
Remaining offering amount authorized		19.5
At-The-Market Offering Under Previous Registration Statement
Class of Stock [Line Items]
Amount sold to date		28.6
At-The-Market Offering Under Current Registration Statement
Class of Stock [Line Items]
Amount sold to date		$ 51.9