PTC Therapeutics (PTCT) 10-K 21 Feb 23 2022 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2022	Feb. 16, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-35969
Entity Registrant Name	PTC THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3416587
Entity Address, Address Line One	100 Corporate Court
Entity Address, City or Town	South Plainfield,
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07080
City Area Code	908
Local Phone Number	222-7000
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	PTCT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,129,532,394
Entity Common Stock, Shares Outstanding		73,815,144
Documents Incorporated By Reference	DOCUMENTS INCORPORATED BY REFERENCE ​ Part III of this Annual Report incorporates by reference information from the definitive Proxy Statement for the registrant’s 2023 Annual Meeting of Shareholders which is expected to be filed with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2022.
Entity Central Index Key	0001070081
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Iselin, New Jersey

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 279,834	$ 189,718
Marketable securities	130,871	583,658
Trade and royalty receivables, net	155,614	110,455
Inventory, net	21,808	15,856
Prepaid expenses and other current assets	105,658	54,681
Total current assets	693,785	954,368
Fixed assets, net	72,590	52,585
Intangible assets, net	705,891	724,841
Goodwill	82,341	82,341
Operating lease ROU assets	102,430	77,421
Deposits and other assets	48,582	46,500
Total assets	1,705,619	1,938,056
Current liabilities:
Accounts payable and accrued expenses	320,366	288,784
Current portion of long-term debt		149,540
Deferred revenue	1,351
Operating lease liabilities- current	9,370	7,273
Finance lease liabilities- current	3,000	3,000
Liability for sale of future royalties - current	72,149	59,291
Other current liabilities		1,460
Total current liabilities	406,236	509,348
Long-term debt	571,722	281,894
Contingent consideration payable	164,000	239,900
Deferred tax liability	102,834	137,110
Operating lease liabilities- noncurrent	100,860	73,619
Finance lease liabilities- noncurrent	18,675	20,053
Liability for sale of future royalties- noncurrent	685,737	674,694
Other long-term liabilities	2,641
Total liabilities	2,052,705	1,936,618
Stockholders' (deficit) equity:
Common stock, $0.001 par value. Authorized 250,000,000 shares; issued and outstanding 73,104,692 shares at December 31, 2022. Authorized 250,000,000 shares; issued and outstanding 70,828,226 shares at December 31, 2021	72	71
Additional paid-in capital	2,305,020	2,123,606
Accumulated other comprehensive income (loss)	4,796	(24,282)
Accumulated deficit	(2,656,974)	(2,097,957)
Total stockholders' (deficit) equity	(347,086)	1,438
Total liabilities and stockholders' (deficit) equity	$ 1,705,619	$ 1,938,056

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares (in shares)	250,000,000	250,000,000
Common stock, issued shares (in shares)	73,104,692	70,828,226
Common stock, outstanding shares (in shares)	73,104,692	70,828,226

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Revenue	$ 698,801	$ 538,593	$ 380,766
Operating expenses:
Cost of product sales, excluding amortization of acquired intangible assets	44,678	32,328	18,942
Amortization of intangible assets	116,554	54,751	36,892
Research and development	651,496	540,684	477,643
Selling, general and administrative	325,998	285,773	245,164
Change in the fair value of deferred and contingent consideration	(25,900)	(500)	23,280
Intangible asset impairment	33,384
Settlement of deferred and contingent consideration			10,613
Total operating expenses	1,146,210	913,036	812,534
Loss from operations	(447,409)	(374,443)	(431,768)
Interest expense, net	(90,871)	(86,022)	(56,352)
Other (expense) income, net	(49,207)	(57,875)	85,188
Loss before income tax expense	(587,487)	(518,340)	(402,932)
Income tax benefit (expense)	28,470	(5,561)	(35,228)
Net loss attributable to common stockholders	$ (559,017)	$ (523,901)	$ (438,160)
Weighted-average shares outstanding:
Basic	71,728,634	70,466,393	66,027,908
Diluted	71,728,634	70,466,393	66,027,908
Net loss per share-basic and diluted (in dollars per share)
Basic	$ (7.79)	$ (7.43)	$ (6.64)
Diluted	$ (7.79)	$ (7.43)	$ (6.64)
Net product revenue
Revenues:
Revenue	$ 535,228	$ 428,904	$ 333,401
Collaboration revenue
Revenues:
Revenue	50,052	55,046	42,579
Royalty revenue
Revenues:
Revenue	$ 113,521	$ 54,643	$ 4,786

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (559,017)	$ (523,901)	$ (438,160)
Other comprehensive loss:
Unrealized gain (loss) on marketable securities, net of tax	108	(2,502)	1,145
Foreign currency translation gain (loss), net of tax	28,970	39,177	(51,518)
Comprehensive loss	$ (529,939)	$ (487,226)	$ (488,533)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' (Deficit) Equity - USD ($) $ in Thousands	Common stock	Additional paid-in capital Cumulative Effect Adjustment	Additional paid-in capital	Accumulated other comprehensive (loss) income	Accumulated deficit Cumulative Effect Adjustment	Accumulated deficit	Cumulative Effect Adjustment	Total
Balance (in shares) at Dec. 31, 2019	61,935,870
Balance at the beginning of the period at Dec. 31, 2019	$ 62		$ 1,795,351	$ (10,584)		$ (1,190,499)		$ 594,330
Increase (Decrease) in Stockholders' Equity
Issuance of common stock related to equity offerings (in shares)	542,470
Issuance of common stock related to equity offering	$ 1		28,091					28,092
Issuance of common stock related to acquisition (in shares)	845,364
Issuance of common stock related to acquisition	$ 1		42,868					42,869
Issuance of common stock related to rights exchange (in shares)	2,821,176
Issuance of common stock related to rights exchange	$ 3		150,525					150,528
Exercise of options (in shares)	3,268,452
Exercise of options	$ 3		70,176					70,179
Restricted stock vesting and issuance (in shares)	180,028
Restricted stock vesting and issuance, net								0
Issuance of common stock in connection with an employee stock purchase plan (in shares)	124,736
Issuance of common stock in connection with an employee stock purchase plan			5,303					5,303
Share-based compensation expense			70,325					70,325
Receivable from investor			9,107					9,107
Other						(218)		(218)
Net loss						(438,160)		(438,160)
Comprehensive income				(50,373)				(50,373)
Balance (in shares) at Dec. 31, 2020	69,718,096
Balance at the end of the period at Dec. 31, 2020	$ 70	$ (175,236)	2,171,746	(60,957)	$ 54,796	(1,628,877)	$ (120,440)	481,982
Increase (Decrease) in Stockholders' Equity
Exercise of options (in shares)	635,871
Exercise of options	$ 1		17,308					17,309
Restricted stock vesting and issuance (in shares)	307,658
Restricted stock vesting and issuance, net								0
Issuance of common stock in connection with an employee stock purchase plan (in shares)	166,601
Issuance of common stock in connection with an employee stock purchase plan			5,792					5,792
Share-based compensation expense			103,513					103,513
Receivable from investor			483					483
Other						25		25
Net loss						(523,901)		(523,901)
Comprehensive income				36,675				36,675
Balance (in shares) at Dec. 31, 2021	70,828,226
Balance at the end of the period at Dec. 31, 2021	$ 71		2,123,606	(24,282)		(2,097,957)		1,438
Increase (Decrease) in Stockholders' Equity
Issuance of common stock related to stock purchase agreement (in shares)	1,095,290
Issuance of common stock related to stock purchase agreement	$ 1		49,999					50,000
Exercise of options (in shares)	496,863
Exercise of options			14,632					14,632
Restricted stock vesting and issuance (in shares)	490,008
Restricted stock vesting and issuance, net								0
Issuance of common stock in connection with an employee stock purchase plan (in shares)	194,305
Issuance of common stock in connection with an employee stock purchase plan			6,450					6,450
Share-based compensation expense			110,333					110,333
Net loss						(559,017)		(559,017)
Comprehensive income				29,078				29,078
Balance (in shares) at Dec. 31, 2022	73,104,692
Balance at the end of the period at Dec. 31, 2022	$ 72		$ 2,305,020	$ 4,796		$ (2,656,974)		$ (347,086)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (559,017)	$ (523,901)	$ (438,160)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	128,836	64,134	43,490
Non-cash operating lease expense	9,884	7,386	6,084
Non-cash finance lease amortization expense			41,382
Non-cash royalty revenue related to sale of future royalties	(48,738)	(23,460)	(2,055)
Non-cash interest expense on liability related to sale of future royalties	72,639	77,683	31,817
Intangible asset impairment	33,384
Change in valuation of deferred and contingent consideration	(25,900)	(500)	23,280
Settlement of deferred and contingent consideration			10,613
Non-cash stock consideration, acquisition			42,869
Unrealized loss (gain) on ClearPoint Equity Investments	3,560	6,078	(14,310)
Unrealized loss (gain) on ClearPoint convertible debt security	5,740	8,281	(19,252)
Unrealized loss (gain) on marketable securities - equity investments	7,992	(1,673)
Disposal of asset	80		16
Deferred income taxes	(34,276)	377	5,872
Amortization of premiums on investments, net	1,713	5,299	409
Amortization of debt issuance costs	1,901	1,848	1,020
Share-based compensation expense	110,333	103,513	70,325
Non-cash interest expense			22,598
Unrealized foreign currency transaction losses, net	13,263	47,391	(56,980)
Non cash foreign currency remeasurement loss on intercompany loan	16,887
Changes in operating assets and liabilities:
Inventory, net	(6,668)	1,800	1,841
Prepaid expenses and other current assets	(51,621)	(15,310)	(12,621)
Trade and royalty receivables, net	(48,468)	(44,991)	(10,483)
Deposits and other assets	(2,913)	(232)	(662)
Accounts payable and accrued expenses	27,542	45,659	71,963
Other liabilities	(4,558)	(6,704)	(3,930)
Deferred revenue	1,351	(4,010)	(8,032)
Payments on contingent consideration	(9,600)		(1,165)
Net cash used in operating activities	(356,654)	(251,332)	(194,071)
Cash flows from investing activities
Purchases of fixed assets	(32,016)	(28,213)	(17,843)
Purchases of marketable securities - available for sale	(52,764)	(333,148)	(1,439,665)
Purchase of convertible debt security			(10,000)
Purchases of marketable securities - equity investments	(22,787)	(210,018)
Sale and redemption of marketable securities- available for sale	405,234	843,498	944,094
Sale and redemption of marketable securities - equity investments	112,958	4,281
Acquisition of product rights and licenses	(120,444)	(57,118)	(38,134)
Purchase of equity investment in ClearPoint		(100)
Net cash provided by (used in) investing activities	290,181	219,182	(561,548)
Cash flows from financing activities
Proceeds from exercise of options	14,632	17,309	70,179
Termination and exit fees related to payoff of secured term loan			(597)
Net proceeds from public offerings			28,092
Debt issuance costs related to secured term loan	(11,454)
Proceeds from issuance of senior secured term loan	300,000
Repayment of Convertible Notes	(150,000)		(28,333)
Payments on deferred and contingent consideration obligation	(40,400)		(38,100)
Proceeds from employee stock purchase plan	6,450	5,792	5,303
Payment of finance lease principal	(1,276)	(2,224)	(17,829)
Proceeds from stock purchase agreement	50,000
Cash consideration received from Royalty Purchase Agreement			650,000
Net cash provided by financing activities	167,952	20,877	668,715
Effect of exchange rate changes on cash	(2,772)	(7,821)	7,688
Net decrease in cash and cash equivalents	98,707	(19,094)	(79,216)
Cash and cash equivalents, and restricted cash beginning of period	197,218	216,312	295,528
Cash and cash equivalents, and restricted cash end of period	295,925	197,218	216,312
Supplemental disclosure of cash information
Cash paid for interest	18,463	9,588	9,802
Cash paid for income taxes	4,922	7,708	26,397
Supplemental disclosure of non-cash investing and financing activity
Unrealized gain (loss) on marketable securities, net of tax	108	(2,502)	1,145
Right-of-use assets obtained in exchange for operating lease obligations	35,817	645	76,811
Right-of-use assets obtained in exchange for finance lease obligations			41,382
Acquisition of product rights and licenses	33,239	$ 22,294	14,191
Issuance of common stock related to rights exchange			150,528
Debt issuance costs related to senior secured term loan	159
Capital expenditures unpaid at the end of period	$ 308		$ 1,060

