0001438533-22-000008 | 10-K | XBRL Viewer

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CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 165,753	$ 84,772
Marketable debt securities, at fair value	387,129	276,817
Accounts receivable, net	15,914	15,925
Inventory, net	7,313	7,608
Tax receivable	247	17,142
Prepaid expenses and other current assets	6,471	8,143
Total current assets	582,827	410,407
Property and equipment, net	11,106	9,418
Operating lease right of use assets	23,196	25,675
Intangible assets, net	148,435	154,125
Other assets	11,069	7,814
Total assets	776,633	607,439
Current liabilities:
Accounts payable	15,144	12,133
Accrued expenses	75,180	56,793
Deferred revenue, current portion	16,268	0
Business combination-related contingent consideration	7,400	17,400
Operating lease liabilities, current portion	3,908	357
Other current liabilities	6,188	5,977
Total current liabilities	124,088	92,660
Convertible debt	226,581	215,339
Deferred revenue, less current portion	20,379	0
Business combination-related contingent consideration, less current portion	59,700	47,700
Operating lease liabilities, less current portion	31,497	28,336
Other non-current liabilities	12,276	12,191
Total liabilities	474,521	396,226
Commitments and Contingencies (See Note 11)
Stockholders' Equity:
Preferred stock $0.0001 par value; 20,000,000 shares authorized; 0 issued and outstanding as of December 31, 2021 and 2020, respectively	0	0
Common stock $0.0001 par value; 200,000,000 shares authorized; 62,491,498 and 52,248,431 issued and outstanding as of December 31, 2021 and 2020, respectively	6	5
Additional paid-in capital	1,068,634	797,985
Accumulated deficit	(765,966)	(585,875)
Accumulated other comprehensive loss	(562)	(902)
Total stockholders' equity	302,112	211,213
Total liabilities and stockholders' equity	$ 776,633	$ 607,439

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD 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 USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	100,000,000
Common stock, shares issued (in shares)	62,491,498	52,248,431
Common stock, shares outstanding (in shares)	62,491,498	52,248,431

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Total revenue	$ 227,490	$ 198,321	$ 175,338
Operating expenses:
Cost of goods sold	6,784	6,126	5,234
Research and development	210,328	131,773	140,963
Selling, general and administrative	149,883	135,799	128,951
Change in fair value of contingent consideration	22,260	3,655	15,051
Impairment of L-UDCA IPR&D intangible asset	0	0	25,500
Write off of L-UDCA contingent consideration	0	0	(18,000)
Acquired IPR&D expense	0	97,131	0
Impairment of long-term investment	0	0	15,000
Total operating expenses	389,255	374,484	312,699
Operating loss	(161,765)	(176,163)	(137,361)
Other Income (expense), net:
Interest income	1,993	5,003	10,055
Interest expense	(20,141)	(19,050)	(18,828)
Other income (expense), net	231	1,420	(314)
Total other expense, net	(17,917)	(12,627)	(9,087)
Loss before (provision) benefit for income taxes	(179,682)	(188,790)	(146,448)
Income tax (provision) benefit	(409)	19,359	21
Net loss	$ (180,091)	$ (169,431)	$ (146,427)
Basic (in USD per share)	$ (3.01)	$ (3.56)	$ (3.46)
Diluted (in USD per share)	$ (3.01)	$ (3.56)	$ (3.46)
Basic weighted average common shares outstanding (in shares)	59,832,287	47,539,631	42,339,961
Diluted weighted average common shares outstanding (in shares)	59,832,287	47,539,631	42,339,961
Comprehensive loss:
Net loss	$ (180,091)	$ (169,431)	$ (146,427)
Foreign currency translation gain (loss)	1,515	(1,452)	92
Unrealized (loss) gain on debt securities	(1,175)	(176)	2,163
Comprehensive loss	(179,751)	(171,059)	(144,172)
Net product sales
Total revenue	210,776	198,321	175,338
License and collaboration revenue
Total revenue	$ 16,714	$ 0	$ 0

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Underwritten Equity Offering	At-The-Market Offering	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	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018				41,389,524
Beginning balance at Dec. 31, 2018	$ 318,253			$ 4			$ 589,795			$ (1,529)	$ (270,017)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based compensation	20,463						20,463
Unrealized gain/(loss) on marketable debt securities	2,163									2,163
Foreign currency translation adjustments	92									92
Issuance of common shares under the equity incentive plan and proceeds from exercise (in shares)				272,730
Issuance of common shares under the equity incentive plan and proceeds from exercise.	1,618						1,618
Employee stock purchase program stock purchase and expense (in shares)				129,324
Employee stock purchase program stock purchase and expense	2,444						2,444
Convertible debt issue (in shares)				1,297,343
Convertible debt issue	22,590						22,590
Net loss	(146,427)										(146,427)
Ending balance (in shares) at Dec. 31, 2019				43,088,921
Ending balance at Dec. 31, 2019	221,196			$ 4			636,910			726	(416,444)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based compensation	22,733						22,733
Unrealized gain/(loss) on marketable debt securities	(176)									(176)
Foreign currency translation adjustments	(1,452)									(1,452)
Issuance of common shares under the equity incentive plan and proceeds from exercise (in shares)				649,075
Issuance of common shares under the equity incentive plan and proceeds from exercise.	3,895						3,895
Issuance of common stock (in shares)					7,475,000	867,806
Issuance of common stock, net of offering costs		$ 108,692	$ 22,828		$ 1			$ 108,691	$ 22,828
Employee stock purchase program stock purchase and expense (in shares)				167,629
Employee stock purchase program stock purchase and expense	2,928						2,928
Net loss	(169,431)										(169,431)
Ending balance (in shares) at Dec. 31, 2020				52,248,431
Ending balance at Dec. 31, 2020	211,213			$ 5			797,985			(902)	(585,875)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based compensation	29,862						29,862
Unrealized gain/(loss) on marketable debt securities	(1,175)									(1,175)
Foreign currency translation adjustments	1,515									1,515
Issuance of common shares under the equity incentive plan and proceeds from exercise (in shares)				1,302,966
Issuance of common shares under the equity incentive plan and proceeds from exercise.	12,841						12,841
Issuance of common stock (in shares)					7,532,500	1,240,640
Issuance of common stock, net of offering costs		$ 189,279	$ 35,656		$ 1			$ 189,278	$ 35,656
Employee stock purchase program stock purchase and expense (in shares)				166,961
Employee stock purchase program stock purchase and expense	3,012						3,012
Net loss	(180,091)										(180,091)
Ending balance (in shares) at Dec. 31, 2021				62,491,498
Ending balance at Dec. 31, 2021	$ 302,112			$ 6			$ 1,068,634			$ (562)	$ (765,966)

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Equity issuance costs	$ 12.2	$ 7.2

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities:
Net loss	$ (180,091)	$ (169,431)	$ (146,427)
Adjustments to reconcile net loss to net cash used in operating activities:
Share based compensation	30,766	23,614	21,105
Depreciation and amortization	26,617	24,579	20,408
Change in estimated fair value of contingent consideration	22,260	3,655	(2,948)
Payments from change in fair value of contingent consideration	(14,375)	(12,407)	(5,661)
Amortization of debt discount and deferred financing costs	11,242	10,478	9,903
Loss on allowance for inventory	2,110	2,225	1,468
Amortization of premiums (discounts) on investments	2,008	703	(788)
Acquired IPR&D expense	0	97,131	0
Impairment of intangible assets	0	0	25,500
Impairment of long-term investment	0	0	15,000
Other	4,692	2,752	1,602
Changes in operating assets and liabilities, net of asset acquisition:
Accounts receivable	(59)	2,301	(5,184)
Inventory	(1,815)	(5,067)	(1,958)
Prepaid expenses and other current assets	(1,438)	(4,314)	208
Tax receivable	17,099	(15,746)	555
Change in lease assets and liabilities, net	5,577	(1,203)	(4,854)
Accounts payable	2,770	(6,036)	9,255
Accrued expenses and other current liabilities	19,545	4,023	4,602
Deferred revenue, current and non-current	38,300	0	0
Net cash used in operating activities	(14,792)	(42,743)	(58,214)
Cash Flows from Investing Activities:
Purchase of fixed assets	(5,101)	(6,767)	(195)
Purchase of intangible assets	(19,050)	(17,799)	(15,370)
Proceeds from the sale/maturity of marketable debt securities	433,604	273,482	259,140
Purchase of marketable debt securities	(547,076)	(214,964)	(223,712)
Purchased IPR&D, net of cash acquired	0	(95,279)	0
Net cash (used in) provided by investing activities	(137,623)	(61,327)	19,863
Cash Flows from Financing Activities:
Payment of acquisition-related contingent consideration	(6,104)	(7,648)	(3,388)
Payment of guaranteed minimum royalty	(2,100)	(2,100)	(2,084)
Proceeds from exercise of stock options	12,841	3,895	1,618
Proceeds from the issuance of common stock under the employee stock purchase program	2,112	2,046	1,777
Net cash provided by (used in) financing activities	231,683	127,713	(2,077)
Effect of exchange rate changes on cash	1,713	(1,307)	(9)
Net increase (decrease) in cash and cash equivalents	80,981	22,336	(40,437)
Cash and cash equivalents, beginning of year	84,772	62,436	102,873
Cash and cash equivalents, end of year	165,753	84,772	62,436
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest	7,327	6,901	7,669
Cash refunded (paid) for income taxes	16,420	3,373	(656)
Non-cash Investing and financing activities:
Accrued royalty in excess of minimum payable to the sellers of Thiola	19,362	18,168	15,815
At-The-Market Offering
Cash Flows from Financing Activities:
Proceeds from issuance of common stock	35,656	22,828	0
Underwritten Equity Offering
Cash Flows from Financing Activities:
Proceeds from issuance of common stock	$ 189,278	$ 108,692	$ 0

DESCRIPTION OF BUSINESS	12 Months Ended
DESCRIPTION OF BUSINESS	Dec. 31, 2021
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 twelve months ended December 31, 2021, 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 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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

A summary of the significant accounting policies applied in the preparation of the accompanying consolidated financial statements follows:

Principles of Consolidation

The consolidated financial statements represent the consolidation of the accounts of the Company and its subsidiaries in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"). All intercompany accounts and transactions have been eliminated in consolidation.

Use of Estimates

In preparing financial statements in conformity with U.S. GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of expenses during the reporting period. Due to inherent uncertainty involved in making estimates, actual results reported in future periods may be affected by changes in these estimates. On an ongoing basis, the Company evaluates its estimates and assumptions. These estimates and assumptions include revenue recognition, forecasting probability-weighted cash flows based upon estimates of forecasted revenues, clinical and regulatory timelines and discount rates, valuing equity securities in share-based payments, estimating expenses of contracted research organizations, estimating the useful lives of depreciable and amortizable assets, goodwill impairment, estimating the fair value of contingent consideration, estimating of valuation allowances and uncertain tax positions, and estimates associated with the assessment of impairment for long-lived assets.

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 Costs

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 the all the factors set forth above and may fluctuate significantly from quarter to quarter.

Share-Based Compensation

The Company recognizes all employee share-based compensation as a cost in the financial statements. Equity-classified awards principally related to stock options, restricted stock units (“RSUs”) and performance stock units ("PSUs"), are measured at the grant date fair value of the award. The Company determines grant date fair value of stock option awards using the Black-Scholes option-pricing model. The fair value of RSUs and PSUs are determined using the closing price of the Company’s common stock on the grant date. For service based vesting grants, expense is recognized over the requisite service period based on the number of options or shares expected to ultimately vest. For PSUs, expense is recognized over the implicit service period, assuming vesting is probable. No expense is recognized for PSUs if it is not probable the vesting criteria will be satisfied. Forfeitures are accounted for as they occur.


	Expiration Term	Vesting Term
Stock Options	10 years	3 to 4 years
Restricted Stock Units	----	1 to 4 years

Earnings (Loss) Per Share

The Company calculates basic earnings per share by dividing net income/(loss) by the weighted average number of shares outstanding during the period. The diluted earnings/(loss) per share computation includes the effect, if any, of shares that would be issuable upon the exercise of outstanding stock options, derivative warrant liability, convertible debt and RSUs, reduced by the number of shares which are assumed to be purchased by the Company from the resulting proceeds at the average market price during the year, when such amounts are dilutive to the earnings per share calculation.

Cash and Cash Equivalents

The Company considers all highly liquid marketable securities with an original maturity of three months or less to be cash equivalents. Due to the short-term maturity of such investments, the carrying amounts are a reasonable estimate of fair value.

Concentration of Credit Risk

The Company maintains its cash and cash equivalents at insured financial institutions, the balances of which may, at times, exceed federally insured limits. Generally, these deposits may be redeemed upon demand, and the Company believes there is minimal risk of losses on such balances.

The Company monitors its investments with counterparties with the objective of minimizing concentrations of credit risk. The Company's investment policy is to invest only in institutions that meet high credit quality standards and established limits on the amount and time to maturity of investments with any individual counterparty. The policy also requires that investments are only entered into with corporate and financial institutions that meet high quality standards.

Marketable Debt Securities

The Company accounts for marketable debt securities held as “available-for-sale” in accordance with ASC 320, “Investments - Debt Securities” (“ASC 320”). The Company classifies these investments as current assets and carries them at fair value. Unrealized gains and losses on marketable debt securities are recorded as a separate component of stockholders’ equity as accumulated other comprehensive 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. Realized gains or losses on debt security transactions and declines in value that are determined to be the result of credit losses, if any, are reported in the Consolidated Statements of Operations and Comprehensive Loss. Marketable debt securities are maintained at one financial institution and are governed by the Company’s investment policy. See Note 6 for further discussion.