The Company

The Company	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company PTC Therapeutics, Inc. (the “Company” or “PTC”) is a science-driven global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. PTC’s ability to innovate to identify new therapies and to globally commercialize products is the foundation that drives investment in a robust and diversified pipeline of transformative medicines. PTC’s mission is to provide access to best-in-class treatments for patients who have little to no treatment options. PTC’s strategy is to leverage its strong scientific and clinical expertise and global commercial infrastructure to bring therapies to patients. PTC believes that this allows it to maximize value for all of its stakeholders. The Company has two products, Translarna™ (ataluren) and Emflaza ® The Company’s marketing authorization for Translarna in the EEA is subject to annual review and renewal by the European Commission following reassessment by the EMA of the benefit-risk balance of the authorization, which the Company refers to as the annual EMA reassessment. The marketing authorization in the EEA was last renewed in June 2022 and is effective, unless extended, through August 5, 2023. In September 2022, the Company submitted a Type II variation to the EMA to support conversion of the conditional marketing authorization for Translarna to a standard marketing authorization, which included a report on the placebo-controlled trial of Study 041 and data from the open-label extension. The Company expects an opinion from the Committee for Medicinal Products for Human Use in the first half of 2023. Translarna is an investigational new drug in the United States. Following the Company’s announcement of top-line results from the placebo-controlled trial of Study 041 in June 2022, the Company submitted a meeting request to the U.S. Food and Drug Administration (“FDA”) to gain clarity on the regulatory pathway for a potential re-submission of New Drug Application (“NDA”) for Translarna. The FDA provided initial written feedback that Study 041 does not provide substantial evidence of effectiveness to support NDA re-submission. The Company recently had an informal meeting with the FDA, during which the Company discussed the potential path to an NDA re-submission for Translarna. Based on the meeting discussion, the Company plans to request an additional Type C meeting with the FDA in the near future to review the totality of data collected to date, including dystrophin and other mechanistic data as well as additional analyses that could support the benefit of Translarna. The Company has a pipeline of gene therapy product candidates for rare monogenic diseases that affect the central nervous system (“CNS”) including Upstaza (eladocagene exuparvovec) for the treatment of Aromatic L-Amino Acid Decarboxylase (“AADC”) deficiency (“AADC deficiency”), a rare CNS disorder arising from reductions in the enzyme AADC that results from mutations in the dopa decarboxylase gene. In July 2022, the European Commission approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA. In November 2022, the Medicines and Healthcare Products Regulatory Agency approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the United Kingdom. The Company is also preparing a biologics license application (“BLA”) for Upstaza for the treatment of AADC deficiency in the United States and it expects to submit a BLA to the FDA in the first half of 2023. The Company holds the rights for the commercialization of Tegsedi ® ® The Company also has a spinal muscular atrophy (“SMA”) collaboration with F. Hoffman-La Roche Ltd and Hoffman-La Roche Inc. (referred to collectively as “Roche”) and the Spinal Muscular Atrophy Foundation (“SMA Foundation”). The SMA program has one approved product, Evrysdi ® second quarter The Company’s Bio-e platform consists of small molecule compounds that target oxidoreductase enzymes that regulate oxidative stress and inflammatory pathways central to the pathology of a number of CNS diseases. The two most advanced molecules in the Company’s Bio-e platform are vatiquinone and utreloxastat. The Company initiated a registration-directed Phase 2/3 placebo-controlled trial of vatiquinone in children with mitochondrial disease associated seizures in the third quarter of 2020. The Company has completed enrollment in this trial after previously experiencing delays in enrollment due to the COVID-19 pandemic. The Company anticipates results from the Phase 2/3 trial to be available in the second quarter of 2023. The Company also initiated a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich ataxia in the fourth quarter of 2020 and anticipates results from this trial to be available in the second quarter of 2023. In the third quarter of 2021, the Company completed a Phase 1 trial in healthy volunteers to evaluate the safety and pharmacology of utreloxastat. Utreloxastat was found to be well-tolerated with no reported serious adverse events while demonstrating predictable pharmacology. The Company initiated a Phase 2 trial of utreloxastat for amyotrophic lateral sclerosis in the first quarter of 2022 and . The most advanced molecule in the Company’s metabolic platform is sepiapterin, a precursor to intracellular tetrahydrobiopterin, which is a critical enzymatic cofactor involved in metabolism and synthesis of numerous metabolic products. The Company initiated a registration-directed Phase 3 trial for sepiapterin for PKU in the third quarter of 2021 with the primary endpoint in the study of achieving statistically-significant reduction in blood Phe level. The primary analysis population includes those patients who have a greater than 30% reduction in blood Phe levels during the Part 1 run-in phase of the trial. In January 2023, the Company announced preliminary data from the Part 1 run-in phase of this trial, including that the mean reduction in blood Phe levels in an initial cohort of subjects during the Part 1 would be recognized as clinically meaningful if maintained in Part 2 of the trial. The Company now expects results from Part 2 of this trial to be available in May 2023 as the trial is overenrolled and additional time is required for the entirety of the primary analysis population to complete the study. Unesbulin is the Company’s most advanced oncology agent. The Company completed its Phase 1 trials evaluating unesbulin in leiomyosarcoma (“LMS”) and diffuse intrinsic pontine glioma (“DIPG”) in the fourth quarter of 2021. The Company initiated a registration-directed Phase 2/3 trial of unesbulin for the treatment of LMS in the first quarter of 2022 and enrollment is ongoing. The initiation of the Company’s registration-directed Phase 2/3 trial of unesbulin for DIPG was delayed as it continued to track the progress of patients in its Phase 1 trial and analyze the corresponding data. The Company now expects to initiate a registration-directed Phase 2/3 trial of unesbulin for the treatment of DIPG in the fourth quarter of 2023. In addition, the Company has a pipeline of product candidates and discovery programs that are in early clinical, pre-clinical and research and development stages focused on the development of new treatments for multiple therapeutic areas for rare diseases. As of 2022, the Company had an accumulated deficit of approximately $2,657.0 million. The Company has financed its operations to date primarily through the private offerings in September 2019 of 1.50% convertible senior notes due 2026 (see Note 8), public offerings of common stock in February 2014, October 2014, April 2018, January 2019, and September 2019, “at the market offering” of its common stock, its initial public offering of common stock in June 2013, proceeds from the Royalty Purchase Agreement dated as of July 17, 2020, by and among the Company, RPI 2019 Intermediate Finance Trust (“RPI”), and, solely for the limited purposes set forth therein, Royalty Pharma PLC (the “Royalty Purchase Agreement”) (see Note 2), net proceeds from our borrowings under our credit agreement with Blackstone (see Note 8), private placements of its convertible preferred stock and common stock, collaborations, bank and institutional lender debt, other convertible debt, grant funding and clinical trial support from governmental and philanthropic organizations and patient advocacy groups in the disease area addressed by the Company’s product candidates. On August 15, 2022, the Company repaid the outstanding principal amount and accrued interest, totaling $152.3 million, of the 3.00% convertible senior notes due August 15, 2022 (the “2022 Convertible Notes”) that was due upon maturity in accordance with the terms of the notes. The Company has also relied on revenue generated from net sales of Translarna for the treatment of nmDMD in territories outside of the United States since 2014, Emflaza for the treatment of DMD in the United States since 2017 and Upstaza for the treatment of AADC deficiency in the EEA since May 2022. The Company has also relied on revenue associated with milestone and royalty payments from Roche pursuant to the License and Collaboration Agreement (the “SMA License Agreement”) dated as of November 23, 2011, by and among the Company, Roche and, for the limited purposes set forth therein, the SMA Foundation, under its SMA program. The Company expects that cash flows from the sales of its products, together with the Company’s cash, cash equivalents and marketable securities, will be sufficient to fund its operations for at least the next twelve months.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of significant accounting policies	2. Summary of significant accounting policies Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. Certain prior period balances have been reclassified to conform to the current period presentation. These reclassifications did not have a material impact on the consolidated statements of operations, consolidated balance sheets, consolidated statements of cash flows, or notes to the consolidated financial statements. Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates in these consolidated financial statements have been made in connection with the calculation of net product sales, royalty revenue, certain accruals related to the Company’s research and development expenses, valuation procedures for liability for sale of future royalties, valuation procedures for the convertible notes, indefinite lived intangible assets annual impairment assessment, fair value of the contingent consideration, and the provision for or benefit from income taxes. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known. Restricted Cash Restricted cash included in deposits and other assets on the consolidated balance sheet relates to an unconditional, irrevocable and transferable letter of credit that was entered into during the twelve-month period ended December 31, 2019 in connection with obligations under a facility lease for the Company’s leased biologics manufacturing facility in Hopewell Township, New Jersey. The amount of the letter of credit is $7.5 million, is to be maintained for a term of not less than five years and has the potential to be reduced to $3.8 million if after five years the Company is not in default of its lease. Restricted cash also contains an unconditional, irrevocable and transferable letter of credit that was entered into during June 2022 in connection with obligations for the Company’s new facility lease in Warren, New Jersey. The amount of the letter of credit is $8.1 million and has the potential to be reduced to $4.1 million if after five years the Company is not in default of its lease. Both amounts are classified within deposits and other assets on the consolidated balance sheet due to the long-term nature of the letter of credit. Restricted cash also includes a bank guarantee of $0.5 million denominated in a foreign currency. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the consolidated balance sheet that sum to the total of the same amounts shown in the statement of cash flows: ​ ​ ​ ​ ​ ​ ​ ​ ​ End of ​ Beginning of ​ period- period- ​ December 31, December 31, ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 279,834 ​ $ 189,718 Restricted cash included in deposits and other assets ​ 16,091 ​ 7,500 Total Cash, cash equivalents and restricted cash per statement of cash flows ​ $ 295,925 ​ $ 197,218 ​ Consolidation The consolidated financial statements include the accounts of PTC Therapeutics, Inc. and its wholly owned subsidiaries. All inter-company accounts, transactions, and profits have been eliminated in consolidation. Segment and geographic information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating and reporting Cash equivalents The Company considers all highly liquid investments with a maturity of 90 days or less at the time of purchase to be cash equivalents. Cash equivalents are carried at cost which approximates fair value due to their short-term nature. Marketable securities The Company’s marketable securities consists of both debt securities and equity investments. The Company considers its investments in debt securities with original maturities of greater than 90 days to be available for sale securities. Securities under this classification are recorded at fair value and unrealized gains and losses within accumulated other comprehensive income. The estimated fair value of the available for sale securities is determined based on quoted market prices or rates for similar instruments. In addition, the cost of debt securities in this category is adjusted for amortization of premium and accretion of discount to maturity. For available for sale debt securities in an unrealized loss position, the Company assesses whether it intends to sell or if it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value. If the criteria are not met, the Company evaluates whether the decline in fair value has resulted from a credit loss or other factors. In making this assessment, management considers, among other factors, the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized costs basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. For the years ended December 31, 2022 and 2021, no allowance was recorded for credit losses. Marketable securities that are equity investments are measured at fair value, as it is readily available, and as such are classified as Level 1 assets. Unrealized holding gains and losses for these equity investments are components of other (expense) income, net within the consolidated statement of operations. Concentration of credit risk The Company’s financial instruments that are exposed to credit risks consist primarily of cash and cash equivalents, available-for-sale marketable securities and accounts receivable. The Company maintains its cash and cash equivalents in bank accounts, which, at times, exceed federally insured limits. The Company has not experienced any credit losses in these accounts and does not believe it is exposed to any significant credit risk on these funds. The Company’s investment policy includes guidelines on the quality of the financial institutions and financial instruments the Company is allowed to invest in, which the Company believes minimizes the exposure to concentration of credit risk. The Company is subject to credit risk from its accounts receivable related to its product sales. The payment terms are predetermined and the Company evaluates the creditworthiness of each customer or distributor on a regular basis. The Company reserves all uninsured amounts billed directly to a patient until the time of cash receipt as collectability is not reasonably assured at the time the product is received. To date, the Company has not incurred any material credit losses. Fixed assets Fixed assets are stated at cost. Depreciation is computed starting when the asset is placed into service on a straight-line basis over the estimated useful life of the related asset as follows: Leasehold improvements Lesser of useful life or lease term Computer equipment and software ​ 3 years Machinery and lab equipment ​ 7 years Furniture and fixtures ​ 7 years ​ Inventory and cost of product sales Inventory Inventories are stated at the lower of cost and net realizable value with cost determined on a first-in, first-out basis by product. The Company capitalizes inventory costs associated with products following regulatory approval when future commercialization is considered probable and the future economic benefit is expected to be realized. Products which may be used in clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and no longer can be used for commercial purposes. Inventory used for marketing efforts are charged to selling, general and administrative expense. Amounts related to clinical development programs and marketing efforts are immaterial. The following table summarizes the components of the Company’s inventory for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 December 31, 2021 Raw materials ​ $ 1,078 ​ $ 1,418 Work in progress ​ 14,074 ​ 7,721 Finished goods ​ 6,656 ​ 6,717 Total inventory ​ $ 21,808 ​ $ 15,856 ​ The Company periodically reviews its inventories for excess amounts or obsolescence and writes down obsolete or otherwise unmarketable inventory to its estimated net realizable value. The Company recorded write downs of $1.7 million and $2.2 million for the years ended December 31, 2022 and 2021, respectively, primarily related to product approaching expiration. Additionally, though the Company’s product is subject to strict quality control and monitoring which it performs throughout the manufacturing processes, certain batches or units of product may not meet quality specifications resulting in a charge to cost of product sales. For the years ended December 31, 2022 and December 31, 2021, these amounts were immaterial. Cost of product sales Cost of product sales consists of the cost of inventory sold, manufacturing and supply chain costs, storage costs, amortization of the acquired intangible asset, royalty payments associated with net product sales, and royalty payments to collaborative partners associated with royalty revenues and collaboration revenue related to milestones. Production costs are expensed as cost of product sales when the related products are sold or royalty revenues and collaboration revenue milestones are earned. Accumulated other comprehensive income (loss) Accumulated other comprehensive income (loss) consists of unrealized gains or losses on marketable securities and foreign currency translation adjustments. Revenue recognition Net product revenue The Company’s net product revenue primarily consists of sales of Translarna in territories outside of the U.S. for the treatment of nmDMD and sales of Emflaza in the U.S. for the treatment of DMD. The Company recognizes revenue when its performance obligations with its customers have been satisfied. The Company’s performance obligations are to provide products based on customer orders from distributors, hospitals, specialty pharmacies or retail pharmacies. The performance obligations are satisfied at a point in time when the Company’s customer obtains control of the product, which is typically upon delivery. The Company invoices its customers after the products have been delivered and invoice payments are generally due within 30 to 90 days of the invoice date. The Company determines the transaction price based on fixed consideration in its