Trade Receivables, Net

Trade accounts receivable are recorded net of reserves for prompt pay discounts and expected credit losses. Estimates for allowances for credit losses are determined based on existing contractual obligations, historical payment patterns and individual customer circumstances. The allowance for credit losses was zero at both December 31, 2021 and 2020, respectively. For the years ended December 31, 2021, 2020 and 2019, bad debt expense recorded in the Consolidated Statements of Operations and Comprehensive Loss was 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.

Inventory, Related Reserves and Cost of Goods Sold

Inventory, which is recorded at the lower of cost or net realizable value, includes materials, labor, and other direct and indirect costs and is valued using the first-in, first-out method. The Company periodically analyzes its inventory levels to identify inventory that may expire prior to expected sale or has a cost basis in excess of its estimated realizable value, and writes down such inventory as appropriate. In addition, the Company's products are subject to strict quality control and monitoring which the Company’s manufacturers perform throughout their manufacturing process. The Company does not directly manufacture any product. The Company has single suppliers for products Chenodal and Thiola, and prospectively arranges for manufacture from contract service providers for its product Cholbam. The inventory reserve was $4.1 million and $3.6 million at December 31, 2021 and 2020, respectively.

Inventory, net of reserve, consisted of the following at December 31, 2021 and 2020 (in thousands):


	December 31, 2021		December 31, 2020
Raw material	$	5,205	$	3,219

Finished goods	2,108		4,389
Total inventory	$	7,313	$	7,608

Cost of goods sold includes the cost of inventory sold, third party manufacturing and supply chain costs, product shipping and handling costs, and provisions for excess and obsolete inventory.

Segment Information

The Company currently operates in one operating segment focused on the development and commercialization of innovative therapies for people with serious and life-threatening rare diseases and medical conditions. The Company is not organized by market and is managed and operated as one business. A single management team reports to the chief operating decision maker who comprehensively manages the entire business. The

Company does not operate any separate lines of business or separate business entities with respect to its products. Accordingly, the Company does not accumulate discrete financial information with respect to separate products, other than revenues, and does not have separately reportable segments.

Property and Equipment, net

Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed using the straight-line method over the related estimated useful lives as presented in the table below. Significant additions and improvements are capitalized, while repairs and maintenance are charged to expense as incurred. Property and equipment purchased for specific research and development projects with no alternative use is expensed as incurred.

The major classifications of property and equipment, including their respective expected useful lives, consist of the following:


Computers and equipment			3 years
Furniture and fixtures			7 years
Leasehold improvements			Shorter of length of lease or life of the asset

Leases

The Company determines whether a contract is, or contains, a lease at inception. The Company classifies each of its leases as operating or financing considering factors such as the length of the lease term, the present value of the lease payments, the nature of the asset being leased, and the potential for ownership of the asset to transfer during the lease term. Leases with terms greater than one year are recognized on the Consolidated Balance Sheets as Right-of-use assets and Lease liabilities and are measured at the present value of the fixed payments due over the expected lease term minus the present value of any incentives, rebates or abatements expected to be received from the lessor. Options to extend a lease are typically excluded from the expected lease term as the exercise of the option is typically not reasonably certain. The interest rate implicit in lease contracts is typically not readily determinable. As such, the Company utilizes the appropriate incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis an amount equal to the lease payments over a similar term and in a similar economic environment. The Company records expense to recognize fixed lease payments on a straight-line basis over the expected lease term. Costs determined to be variable and not based on an index or rate are not included in the measurement of the lease liability and are expensed as incurred.

Intangible Assets, Net

The Company's intangible assets consist of licenses and purchased technology. Intangible assets with definite lives are amortized on a straight-line basis over their estimated useful lives and are reviewed periodically for impairment.

Intangible assets related to in-process research and development (IPR&D) projects are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. During the period the assets are considered indefinite-lived, they will not be amortized but will be tested for impairment. If and when development is complete, which generally occurs when regulatory approval to market a product is obtained, the associated assets are deemed finite-lived and are amortized over a period that best reflects the economic benefits provided by these assets.

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 royalties in excess of the annual contractual minimum at December 31, 2021 as such royalties are not yet probable and estimable.

Goodwill

Goodwill represents the excess of purchase price over fair value of net assets acquired in a business combination and is not amortized. Goodwill is subject to impairment testing at least annually or when a triggering event occurs that could indicate a potential impairment. The Company has one segment and one reporting unit and as such reviews goodwill for impairment at the consolidated level.

For the years ended December 31, 2021, 2020 and 2019 there were no impairments to goodwill.

Impairment of Long-Lived Assets

The Company's long-lived assets are primarily comprised of intangible assets, right-of-use assets, and property and equipment. The Company evaluates its finite-lived intangible assets, right-of-use assets, and property and equipment for impairment whenever events or changes in circumstances indicate the carrying value of an asset or group of assets may not be recoverable. If these circumstances exist, recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset group to future undiscounted net cash flows expected to be generated by the use and eventual disposition of the asset group. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets.

In addition, indefinite-lived intangible assets, comprised of IPR&D, are reviewed for impairment annually and whenever events or changes in circumstances indicate that it is more likely than not that the asset is impaired by comparing the fair value to the carrying value of the asset. To determine the fair value of the asset, the Company used the multi-period excess earnings method of the income approach. The more significant assumptions inherent in the application of this method include: the amount and timing of projected future cash flows (including revenue, cost of sales, research and development costs, and sales and marketing expenses), and the discount rate selected to measure the risks inherent in the future cash flows.

There were no impairments related to finite-lived intangible assets in the years ended December 31, 2021, 2020 and 2019.

Contingent Consideration

The Company records contingent consideration resulting from a business combination at its fair value on the acquisition date. On a quarterly basis, the Company revalues these obligations and record increases or decreases from their fair value as an adjustment to the consolidated statement of operations. Changes to contingent consideration obligations can result from changes to discount rates, accretion of the liability due to the passage of time, changes in revenue forecasts and changes in our estimates of the likelihood or timing of achieving commercial revenue milestones.

Income Taxes

The Company follows ASC 740, Income Taxes, which requires recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Under this method, deferred tax assets and liabilities are based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance to the extent management concludes it is more likely than not that the asset will not be realized.

The standard addresses the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the financial statements. Under ASC 740, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position should be measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. ASC 740 also provides guidance on de-recognition, classification, interest and penalties on income taxes, accounting in interim periods and requires increased disclosures. The Company’s policy is to record estimated interest and penalty related to the underpayment of income taxes or unrecognized tax benefits as a component of its income tax provision.

Foreign Currency Translation

Functional and presentation currency

Items included in the financial statements of each entity comprising the Company are measured using the currency of the primary economic environment in which the entity operates (the functional currency).

Transactions and balances

Foreign currency transactions in each entity comprising the Company are remeasured into the functional currency of the entity using the exchange rates prevailing at the respective transaction dates. Foreign exchange gains and losses resulting from the settlement of such transactions and from the remeasurement at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized within Other operating expense, net except for changes related to the liability related to the sale of future royalties which are recorded in Other non-operating (income) expense, net in the Consolidated Statements of Operations and Comprehensive Loss.

The results and financial position of the Company that have a functional currency different from the US dollar are translated as follows:

a.assets and liabilities presented are translated at the closing exchange rate as of December 31, 2021 and 2020;

b.income and expenses for the statements of operations and comprehensive loss are translated at average exchange rates that are relevant for the respective periods for which the income and expenses occurred; and

c.significant transactions use the exchange rate on the date of the transaction;

All resulting exchange differences arising from such translations are recognized directly in comprehensive income and presented as a separate component of equity.

Reclassifications

Certain reclassifications have been made to the prior year financial statements in order to conform to the current year’s presentation, including reclassifying operating lease right of use assets and operating lease liabilities from other assets and other liabilities, respectively on the Consolidated Balance Sheets. These reclassifications did not have an impact on total assets or total liabilities of the Consolidated Balance Sheets.

Patents

The Company expenses external costs, such as filing fees and associated attorney fees, incurred to obtain issued patents and patent applications pending. The Company also expenses costs associated with maintaining and defending patents subsequent to their issuance in the period incurred.

Legal Contingencies

The Company may, from time to time, be involved in various claims and legal actions that arise in the ordinary course of business. The Company accrues for legal contingencies when it is determined probable that a liability has been incurred and the amount of the loss can be reasonably estimated. See Note 11 for further discussion.

Recently Issued Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board ("FASB") or other standard setting bodies. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its consolidated financial position or results of operations upon adoption.

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 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 new standard will impact the Company's accounting for its Convertible Senior Notes Due 2025 (2025 Notes), discussed in Note 7, which are currently accounted for using the cash conversion model applied under ASC 470-20, Debt with Conversion and Other Options ("ASC 470-20"). Under the new guidance, the Company intends to apply the modified retrospective method as the transition approach at adoption, which will result in adjustments to the January 1, 2022 opening balances of convertible debt, additional paid-in capital, and accumulated deficit. Additionally, from January 1, 2022, the Company will no longer incur non-cash interest expense for the amortization of debt discount resulting in lower interest expense for the 2025 Notes.

REVENUE RECOGNITION

12 Months Ended

Dec. 31, 2021

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 United States and Canada representing 98% and 2% of net product sales, respectively, 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 its 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 the 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 accrued expenses 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 accrued expenses 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 twelve months ended December 31, 2021, 2020 and 2019 (in thousands):


	Twelve Months Ended December 31,
	2021		2020		2019
Tiopronin products	$	115,122	$	108,883	$	95,638
Bile acid products	95,654		89,438		79,700
Total net product revenue	$	210,776	$	198,321	$	175,338

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130550-203045

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

+ Details

COLLABORATION AND LICENSE AGREEMENTS	12 Months Ended
COLLABORATION AND LICENSE AGREEMENTS	Dec. 31, 2021
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 ("ASC 808") 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 the license has stand-alone functionality due to sparsentan being a later stage asset and the clinical development services are primarily related to achieving regulatory approval. 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. 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 a total of $16.7 million in license and collaboration revenue for the twelve months ended December 31, 2021, which consisted of $12.0 million from the license and $4.7 million from the clinical development activities, based upon the ratio of costs incurred to total estimated costs. Deferred revenue related to the clinical development activities as of December 31, 2021 was $36.6 million. Of this amount, $16.3 million was classified as current as of December 31, 2021, based upon amount 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 dedicate 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 year ended December 31, 2021, the Company recognized $1.8 million, offset against selling, general, and administrative expenses.

ACQUISITIONS	12 Months Ended
ACQUISITIONS	Dec. 31, 2021
Business Combination and Asset Acquisition [Abstract]
ACQUISITIONS	ACQUISITIONS Acquisition of Orphan Technologies Limited In November 2020, the Company completed the acquisition of Orphan Technologies Limited (“Orphan”), including Orphan’s rare metabolic disorder drug pegtibatinase (TVT-058). The Company acquired Orphan by purchasing all of the outstanding shares. In exchange for the shares, the Company made an upfront cash payment at closing of $90.0 million plus closing adjustments, net liabilities assumed, and transaction expenses of $1.2 million, $1.8 million, and $4.2 million, respectively. Under the Agreement, the Company has also agreed to make contingent cash payments up to an aggregate of $427.0 million based on the achievement of certain development, regulatory and commercialization events as set forth in the Agreement, as well as additional tiered mid-single digit royalty payments based upon future net sales of any pegtibatinase products in the US and Europe, subject to certain reductions as set forth in the Agreement, and a contingent payment in the event a pediatric rare disease voucher for any pegtibatinase product is granted. The Company applied the principles of ASC 805 in determining the proper accounting treatment for the acquisition. Substantially all of the value of the assets acquired was concentrated within pegtibatinase, and as of the acquisition date, the Company did not anticipate any economic benefit to be derived from pegtibatinase other than the primary indication. Accordingly, the transaction was treated as an asset acquisition with amounts charged to expense for the acquired in-process research and development on the date of acquisition. The Company incurred $97.1 million in expenses related to the Orphan acquisition, which was recognized in 2020. In accordance with ASC 450, contingent cash payments will be accrued for when it is probable that a liability has been incurred and the amount can be reasonably estimated. As of December 31, 2021, no contingent cash payments have been accrued.

MARKETABLE DEBT SECURITIES

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

MARKETABLE DEBT SECURITIES

The Company's marketable debt securities as of December 31, 2021 and 2020 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.

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


	As of December 31,
	2021		2020
Marketable debt securities:
Commercial paper	$	127,379	$	135,145
Corporate debt securities	233,319		98,646
Securities of government sponsored entities	26,431		43,026
Total marketable debt securities	$	387,129	$	276,817

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


	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 following is a summary of short-term marketable debt securities classified as available-for-sale as of December 31, 2020 (in thousands):


	Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	135,161	$	1	$	(17)	$	135,145
Corporate debt securities	Less than 1	92,906		723		—		93,629
Securities of government-sponsored entities	Less than 1	43,031		—		(5)		43,026
Total maturity less than 1 year		271,098		724		(22)		271,800
Corporate debt securities	1 to 2	5,013		4		—		5,017

Total maturity 1 to 2 years		5,013		4		—		5,017
Total available-for-sale marketable debt securities		$	276,111	$	728	$	(22)	$	276,817

During 2021, the Company had less than $0.1 million in realized gains on marketable debt securities. During 2020, the Company had $0.1 million in realized gains on marketable debt securities. The Company received proceeds from the sale or maturity of marketable debt securities of $433.6 million, $273.5 million and $259.1 million for 2021, 2020 and 2019, respectively.

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 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

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, 2020 (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	$	112,148	$	17	$	—	$	—	$	112,148	$	17

Securities of government-sponsored entities	43,026		5		—		—		43,026		5
Total	$	155,174	$	22	$	—	$	—	$	155,174	$	22

As of December 31, 2021 and December 31, 2020, the amortized cost of the available-for-sale marketable debt securities in an unrealized loss position was $381.2 million and $155.2 million, respectively.

As of December 31, 2021 and December 31, 2020, 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. 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. While certain securities in the portfolio may be downgraded momentarily, the Federal Reserve has allowed institutions to continue to issue debt where there is need, with the government itself purchasing such securities. 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.