contractual agreements. Contract liabilities arise in certain circumstances when consideration is due for goods the Company has yet to provide. As the Company has identified only one distinct performance obligation, the transaction price is allocated entirely to product sales. In determining the transaction price, a significant financing component does not exist since the timing from when the Company delivers product to when the customers pay for the product is typically less than one year. Customers in certain countries pay in advance of product delivery. In those instances, payment and delivery typically occur in the same month. The Company records product sales net of any variable consideration, which includes discounts, allowances, rebates related to Medicaid and other government pricing programs, and distribution fees. The Company uses the expected value or most likely amount method when estimating its variable consideration, unless discount or rebate terms are specified within contracts. The identified variable consideration is recorded as a reduction of revenue at the time revenues from product sales are recognized. These estimates for variable consideration are adjusted to reflect known changes in factors and may impact such estimates in the quarter those changes are known. Revenue recognized does not include amounts of variable consideration that are constrained. During the years ended December 31, 2022, 2021, and 2020, net product sales in the United States were $218.3 million, $187.3 million, and $139.0 million, respectively, consisting solely of sales of Emflaza, and net product sales outside of the United States were $316.9 million, $241.6 million, and $194.4 million respectively, consisting of sales of Translarna, Tegsedi, Waylivra, and Upstaza. Translarna net product revenues made up $288.6 million, $236.0 million, and $191.9 million of the net product sales outside of the United States for the years ended December 31, 2022, 2021, and 2020, respectively. During the year ended December 31, 2022, two countries, the United States and Russia, accounted for at least 10% of the Company’s net product sales, representing $218.3 million and $59.7 million of net product sales, respectively. During the years ended December 31, 2021 and 2020, only the United States accounted for at least 10% of the Company’s net product sales. In relation to customer contracts, the Company incurs costs to fulfill a contract but does not incur costs to obtain a contract. These costs to fulfill a contract do not meet the criteria for capitalization and are expensed as incurred. The Company considers any shipping and handling costs that are incurred after the customer has obtained control of the product as a cost to fulfill a promise. Shipping and handling costs associated with finished goods delivered to customers are recorded as a selling expense. Collaboration and royalty revenue The terms of these agreements typically include payments to the Company of one or more of the following: nonrefundable, upfront license fees; milestone payments; research funding and royalties on future product sales. In addition, the Company generates service revenue through agreements that generally provide for fees for research and development services and may include additional payments upon achievement of specified events. At the inception of a collaboration arrangement, the Company needs to first evaluate if the arrangement meets the criteria in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 808 “Collaborative Arrangements” to then determine if ASC Topic 606 is applicable by considering whether the collaborator meets the definition of a customer. If the criteria are met, the Company assesses the promises in the arrangement to identify distinct performance obligations. For licenses of intellectual property, the Company assesses, at contract inception, whether the intellectual property is distinct from other performance obligations identified in the arrangement. If the licensing of intellectual property is determined to be distinct, revenue is recognized for nonrefundable, upfront license fees when the license is transferred to the customer and the customer can use and benefit from the license. If the licensing of intellectual property is determined not to be distinct, then the license will be bundled with other promises in the arrangement into one distinct performance obligation. The Company needs to determine if the bundled performance obligation is satisfied over time or at a point in time. If the Company concludes that the nonrefundable, upfront license fees will be recognized over time, the Company will need to assess the appropriate method of measuring proportional performance. For milestone payments, the Company assesses, at contract inception, whether the development or sales-based milestones are considered probable of being achieved. If it is probable that a significant revenue reversal will occur, the Company will not record revenue until the uncertainty has been resolved. Milestone payments that are contingent upon regulatory approval are not considered probable of being achieved until the applicable regulatory approvals or other external conditions are obtained as such conditions are not within the Company’s control. If it is probable that a significant revenue reversal will not occur, the Company will estimate the milestone payments using the most likely amount method. The Company will re-assess the development and sales-based milestones each reporting period to determine the probability of achievement. The Company recognizes royalties from product sales at the later of when the related sales occur or when the performance obligation to which the royalty has been allocated has been satisfied. If it is probable that a significant revenue reversal will not occur, the Company will estimate the royalty payments using the most likely amount method. The Company recognizes revenue for reimbursements of research and development costs under collaboration agreements as the services are performed. The Company records these reimbursements as revenue and not as a reduction of research and development expenses as the Company has the risks and rewards as the principal in the research and development activities. For the years ended December 31, 2022, 2021, and 2020, the Company has recognized $50.1 million, $55.0 million, and $42.6 million of collaboration revenue, respectively, related to the SMA License Agreement with Roche. For the years ended December 31, 2022, 2021 and 2020, the Company has recognized $113.5 million, $54.6 million, and $4.8 million of royalty revenue, respectively, related to Evrysdi. Allowance for doubtful accounts The Company maintains an allowance for estimated losses resulting from the inability of its customers to make required payments. The Company estimates uncollectible amounts based upon current customer receivable balances, the age of customer receivable balances, the customer’s financial condition and current economic trends. The Company also assesses whether an allowance for expected credit losses may be required which includes a review of the Company’s receivables portfolio, which are pooled on a customer basis or country basis. In making its assessment of whether an allowance for credit losses is required, the Company considers its historical experience with customers, current balances, levels of delinquency, regulatory and legal environments, and other relevant current and future forecasted economic conditions Liability for sale of future royalties On July 17, 2020, the Company, RPI Intermediate Finance Trust (“RPI”), and, for the limited purposes set forth in the agreement, Royalty Pharma PLC, entered into a Royalty Purchase Agreement (the “Royalty Purchase Agreement”). Pursuant to the Royalty Purchase Agreement, the Company sold to RPI 42.933% (the “Assigned Royalty Payment”) of the Company’s right to receive sales-based royalty payments (the “Royalty”) on worldwide net sales of Evrysdi and any other product developed pursuant to the License and Collaboration Agreement (the “License Agreement”), dated as of November 23, 2011, by and among the Company, Roche and, for the limited purposes set forth therein, the SMA Foundation under the SMA program. In consideration for the sale of the Assigned Royalty Payments, RPI paid the Company $650.0 million in cash consideration. The Company has retained a 57.067% interest in the Royalty and all economic rights to receive the remaining potential regulatory and sales milestone payments under the License Agreement, which remaining milestone payments equal $250.0 million in the aggregate as of December 31, 2022. The Royalty Purchase Agreement will terminate 60 days following the earlier of the date on which Roche is no longer obligated to make any payments of the Royalty pursuant to the License Agreement and the date on which RPI has received $1.3 billion in respect of the Assigned Royalty Payments. The cash consideration obtained pursuant to the Royalty Purchase Agreement is classified as debt and is recorded as “liability for sale of future royalties-current” and “liability for sale of future royalties-noncurrent” on the Company’s consolidated balance sheet based on the timing of the expected payments to be made to RPI. The fair value for the liability for sale of future royalties at the time of the transaction was based on the Company’s estimates of future royalties expected to be paid to RPI over the life of the arrangement, which was determined using forecasts from market data sources, which are considered Level 3 inputs. The liability is being amortized using the effective interest method over the life of the arrangement, in accordance with the respective guidance. The Company utilizes the prospective method to account for subsequent changes in the estimated future payments to be made to RPI. Refer to Note 8 for further details. ​ Leases The Company determines if an arrangement is a lease at inception. This determination generally depends on whether the arrangement conveys to the Company the right to control the use of an explicitly or implicitly identified fixed asset for a period of time in exchange for consideration. Control of an underlying asset is conveyed to the Company if the Company obtains the rights to direct the use of and to obtain substantially all of the economic benefits from using the underlying asset. The Company has lease agreements which include lease and non-lease components, which the Company accounts for as a single lease component for all leases. Operating and finance leases are classified as right of use ("ROU") assets, short term lease liabilities, and long term lease liabilities. Operating and finance lease ROU assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. ROU assets are Variable lease payments associated with the Company’s leases are recognized when the event, activity, or circumstance in the lease agreement on which those payments are assessed occurs. Variable lease payments are presented in the Company’s consolidated statements of operations in the same line item as expense arising from fixed lease payments for operating leases. Leases with an initial term of 12 months or less are not recorded on the consolidated balance sheet and the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company applies this policy to all underlying asset categories. A lessee is required to discount its unpaid lease payments using the interest rate implicit in the lease or, if that rate cannot be readily determined, its incremental borrowing rate. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company gives consideration to its recent debt issuances as well as publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The lease term for all of the Company’s leases includes the non-cancellable period of the lease plus any additional periods covered by either a Company option to extend (or not to terminate) the le Research and development costs Research and development expenses include the clinical development costs associated with the Company’s product development programs and research and development costs associated with the Company’s discovery programs. These expenses include internal research and development costs and the costs of research and development conducted on behalf of the Company by third parties, including sponsored university-based research agreements and clinical study vendors. All research and development costs are expensed as incurred. Costs incurred in obtaining technology licenses are charged immediately to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future uses. Advance payments made for goods and services that will be used in future research and development activities are deferred if the contracted party has not yet performed the related activities. The amount deferred is then recognized as expense when the research and development activities are performed. The short term deferred research and development advance payments were $2.4 million and $1.4 million and are classified as prepaid expenses and other current assets on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. The long term deferred research and development advance payments were $3.9 million and $1.8 million and are classified as deposits and other assets on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. Fair value of financial instruments The Company follows the fair value measurement rules, which provides guidance on the use of fair value in accounting and disclosure for assets and liabilities when such accounting and disclosure is called for by other accounting literature. These rules establish a fair value hierarchy for inputs to be used to measure fair value of financial assets and liabilities. This hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels: Level 1 (highest priority), Level 2, and Level 3 (lowest priority). ● Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the balance sheet date. ● Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). ● Level 3—Inputs are unobservable and reflect the Company’s assumptions as to what market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available. Cash equivalents, marketable securities, and equity investments are reflected in the accompanying financial statements at fair value. The carrying amount of receivables and accounts payable and accrued expenses approximates fair value due to the short-term nature of those instruments. Share-based compensation The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant date fair value of the award. Restricted stock awards are measured based on the fair market values of the underlying stock on the dates of grant. For service type awards, share-based compensation expense is recognized on a straight-line basis over the period during which the employee is required to provide service in exchange for the entire award. The fair value of options is calculated using the Black-Scholes option pricing model to determine the fair value of stock options on the date of grant based on key assumptions such as expected volatility and expected term. The Company estimates the expected volatility of options utilizing the Company’s historical stock volatility. The Company estimates the expected term of options utilizing the Company’s historical exercise data. The risk-free rate of the option is based on U.S. Government Securities Treasury Constant Maturities yields at the date of grant for a term similar to the expected term of the option. In connection with the adoption of FASB Accounting Standards Update (“ASU”) 2016-9, the Company made a policy election to continue its methodology for estimating its forfeiture rate. Income taxes On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act, referred to herein as the CARES Act, as a response to the economic uncertainty resulting from a strain of novel coronavirus, COVID-19. The CARES Act includes modifications for net operating loss carryovers and carrybacks, limitations of business interest expense for tax, immediate refund of alternative minimum tax (“AMT”) credit carryovers as well as a technical correction to the 2017 Tax Cuts and Jobs Act ("the 2017 Tax Act") for qualified improvement property. On December 27, 2020, the Coronavirus Response and Relief Supplemental Appropriations Act of 2021 – a $900 billion relief package to deliver the second round of economic stimulus for individuals, families, and businesses was signed into law. The bill provides relief through multiple measures and expands many of the provisions already put into place under the CARES Act. As of December 31, 2022, the Company expects that these provisions will not have a material impact. Tax provisions of the CARES Act also include the deferral of certain payroll taxes, relief for retaining employees, and other provisions. The relief for retaining employees was not material to the financial statements and there were no deferrals of certain payroll taxes as of December 31, 2022, which is no longer accrued in other current liabilities on the consolidated balance sheet. Additionally, the Organization for Economic Co-operation and Development, or OECD, the EC, and individual taxing jurisdictions where the Company and its affiliates do business have recently focused on issues related to the taxation of multinational corporations. The OECD has released its comprehensive plan to create an agreed set of international rules for fighting base erosion and profit shifting. In addition, the OECD, the EC, and individual counties are examining changes to how taxing rights should be allocated among countries considering the digital economy. As a result, the tax laws in the U.S. and other countries in which PTC and its affiliates do business could change on a prospective or retroactive basis and any such changes could materially adversely affect the Company’s business. On December 22, 2017, the U.S. government enacted the 2017 Tax Cuts and Jobs Act (“TCJA”), which significantly revised U.S. tax law by, among other provisions, lowering the U.S. federal statutory income tax rate to 21%, imposing a mandatory one-time transition tax on previously deferred foreign earnings, and eliminating or reducing certain income tax deductions. The Global Intangible Low-tax Income ("GILTI") provisions of the TCJA require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. The Company has elected to account for GILTI tax in the period in which it is incurred, and therefore has not provided any deferred tax impacts of GILTI in its consolidated financial statements for the period ended December 31, 2022. Starting in 2022, TCJA amendments to IRC Section 174 will no longer permit an immediate deduction for research and development (R&D) expenditures in the tax year that such costs are incurred. Instead, these IRC Section 174 development costs must now be capitalized and amortized over either a five- or 15-year period, depending on the location of the activities performed. The new amortization period begins with the midpoint of any taxable year that IRC Section 174 costs are first incurred, regardless of whether the expenditures were made prior to or after July 1 and runs until the midpoint of year five for activities conducted in the United States or year 15 in the case of development conducted on foreign soil. This tax law change resulted in an increased current taxable income of the Company by $450.1 million for the year ended December 31, 2022. In December 2

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2022
Business Combinations [Abstract]
Acquisitions	3. Acquisitions Censa Asset Acquisition On May 29, 2020, the Company completed its acquisition of Censa Pharmaceuticals, Inc. (“Censa”) pursuant to an Agreement and Plan of Merger, dated as of May 5, 2020 (the "Censa Merger Agreement"), by and among the Company, Hydro Merger Sub, Inc., the Company’s wholly owned, indirect subsidiary, and, solely in its capacity as the representative, agent and attorney-in-fact of the securityholders of Censa, Shareholder Representative Services LLC (the "Censa Merger"). Upon the closing of the Censa Merger, the Company paid to the Censa securityholders (i) cash consideration of $15.0 million, which consisted of an upfront payment of $10.4 million and an additional $4.6 million for the net assets on Censa’s opening balance sheet as of the date of the acquisition, and (ii) 845,364 shares of the Company’s common stock, which were valued at $42.9 million based on the closing stock price on the acquisition date. The number of shares issued was determined using a 30-day volume weighted average price (“VWAP”) pursuant to the Censa Merger Agreement. The Company determined that substantially all of the fair value is concentrated in sepiapterin, formerly known as PTC923, and accounted for the transaction as an asset acquisition under ASC 805-50. The purchase price consisted of the cash consideration of $15.0 million and $42.9 million in the Company’s common stock, in addition to $0.7 million of acquisition costs. As such, the total consideration transferred was determined to be $58.6 million. The opening balance sheet net assets of $4.6 million, which consisted of cash of $3.8 million and other current assets of $0.8 million, were determined to be non-qualifying assets and recorded at their fair values, respectively. The remaining consideration of $54.0 million was allocated to sepiapterin. As sepiapterin is an IPR&D asset, the Company concluded that it did not have any alternative future use, and accordingly, the fair value amount allocated to the IPR&D was expensed. Of the $54.0 million, $53.3 million is included in research and development expense and the $0.7 million related to the acquisition costs, is included in selling, general, and administrative expense within the Company’s statement of operations for the year ended December 31, 2020. Refer to Note 15 for to the terms and conditions of the Censa Merger Agreement. ​ ​