CONVERTIBLE SENIOR NOTES

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

CONVERTIBLE SENIOR NOTES

Convertible Senior Notes Due 2025

On September 10, 2018, the Company completed its registered underwritten public offering of the "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 ("Maturity Date”), 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 composition of the Company’s 2025 Notes are as follows (in thousands):


	December 31, 2021		December 31, 2020
2.50% convertible senior notes due 2025	$	276,000	$	276,000
Unamortized debt discount	(46,045)		(56,384)
Unamortized debt issuance costs	(3,374)		(4,277)
Total 2025 Notes, net of unamortized debt discount and debt issuance costs	$	226,581	$	215,339

The net proceeds from the issuance of the 2025 Notes were approximately $267.2 million, after deducting commissions and the offering expenses payable by the Company. A portion of the net proceeds from the 2025 Notes were used by the Company to repurchase $23.4 million aggregate principal amount of its 4.5% senior convertible notes due in 2019 in privately-negotiated transactions.

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.

As of December 31, 2021, the 2025 Notes had a market price of $1,089 per $1,000 principal amount, or $300.6 million. 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 $276.0 million in principal value 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 2025 Notes are the Company’s general unsecured obligations that rank senior in right of payment to all of its indebtedness that is expressly subordinated in right of payment to the 2025 Notes, and equal in right of payment to the Company’s unsecured indebtedness.

The 2025 Notes are currently classified on the Company’s consolidated balance sheet at December 31, 2021 as long-term convertible debt.

Under ASC 470-20, an entity must separately account for the liability and equity components of convertible debt instruments (such as the 2025 Notes) that may be settled entirely or partially in cash upon conversion, in a manner that reflects the issuer’s economic interest cost. The liability component of the instrument is valued in a manner that reflects the market interest rate for a similar nonconvertible instrument at the date of issuance. The initial carrying value of the liability component was $198.6 million. The equity component of $77.4 million, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the 2025 Notes and was recorded in additional paid-in capital on the Consolidated Balance Sheets at the issuance date. That equity component is treated as a discount on the liability component of the 2025 Notes, which is amortized over the seven-year term of the 2025 Notes using the effective interest rate method. The equity component is not re-measured as long as it continues to meet the conditions for equity classification. The Company allocated the total transaction costs of approximately $8.8 million related to the issuance of the 2025 Notes to the liability and equity components of the 2025 Notes based on their relative values. Transaction costs attributable to the liability component are amortized to interest expense over the seven-year term of the 2025 Notes, and transaction costs attributable to the equity component are netted with the equity component in stockholders’ equity.

The effective interest rate on the liability components of the 2025 Notes for the years ended December 31, 2021, 2020 and 2019 was 7.7%. The following table sets forth total interest expense recognized related to the 2025 Notes (in thousands):


	Twelve Months Ended December 31,
	2021		2020		2019
Contractual interest expense	$	6,900	$	6,900	$	6,900
Amortization of debt discount	10,339		9,578		8,874
Amortization of debt issuance costs	903		900		896
Total interest expense for the 2025 Notes	$	18,142	$	17,378	$	16,670

The 2025 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. The 2025 Indenture contains customary events of default with respect to the 2025 Notes, including that upon certain events of default, 100% of the principal and accrued and unpaid interest on the 2025 Notes will automatically become due and payable.

Interest Expense

Total interest expense recognized for the years ended December 31, 2021, 2020 and 2019 was $20.1 million, $19.1 million and $18.8 million, respectively.

- 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI http://asc.fasb.org/topic&trid=2208564

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1C
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495334-112611

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1E
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1I
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

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 judgments 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 December 31, 2021 and 2020 are as follows:


	Revenue Discount		Payment Discount
	Cholbam	Chenodal
December 31, 2021	6.25%	7.25%	6.48%
December 31, 2020	6.50%	8.50%	7.45%

Based on the fair value hierarchy, the Company classified the fair value 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 December 31, 2021, the fair value of the Company's 2.5% Convertible Senior Notes due 2025 was $300.6 million, which was estimated utilizing market quotations, and are considered Level 2.

The following table presents the Company’s asset and liabilities, measured and recognized at fair value on a recurring basis, classified under the appropriate level of the fair value hierarchy as of December 31, 2021 (in thousands):


	As of December 31, 2021		Fair Value Hierarchy at 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)
Asset:
Cash and Cash Equivalents	$	165,753	$	165,753	$	—	$	—
Marketable 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 presents the Company’s assets and liabilities that are measured and recognized at fair value on a recurring basis, classified under the appropriate level of the fair value hierarchy as of December 31, 2020 (in thousands):


	As of December 31, 2020		Fair Value Hierarchy at December 31, 2020
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset:
Cash and Cash Equivalents	$	84,772	$	84,772	$	—	$	—
Marketable debt securities, available-for-sale	276,817		—		276,817		—
Total	$	361,589	$	84,772	$	276,817	$	—
Liabilities:

Business combination-related contingent consideration	$	65,100	$	—	$	—	$	65,100
Total	$	65,100	$	—	$	—	$	65,100

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 years ended December 31, 2021 and 2020 (in thousands):


	Fair Value Measurements of Acquisition-Related Contingent Consideration (Level 3)
	2021		2020
Balance at January 1,	$	65,100	$	70,900

Changes in the fair value of contingent consideration	22,260		3,655
Contractual payments	(17,444)		(7,003)
Contractual payments included in accrued liabilities at December 31	(2,700)		(2,488)
Foreign currency impact	(116)		36
Balance at December 31,	$	67,100	$	65,100

- 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

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

INTANGIBLE ASSETS

Ligand License Agreement

In 2013, the Company entered into a $2.5 million agreement with 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, we are required to make substantial payments upon the achievement of certain milestones, totaling up to $114.1 million. Through 2021, we have made milestone payments to Ligand of $7.2 million under the terms of the Ligand License Agreement. Should we commercialize sparsentan or any products containing related compounds, we will be obligated to pay to Ligand an escalating annual royalty between 15% and 17% of net sales of all such products.

In September 2015, the Ligand License Agreement was amended to facilitate sub-licensing in Asia-Pacific. As consideration for the amendment the Company paid $1.0 million.

In March 2018, the Ligand License Agreement was amended to update certain development milestones set forth in the Sublicense Agreement to comport with the current development timeline for sparsentan. As consideration, the Company paid Ligand $4.6 million, which replaced the amount that would have been due upon initiation of the first Phase 3 trial for sparsentan.

Manchester Pharmaceuticals LLC

In 2014, the Company acquired intangible assets with finite lives related to the Chenodal product rights, trade names, and customer relationships with the values of $67.8 million, $0.2 million, and $0.4 million, respectively. The useful lives related to the acquired product rights, trade names, and customer relationships are expected to be approximately 16, 1 and, 10 years, respectively. Amortization of product rights, trade names and customer relationships are being recorded in selling, general and administrative expense over their respective lives.

Thiola License Agreement

The Company entered into a license agreement with Mission Pharmacal in 2014, in which the Company obtained an exclusive, royalty-bearing license to market, sell and commercialize Thiola (tiopronin) in the United States and Canada, and a non-exclusive license to use know-how relating to Thiola to the extent necessary to market Thiola. The initial term of the license is 10 years and will automatically renew thereafter for periods of one year.

The acquisition of the Thiola license qualified as an asset acquisition under the principles of 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.

The Company paid Mission an up-front license fee of $3 million and will pay guaranteed minimum royalties during each calendar year the greater of $2 million or twenty percent (20%) of the Company’s net sales of Thiola through May 28, 2024.

In November 2017, the Company amended its agreement with Mission to extend the term of the current exclusive U.S. and Canada licensing agreement by an additional five years, to 2029. The royalty rate and guaranteed minimum payment were also extended through the new agreement term. Upon execution of the amendment, the Company capitalized an additional $5.9 million in intangible assets and recorded a guaranteed minimum liability for the same amount.

In November 2018, the Company amended its agreement with Mission to remove all territorial restrictions on our license. As consideration for the expanded territory the Company paid an up-front fee of $0.3 million and will pay guaranteed minimum royalties equaling the greater of $0.1 million or 20% of our Thiola net sales generated outside of the United States during each calendar year. Upon execution of the amendment, the Company capitalized an additional $1.0 million in intangible assets and recorded a guaranteed minimum liability of $0.7 million related to this amendment.

The present value of guaranteed minimum royalties payable using a discount rate of ranging from approximately 7% to 11% based on the Company’s then borrowing rate is $12.3 million and $13.4 million as of December 31, 2021 and 2020, respectively. As of December 31, 2021, the guaranteed minimum royalty current and long-term liability was approximately $2.1 million and $10.2 million, respectively, and is recorded as Other Liability in the Consolidated Balance Sheet. As of December 31, 2020, the guaranteed minimum royalty current and long-term liability was approximately $2.1 million and $11.3 million, respectively, and is recorded as Other Liability in the Consolidated Balance Sheet. The Company has capitalized $123.3 million related to the Thiola intangible asset which consists of the up-front license fee, professional fees, present value of the guaranteed minimum royalties and any additional payments through 2021 in excess of minimum royalties. In 2021 the Company added $19.4 million to the intangible asset related to the royalties in excess of the minimum. Consistent with all prior periods since Thiola was acquired, the Company has not accrued any liability for royalties in excess of the annual contractual minimum at December 31, 2021, as such royalties are not yet probable and estimable.

There are 7.4 years remaining in the term of the license agreement.

Cholbam Asset Purchase

On March 31, 2015, the Company completed its acquisition from Asklepion of all worldwide rights, titles and ownership of Cholbam, including all related contracts, data assets, intellectual property, regulatory assets and the PRV. The Company capitalized $75.9 million and $7.3 million for the U.S. and international economic interest, respectively.

Amortizable intangible assets as of December 31, 2021 (in thousands):


	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Book Value
Thiola License	15	$	123,316	$	(37,992)	$	85,324
Chenodal Product Rights	16	67,849		(32,938)		34,911
Economic Interest - U.S. revenue Cholbam	10	75,900		(51,258)		24,642
Ligand License	11	7,900		(5,875)		2,025
Economic Interest - International revenue Cholbam	10	7,982		(7,483)		499
Manchester Customer Relationships	10	403		(313)		90
Internal use software	5	207		(199)		8
Total		$	283,557	$	(136,058)	$	147,499

Amortizable intangible assets as of December 31, 2020 (in thousands):


	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Book Value
Thiola License	15	$	103,992	$	(28,117)	$	75,875
Chenodal Product Rights	16	67,849		(28,700)		39,149
Economic Interest - U.S. revenue Cholbam	10	75,900		(43,675)		32,225
Ligand License	11	7,900		(4,717)		3,183
Economic Interest - International revenue Cholbam	10	8,250		(5,673)		2,577
Manchester Customer Relationships	10	403		(273)		130
Internal use software	5	207		(157)		50
Manchester trade name	1	175		(175)		—
Total		$	264,676	$	(111,487)	$	153,189

The following table summarizes amortization expense for the twelve months ended December 31, 2021, 2020 and 2019 (in thousands):


	2021		2020		2019
Research and development	$	1,158	$	1,162	$	1,158
Selling, general and administrative	23,788		21,275		18,549
Total amortization expense	$	24,946	$	22,437	$	19,707

As of December 31, 2021, amortization expense for the next five years and thereafter is expected to be as follows (in thousands):


2022	$	25,040
2023	24,241
2024	23,408
2025	17,621
2026	15,751
Thereafter	41,438
Total	$	147,499

Goodwill

As of December 31, 2021 and 2020, the Company had goodwill of $0.9 million.

ACCRUED EXPENSES

12 Months Ended

Dec. 31, 2021

Payables and Accruals [Abstract]

ACCRUED EXPENSES

Accrued expenses consist of the following at December 31, 2021 and 2020 (in thousands):


	2021		2020
Research and development	$	26,841	$	10,166
Compensation related costs	25,998		17,912
Accrued royalties and contingent consideration	8,402		7,857
Government rebates payable	7,493		10,707
Miscellaneous accrued	3,302		6,207
Selling, general and administrative	3,144		3,944
Total accrued expenses	$	75,180	$	56,793

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2021
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 are 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.

STOCKHOLDERS’ EQUITY

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

STOCKHOLDERS’ EQUITY

Common Stock

The Company is currently authorized to issue up to 200,000,000 shares of $0.0001 par value common stock. All issued shares of common stock are entitled to vote on a 1 share/1 vote basis.

Preferred Stock

The Company is currently authorized to issue up to 20,000,000 shares of $0.0001 par value preferred stock, of which 1,000 shares are designated Class "A" Preferred shares. Class A Preferred Shares are not entitled to interest, have certain liquidation preferences, special voting rights and other provisions. No preferred stock has been issued to date.

2015 Equity Incentive Plan

On June 8, 2015, the Company's stockholders approved the 2015 Equity Incentive Plan (the "2015 Plan"). The 2015 Plan is intended as the successor to and continuation of the Company’s 2014 Incentive Compensation Plan. Stockholders approved 1.4 million new shares to be issued under the 2015 Plan, in addition to 0.6 million unallocated shares remaining available for issuance under the 2014 Incentive Compensation Plan that were added to the 2015 Plan. Options issued under the 2015 Plan will generally expire ten years from the date of grant and vest over a three-year or four-year period.

On May 18, 2016, the Company's stockholders approved an amendment to the 2015 Plan (the "Amended 2015 Plan"). The amendment provides for an additional 1.6 million new shares to be issued under the Amended 2015 Plan, in addition to 0.7 million unallocated shares remaining available for issuance. The amendment also includes a provision that on or after March 21, 2016, the number of shares available for issuance under the Amended 2015 Plan will be reduced by one share for each share subject to a stock option or stock appreciation right and by 2.0 shares for each share subject to any other type of stock award issued pursuant to the Amended 2015 Plan, and any such shares will return to the share reserve at the same rates upon cancellation or other forfeiture of such awards or shares.