Fair value of financial instrum

Fair value of financial instruments and investments	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair value of financial instruments and investments	The Company follows the fair value measurement rules, which provide guidance on the use of fair value in accounting and disclosure for assets and liabilities when such accounting and disclosure is called for by other accounting literature. Company’s marketable securities are classified as Level 2 as they primarily utilize broker quotes in a nonactive market to value these securities. The Company owns common stock in ClearPoint Neuro, Inc. (“ClearPoint”) (formerly MRI Interventions, Inc.), a publicly traded medical device company. The ClearPoint equity investments (collectively, the “ClearPoint Equity Investments”) represent financial instruments, and therefore, are recorded at fair value, which is readily determinable. The ClearPoint Equity Investments are components of deposits and other assets on the consolidated balance sheet. During the years ended December 31, 2022 and 2021, the Company recorded unrealized losses of $3.5 million and $6.1 million, respectively, which are components of other (expense) income, net within the consolidated statement of operations. The fair value of the equity investments was $11.0 million and $14.5 million as of December 31, 2022 and 2021, respectively. The Company classifies its equity investments in ClearPoint as a Level 1 asset within the fair value hierarchy, as the value is based on a quoted market price in an active market, which is not adjusted. ​ In January 2020, the Company purchased a $10.0 million convertible note from ClearPoint that the Company can convert into ClearPoint shares at a conversion rate of $6.00 per share at any point throughout the term of the loan, which matures five years from the purchase date. The Company determined that the convertible note represents an available for sale debt security and the Company has elected to record it at fair value under ASC 825. The Company classifies its ClearPoint convertible debt security as a Level 2 asset within the fair value hierarchy, as the value is based on inputs other than quoted prices that are observable. The fair value of the ClearPoint convertible debt security is determined at each reporting period by utilizing a Black-Scholes option pricing model, as well as a present value of expected cash flows from the debt security utilizing the risk free rate and the estimated credit spread as of the valuation date as the discount rate. During the years ended December 31, 2022 and 2021, the Company recorded unrealized losses of $5.8 million and $8.3 million, respectively. These unrealized losses are components of other (expense) income, net within the consolidated statement of operations. The fair value of the convertible debt security was $15.2 million and $21.0 million as of December 31, 2022 and 2021, respectively. The convertible debt security is considered to be long term and is included as a component of deposits and other assets on the consolidated balance sheet. Other than the equity investment and the convertible debt security, no other items included in deposits and other assets on the consolidated balance sheets are fair valued. The Company has investments in mutual funds, including one that is denominated in a foreign currency. All of these are equity investments and are classified as marketable securities on the Company’s consolidated balance sheets. These equity investments are reported at fair value, as it is readily available, and as such are classified as Level 1 assets. Unrealized holding gains and losses for these equity investments are included as components of other (expense) income, net within the consolidated statement of operations. During the years ended December 31, 2022 and 2021, the Company had $8.0 million unrealized losses and $1.7 million unrealized net gains, respectively, relating to the equity investments still held at the reporting date. During the years ended December 31, 2022 and 2021, the Company had redemptions of $113.0 million and $4.3 million, respectively. During the years ended December 31, 2022 and 2021, the Company had $0.5 million and $0.4 million foreign currency unrealized losses, respectively, relating to these equity investments. Fair value of marketable securities that are classified as available for sale debt securities is based upon market prices using quoted prices in active markets for identical assets quoted on the last day of the period. In establishing the estimated fair value of the remaining available for sale debt securities, the Company used the fair value as determined by its investment advisors using observable inputs other than quoted prices. The following represents the fair value using the hierarchy described in Note 2 for the Company’s financial assets and liabilities that are required to be measured at fair value on a recurring basis as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ ​ Quoted prices Significant ​ ​ ​ ​ ​ ​ in active other Significant ​ ​ ​ ​ markets for observable unobservable ​ ​ ​ ​ identical assets inputs inputs ​ Total (level 1) (level 2) (level 3) Marketable securities - available for sale ​ $ 22,610 ​ $ — ​ $ 22,610 ​ $ — Marketable securities - equity investments ​ $ 108,261 ​ $ 108,261 ​ $ — ​ $ — ClearPoint Equity Investments ​ $ 10,965 ​ $ 10,965 ​ $ — ​ $ — ClearPoint convertible debt security ​ $ 15,231 ​ $ — ​ $ 15,231 ​ $ — Contingent consideration payable- development and regulatory milestones ​ $ 82,500 ​ $ — ​ $ — ​ $ 82,500 Contingent consideration payable- net sales milestones and royalties ​ $ 81,500 ​ $ — ​ $ — ​ $ 81,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Quoted prices Significant ​ ​ ​ ​ ​ ​ in active other Significant ​ ​ ​ ​ markets for observable unobservable ​ ​ ​ ​ identical assets inputs inputs ​ Total (level 1) (level 2) (level 3) Marketable securities - available for sale ​ $ 376,685 ​ $ — ​ $ 376,685 ​ $ — Marketable securities - equity investments ​ $ 206,973 ​ $ 206,973 ​ $ — ​ $ — ClearPoint Equity Investments ​ $ 14,525 ​ $ 14,525 ​ $ — ​ $ — ClearPoint convertible debt security ​ $ 20,971 ​ $ — ​ $ 20,971 ​ $ — Contingent consideration payable- development and regulatory milestones ​ $ 139,300 ​ $ — ​ $ — ​ $ 139,300 Contingent consideration payable- net sales milestones and royalties ​ $ 100,600 ​ $ — ​ $ — ​ $ 100,600 ​ No transfers of assets between Level 1 and Level 2 of the fair value measurement hierarchy occurred during the years ended December 31, 2022 and 2021. The following is a summary of marketable securities accounted for as available for sale debt securities at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Amortized Gross Unrealized ​ ​ ​ ​ Cost Gains Losses Fair Value Commercial paper ​ $ 12,419 ​ $ 5 ​ $ — ​ $ 12,424 Corporate debt securities ​ 10,685 ​ ​ — ​ ​ (499) ​ ​ 10,186 Total ​ $ 23,104 ​ $ 5 ​ $ (499) ​ $ 22,610 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Amortized Gross Unrealized ​ ​ ​ ​ Cost Gains Losses Fair Value Commercial paper ​ $ 75,275 ​ $ 5 ​ $ (1) ​ $ 75,279 Corporate debt securities ​ 268,246 ​ ​ 81 ​ ​ (644) ​ 267,683 Asset-backed securities ​ 15,287 ​ ​ 16 ​ ​ (5) ​ 15,298 Government obligations ​ ​ 18,479 ​ ​ 5 ​ ​ (59) ​ ​ 18,425 Total ​ $ 377,287 ​ $ 107 ​ $ (709) ​ $ 376,685 ​ For available for sale debt securities in an unrealized loss position, the Company assesses whether it intends to sell or if it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value. For the years ended December 31, 2022 and 2021, no write downs occurred. The Company does not intend to sell the 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, which may be maturity. The Company also reviews its available for sale debt securities in an unrealized loss position and evaluates whether the decline in fair value has resulted from credit losses or other factors. This review is subjective, as it requires management to evaluate whether an event or change in circumstances has occurred in that period that may be related to credit issues. For the years ended December 31, 2022 and 2021, no allowance was recorded for credit losses. Unrealized gains and losses are reported as a component of accumulated other comprehensive (loss) income in stockholders’ equity. For the year ended December 31, 2022, the Company had $4.0 million of realized losses from the sale of available for sale debt securities. For the year ended December 31, 2021, the Company had $0.8 million of realized gains from the sale of available for sale debt securities. Realized gains and losses are reported as a component of interest expense, net in the consolidated statement of operations. The unrealized losses and fair values of available for sale debt securities that have been in an unrealized loss position for a period of less than and greater than or equal to 12 months as of December 31, 2022 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Securities in an unrealized loss Securities in an unrealized loss ​ ​ ​ ​ ​ ​ position less than 12 months position greater than or equal to 12 months ​ Total ​ Unrealized losses Fair Value Unrealized losses Fair Value Unrealized losses Fair Value Corporate debt securities ​ $ — ​ ​ — ​ ​ (499) ​ ​ 10,186 ​ ​ (499) ​ $ 10,186 Total ​ $ — ​ $ — ​ $ (499) ​ $ 10,186 ​ $ (499) ​ $ 10,186 ​ The unrealized losses and fair values of available for sale debt securities that have been in an unrealized loss position for a period of less than and greater than or equal to 12 months as of December 31, 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Securities in an unrealized loss Securities in an unrealized loss ​ ​ ​ ​ ​ ​ position less than 12 months position greater than or equal to 12 months ​ Total ​ Unrealized losses Fair Value Unrealized losses Fair Value Unrealized losses Fair Value Commercial paper ​ $ (1) ​ ​ 12,992 ​ ​ — ​ ​ — ​ ​ (1) ​ $ 12,992 Corporate debt securities ​ ​ (608) ​ ​ 217,540 ​ ​ (36) ​ ​ 4,985 ​ ​ (644) ​ ​ 222,525 Asset-backed securities ​ (5) ​ ​ 10,786 ​ ​ — ​ ​ — ​ (5) ​ ​ 10,786 Government obligations ​ ​ (59) ​ ​ 15,483 ​ ​ — ​ ​ — ​ ​ (59) ​ ​ 15,483 Total ​ $ (673) ​ $ 256,801 ​ $ (36) ​ $ 4,985 ​ $ (709) ​ $ 261,786 ​ Available for sale debt securities on the balance sheet at December 31, 2022 and 2021 mature as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Less Than More Than ​ 12 Months 12 Months Commercial paper ​ $ 12,424 ​ $ — Corporate debt securities ​ — ​ 10,186 Total ​ $ 12,424 ​ $ 10,186 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Less Than More Than ​ 12 Months 12 Months Commercial paper ​ $ 75,279 ​ $ — Corporate debt securities ​ 131,606 ​ 136,077 Asset-backed securities ​ 8,724 ​ 6,574 Government obligations ​ ​ 6,002 ​ ​ 12,423 Total ​ $ 221,611 ​ $ 155,074 ​ The Company classifies all of its marketable securities as current as they are all either available for sale debt securities or equity investments and are available for current operations. Convertible senior notes In August 2015, the Company issued $150.0 million of 3.0% convertible senior notes due August 15, 2022 (the “2022 Convertible Notes”). In September 2019, the Company issued $287.5 million of 1.5% convertible senior notes due September 15, 2026 (the “2026 Convertible Notes,” together with the “2022 Convertible Notes,” the “Convertible Notes”). On August 15, 2022, the Company repaid the outstanding principal amount and accrued interest, totaling $152.3 million, of the 2022 Convertible Notes that was due upon maturity in accordance with the terms of the notes. The fair value of the Convertible Notes, which differs from their carrying values, is influenced by interest rates, the Company’s stock price and stock price volatility and is determined by prices for the Convertible Notes observed in market trading which are Level 2 inputs. As the 2022 Convertible Notes have been repaid, they are no longer on the balance sheet as of December 31, 2022. The estimated fair value of the 2022 Convertible Notes at December 31, 2021 was $158.3 million. The estimated fair value of the 2026 Convertible Notes at December 31, 2022 and December 31, 2021 was $281.7 million and $305.3 million, respectively. Level 3 valuation The contingent consideration payable is fair valued each reporting period with the change in fair value recorded as a gain or loss in the consolidated statements of operations. The fair value of the development and regulatory milestones are estimated utilizing a probability adjusted, discounted cash flow approach. The discount rates are estimated utilizing Corporate B rated bonds maturing in the years of expected payments based on the Company’s estimated development timelines for the acquired product candidate. On December 31, 2022, the weighted average discount rate for the development and regulatory milestones was 7.8% and the weighted average probability of success was 35%. The fair value of the net sales milestones and royalties is determined utilizing an option pricing model with Monte Carlo simulation to simulate a range of possible payment scenarios, and the average of the payments in these scenarios is then discounted to calculate present fair value. On December 31, 2022, the weighted average discount rate for the net sales milestones and royalties was 11.5% and the weighted average probability of success for the net sales milestones was 50%. The table presented below is a summary of changes in the fair value of the Company’s Level 3 valuation for the contingent consideration payables for the years ended December 31, 2022, and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration payable- ​ Contingent consideration payable- ​ ​ development and regulatory ​ net sales milestones and royalties ​ milestones - Agilis - Agilis Beginning balance as of December 31, 2020 ​ $ 139,200 ​ $ 101,200 Additions ​ — ​ — Change in fair value ​ 100 ​ (600) Payments ​ ​ — ​ ​ — Ending balance as of December 31, 2021 ​ $ 139,300 ​ $ 100,600 Additions ​ — ​ — Change in fair value ​ (6,800) ​ (19,100) Payments ​ (50,000) ​ — Ending balance as of December 31, 2022 ​ $ 82,500 ​ $ 81,500 ​ In July 2022, the European Commission approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA, which triggered a $50.0 million milestone payment to the former equityholders of Agilis in accordance with the terms of the Agilis Merger Agreement. In accordance with ASC 230, the portion of the $50.0 million milestone payment up to the acquisition date fair value of the contingent consideration liability is classified as a financing outflow and the amount paid in excess of the acquisition date fair value of that liability is classified as an operating outflow on the consolidated statements of cash flows. The following significant unobservable inputs were used in the valuation of the contingent consideration payables for the years ended December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Fair Value Valuation Technique Unobservable Input Range Contingent consideration payable- ​ $82,500 Probability-adjusted discounted cash flow Potential development and regulatory milestones ​ $0 - $331 million Contingent considerable payable- net sales ​ $81,500 Option-pricing model with Monte Carlo simulation Potential net sales milestones ​ $0 - $150 million ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Fair Value Valuation Technique Unobservable Input Range Contingent consideration payable- ​ $139,300 Probability-adjusted discounted cash flow Potential development and regulatory milestones ​ $0 - $381 million Contingent considerable payable- net sales ​ $100,600 Option-pricing model with Monte Carlo simulation Potential net sales milestones ​ $0 - $150 million ​ The contingent consideration payables are classified Level 3 liabilities as their valuation requires substantial judgment and estimation of factors that are not currently observable in the market. If different assumptions were used for the various inputs to the valuation approaches, including but not limited to, assumptions involving probability adjusted sales estimates for the gene therapy platform and estimated discount rates, the estimated fair value could be significantly higher or lower than the fair value determined.

Fixed assets

Fixed assets	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Fixed assets	5. Fixed assets Fixed assets, net were as follows at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 Leasehold improvements ​ $ 28,969 ​ $ 19,937 Computer equipment and software ​ 15,332 ​ 13,812 Machinery and lab equipment ​ ​ 47,496 ​ ​ 33,187 Furniture and fixtures ​ 3,812 ​ 3,805 Assets in process ​ 14,349 ​ 9,017 ​ ​ 109,958 ​ 79,758 Less accumulated depreciation ​ (37,368) ​ (27,173) Total ​ $ 72,590 ​ $ 52,585 ​ Depreciation expense was approximately $12.3 million, $9.4 million, and $6.6 million for the years ended December 31, 2022, 2021, and 2020, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases
Leases	6. Leases The Company leases office space in South Plainfield, New Jersey for its principal office under two noncancelable operating leases through August 2024, in addition to office and laboratory space in Bridgewater, New Jersey and office space in various countries for international employees primarily through workspace providers. The Company also leases approximately 220,500 square feet of office, manufacturing and laboratory space at a facility located in Hopewell Township, New Jersey (the “Campus”) pursuant to a Lease Agreement (the “Lease”) with Hopewell Campus Owner LLC (the “Landlord”). The rental term of the Lease commenced on July 1, 2020 and has an initial term of fifteen years (the “Initial Term”), with two consecutive ten year renewal periods, each at the Company’s option. The aggregate rent for the Initial Term will be approximately $111.5 million. The rental rate for the renewal periods will be 95% of the Prevailing Market Rate (as defined in the Lease) and determined at the time of the exercise of the renewal. The Company is also responsible for maintaining certain insurance and the payment of proportional taxes, utilities and common area operating expenses. The Lease contains customary events of default, representations, warranties and covenants. Subject to the terms of the Lease, the Company has a right of first refusal to rent certain other space of the Campus, which would be triggered upon the Landlord’s issuance of a second round proposal or letter of intent to another tenant for such space. The Company also may seek to build a new separate building on the Campus, which may not contain less than 75,000 square feet (the “New Building”). Upon receipt of notice of the Company’s intention to build the New Building, the Landlord may, in its sole discretion, construct and lease the New Building to the Company or enter into a ground lease with the Company permitting the Company to construct the New Building. Rent terms for the New Building would be determined based on the land value, construction and project costs subject to whether the Landlord or Company constructs the New Building. In May 2022, the Company entered into a Lease Agreement (the “Warren Lease”) with Warren CC Acquisitions, LLC (the “Warren Landlord”) relating to the lease of two entire buildings comprised of approximately 360,000 square feet of shell condition, modifiable space (the “Warren Premises”) at a facility located in Warren, New Jersey. The rental term of the Warren Lease commenced on June 1, 2022 (the “Commencement Date”), with an initial term of seventeen years (the “Warren Initial Term”), followed by three consecutive five-year renewal periods at the Company’s option. The aggregate base rent for the Warren Initial Term will be approximately $163.0 million; provided, however, that if the Company is not subject to an Event of Default (as defined in the Warren Lease), the Company will be entitled to a base rent abatement over the first three years of the Warren Initial Term of approximately $18.6 million, reducing the Company’s total base rent obligation to $144.4 million. The rental rate for the renewal periods will be at the Fair Market Rental Value (as defined in the Warren Lease) and determined at the time of the exercise of the renewal. Beginning in the second lease year, the Company is also responsible for the payment of all taxes and operating expenses for the Warren Premises. As a result, the Company recorded an operating lease ROU asset of $28.9 million and an operating lease ROU liability of $28.9 million as of the Commencement Date. The Company plans on developing the Warren Premises into office and laboratory space. The Company is entitled to an allowance of approximately $36.2 million to be provided by the Warren Landlord to be used towards such improvements. The Landlord is providing the allowance to cover those assets that are real property improvements, such as structural components, roofs, flooring, etc., whose useful lives are typically longer in nature. Upon the first issuance of a temporary certificate of occupancy for the Warren Premises, the Company will receive $5.0 million from the Landlord, which the Company has committed to fund into the construction account. The Company evaluated the leasehold improvements under ASC 842 and determined that the Company will be the owner of the improvements, and therefore the $36.2 million allowance and $5.0 million due from the Landlord were treated as lease incentives at the commencement of the lease and included in the calculation of the lease ROU asset and lease ROU liability, effectively reducing both at Commencement Date. On June 19, 2020, the Company entered into a commercial manufacturing service agreement for a term of 12.5 years with MassBiologics of the University of Massachusetts Medical School ("MassBio"). The Company determined that the agreement was a finance lease, for which the Company recorded a finance lease ROU asset for $41.4 million and corresponding finance lease liability for $41.4 million at the onset of the lease agreement. Given that the leased asset is designed for the production of PTC’s AADC program and would not have an alternate use outside the PTC gene therapy platform without incurring significant costs, the Company determined that the lease should be treated as research and development expense under ASC 730. Accordingly, the full $41.4 million relating to the finance lease ROU asset was written off and expensed to research and development during the year ended December 31, 2020. As of December 31, 2022, the balance of the finance lease liabilities-current and finance lease liabilities-non-current are $3.0 million and $18.7 million, respectively, and are directly related to the Company’s MassBio agreement. As of December 31, 2021, the balance of the finance lease liabilities-current and finance lease liabilities non-current were $3.0 million and $20.1 million, respectively. Additionally, during the years ended December 31, 2022 and December 31, 2021, the Company recorded finance lease costs of $1.6 million and $1.7 million, respectively, related to interest on the lease liability. The Company also leases certain vehicles, lab equipment, and office equipment under operating leases. The Company’s operating leases have remaining lease terms ranging from 1.2 years to 16.4 years and certain leases include renewal options to extend the lease for up to 15 years. Rent expense was approximately $25.2 million, $21.4 million, and $15.3 million for the years ended December 31, 2022, 2021 and 2020. The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2022 ​ Year Ended December 31, 2021 ​ Year Ended December 31, 2020 Operating Lease Cost ​ ​ ​ ​ ​ ​ ​ ​ Fixed lease cost ​ $ 19,804 ​ $ 16,411 ​ $ 12,368 Variable lease cost ​ ​ 4,557 ​ ​ 4,361 ​ ​ 2,448 Short-term lease cost ​ ​ 808 ​ ​ 656 ​ ​ 450 Total operating lease cost ​ $ 25,169 ​ $ 21,428 ​ $ 15,266 ​ Total operating lease cost is a component of operating expenses on the consolidated statements of operations. ​ Supplemental lease term and discount rate information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 Weighted-average remaining lease terms - operating leases (years) 11.61 ​ ​ 10.87 ​ Weighted-average discount rate - operating leases ​ 8.61 % ​ 8.91 % Weighted-average remaining lease terms - finance lease (years) 10.01 ​ ​ 11.00 ​ Weighted-average discount rate - finance lease 7.80 % ​ 7.80 % ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 ​ 2020 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases $ 14,736 ​ $ 13,683 ​ $ 8,462 Financing cash flows from finance lease ​ 1,276 ​ ​ 2,224 ​ ​ 17,829 Operating cash flows from finance leases ​ 1,724 ​ ​ 776 ​ ​ 171 ​ ​ ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease obligations: ​ ​ ​ ​ ​ Operating leases $ 35,817 ​ $ 645 ​ $ 76,811 Finance lease ​ — ​ ​ — ​ ​ 41,382 ​ Future minimum lease payments under non-cancelable leases as of December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Lease 2023 ​ $ 15,373 ​ $ 3,000 2024 ​ 18,456 ​ 3,000 2025 ​ 20,431 ​ 3,000 2026 ​ 19,985 ​ 3,000 2027 and thereafter ​ 193,792 ​ 18,000 Total lease payments ​ 268,037 ​ 30,000 Less: Imputed Interest expense ​ 157,807 ​ 8,325 Total ​ $ 110,230 ​ $ 21,675 ​