On May 17, 2017, the Company's stockholders approved an amendment to the Amended 2015 Plan. The amendment provides for an additional 1.8 million new shares to be issued under the Amended 2015 Plan.

2018 Equity Incentive Plan

On May 9, 2018, the Company's stockholders approved the 2018 Equity Incentive Plan (the "2018 Plan"). The 2018 Plan is intended as the successor to and continuation of the Amended 2015 Plan. Stockholders approved 1.8 million new shares to be issued under the 2018 Plan, in addition to 1.6 million unallocated shares remaining available for issuance under the Amended 2015 Plan that were added to the 2018 Plan. Options issued under the 2018 Plan will generally expire ten years from the date of grant and vest over a four-year period.

On May 9, 2019, the Company’s stockholders approved an amendment to the 2018 Plan that increased the number of authorized shares issuable under the 2018 Plan by 2.0 million shares.

On May 15, 2020, the Company's stockholders approved an amendment to the 2018 Plan that increased the number of authorized shares issuable under the 2018 Plan by 2.4 million shares.

On May 14, 2021, the Company’s stockholders approved an amendment to the 2018 Plan that increased the number of authorized shares issuable under the 2018 Plan by 3.2 million shares.

2017 Employee Stock Purchase Plan

The 2017 Employee Stock Purchase Plan ("2017 ESPP") originated with 380,000 shares of common stock available for issuance. Beginning on January 1, 2018, and ending on (and including) January 1, 2026, the number of shares of common stock available for issuance under the 2017 ESPP shall increase by an amount equal to the lesser of (i) one percent (1%) of the total number of shares of common stock outstanding on December 31st of the preceding calendar year and (ii) 300,000 shares of common stock.

Substantially all employees are eligible to participate and, through payroll deductions, can purchase shares on established dates semi-annually. The purchase price per share sold pursuant to the 2017 ESPP will be the lower of (i) 85% of the fair market value of common stock on the first day of the offering period or (ii) 85% of the fair market value on the purchase date. Each offering period will span up to six months. Purchases may be up to 15% of qualified compensation, with an annual limit of $25,000. The 2017 ESPP is intended to qualify as an “employee stock purchase plan” under Section 423 of the Internal Revenue Code.

As of December 31, 2021, there were approximately 1,580,000 shares authorized and 989,052 shares reserved for future issuance under the 2017 ESPP.

Stock Options

The fair values of stock option grants during the years ended December 31, 2021, 2020 and 2019 were calculated on the date of grant using the Black-Scholes option pricing model. Compensation expense is recognized over the period of service, generally the vesting period. During the year ended December 31, 2021, 1,850,407 stock options were granted by the Company. The following weighted average assumptions were used in the Black-Scholes options pricing model to estimate the fair value of stock options for the specified reporting periods:


	Twelve Months Ended December 31,
	2021		2020		2019
Risk free rate	0.6	%	1.5	%	2.3	%
Expected volatility	59	%	64	%	68	%
Expected life (in years)	6.4		6.3		6.2
Expected dividend yield	—		—		—

The risk-free interest rate was based on rates established by the Federal Reserve. The Company’s expected volatility was based on analysis of the Company’s volatility. In years prior to 2020, the assessment also took into account the volatilities of guideline companies due to limited history of the Company's own activity. The expected life of the Company’s options was determined using the Company's historical exercise activity. In years prior to 2020, the Company applied the simplified method as a result of limited historical data regarding the Company’s exercise activity. The dividend yield is based upon the fact that the Company has not historically paid dividends, and does not expect to pay dividends in the foreseeable future.

The following table summarizes our stock option activity and related information for the year ended December 31, 2021:


		Weighted Average
	Shares Underlying Options	Exercise Price		Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2020	8,242,996	$	18.97	6.43	$	71,641
Granted	1,850,407	25.32		—	—
Forfeited and expired	(427,289)	24.37		—	—
Exercised	(779,830)	16.47		—	7,538
Outstanding at December 31, 2021	8,886,284	$	20.26	6.27	$	96,577

The following table summarizes our stock options exercisable at December 31, 2021, 2020 and 2019:


		Weighted Average
	Shares Underlying Options	Exercise Price		Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
2019	4,936,995	$	18.93	5.62	$	4,490
2020	5,488,207	$	19.37	5.36	$	46,626
2021	6,011,349	$	19.34	5.16	$	71,063

The weighted average grant date fair value of options granted was $14.00, $9.54, and $12.11 during the years ended December 31, 2021, 2020 and 2019, respectively. The aggregate intrinsic value for outstanding options is calculated as the difference between the exercise price of the underlying awards and the closing price of the Company’s common stock of $31.04, $27.25 and $14.20 as of December 31, 2021, 2020 and 2019, respectively. Unrecognized compensation cost associated with unvested stock options amounts to $30.0 million as of December 31, 2021, which will be expensed over a weighted average remaining vesting period of 2.5 years.

Restricted Stock Units

As of December 31, 2021, there was approximately $23.2 million of unrecognized compensation cost related to restricted stock units ("RSUs") granted. This amount is expected to be recognized over a weighted average period of 2.4 years.

The following table summarizes our restricted stock unit activity for the year ended December 31, 2021:


	Number of RSUs	Weighted Average Grant Date Fair Value
Unvested December 31, 2020	1,109,942	$	17.84
Granted	911,523	25.06
Vested	(408,136)	18.08
Forfeited/cancelled	(139,380)	21.62
Unvested December 31, 2021	1,473,949	$	21.88

Performance-based Stock Units

PSUs are subject to vest only if certain specified criteria are achieved. As of December 31, 2021, there was less than $0.1 million of unrecognized compensation cost related to performance-based stock units ("PSUs") granted. This amount is expected to be recognized over a weighted average period of 0.5 years.

The following table summarizes our performance-based stock unit activity for the year ended December 31, 2021:


	Number of PSUs	Weighted Average Grant Date Fair Value
Unvested December 31, 2020	167,500	$	16.48
Granted	—	—
Vested	(115,000)	15.46
Forfeited/cancelled	—	—
Unvested December 31, 2021	52,500	$	18.73

Share Based Compensation

Total non-cash stock-based compensation expense consisted of the following for the years ended December 31, 2021, 2020 and 2019 (in thousands):


	Twelve Months Ended December 31,
	2021		2020		2019
Selling, general and administrative expenses	$	18,134	$	14,247	$	14,195
Research and development expenses	12,632		9,367		6,910
Total	$	30,766	$	23,614	$	21,105

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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+ Details

NET LOSS PER COMMON SHARE

12 Months Ended

Dec. 31, 2021

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, 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):


	For the year ended December 31,
	2021					2020					2019
	Shares	Net loss		EPS		Shares	Net loss		EPS		Shares	Net loss		EPS



Basic and diluted loss per share	59,832,287	$	(180,091)	$	(3.01)	47,539,631	$	(169,431)	$	(3.56)	42,339,961	$	(146,427)	$	(3.46)

For the years ended December 31, 2021, 2020 and 2019, the following shares were excluded because they were anti-dilutive:


	For the year ended December 31,
	2021	2020	2019
Convertible debt	7,113,402	7,113,402	7,632,414
Restricted stock	1,569,470	1,368,096	599,298
Options	9,214,188	8,349,310	7,644,251

Total anti-dilutive shares	17,897,060	16,830,808	15,875,963

INCOME TAXES

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

INCOME TAXES

For financial reporting purposes, net loss before income taxes includes the following components (in thousands):


	Year Ended December 31,
	2021		2020		2019
United States	$	(124,132)	$	(65,881)	$	(129,452)
Foreign*	(55,550)		(122,909)		(16,996)
Total	$	(179,682)	$	(188,790)	$	(146,448)

*Foreign losses in 2020 include charges relate to IPR&D. See Note 5 for further discussion.

The components of the provision (benefit) for income taxes, in the Consolidated Statements of Operations are as follows (in thousands):


	2021		2020		2019
Current
Federal	$	—	$	(19,436)	$	(319)
State	412		74		298
Foreign	(3)		3		—
	409		(19,359)		(21)
Deferred
Federal	—		—		—
State	—		—		—
	—		—		—
Total tax provision (benefit)	$	409	$	(19,359)	$	(21)

The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate expressed as a percentage of loss before income taxes:


	2021		2020		2019
Statutory rate - federal	(21.00)	%	(21.00)	%	(21.00)	%
State taxes, net of federal benefit	(2.71)	%	(1.57)	%	(4.35)	%
Foreign rate differential	3.28	%	6.65	%	—	%
IPR&D	—	%	6.50	%	—	%
Federal IRS Audit settlement	—	%	1.62	%	—	%
Nondeductible executive compensation	0.48	%	—	%	—	%
Excess tax benefits associated with share-based awards	0.19	%	—	%	—	%
Other permanent differences	0.15	%	0.09	%	0.24	%
Tax credits	(10.87)	%	(4.49)	%	(15.17)	%
Return to provision adjustments and other true-ups	2.42	%	4.88	%	0.44	%
CARES Act-Net operating loss carryback	—	%	(9.58)	%	—	%
Other	0.20	%	(0.10)	%	2.32	%
Change in valuation allowance	28.09	%	6.75	%	37.50	%
Income tax provision (benefit)	0.23	%	(10.25)	%	(0.02)	%

The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are as follows (in thousands):


	2021		2020
Deferred Tax Assets:
Net operating loss	$	38,618	$	19,114
Research and development and other tax credits	69,213		46,294
Contingent consideration	16,726		16,311
Other accrued expenses	8,678		7,489
Stock based compensation	18,003		21,886
Charitable contributions	3,427		2,575
Intangible assets greater than book	48,801		45,520
Interest expense limitation	2,802		1,659
Operating lease liabilities	8,825		7,314
Tax basis depreciation greater than book depreciation	13		76

	215,106		168,238
Deferred Tax Liabilities:

Operating lease right of use assets	(5,782)		(6,544)
Convertible debt	(11,020)		(13,868)

	(16,802)		(20,412)

Net deferred tax assets before valuation allowance	198,304		147,826
Valuation allowance	(198,304)		(147,826)
Total deferred tax assets	$	—	$	—

The Company has established a full valuation allowance against its U.S. federal, state, and foreign deferred tax assets due to the uncertainty surrounding the realization of such assets in future periods. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which temporary differences become deductible. Management considers the scheduled reversal of deferred liabilities and tax planning strategies in making this assessment and evaluates the recoverability of the deferred tax assets as of each reporting date. At such time as it is determined that it is more likely than not that deferred assets are realizable, the valuation allowance will be reduced accordingly and recorded as a tax benefit.

The Company has recorded a valuation allowance of $198.3 million as of December 31, 2021 to reflect the estimated amount of deferred tax assets that may not be realized. The Company increased its valuation allowance by $50.5 million and $63.1 million for the years ended December 31, 2021 and 2020, respectively.

At December 31, 2021, the Company had available unused U.S. federal and state net operating loss (“NOL”) carryforwards of $85.8 million and $151.2 million, respectively, all of which are fully offset by a valuation allowance. Additionally, the Company had an interest expense limitation carryforward of $12.6 million that is fully offset by a valuation allowance. The federal NOL and interest expense limitation carryforward have an indefinite life. The state NOL carryforwards will begin to expire in 2022. In addition, at December 31, 2021, the Company had federal orphan drug tax credit carryforwards of $61.7 million that begin to expire in 2035 unless utilized, federal research and development tax credit carryforwards of $5.4 million that begin to expire in 2033 unless utilized, state research and development tax credit carryforwards of $10.1 million that begin to expire in 2030 unless utilized, and California Competes tax credit carryforwards of $2.0 million that begin to expire in 2022. Pursuant to Internal Revenue Code Sections 382 and 383, use of the Company’s federal net operating loss and credit carryforwards may be limited upon a cumulative change in ownership of more than 50% within a three-year period.

At December 31, 2021, the Company had Irish NOL carryforwards of $15.9 million which are fully offset by a valuation allowance and have an indefinite life. The Company also had Swiss NOL carryforwards of $77.3 million which are fully offset by a valuation allowance and begin to expire in 2023 as well as Federal Act on Tax Reform and AHV Financing (“TRAF”) cantonal tax benefits of $526.2 million which expire in 2029.

The Company accounts for uncertain tax benefits in accordance with the provisions of ASC 740-10 of the Accounting for Uncertainty in Income Taxes. As of December 31, 2021, the Company had $7.8 million in unrecognized tax benefits of which $7.5 million related to orphan drug and research and development tax credits which was recorded as a reduction to the deferred tax assets with a corresponding reduction in the Company’s valuation allowance of $7.5 million. To the extent unrecognized tax benefits are recognized at a time when a valuation allowance does not exist, the recognition of the $7.5 million tax benefit would reduce the effective tax rate.

The Company does not anticipate that the amount of unrecognized tax benefits as of December 31, 2021 will change materially within the following 12 months.

A reconciliation of the Company's unrecognized tax benefits for the years 2021 and 2020 is provided in the following table (in thousands):


	2021		2020
Balance as of January 1:	$	5,193	$	235
Increase in current period positions	2,255		1,187
Decrease in prior period positions	—		(235)
Increase in prior period positions	377		4,006
Balance as of December 31:	$	7,825	$	5,193

The Company files income tax returns in the U.S. federal jurisdiction, various state and local, and foreign jurisdictions. With few exceptions, the Company’s income tax returns are open to examination by federal authorities for the years ended December 31, 2018, and forward, and for state and foreign tax authorities, for the years ended December 31, 2017, and forward.

The Company recognizes interest and penalties as a component of income tax expense. Interest and penalties for the year ended December 31, 2021 were less than $0.1 million. The Company did not recognize any interest or penalties for the years ended December 31, 2020 and 2019.

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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+ Details

EQUITY OFFERINGS	12 Months Ended
EQUITY OFFERINGS	Dec. 31, 2021
Equity [Abstract]
EQUITY OFFERINGS	EQUITY OFFERINGS Underwritten Public Offerings of Common Stock In February 2021, we sold an aggregate of 7.5 million shares of our common stock in an underwritten public offering, at a price to the public of $26.75 per share. The net proceeds to us from the offering, after deducting the underwriting discounts and offering expenses, were $189.3 million. In June 2020, the Company sold an aggregate of 7.5 million shares of its common stock in an underwritten public offering, at a price to the public of $15.50 per share. The net proceeds to the Company from the offering, after deducting the underwriting discounts and offering expenses, were $108.7 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 our prior registration statement on Form S-3 (Registration Statement No. 333-227182). An additional $31.7 million were sold under our effective registration statement on Form S-3 (Registration Statement No. 333-259311). In 2020, the Company sold 867,806 shares under the ATM Agreement, resulting in gross proceeds of $23.5 million. In 2021, the Company sold a combined 1,240,640 shares under the ATM Agreement, resulting in gross proceeds of $36.8 million. Through December 31, 2021, the Company has sold a total of 2,108,446 shares under the ATM Agreement, resulting in gross proceeds of $60.3 million. As of December 31, 2021, an aggregate amount of $39.7 million remained eligible for sale under the facility. 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.

RETIREMENT PLAN	12 Months Ended
RETIREMENT PLAN	Dec. 31, 2021
Retirement Benefits [Abstract]
RETIREMENT PLAN	RETIREMENT PLANThe Company has a 401(k) defined contribution savings plan for the benefit of all eligible employees. Employer matching contributions were $1.3 million, $1.2 million, and $1.0 million for the years ended December 31, 2021, 2020 and 2019, respectively.

PROPERTY AND EQUIPMENT

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

PROPERTY AND EQUIPMENT

Property, plant and equipment, net consisted of the following (in thousands):


	December 31,
	2021		2020
Computers and equipment	$	1,950	$	595
Furniture and fixtures	2,783		1,791
Leasehold improvements	8,790		4,630
Construction-in-progress	631		6,339
	14,154		13,355
Less: Accumulated depreciation	(3,048)		(3,937)
Total property and equipment, net	$	11,106	$	9,418

The construction-in-process balance consists of costs related to the Company’s leasehold improvements at its facilities in San Diego, California.

Non-cash investing activities for the years ending December 31, 2021 and 2020 included accrued capital expenditures of $0.1 million and $1.9 million, respectively. There were no accrued capital expenditures for the year ending December 31, 2019.

Depreciation expense for the years ended December 31, 2021, 2020 and 2019 was $1.7 million, $2.1 million and $0.7 million, respectively.

LEASES

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

LEASES

As of December 31, 2021, 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 December 31, 2021 (in thousands):


	December 31, 2021
2022	$	6,020
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	43,719

Present value discount	(8,314)
Total operating lease liability	35,405
Unamortized lease incentives	(6,559)
Cash payments in excess of straight-line lease expense	(5,650)
Total ROU asset	$	23,196

For the twelve months ended December 31, 2021, 2020 and 2019 the Company recorded $4.9 million, $2.0 million, and $2.4 million, respectively, in expense related to operating leases, including amortized tenant improvement allowances.

Supplemental cash flow information related to leases is as follows (in thousands):


	2021		2020		2019
Operating cash flows used for operating leases	$	2,205	$	2,537	$	2,639

SUBSEQUENT EVENTS	12 Months Ended
SUBSEQUENT EVENTS	Dec. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTSAt-the-Market Equity OfferingFrom January 1, 2022 through February 22, 2022, the Company sold 701,600 shares of its common stock under the ATM Agreement, resulting in gross proceeds of $20.1 million. After giving effect to such sales as of February 22, 2022, an aggregate amount of $19.6 million remained eligible for sale under the facility.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Principles of Consolidation

Use of Estimates

Revenue Recognition

Research and Development Costs

Research and Development CostsResearch 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

Share-Based Compensation


	Expiration Term	Vesting Term
Stock Options	10 years	3 to 4 years
Restricted Stock Units	----	1 to 4 years

Earnings (Loss) Per Share

Cash and Cash Equivalents

Cash and Cash EquivalentsThe Company considers all highly liquid marketable securities with an original maturity of three months or less to be cash equivalents. Due to the short-term maturity of such investments, the carrying amounts are a reasonable estimate of fair value.

Concentration of Credit Risk

Marketable Debt Securities

Trade Receivables, Net

Trade Receivables, NetTrade accounts receivable are recorded net of reserves for prompt pay discounts and expected credit losses. Estimates for allowances for credit losses are determined based on existing contractual obligations, historical payment patterns and individual customer circumstances. The allowance for credit losses was zero at both December 31, 2021 and 2020, respectively. For the years ended December 31, 2021, 2020 and 2019, bad debt expense recorded in the Consolidated Statements of Operations and Comprehensive Loss was 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.

Inventory, Related Reserves and Cost of Goods SoldInventory, which is recorded at the lower of cost or net realizable value, includes materials, labor, and other direct and indirect costs and is valued using the first-in, first-out method. The Company periodically analyzes its inventory levels to identify inventory that may expire prior to expected sale or has a cost basis in excess of its estimated realizable value, and writes down such inventory as appropriate. In addition, the Company's products are subject to strict quality control and monitoring which the Company’s manufacturers perform throughout their manufacturing process. The Company does not directly manufacture any product. The Company has single suppliers for products Chenodal and Thiola, and prospectively arranges for manufacture from contract service providers for its product Cholbam. The inventory reserve was $4.1 million and $3.6 million at December 31, 2021 and 2020, respectively.

Segment Information

Property and Equipment, net

The major classifications of property and equipment, including their respective expected useful lives, consist of the following:


Computers and equipment			3 years
Furniture and fixtures			7 years
Leasehold improvements			Shorter of length of lease or life of the asset

Leases

Intangible Assets, Net

Intangible Assets with Cost Accumulation Model

Goodwill

GoodwillGoodwill represents the excess of purchase price over fair value of net assets acquired in a business combination and is not amortized. Goodwill is subject to impairment testing at least annually or when a triggering event occurs that could indicate a potential impairment. The Company has one segment and one reporting unit and as such reviews goodwill for impairment at the consolidated level.

Impairment of Long-Lived Assets

Contingent Consideration

Income Taxes

Foreign Currency Translation

Functional and presentation currency

Transactions and balances

The results and financial position of the Company that have a functional currency different from the US dollar are translated as follows:

a.assets and liabilities presented are translated at the closing exchange rate as of December 31, 2021 and 2020;

c.significant transactions use the exchange rate on the date of the transaction;

All resulting exchange differences arising from such translations are recognized directly in comprehensive income and presented as a separate component of equity.

Reclassifications

Patents

PatentsThe Company expenses external costs, such as filing fees and associated attorney fees, incurred to obtain issued patents and patent applications pending. The Company also expenses costs associated with maintaining and defending patents subsequent to their issuance in the period incurred.

Legal Contingencies

Recently Issued Accounting Pronouncements

Fair Value Measurements

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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of Vesting Award Terms


	Expiration Term	Vesting Term
Stock Options	10 years	3 to 4 years
Restricted Stock Units	----	1 to 4 years

Schedule of inventory, net of reserve

Inventory, net of reserve, consisted of the following at December 31, 2021 and 2020 (in thousands):


	December 31, 2021		December 31, 2020
Raw material	$	5,205	$	3,219

Finished goods	2,108		4,389
Total inventory	$	7,313	$	7,608

Schedule of major classifications of property, equipment and software, including their respective expected useful lives

The major classifications of property and equipment, including their respective expected useful lives, consist of the following:


Computers and equipment			3 years
Furniture and fixtures			7 years
Leasehold improvements			Shorter of length of lease or life of the asset

Property, plant and equipment, net consisted of the following (in thousands):


	December 31,
	2021		2020
Computers and equipment	$	1,950	$	595
Furniture and fixtures	2,783		1,791
Leasehold improvements	8,790		4,630
Construction-in-progress	631		6,339
	14,154		13,355
Less: Accumulated depreciation	(3,048)		(3,937)
Total property and equipment, net	$	11,106	$	9,418

REVENUE RECOGNITION (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Summary of Net Product Revenue

The following table summarizes net product sales for the twelve months ended December 31, 2021, 2020 and 2019 (in thousands):


	Twelve Months Ended December 31,
	2021		2020		2019
Tiopronin products	$	115,122	$	108,883	$	95,638
Bile acid products	95,654		89,438		79,700
Total net product revenue	$	210,776	$	198,321	$	175,338

MARKETABLE DEBT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Schedule of debt securities

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


	As of December 31,
	2021		2020
Marketable debt securities:
Commercial paper	$	127,379	$	135,145
Corporate debt securities	233,319		98,646
Securities of government sponsored entities	26,431		43,026
Total marketable debt securities	$	387,129	$	276,817

Schedule of available for sale securities

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


	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 following is a summary of short-term marketable debt securities classified as available-for-sale as of December 31, 2020 (in thousands):


	Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Marketable debt securities:
Commercial paper	Less than 1	$	135,161	$	1	$	(17)	$	135,145
Corporate debt securities	Less than 1	92,906		723		—		93,629
Securities of government-sponsored entities	Less than 1	43,031		—		(5)		43,026
Total maturity less than 1 year		271,098		724		(22)		271,800
Corporate debt securities	1 to 2	5,013		4		—		5,017

Total maturity 1 to 2 years		5,013		4		—		5,017
Total available-for-sale marketable debt securities		$	276,111	$	728	$	(22)	$	276,817

Schedule of debt securities in 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 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

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, 2020 (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	$	112,148	$	17	$	—	$	—	$	112,148	$	17

Securities of government-sponsored entities	43,026		5		—		—		43,026		5
Total	$	155,174	$	22	$	—	$	—	$	155,174	$	22

CONVERTIBLE SENIOR NOTES (Tables)

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The composition of the Company’s 2025 Notes are as follows (in thousands):


	December 31, 2021		December 31, 2020
2.50% convertible senior notes due 2025	$	276,000	$	276,000
Unamortized debt discount	(46,045)		(56,384)
Unamortized debt issuance costs	(3,374)		(4,277)
Total 2025 Notes, net of unamortized debt discount and debt issuance costs	$	226,581	$	215,339

Schedule of fair value of warrants


	Twelve Months Ended December 31,
	2021		2020		2019
Contractual interest expense	$	6,900	$	6,900	$	6,900
Amortization of debt discount	10,339		9,578		8,874
Amortization of debt issuance costs	903		900		896
Total interest expense for the 2025 Notes	$	18,142	$	17,378	$	16,670

- 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

FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of discounts rates used

Discount rates used to determine the fair value at December 31, 2021 and 2020 are as follows:


	Revenue Discount		Payment Discount
	Cholbam	Chenodal
December 31, 2021	6.25%	7.25%	6.48%
December 31, 2020	6.50%	8.50%	7.45%

Schedule of fair value on a recurring basis


	As of December 31, 2021		Fair Value Hierarchy at 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)
Asset:
Cash and Cash Equivalents	$	165,753	$	165,753	$	—	$	—
Marketable 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


	As of December 31, 2020		Fair Value Hierarchy at December 31, 2020
	Total carrying and estimated fair value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Asset:
Cash and Cash Equivalents	$	84,772	$	84,772	$	—	$	—
Marketable debt securities, available-for-sale	276,817		—		276,817		—
Total	$	361,589	$	84,772	$	276,817	$	—
Liabilities:

Business combination-related contingent consideration	$	65,100	$	—	$	—	$	65,100
Total	$	65,100	$	—	$	—	$	65,100

Schedule of fair value measurements of acquisition-related contingent consideration


	Fair Value Measurements of Acquisition-Related Contingent Consideration (Level 3)
	2021		2020
Balance at January 1,	$	65,100	$	70,900

Changes in the fair value of contingent consideration	22,260		3,655
Contractual payments	(17,444)		(7,003)
Contractual payments included in accrued liabilities at December 31	(2,700)		(2,488)
Foreign currency impact	(116)		36
Balance at December 31,	$	67,100	$	65,100

INTANGIBLE ASSETS (Tables)

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of amortizable intangible assets

Amortizable intangible assets as of December 31, 2021 (in thousands):


	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Book Value
Thiola License	15	$	123,316	$	(37,992)	$	85,324
Chenodal Product Rights	16	67,849		(32,938)		34,911
Economic Interest - U.S. revenue Cholbam	10	75,900		(51,258)		24,642
Ligand License	11	7,900		(5,875)		2,025
Economic Interest - International revenue Cholbam	10	7,982		(7,483)		499
Manchester Customer Relationships	10	403		(313)		90
Internal use software	5	207		(199)		8
Total		$	283,557	$	(136,058)	$	147,499

Amortizable intangible assets as of December 31, 2020 (in thousands):


	Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Book Value
Thiola License	15	$	103,992	$	(28,117)	$	75,875
Chenodal Product Rights	16	67,849		(28,700)		39,149
Economic Interest - U.S. revenue Cholbam	10	75,900		(43,675)		32,225
Ligand License	11	7,900		(4,717)		3,183
Economic Interest - International revenue Cholbam	10	8,250		(5,673)		2,577
Manchester Customer Relationships	10	403		(273)		130
Internal use software	5	207		(157)		50
Manchester trade name	1	175		(175)		—
Total		$	264,676	$	(111,487)	$	153,189

Schedule of amortization expense for the next 5 years

The following table summarizes amortization expense for the twelve months ended December 31, 2021, 2020 and 2019 (in thousands):


	2021		2020		2019
Research and development	$	1,158	$	1,162	$	1,158
Selling, general and administrative	23,788		21,275		18,549
Total amortization expense	$	24,946	$	22,437	$	19,707

As of December 31, 2021, amortization expense for the next five years and thereafter is expected to be as follows (in thousands):