Accounts payable and accrued ex

Accounts payable and accrued expenses	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accounts payable and accrued expenses	7. Accounts payable and accrued expenses Accounts payable and accrued expenses at December 31, 2022 and 2021 consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 Employee compensation, benefits, and related accruals ​ $ 62,669 ​ $ 55,733 Income tax payable ​ ​ 4,712 ​ ​ 1,287 Consulting and contracted research ​ 38,882 ​ 26,434 Professional fees ​ 3,093 ​ 3,547 Sales allowance ​ 63,787 ​ 61,662 Sales rebates ​ 67,355 ​ 68,770 Royalties ​ ​ 40,546 ​ ​ 35,679 Accounts payable ​ 27,268 ​ 23,033 Other ​ 12,054 ​ 12,639 Total ​ $ 320,366 ​ $ 288,784 ​

Debt

Debt	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Debt	8. Debt Liability for sale of future royalties In July 2020, the Company entered into the Royalty Purchase Agreement. As RPI’s interest is explicitly limited, the $650.0 million cash consideration was classified as debt and is recorded as “liability for sale of future royalties-current” and “liability for sale of future royalties-noncurrent” on the Company’s consolidated balance sheet based on the timing of the expected payments to be made to RPI. The fair value for the liability for sale of future royalties at the time of the transaction was based on the Company’s estimates of future royalties expected to be paid to RPI over the life of the arrangement, which was determined using forecasts from market data sources, which are considered Level 3 inputs. The liability will be amortized using the effective interest method over the life of the arrangement, in accordance ASC 470 and ASC 835. The initial annual effective interest rate was determined to be 11.0%. The Company utilizes the prospective method to account for subsequent changes in the estimated future payments to be made to RPI and updates the effective interest rate on a quarterly basis. Issuance costs related to the transaction were determined to be immaterial. ​ The following table shows the activity within the “liability for sale of future royalties- current” and “liability for sale of future royalties- noncurrent” accounts for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Liability for sale of future royalties- (current and noncurrent) ​ 2022 ​ Beginning balance as of December 31, 2021 ​ $ 733,985 ​ Less: Non-cash royalty revenue payable to RPI ​ ​ (48,738) ​ Plus: Non-cash interest expense recognized ​ ​ 72,639 ​ Ending balance ​ $ 757,886 ​ Effective interest rate as of December 31, 2022 ​ 8.7 % ​ ​ Non-cash interest expense is recorded in the statement of operations within “Interest expense, net”. ​ Senior Secured Term Loan ​ On October 27, 2022 (the “Closing Date”), the Company entered into a credit agreement (the “Blackstone Credit Agreement”) for fundings of up to $950.0 million consisting of a committed loan facility of $450.0 million and further contemplating the potential for up to $500.0 million of additional financing, to the extent that the Company requests such additional financing and subject to the Lenders’ agreement to provide such additional financing and to mutual agreement on terms, among the Company, certain subsidiaries of the Company (together with the Company, the “Loan Parties”) and funds and other affiliated entities advised or managed by Blackstone Life Sciences and Blackstone Credit (collectively, “Blackstone”, and such lenders, together with their permitted assignees, the “Lenders” and each a “Lender”) and Wilmington Trust, National Association, as the administrative agent for the Lenders. ​ The Blackstone Credit Agreement provides for a senior secured term loan facility funded on the Closing Date in the aggregate principal amount of $300.0 million (the “Initial Loans”) and a committed delayed draw term loan facility of up to $150.0 million (the “Delayed Draw Loans” and, together with the Initial Loans, the “Loans”) to be funded at the Company’s request within 18 months of the Closing Date subject to specified conditions. In addition, the Blackstone Credit Agreement contemplates the potential for further financings by Blackstone, by providing for incremental discretionary uncommitted further financings of up to $500.0 million. The Company capitalized approximately $11.6 million of debt issuance costs which are presented on the balance sheet as a direct deduction from the debt liability and are being amortized over the term of the senior secured term loan facility using the effective interest rate method. ​ The Loans mature on the date that is seven years from the Closing Date. Borrowings under the Blackstone Credit Agreement bear interest at a variable rate equal to, at the Company’s option, either an adjusted Term SOFR rate plus seven and a quarter percent (7.25%) or the Base Rate plus six and a quarter percent (6.25%), subject to a floor of one percent (1%) and two percent (2%) with respect to Term SOFR rate and Base Rate (each as defined in the Blackstone Credit Agreement), respectively. Payment of the Loans are subject to certain premiums specified in the Blackstone Credit Agreement, in each case, from the date of the applicable Loan funded. ​ All obligations under the Blackstone Credit Agreement are secured, subject to certain exceptions and specified inclusions, by security interests in certain assets of the Loan Parties, including (1) intellectual property and other assets related to Translarna, Emflaza, Upstaza, sepiapterin and, until certain release conditions are met, vatiquinone, in each case, together with any other forms, formulations, or methods of delivery of any such products, and regardless of trade or brand name, (2) future acquired intellectual property (but not internally developed intellectual property unrelated to other intellectual property collateral) and other related assets, and (3) the equity interests held by the Loan Parties in certain of their subsidiaries. The Blackstone Credit Agreement contains certain negative covenants with which the Company must remain in compliance. The Blackstone Credit Agreement also requires that the Company maintains consolidated liquidity of at least $100.0 million as of the last day of each fiscal quarter, which shall be increased to $200.0 million upon the Company consummating acquisitions meeting certain consolidated thresholds described therein. In addition, the Company will be required under conditions specified in the Blackstone Credit Agreement to fund a reserve account up to certain amounts specified therein. The funds in the reserve account are available to prepay the Loans at any time at the Company’s option, and are, if funded, subject to release upon certain further conditions. Upon any such release, such funds are freely available for use by the Company subject to the generally applicable terms and conditions of the Blackstone Credit Agreement. The Blackstone Credit Agreement contains certain customary representations and warranties, affirmative covenants and provisions relating to events of default. ​ The following table sets forth total interest expense recognized related to the senior secured term loan: ​ ​ ​ ​ ​ ​ Year ended ​ December 31, ​ 2022 ​ Contractual interest expense $ 6,069 ​ Amortization of debt issuance costs 290 ​ Total $ 6,359 ​ Effective interest rate ​ 12.2 % ​ ​ 2026 Convertible Notes In September 2019, the Company issued, at par value, $287.5 million aggregate principal amount of 1.50% convertible senior notes due 2026, which included an option to purchase up to an additional $37.5 million in aggregate principal amount of the 2026 Convertible Notes, which was exercised in full by the initial purchasers. The 2026 Convertible Notes bear cash interest at a rate of 1.50% per year, payable semi-annually on March 15 and September 15 of each year, beginning on March 15, 2020. The 2026 Convertible Notes will mature on September 15, 2026, unless earlier repurchased or converted. The net proceeds to the Company from the offering were $279.3 million after deducting the initial purchasers’ discounts and commissions and the offering expenses payable by the Company. The 2026 Convertible Notes are governed by an indenture (the “2026 Convertible Notes Indenture”) with U.S Bank National Association as trustee (the “2026 Convertible Notes Trustee”). Holders of the 2026 Convertible Notes may convert their 2026 Convertible Notes at their option at any time prior to the close of business on the business day immediately preceding March 15, 2026 only under the following circumstances: ● during any calendar quarter commencing on or after December 31, 2019 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; ● during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the 2026 Convertible Notes Indenture) per $1,000 principal amount of 2026 Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; ● during any period after the Company has issued notice of redemption until the close of business on the scheduled trading day immediately preceding the relevant redemption date; or ● upon the occurrence of specified corporate events. On or after March 15, 2026, until the close of business on the business day immediately preceding the maturity date, holders may convert their 2026 Convertible Notes at any time, regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of the Company’s common stock or any combination thereof at the Company’s election. The conversion rate for the 2026 Convertible Notes was initially, and remains, 19.0404 shares of the Company’s common stock per $1,000 principal amount of the 2026 Convertible Notes, which is equivalent to an initial conversion price of approximately $52.52 per share of the Company’s common stock. The conversion rate may be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. The Company is not permitted to redeem the 2026 Convertible Notes prior to September 20, 2023. The Company may redeem for cash all or any portion of the 2026 Convertible Notes, at its option, if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect on the last trading day of, and for at least 19 other trading days (whether or not consecutive) during, any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption, at a redemption price equal to 100% of the principal amount of the 2026 Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the 2026 Convertible Notes, which means that the Company is not required to redeem or retire the 2026 Convertible Notes periodically. If the Company undergoes a “fundamental change” (as defined in the 2026 Convertible Notes Indenture), subject to certain conditions, holders of the 2026 Convertible Notes may require the Company to repurchase for cash all or part of their 2026 Convertible Notes at a repurchase price equal to 100% of the principal amount of the 2026 Convertible Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The 2026 Convertible Notes represent senior unsecured obligations and will rank senior in right of payment to the Company’s future indebtedness that is expressly subordinated in right of payment to the notes, equal in right of payment to the Company’s existing and future unsecured indebtedness that is not so subordinated, effectively junior in right of payment to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness, and structurally subordinated to all existing and future indebtedness and other liabilities (including trade payables) incurred by the Company’s subsidiaries. The 2026 Convertible Notes Indenture contains customary events of default with respect to the 2026 Convertible Notes, including that upon certain events of default (including the Company’s failure to make any payment of principal or interest on the 2026 Convertible Notes when due and payable) occurring and continuing, the 2026 Convertible Notes Trustee by notice to the Company, or the holders of at least 25% in principal amount of the outstanding 2026 Convertible Notes by notice to the Company and the Convertible Notes Trustee, may, and the 2026 Convertible Notes Trustee at the request of such holders (subject to the provisions of the 2026 Convertible Notes Indenture) will, declare 100% of the principal of and accrued and unpaid interest, if any, on all the 2026 Convertible Notes to be due and payable. In case of certain events of bankruptcy, insolvency or reorganization, involving the Company or a significant subsidiary, 100% of the principal of and accrued and unpaid interest on the 2026 Convertible Notes will automatically become due and payable. Upon such a declaration of acceleration, such principal and accrued and unpaid interest, if any, will be due and payable immediately. Prior to the adoption of ASU 2020-06, the Company accounted for the 2026 Convertible Notes as a liability and equity component where the carrying value of the liability component was valued based on a similar instrument. In accounting for the issuance of the 2026 Convertible Notes, the Company separated the 2026 Convertible Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that did not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2026 Convertible Notes as a whole. The excess of the principal amount of the liability component over its carrying amount, referred to as the debt discount, was amortized to interest expense over the seven-year term of the 2026 Convertible Notes. The equity component was not re-measured as long as it continued to meet the conditions for equity classification. The equity component recorded at issuance related to the 2026 Convertible Notes was $123.0 million and was recorded in additional paid-in capital. In accounting for the transaction costs related to the issuance of the 2026 Convertible Notes, the Company allocated the total costs incurred to the liability and equity components of the 2026 Convertible Notes based on their relative values. Transaction costs attributable to the liability component were amortized to interest expense over the seven-year term of the 2026 Convertible Notes, and transaction costs attributable to the equity component were netted with the equity components in stockholders’ equity. Additionally, the Company initially recorded a net deferred tax liability of $25.3 million in connection with the 2026 Convertible Notes. Effective January 1, 2021 the Company adopted ASU 2020-06. After adoption, the Company now accounts for the 2026 Convertible Notes as a single liability measured at amortized cost. As the equity component is no longer required to be split into a separate component, the Company recorded an adjustment for the initial $123.0 million that was allocated to additional paid in capital and $16.1 million of life to date interest expense recorded as amortization of debt discount. Additionally, the net deferred tax liability recorded for the 2026 Convertible Notes was reversed. The principal amount of the liability over its carrying amount is amortized to interest expense over the seven-year term of the 2026 Convertible Notes. Since the 2026 Convertible Notes are classified as a single liability, there is no debt discount required to be amortized. The 2026 Convertible Notes consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, Liability component ​ 2022 ​ ​ 2021 Principal ​ $ 287,500 ​ $ 287,500 Less: Debt issuance costs ​ (4,456) ​ ​ (5,606) Net carrying amount ​ $ 283,044 ​ $ 281,894 ​ As of December 31, 2022, the remaining contractual life of the 2026 Convertible Notes is approximately 3.7 years. The following table sets forth total interest expense recognized related to the 2026 Convertible Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 ​ Contractual interest expense ​ $ 4,313 ​ $ 4,313 ​ Amortization of debt issuance costs ​ 1,150 ​ ​ 1,128 ​ Total ​ $ 5,463 ​ $ 5,441 ​ Effective interest rate ​ 1.9 % ​ 1.9 % ​ In April 2022, under the terms of the 2026 Convertible Notes Indenture, the Company paid additional interest on the 2026 Convertible Notes at a rate equal to 0.5% per annum, for a total interest payment of approximately $2.1 million, for the period beginning September 25, 2020 and ending March 14, 2022. In September 2022, under the terms of the 2026 Convertible Notes Indenture, the Company paid additional interest on the 2026 Convertible Notes at a rate equal to 0.5% per annum, for a total interest payment of approximately $0.1 million, for the period beginning March 15, 2022 and ending April 8, 2022. These amounts are not included in the table above, but were recorded as interest expense, net within the statement of operations for the year ended December 31, 2022. ​ 2022 Convertible Notes In August 2015, the Company issued, at par value, $150.0 million aggregate principal amount of 3.00% convertible senior notes due 2022. On August 15, 2022, the Company repaid the outstanding principal amount and accrued interest, totaling $152.3 million, of the 2022 Convertible Notes that was due upon maturity in accordance with the terms of the notes. The 2022 Convertible Notes consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, Liability component ​ 2022 2021 Principal ​ $ 150,000 ​ $ 150,000 Less: Debt issuance costs ​ — ​ (460) Repayment of Convertible Notes ​ (150,000) ​ — Net carrying amount ​ $ — ​ $ 149,540 ​ The following table sets forth total interest expense recognized related to the 2022 Convertible Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, ​ ​ 2022 2021 Contractual interest expense ​ $ 2,800 ​ $ 4,500 ​ Amortization of debt issuance costs ​ 460 ​ 720 ​ Total ​ $ 3,260 ​ $ 5,220 ​ Effective interest rate ​ 3.5 % 3.5 % ​