2022	$	25,040
2023	24,241
2024	23,408
2025	17,621
2026	15,751
Thereafter	41,438
Total	$	147,499

ACCRUED EXPENSES (Tables)

12 Months Ended

Dec. 31, 2021

Payables and Accruals [Abstract]

Schedule of accrued expenses

Accrued expenses consist of the following at December 31, 2021 and 2020 (in thousands):


	2021		2020
Research and development	$	26,841	$	10,166
Compensation related costs	25,998		17,912
Accrued royalties and contingent consideration	8,402		7,857
Government rebates payable	7,493		10,707
Miscellaneous accrued	3,302		6,207
Selling, general and administrative	3,144		3,944
Total accrued expenses	$	75,180	$	56,793

STOCKHOLDERS’ EQUITY (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Assumptions used in black-scholes options pricing model

The following weighted average assumptions were used in the Black-Scholes options pricing model to estimate the fair value of stock options for the specified reporting periods:


	Twelve Months Ended December 31,
	2021		2020		2019
Risk free rate	0.6	%	1.5	%	2.3	%
Expected volatility	59	%	64	%	68	%
Expected life (in years)	6.4		6.3		6.2
Expected dividend yield	—		—		—

Share-based compensation, stock options, activity

The following table summarizes our stock option activity and related information for the year ended December 31, 2021:


		Weighted Average
	Shares Underlying Options	Exercise Price		Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2020	8,242,996	$	18.97	6.43	$	71,641
Granted	1,850,407	25.32		—	—
Forfeited and expired	(427,289)	24.37		—	—
Exercised	(779,830)	16.47		—	7,538
Outstanding at December 31, 2021	8,886,284	$	20.26	6.27	$	96,577

The following table summarizes our stock options exercisable at December 31, 2021, 2020 and 2019:


		Weighted Average
	Shares Underlying Options	Exercise Price		Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
2019	4,936,995	$	18.93	5.62	$	4,490
2020	5,488,207	$	19.37	5.36	$	46,626
2021	6,011,349	$	19.34	5.16	$	71,063

Schedule of unvested restricted shares

The following table summarizes our restricted stock unit activity for the year ended December 31, 2021:


	Number of RSUs	Weighted Average Grant Date Fair Value
Unvested December 31, 2020	1,109,942	$	17.84
Granted	911,523	25.06
Vested	(408,136)	18.08
Forfeited/cancelled	(139,380)	21.62
Unvested December 31, 2021	1,473,949	$	21.88

Share-based compensation, performance shares award nonvested activity

The following table summarizes our performance-based stock unit activity for the year ended December 31, 2021:


	Number of PSUs	Weighted Average Grant Date Fair Value
Unvested December 31, 2020	167,500	$	16.48
Granted	—	—
Vested	(115,000)	15.46
Forfeited/cancelled	—	—
Unvested December 31, 2021	52,500	$	18.73

Schedule of share based compensation expenses

Total non-cash stock-based compensation expense consisted of the following for the years ended December 31, 2021, 2020 and 2019 (in thousands):


	Twelve Months Ended December 31,
	2021		2020		2019
Selling, general and administrative expenses	$	18,134	$	14,247	$	14,195
Research and development expenses	12,632		9,367		6,910
Total	$	30,766	$	23,614	$	21,105

NET LOSS PER COMMON SHARE (Tables)

12 Months Ended

Dec. 31, 2021

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):


	For the year ended December 31,
	2021					2020					2019
	Shares	Net loss		EPS		Shares	Net loss		EPS		Shares	Net loss		EPS



Basic and diluted loss per share	59,832,287	$	(180,091)	$	(3.01)	47,539,631	$	(169,431)	$	(3.56)	42,339,961	$	(146,427)	$	(3.46)

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

For the years ended December 31, 2021, 2020 and 2019, the following shares were excluded because they were anti-dilutive:


	For the year ended December 31,
	2021	2020	2019
Convertible debt	7,113,402	7,113,402	7,632,414
Restricted stock	1,569,470	1,368,096	599,298
Options	9,214,188	8,349,310	7,644,251

Total anti-dilutive shares	17,897,060	16,830,808	15,875,963

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of components of net income before incomes taxes

For financial reporting purposes, net loss before income taxes includes the following components (in thousands):


	Year Ended December 31,
	2021		2020		2019
United States	$	(124,132)	$	(65,881)	$	(129,452)
Foreign*	(55,550)		(122,909)		(16,996)
Total	$	(179,682)	$	(188,790)	$	(146,448)

*Foreign losses in 2020 include charges relate to IPR&D. See Note 5 for further discussion.

Schedule of income tax provision (benefit)

The components of the provision (benefit) for income taxes, in the Consolidated Statements of Operations are as follows (in thousands):


	2021		2020		2019
Current
Federal	$	—	$	(19,436)	$	(319)
State	412		74		298
Foreign	(3)		3		—
	409		(19,359)		(21)
Deferred
Federal	—		—		—
State	—		—		—
	—		—		—
Total tax provision (benefit)	$	409	$	(19,359)	$	(21)

Schedule of reconciliation of the statutory federal income tax expense (benefit)

The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate expressed as a percentage of loss before income taxes:


	2021		2020		2019
Statutory rate - federal	(21.00)	%	(21.00)	%	(21.00)	%
State taxes, net of federal benefit	(2.71)	%	(1.57)	%	(4.35)	%
Foreign rate differential	3.28	%	6.65	%	—	%
IPR&D	—	%	6.50	%	—	%
Federal IRS Audit settlement	—	%	1.62	%	—	%
Nondeductible executive compensation	0.48	%	—	%	—	%
Excess tax benefits associated with share-based awards	0.19	%	—	%	—	%
Other permanent differences	0.15	%	0.09	%	0.24	%
Tax credits	(10.87)	%	(4.49)	%	(15.17)	%
Return to provision adjustments and other true-ups	2.42	%	4.88	%	0.44	%
CARES Act-Net operating loss carryback	—	%	(9.58)	%	—	%
Other	0.20	%	(0.10)	%	2.32	%
Change in valuation allowance	28.09	%	6.75	%	37.50	%
Income tax provision (benefit)	0.23	%	(10.25)	%	(0.02)	%

Schedule of deferred tax assets and liabilities

The significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are as follows (in thousands):


	2021		2020
Deferred Tax Assets:
Net operating loss	$	38,618	$	19,114
Research and development and other tax credits	69,213		46,294
Contingent consideration	16,726		16,311
Other accrued expenses	8,678		7,489
Stock based compensation	18,003		21,886
Charitable contributions	3,427		2,575
Intangible assets greater than book	48,801		45,520
Interest expense limitation	2,802		1,659
Operating lease liabilities	8,825		7,314
Tax basis depreciation greater than book depreciation	13		76

	215,106		168,238
Deferred Tax Liabilities:

Operating lease right of use assets	(5,782)		(6,544)
Convertible debt	(11,020)		(13,868)

	(16,802)		(20,412)

Net deferred tax assets before valuation allowance	198,304		147,826
Valuation allowance	(198,304)		(147,826)
Total deferred tax assets	$	—	$	—

Schedule of unrecognized tax benefits

A reconciliation of the Company's unrecognized tax benefits for the years 2021 and 2020 is provided in the following table (in thousands):


	2021		2020
Balance as of January 1:	$	5,193	$	235
Increase in current period positions	2,255		1,187
Decrease in prior period positions	—		(235)
Increase in prior period positions	377		4,006
Balance as of December 31:	$	7,825	$	5,193

PROPERTY AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Summary of Property, Plant, and Equipment

The major classifications of property and equipment, including their respective expected useful lives, consist of the following:


Computers and equipment			3 years
Furniture and fixtures			7 years
Leasehold improvements			Shorter of length of lease or life of the asset

Property, plant and equipment, net consisted of the following (in thousands):


	December 31,
	2021		2020
Computers and equipment	$	1,950	$	595
Furniture and fixtures	2,783		1,791
Leasehold improvements	8,790		4,630
Construction-in-progress	631		6,339
	14,154		13,355
Less: Accumulated depreciation	(3,048)		(3,937)
Total property and equipment, net	$	11,106	$	9,418

LEASES (Tables)

12 Months Ended

Dec. 31, 2021

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 December 31, 2021 (in thousands):


	December 31, 2021
2022	$	6,020
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	43,719

Present value discount	(8,314)
Total operating lease liability	35,405
Unamortized lease incentives	(6,559)
Cash payments in excess of straight-line lease expense	(5,650)
Total ROU asset	$	23,196

Supplemental cash flow information

Supplemental cash flow information related to leases is as follows (in thousands):


	2021		2020		2019
Operating cash flows used for operating leases	$	2,205	$	2,537	$	2,639

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) clinical_trial segment reportingUnit	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Accounting Policies [Abstract]
Number of Phase 3 clinical trials \| clinical_trial	3
Allowance for doubtful accounts	$ 0	$ 0
Inventory reserve	$ 4,100,000	3,600,000
Number of segments \| segment	1
Number of reporting units \| reportingUnit	1
Goodwill, impairment	$ 0	0	$ 0
Impairment of intangible assets	$ 0	$ 0	$ 0

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Vesting Awards (Details)	12 Months Ended
	Dec. 31, 2021
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration Term	10 years
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	3 years
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	4 years
Restricted Stock Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	1 year
Restricted Stock Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	4 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Inventory, Net of Reserve (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Raw material	$ 5,205	$ 3,219
Finished goods	2,108	4,389
Total inventory	$ 7,313	$ 7,608

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Computers and equipment
Property, Plant and Equipment [Line Items]
Use life (in years)	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Use life (in years)	7 years

REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	12 Months Ended
REVENUE RECOGNITION (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 227,490	$ 198,321	$ 175,338
Tiopronin products
Disaggregation of Revenue [Line Items]
Total revenue	115,122	108,883	95,638
Bile acid products
Disaggregation of Revenue [Line Items]
Total revenue	95,654	89,438	79,700
Net product sales
Disaggregation of Revenue [Line Items]
Total revenue	$ 210,776	$ 198,321	$ 175,338
Geographic Concentration Risk \| Revenue Benchmark \| United States
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	98.00%
Geographic Concentration Risk \| Revenue Benchmark \| Canada
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	2.00%

COLLABORATION AND LICENSE AGREEMENTS (Details) $ in Thousands		1 Months Ended	12 Months Ended
	Sep. 15, 2021 USD ($) performanceObligation	Feb. 28, 2021	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			$ 227,490	$ 198,321	$ 175,338
Deferred revenue, current portion			16,268	0
License and collaboration revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			16,714	$ 0	$ 0
Vifor Ltd. \| Collaborative Arrangement
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	4000.00%
Revenue	$ 55,000
Number of performance obligations \| performanceObligation	2
Deferred revenue	$ 43,000		36,600
Revenue recognized during the period			16,700
Deferred revenue, current portion			16,300
Vifor Ltd. \| Collaborative Arrangement \| Sales-based Milestone Payments
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments	655,000
Vifor Ltd. \| Collaborative Arrangement \| Regulatory and Market Access Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments	$ 135,000
Vifor Ltd. \| Collaborative Arrangement \| License and collaboration revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			12,000
Revenue recognized during the period			12,000
Vifor Ltd. \| Collaborative Arrangement \| Clinical Development Activity
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue recognized during the period			4,700
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			$ 1,800

ACQUISITIONS - Acquisition of Orphan Technologies Limited (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Cash paid for acquisition		$ 0	$ 95,279	$ 0
Contingent consideration, liability		$ 67,100	65,100
Orphan Technologies Limited
Business Acquisition [Line Items]
Cash paid for acquisition	$ 90,000
Closing price adjustments	1,200
Liabilities assumed in acquisition	1,800
Acquisition transaction costs	4,200		$ 97,100
Contingent consideration, liability	$ 427,000

MARKETABLE DEBT SECURITIES - Schedule of Debt Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	$ 387,129	$ 276,817
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	127,379	135,145
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	233,319	98,646
Securities of government sponsored entities
Debt Securities, Available-for-sale [Line Items]
Total marketable debt securities	$ 26,431	$ 43,026

MARKETABLE DEBT SECURITIES - Schedule of Short Term Debt Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	$ 262,345	$ 271,098
Marketable debt securities available for sale, unrealized gain, current	0	724
Marketable debt securities available for sale unrealized loss, current	(159)	(22)
Marketable debt securities, available-for-sale, current	262,186	271,800
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	125,254	5,013
Marketable debt securities, available for sale unrealized gain, noncurrent	0	4
Marketable debt securities available for sale unrealized loss, noncurrent	(311)	0
Marketable debt securities, available-for-sale, noncurrent	124,943	5,017
Marketable debt securities, available-for-sale, amortized cost	387,599	276,111
Marketable debt securities, available-for-sale, accumulated gross unrealized gain, before tax	0	728
Marketable debt securities, available-for-sale, accumulated gross unrealized loss, before tax	(470)	(22)
Marketable debt securities, available-for-sale	387,129	276,817
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	127,435	135,161
Marketable debt securities available for sale, unrealized gain, current	0	1
Marketable debt securities available for sale unrealized loss, current	(57)	(17)
Marketable debt securities, available-for-sale, current	127,378	135,145
Marketable debt securities, available-for-sale	127,379	135,145
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	113,001	92,906
Marketable debt securities available for sale, unrealized gain, current	0	723
Marketable debt securities available for sale unrealized loss, current	(97)	0
Marketable debt securities, available-for-sale, current	112,904	93,629
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	120,705	5,013
Marketable debt securities, available for sale unrealized gain, noncurrent	0	4
Marketable debt securities available for sale unrealized loss, noncurrent	(289)	0
Marketable debt securities, available-for-sale, noncurrent	120,416	5,017
Marketable debt securities, available-for-sale	233,319	98,646
Securities of government-sponsored entities
Debt Securities, Available-for-sale [Line Items]
Marketable debt securities, available-for-sale, amortized cost basis, current	21,909	43,031
Marketable debt securities available for sale, unrealized gain, current	0	0
Marketable debt securities available for sale unrealized loss, current	(5)	(5)
Marketable debt securities, available-for-sale, current	21,904	43,026
Marketable debt securities, available-for-sale, amortized cost basis, noncurrent	4,549
Marketable debt securities, available for sale unrealized gain, noncurrent	0
Marketable debt securities available for sale unrealized loss, noncurrent	(22)
Marketable debt securities, available-for-sale, noncurrent	4,527
Marketable debt securities, available-for-sale	$ 26,431	$ 43,026

MARKETABLE DEBT SECURITIES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Debt securities, unrealized gains	$ 100	$ 100
Proceeds from the sale/maturity of marketable debt securities	433,604	273,482	$ 259,140
Available-for-sale marketable debt securities in an unrealized loss position	$ 381,200	$ 155,200

MARKETABLE DEBT SECURITIES - Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 380,690	$ 155,174
Less than 12 months, unrealized losses	470	22
12 months or greater, fair value	0	0
12 months or greater, unrealized losses	0	0
Total, fair value	380,690	155,174
Total, unrealized losses	470	22
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	122,380	112,148
Less than 12 months, unrealized losses	57	17
12 months or greater, fair value	0	0
12 months or greater, unrealized losses	0	0
Total, fair value	122,380	112,148
Total, unrealized losses	57	17
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	231,879
Less than 12 months, unrealized losses	386
12 months or greater, fair value	0
12 months or greater, unrealized losses	0
Total, fair value	231,879
Total, unrealized losses	386
Securities of government sponsored entities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	26,431	43,026
Less than 12 months, unrealized losses	27	5
12 months or greater, fair value	0	0
12 months or greater, unrealized losses	0	0
Total, fair value	26,431	43,026
Total, unrealized losses	$ 27	$ 5

CONVERTIBLE SENIOR NOTES - Narrative (Details)		12 Months Ended
CONVERTIBLE SENIOR NOTES - Narrative (Details)	Sep. 10, 2018 USD ($)	Dec. 31, 2021 USD ($) d $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Debt instrument, repurchase amount	$ 23,400,000
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%
Debt instrument, convertible note, market price, per $1,000		$ 1,089
Debt conversion, liability		198,600,000
Debt conversion, equity		77,400,000
Debt issuance costs, net		$ 8,800,000
Debt instrument, interest rate, effective percentage		7.70%	7.70%	7.70%
Interest expense		$ 20,100,000	$ 19,100,000	$ 18,800,000
Senior Notes \| Senior Notes Due 2025
Debt Instrument [Line Items]
Interest rate percentage		2.50%
Proceeds from issuance of debt	$ 267,200,000
Debt instrument, convertible, conversion price (in USD per share) \| $ / shares		$ 38.80
Long-term debt, excluding current maturities, repaid if converted		$ 276,000,000
Debt instrument, convertible, conversion ratio		0.0257739
Long-term debt, term		7 years
Debt issuance costs, net		$ 3,374,000	$ 4,277,000
Debt redeemable by holders		100.00%
Senior Notes \| Convertible Notes Due 2019
Debt Instrument [Line Items]
Interest rate percentage	4.50%
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%
Debt instrument, convertible, threshold consecutive days measuring period \| d		10
Trading price per principal, percentage		98.00%

CONVERTIBLE SENIOR NOTES - Schedule of Carrying Amount of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (8,800)
Senior Notes Due 2025 \| Senior Notes
Debt Instrument [Line Items]
2.50% convertible senior notes due 2025	276,000	$ 276,000
Unamortized debt discount	(46,045)	(56,384)
Unamortized debt issuance costs	(3,374)	(4,277)
Net carrying amount	$ 226,581	$ 215,339

- 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 SENIOR NOTES - Convertible Notes Payable (Details) - Senior Notes - Senior Notes Due 2025 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Contractual interest expense	$ 6,900	$ 6,900	$ 6,900
Amortization of debt discount	10,339	9,578	8,874
Amortization of debt issuance costs	903	900	896
Total interest expense for the 2025 Notes	$ 18,142	$ 17,378	$ 16,670

FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Millions	12 Months Ended
FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Millions	Dec. 31, 2021 USD ($) business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of businesses acquired \| business	2
Fair value of convertible debt \| $	$ 300.6
Senior Notes Due 2025 \| Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate percentage	2.50%

FAIR VALUE MEASUREMENTS - Discount Rates Used (Details)	Dec. 31, 2021	Dec. 31, 2020
Payment Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0648	0.0745
Cholbam \| Revenue Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0625	0.0650
Chenodal \| Revenue Discount
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.0725	0.0850

FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Asset:
Cash and Cash Equivalents	$ 165,753	$ 84,772
Marketable debt securities, available-for-sale	387,129	276,817
Total	552,882	361,589
Liabilities:
Business combination-related contingent consideration	67,100	65,100
Total	67,100	65,100
Quoted prices in active markets (Level 1)
Asset:
Cash and Cash Equivalents	165,753	84,772
Marketable debt securities, available-for-sale	0	0
Total	165,753	84,772
Liabilities:
Business combination-related contingent consideration	0	0
Total	0	0
Significant other observable inputs (Level 2)
Asset:
Cash and Cash Equivalents	0	0
Marketable debt securities, available-for-sale	387,129	276,817
Total	387,129	276,817
Liabilities:
Business combination-related contingent consideration	0	0
Total	0	0
Significant unobservable inputs (Level 3)
Asset:
Cash and Cash Equivalents	0	0
Marketable debt securities, available-for-sale	0	0
Total	0	0
Liabilities:
Business combination-related contingent consideration	67,100	65,100	$ 70,900
Total	$ 67,100	$ 65,100

FAIR VALUE MEASUREMENTS - Fair Value of Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1	$ 65,100
Changes in the fair value of contingent consideration	14,375	$ 12,407	$ 5,661
Balance at December 31	67,100	65,100
Significant unobservable inputs (Level 3)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1	65,100	70,900
Changes in the fair value of contingent consideration	22,260	3,655
Contractual payments	(17,444)	(7,003)
Contractual payments included in accrued liabilities at December 31	(2,700)	(2,488)
Foreign currency impact	(116)	36
Balance at December 31	$ 67,100	$ 65,100	$ 70,900

INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended				12 Months Ended
	Nov. 30, 2018	Mar. 31, 2018	Nov. 30, 2017	Sep. 30, 2015	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net					$ 147,499	$ 153,189
Payments to date under terms of licensing agreement					19,050	17,799	$ 15,370
Finite-lived intangible asset					283,557	264,676
Amortization expense					24,946	22,437	$ 19,707
Goodwill					900	900
Ligand License Agreement
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net									$ 2,500
Require to make substantial payments payable upon achievement of milestones									$ 114,100
Payments to date under terms of licensing agreement					$ 7,200
Payment of amendment consideration				$ 1,000
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%
Licensing Agreements
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired		$ 4,600
Product rights
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net					$ 34,911	$ 39,149
Assets useful life (in years)					16 years	16 years
Finite-lived intangible asset					$ 67,849	$ 67,849
Product rights \| Manchester Pharmaceuticals LLC
Finite-Lived Intangible Assets [Line Items]
Intangible assets with definite lives								$ 67,800
Assets useful life (in years)								16 years
Trade Name
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net						$ 0
Assets useful life (in years)						1 year
Finite-lived intangible asset						$ 175
Trade Name \| Manchester Pharmaceuticals LLC
Finite-Lived Intangible Assets [Line Items]
Intangible assets with definite lives								$ 200
Assets useful life (in years)								1 year
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net					$ 90	$ 130
Assets useful life (in years)					10 years	10 years
Finite-lived intangible asset					$ 403	$ 403
Customer relationships \| Manchester Pharmaceuticals LLC
Finite-Lived Intangible Assets [Line Items]
Intangible assets with definite lives								$ 400
Assets useful life (in years)								10 years
Thiola License Agreement
Finite-Lived Intangible Assets [Line Items]
Annual royalty percentage					20.00%
Assets useful life (in years)								10 years
Automatic renewal periods								1 year
Mission an up-front license fee					$ 3,000
Guaranteed minimum royalties					2,000
Present value of guaranteed minimum royalties payable					$ 12,300	13,400
Remaining weighed average period of amortization (in years)					7 years 4 months 24 days
Thiola License Agreement \| Other Current Liabilities
Finite-Lived Intangible Assets [Line Items]
Guaranteed minimum royalties					$ 2,100	2,100
Thiola License Agreement \| Other Noncurrent Liabilities
Finite-Lived Intangible Assets [Line Items]
Guaranteed minimum royalties					$ 10,200	11,300
Thiola License Agreement \| Minimum
Finite-Lived Intangible Assets [Line Items]
Discount rate					7.00%
Thiola License Agreement \| Maximum
Finite-Lived Intangible Assets [Line Items]
Discount rate					11.00%
Thiola
Finite-Lived Intangible Assets [Line Items]
Intangible assets finite-lived, net					$ 85,324	$ 75,875
Assets useful life (in years)					15 years	15 years
Licensing agreement, extension term			5 years
Finite-lived intangible asset			$ 5,900		$ 123,316	$ 103,992
Payments for the option to acquire business	$ 300
Payment of guaranteed minimum royalty	$ 100
Minimum royalty, percentage	20.00%
Amortization expense	$ 1,000
Guaranteed minimum liability	$ 700
Increase in intangible assets					$ 19,400
United States \| Asklepion Pharmaceuticals LLC
Finite-Lived Intangible Assets [Line Items]
Capitalized economic interest										$ 75,900
International \| Asklepion Pharmaceuticals LLC
Finite-Lived Intangible Assets [Line Items]
Capitalized economic interest										$ 7,300

INTANGIBLE ASSETS - Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 283,557	$ 264,676
Accumulated Amortization	(136,058)	(111,487)
Intangible assets finite-lived, net	$ 147,499	$ 153,189
Thiola License
Finite-Lived Intangible Assets [Line Items]
Useful Life	15 years	15 years
Gross Carrying Amount	$ 123,316	$ 103,992	$ 5,900
Accumulated Amortization	(37,992)	(28,117)
Intangible assets finite-lived, net	$ 85,324	$ 75,875
Chenodal Product Rights
Finite-Lived Intangible Assets [Line Items]
Useful Life	16 years	16 years
Gross Carrying Amount	$ 67,849	$ 67,849
Accumulated Amortization	(32,938)	(28,700)
Intangible assets finite-lived, net	$ 34,911	$ 39,149
Economic Interest - U.S. revenue Cholbam
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 years	10 years
Gross Carrying Amount	$ 75,900	$ 75,900
Accumulated Amortization	(51,258)	(43,675)
Intangible assets finite-lived, net	$ 24,642	$ 32,225
Ligand License
Finite-Lived Intangible Assets [Line Items]
Useful Life	11 years	11 years
Gross Carrying Amount	$ 7,900	$ 7,900
Accumulated Amortization	(5,875)	(4,717)
Intangible assets finite-lived, net	$ 2,025	$ 3,183
Economic Interest - International revenue Cholbam
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 years	10 years
Gross Carrying Amount	$ 7,982	$ 8,250
Accumulated Amortization	(7,483)	(5,673)
Intangible assets finite-lived, net	$ 499	$ 2,577
Manchester Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Useful Life	10 years	10 years
Gross Carrying Amount	$ 403	$ 403
Accumulated Amortization	(313)	(273)
Intangible assets finite-lived, net	$ 90	$ 130
Internal use software
Finite-Lived Intangible Assets [Line Items]
Useful Life	5 years	5 years
Gross Carrying Amount	$ 207	$ 207
Accumulated Amortization	(199)	(157)
Intangible assets finite-lived, net	$ 8	$ 50
Manchester trade name
Finite-Lived Intangible Assets [Line Items]
Useful Life		1 year
Gross Carrying Amount		$ 175
Accumulated Amortization		(175)
Intangible assets finite-lived, net		$ 0

INTANGIBLE ASSETS - Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 24,946	$ 22,437	$ 19,707
Research and development
Finite-Lived Intangible Assets [Line Items]
Amortization expense	1,158	1,162	1,158
Selling, general and administrative
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 23,788	$ 21,275	$ 18,549

INTANGIBLE ASSETS - Amortization Expense Next Five Years (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 25,040
2023	24,241
2024	23,408
2025	17,621
2026	15,751
Thereafter	41,438
Intangible assets finite-lived, net	$ 147,499	$ 153,189

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Research and development	$ 26,841	$ 10,166
Compensation related costs	25,998	17,912
Accrued royalties and contingent consideration	8,402	7,857
Government rebates payable	7,493	10,707
Miscellaneous accrued	3,302	6,207
Selling, general and administrative	3,144	3,944
Total accrued expenses	$ 75,180	$ 56,793

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	12 Months Ended			72 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Other Commitments [Line Items]
Revenue	$ 227,490	$ 198,321	$ 175,338
France \| Kolbam
Other Commitments [Line Items]
Revenue				$ 8,000

- 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.

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+ Details

STOCKHOLDERS’ EQUITY - Common Stock and Preferred Stock (Details)	12 Months Ended
	Dec. 31, 2021 vote $ / shares shares	May 18, 2021 shares	May 17, 2021 shares	Dec. 31, 2020 $ / shares shares
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	200,000,000	200,000,000	100,000,000	100,000,000
Common stock, par value (in USD per share) \| $ / shares	$ 0.0001			$ 0.0001
Number of votes per common share owned \| vote	1
Preferred stock, shares authorized (in shares)	20,000,000			20,000,000
Preferred stock, par value (in USD per share) \| $ / shares	$ 0.0001			$ 0.0001
Preferred stock, shares issued (in shares)	0			0
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	1,000

STOCKHOLDERS’ EQUITY - 2015 Equity Incentive Plan (Details)		12 Months Ended
	May 18, 2016 shares	Dec. 31, 2021 shares	May 18, 2021 shares	May 17, 2021 shares	Dec. 31, 2020 shares	May 17, 2017 shares	Jun. 08, 2015 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized (in shares)		200,000,000	200,000,000	100,000,000	100,000,000
2015 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized (in shares)							1,400,000
Shares remaining available for issuance under the plan (in shares)							600,000
Expiration Term		10 years
2015 Equity Incentive Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		3 years
2015 Equity Incentive Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		4 years
2015 Equity Incentive Plan Amended
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized (in shares)	1,600,000					1,800,000
Shares remaining available for issuance under the plan (in shares)	700,000
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration Term		10 years
Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		3 years
Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term		4 years
Options \| 2015 Equity Incentive Plan Amended
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, reduction in number of shares available for grant (in shares)	1
Restricted stock \| 2015 Equity Incentive Plan Amended
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, reduction in number of shares available for grant (in shares)	2.0

STOCKHOLDERS’ EQUITY - 2018 Equity Incentive Plan (Details) - shares	12 Months Ended
	Dec. 31, 2021	May 18, 2021	May 17, 2021	May 14, 2021	Dec. 31, 2020	May 15, 2020	May 09, 2019	May 09, 2018
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	200,000,000	200,000,000	100,000,000		100,000,000
2018 Equity Incentive Plan
Class of Stock [Line Items]
Common stock, shares authorized (in shares)								1,800,000
Shares remaining available for issuance under the plan (in shares)								1,600,000
Expiration Term	10 years
Vesting Term	4 years
Increase in authorized shares issuable (in shares)				3,200,000		2,400,000	2,000,000

STOCKHOLDERS’ EQUITY - 2017 Employee Stock Purchase Plan (Details) - 2017 ESPP - USD ($)	12 Months Ended
	Dec. 31, 2021	Jan. 01, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remaining available for issuance under the plan (in shares)	1,580,000	380,000
Potential increase in shares available for issuance, as a percent of total outstanding common stock	1.00%
Maximum number of additional shares authorized for issuance (in shares)	300,000
Purchase price of common stock, percent of fair market value	85.00%
Stock purchase offering period	6 months
Employee stock purchase plan, maximum compensation	15.00%
Employee stock purchase plan annual limit	$ 25,000
Shares reserved for future issuance (in shares)	989,052

STOCKHOLDERS’ EQUITY - Black Scholes Assumptions (Details) - Stock Options - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued (in shares)	1,850,407
Risk free rate	0.60%	1.50%	2.30%
Expected volatility	59.00%	64.00%	68.00%
Expected life (in years)	6 years 4 months 24 days	6 years 3 months 18 days	6 years 2 months 12 days
Expected dividend yield	0.00%	0.00%	0.00%

STOCKHOLDERS’ EQUITY - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercised, aggregate intrinsic value	$ 7,538
Shares underlying options (in shares)	6,011,349	5,488,207	4,936,995
Exercise Price (in USD per share)	$ 19.34	$ 19.37	$ 18.93
Remaining contractual term, exercisable (in years)	5 years 1 month 28 days	5 years 4 months 9 days	5 years 7 months 13 days
Exercisable, aggregate intrinsic value	$ 71,063	$ 46,626	$ 4,490
Closing stock price of stock options outstanding and exercisable (in USD per share)	$ 31.04	$ 27.25	$ 14.20
Stock Options
Shares
Outstanding, beginning balance (in shares)	8,242,996
Granted (in shares)	1,850,407
Forfeited and expired (in shares)	(427,289)
Exercised (in shares)	(779,830)
Outstanding, ending balance (in shares)	8,886,284	8,242,996
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 18.97
Granted (in USD per share)	25.32
Forfeited and expired (in dollars per share)	24.37
Exercised (in USD per share)	16.47
Outstanding, ending balance (in USD per share)	$ 20.26	$ 18.97
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Remaining contractual term, outstanding (in years)	6 years 3 months 7 days	6 years 5 months 4 days
Outstanding, aggregate intrinsic value	$ 96,577	$ 71,641
Weighted average grant date fair value of options (in USD per share)	$ 14.00	$ 9.54	$ 12.11
Compensation expense not yet recognized, stock options	$ 30,000
Weighted average period for unrecognized costs (in years)	2 years 6 months

STOCKHOLDERS’ EQUITY- Unvested Restricted Stock (Details) - Restricted shares $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to restricted shares granted \| $	$ 23.2
Weighted average period for unrecognized costs (in years)	2 years 4 months 24 days
Number of shares
Unvested beginning balance (in shares) \| shares	1,109,942
Granted (in shares) \| shares	911,523
Vested (in shares) \| shares	(408,136)
Forfeited/cancelled (in shares) \| shares	(139,380)
Unvested ending balance (in shares) \| shares	1,473,949
Weighted Average Grant Date Fair Value
Unvested beginning balance (in USD per share) \| $ / shares	$ 17.84
Granted (in USD per share) \| $ / shares	25.06
Vested (in USD per share) \| $ / shares	18.08
Forfeited/cancelled (in USD per share) \| $ / shares	21.62
Unvested ending balance (in USD per share) \| $ / shares	$ 21.88

STOCKHOLDERS’ EQUITY - Performance-based Stock Options (Details) - Performance Shares $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to restricted shares granted \| $	$ 0.1
Weighted average period for unrecognized costs (in years)	6 months
Number of shares
Unvested beginning balance (in shares) \| shares	167,500
Granted (in shares) \| shares	0
Vested (in shares) \| shares	(115,000)
Forfeited/cancelled (in shares) \| shares	0
Unvested ending balance (in shares) \| shares	52,500
Weighted Average Grant Date Fair Value
Unvested beginning balance (in USD per share) \| $ / shares	$ 16.48
Granted (in USD per share) \| $ / shares	0
Vested (in USD per share) \| $ / shares	15.46
Forfeited/cancelled (in USD per share) \| $ / shares	0
Unvested ending balance (in USD per share) \| $ / shares	$ 18.73

STOCKHOLDERS’ EQUITY - Share Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 30,766	$ 23,614	$ 21,105
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	18,134	14,247	14,195
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 12,632	$ 9,367	$ 6,910

NET LOSS PER COMMON SHARE - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding (in shares)	59,832,287	47,539,631	42,339,961
Diluted weighted average common shares outstanding (in shares)	59,832,287	47,539,631	42,339,961
Net loss (basic)	$ (180,091)	$ (169,431)	$ (146,427)
Net loss (diluted)	$ (180,091)	$ (169,431)	$ (146,427)
Basic (in USD per share)	$ (3.01)	$ (3.56)	$ (3.46)
Diluted (in USD per share)	$ (3.01)	$ (3.56)	$ (3.46)

- 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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- Definition

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 Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation (in shares)	17,897,060	16,830,808	15,875,963
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation (in shares)	7,113,402	7,113,402	7,632,414
Restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation (in shares)	1,569,470	1,368,096	599,298
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from the calculation (in shares)	9,214,188	8,349,310	7,644,251

INCOME TAXES - Components of Net Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Loss before provision for income taxes	$ (179,682)	$ (188,790)	$ (146,448)
United States
Operating Loss Carryforwards [Line Items]
Loss before provision for income taxes	(124,132)	(65,881)	(129,452)
Foreign
Operating Loss Carryforwards [Line Items]
Loss before provision for income taxes	$ (55,550)	$ (122,909)	$ (16,996)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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INCOME TAXES - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current
Federal	$ 0	$ (19,436)	$ (319)
State	412	74	298
Foreign	(3)	3	0
Total	409	(19,359)	(21)
Deferred
Federal	0	0	0
State	0	0	0
Total	0	0	0
Total tax provision (benefit)	$ 409	$ (19,359)	$ (21)

INCOME TAXES - Reconciliation of Federal Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory rate - federal	(21.00%)	(21.00%)	(21.00%)
State taxes, net of federal benefit	(2.71%)	(1.57%)	(4.35%)
Foreign rate differential	3.28%	6.65%	0.00%
IPR&D	0.00%	6.50%	0.00%
Federal IRS Audit settlement	0.00%	1.62%	0.00%
Nondeductible executive compensation	0.48%	0.00%	0.00%
Excess tax benefits associated with share-based awards	0.19%	0.00%	0.00%
Other permanent differences	0.15%	0.09%	0.24%
Tax credits	(10.87%)	(4.49%)	(15.17%)
Return to provision adjustments and other true-ups	2.42%	4.88%	0.44%
CARES Act-Net operating loss carryback	0.00%	(9.58%)	0.00%
Other	0.20%	(0.10%)	2.32%
Change in valuation allowance	28.09%	6.75%	37.50%
Income tax provision (benefit)	0.23%	(10.25%)	(0.02%)

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets:
Net operating loss	$ 38,618	$ 19,114
Research and development and other tax credits	69,213	46,294
Contingent consideration	16,726	16,311
Other accrued expenses	8,678	7,489
Stock based compensation	18,003	21,886
Charitable contributions	3,427	2,575
Intangible assets greater than book	48,801	45,520
Interest expense limitation	2,802	1,659
Operating lease liabilities	8,825	7,314
Tax basis depreciation greater than book depreciation	13	76
Deferred tax assets	215,106	168,238
Deferred Tax Liabilities:
Operating lease right of use assets	(5,782)	(6,544)
Convertible debt	(11,020)	(13,868)
Deferred tax liabilities	(16,802)	(20,412)
Net deferred tax assets before valuation allowance	198,304	147,826
Valuation allowance	(198,304)	(147,826)
Total deferred tax assets	$ 0	$ 0

INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
INCOME TAXES - Narrative (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 198,304,000	$ 147,826,000
Increase in valuation allowance increase (decrease)	50,500,000	63,100,000
Unrecognized tax benefits	7,825,000	5,193,000	$ 235,000
Unrecognized tax benefits that would impact effective tax rate	7,500,000
Income tax examination, penalties and interest expense	100,000	$ 0	$ 0
U.S. federal
Operating Loss Carryforwards [Line Items]
Available unused NOL carryforwards	85,800,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Available unused NOL carryforwards	151,200,000
Foreign \| Irish
Operating Loss Carryforwards [Line Items]
Available unused NOL carryforwards	15,900,000
Foreign \| Swiss
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	526,200,000
Available unused NOL carryforwards	77,300,000
Interest Expense Limitation Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	12,600,000
Federal Orphan Drug Tax Credit
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	61,700,000
Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Increase in valuation allowance increase (decrease)	(7,500,000)
Unrecognized tax benefits	7,500,000
Research Tax Credit Carryforward \| U.S. federal
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	5,400,000
Research Tax Credit Carryforward \| State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	10,100,000
Tax Competes Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 2,000,000

INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 5,193	$ 235
Increase in current period positions	2,255	1,187
Decrease in prior period positions	0	(235)
Increase in prior period positions	377	4,006
Ending balance	$ 7,825	$ 5,193

EQUITY OFFERINGS (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		12 Months Ended
	Feb. 28, 2021	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	May 18, 2021	May 17, 2021	Feb. 29, 2020
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			200,000,000	100,000,000	200,000,000	100,000,000
Underwritten Equity Offering
Class of Stock [Line Items]
Shares issued (in shares)	7,500,000	7,500,000
Stock price (USD per share)	$ 26.75	$ 15.50
Proceeds from issuance of common stock	$ 189.3	$ 108.7
At-The-Market Offering
Class of Stock [Line Items]
Shares issued (in shares)			1,240,640	867,806
Proceeds from issuance of common stock			$ 36.8	$ 23.5
Aggregate offering amount authorized							$ 100.0
Shares sold to date (in shares)			2,108,446
Amount sold to date			$ 60.3
Remaining offering amount authorized			39.7
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			$ 31.7

RETIREMENT PLAN (Details) - USD ($) $ in Millions	12 Months Ended
RETIREMENT PLAN (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Defined contribution plan, employer contributions	$ 1.3	$ 1.2	$ 1.0

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,154	$ 13,355
Less: Accumulated depreciation	(3,048)	(3,937)
Total property and equipment, net	11,106	9,418
Accrued capital expenditures	100	1,900
Depreciation expense	1,700	2,100	$ 700
Computers and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,950	595
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,783	1,791
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,790	4,630
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 631	$ 6,339

LEASES - Additional Information (Details) $ in Thousands	12 Months Ended
LEASES - Additional Information (Details) $ in Thousands	Dec. 31, 2021 USD ($) lease	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right of use assets	$ 23,196	$ 25,675
Operating lease liability	35,405
Future minimum lease payments	43,719
Operating lease expense	$ 4,900	2,000	$ 2,400
Office Lease 2020
Lessee, Lease, Description [Line Items]
Operating lease right of use assets		34,600
Operating lease liability		34,500
Tenant improvement allowance		$ 7,900
Operating lease extension term				5 years
Future minimum lease payments				$ 49,500
Kilroy Realty, L.P.
Lessee, Lease, Description [Line Items]
Number of operating leases \| lease	1

LEASES - Future Minimum Rent Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022	$ 6,020
2023	6,200
2024	6,386
2025	6,578
2026	6,775
Thereafter	11,760
Total undiscounted future minimum payments	43,719
Present value discount	(8,314)
Total operating lease liability	35,405
Unamortized lease incentives	(6,559)
Cash payments in excess of straight-line lease expense	(5,650)
Total ROU asset	$ 23,196	$ 25,675

LEASES - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows used for operating leases	$ 2,205	$ 2,537	$ 2,639

SUBSEQUENT EVENTS (Details) - At-The-Market Offering - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 22, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Shares issued (in shares)		1,240,640	867,806
Proceeds from issuance of common stock		$ 36.8	$ 23.5
Remaining offering amount		$ 39.7
Subsequent Event
Subsequent Event [Line Items]
Shares issued (in shares)	701,600
Proceeds from issuance of common stock	$ 20.1
Remaining offering amount	$ 19.6