Capital structure

Capital structure	12 Months Ended
	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Capital structure	9. Capital structure Common stock In August 2019, the Company entered into an At the Market Offering Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald and RBC Capital Markets, LLC (together, the “Sales Agents”), pursuant to which, the Company may offer and sell shares of its common stock, having an aggregate offering price of up to $125.0 million from time to time through the Sales Agents by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended. During the year ended December 31, 2020, the Company issued and sold an aggregate of 542,470 shares of common stock pursuant to the Sales Agreement at a weighted average public offering price of $53.37 per share. During the year ended December 31, 2020, the Company received net proceeds of $28.1 million after deducting agent discounts and commissions and other offering expenses payable by the Company. No shares were sold during the years ended December 31, 2021 and 2022. The remaining shares of the Company’s common stock available to be issued and sold, under the Sales Agreement, have an aggregate offering price of up to $93.0 million as of December 31, 2022. On April 29, 2020, the Company, certain of the former equity holders of Agilis (“the Participating Rightholders”), and, for the limited purposes set forth in the agreement, Shareholder Representative Services LLC, entered into a Rights Exchange Agreement (the “Rights Exchange Agreement”). As a result of the Rights Exchange Agreement, during the year ended December 31, 2020, the Company issued 2,821,176 shares of its common stock to Participating Rightholders. The shares had a fair value of $150.5 million upon issuance. As a result of the Censa Merger, during the year ended December 31, 2020, the Company issued 845,364 shares of the Company’s common stock to Censa securityholders, which were valued at $42.9 million based on the closing stock price on the acquisition date. The number of shares issued was determined using a 30-day VWAP pursuant to the Censa Merger Agreement. ​ In June 2021, the Company filed a Certificate of Amendment to its Restated Certificate of Incorporation, which increased the number of authorized shares of the Company’s common stock from 125,000,000 to 250,000,000 shares. ​ In connection with the execution of the Blackstone Credit Agreement, the Company and certain entities affiliated with the Lenders (the “Purchasers”) also entered into a stock purchase agreement (the “Stock Purchase Agreement”) on the Closing Date for the sale and issuance of 1,095,290 shares of common stock (the “Shares”) to the Purchasers at a price of $45.65 per share, for an aggregate purchase price of approximately $50.0 million. The per share price represents the closing price of the Company’s common stock on the Nasdaq Global Select Market on October 26, 2022. ​ Under the Stock Purchase Agreement, the Company agreed to register the resale of the Shares on a registration statement to be filed with the Securities and Exchange Commission within 60 days of the Closing Date. The Company has agreed to keep such registration statement effective for a period of six months following the Closing Date. In addition, subject to certain conditions, the Purchasers will be entitled to participate in registered underwritten public offerings by the Company during such period. ​ Pursuant to the terms of the Stock Purchase Agreement, the Purchasers and certain of their controlled affiliates have agreed not to, without the prior written approval of the Company and subject to specified conditions, directly or indirectly acquire shares of the Company’s outstanding common stock in excess of specified thresholds, seek or propose any acquisition of all or substantially all of the assets of the Company, seek or propose a merger or other business combination involving the Company, solicit proxies or consents with respect to any securities of the Company, seek to influence the management, board of directors or policies of the Company, or undertake other specified actions related to the potential acquisition of additional equity interests in the Company, or to encourage others to do any of the above (the “Standstill Restrictions”). The Standstill Restrictions terminate on the earliest of (i) the commencement of a tender offer or exchange offer by a third party unaffiliated with the Purchasers for more than 50% of the Company’s outstanding common stock, (ii) the public announcement by the Company of a written agreement to consummate a change of control of the Company, (iii) the public announcement of the Company’s voluntary or involuntary bankruptcy and (iv) the termination of the Blackstone Credit Agreement. ​ The Purchasers have also agreed not to sell or transfer the Shares without the prior written approval of the Company for a period of 90 days following the Closing Date, subject to certain exceptions. ​ As of December 31, 2022, the Company’s number of authorized shares of common stock was 250,000,000. ​

Net loss per share

Net loss per share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net loss per share	10. Net loss per share Basic and diluted net loss per share is computed by dividing net loss available to common stockholders by the weighted-average number of common shares outstanding. Potentially dilutive securities were excluded from the diluted calculation because their effect would be anti-dilutive. The following table sets forth the computation of basic and diluted net loss per share for common stockholders: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ ​ 2022 2021 2020 ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (559,017) $ (523,901) $ (438,160) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for basic and diluted net loss per share ​ 71,728,634 70,466,393 66,027,908 Net loss per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic and diluted ​ $ (7.79) * $ (7.43) * $ (6.64) * * For the years ended December 31, 2022, 2021, and 2020, the Company experienced a net loss and therefore did not report any dilutive share impact. The following table shows historical dilutive common share equivalents outstanding, which are not included in the above historical calculation, as the effect of their inclusion is anti-dilutive during each period. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2022 2021 2020 Stock Options ​ 11,502,417 ​ 10,772,582 ​ 9,663,677 Unvested restricted stock awards and units 2,516,336 1,519,831 982,058 Total 14,018,753 12,292,413 10,645,735 ​

Stock award plan

Stock award plan	12 Months Ended
	Dec. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock award plan	11. Stock award plan In May 2013, the Company’s Board of Directors and stockholders approved the 2013 Long Term Incentive Plan, which became effective upon the closing of the Company’s IPO. The 2013 Long Term Incentive Plan provides for the grant of incentive stock options, nonstatutory stock options, restricted stock awards and other stock-based awards. On June 8, 2022 (the “Restatement Effective Date”), the Company’s stockholders approved the Amended and Restated 2013 Long-Term Incentive Plan (the “Amended 2013 LTIP”). The Amended 2013 LTIP provides for the grant of incentive stock options, nonstatutory stock options, restricted stock units and other stock-based awards. The number of shares of common stock reserved for issuance under the Amended 2013 LTIP is the sum of (A) the number of shares of the Company’s common stock (up to 16,724,212 shares) that is equal to the sum of (1) the number of shares issued under the 2013 Long-Term Incentive Plan prior to the Restatement Effective Date, (2) the number of shares that remain available for issuance under the 2013 Long-Term Incentive Plan immediately prior to the Restatement Effective Date and (3) the number of shares subject to awards granted under the 2013 Long-Term Incentive Plan prior to the Restatement Effective Date that are outstanding as of the Restatement Effective Date, plus (B) from and after the Restatement Effective Date, an additional 8,475,000 shares of Common Stock. As of December 31, 2022, awards for 9,126,463 shares of common stock were available for issuance under the Amended 2013 LTIP. There are no additional shares of common stock available for issuance under the Company’s 1998 Employee, Director and Consultant Stock Option Plan, 2009 Equity and Long Term Incentive Plan or 2013 Stock Incentive Plan. In January 2020, the Company’s Board of Directors approved the 2020 Inducement Stock Incentive Plan. The 2020 Inducement Stock Incentive Plan provides for the grant of incentive stock options, nonstatutory stock options, restricted stock awards and other stock-based awards, initially up to an aggregate of 1,000,000 shares of common stock. Any grants made under the 2020 Inducement Stock Incentive Plan must be made pursuant to the Nasdaq Listing Rule 5635(c)(4) inducement grant exception as a material component of the Company’s new hires’ employment compensation. In December 2020, the Company’s Board of Directors approved an additional 1,000,000 shares of common stock that may be issued under the 2020 Inducement Stock Incentive Plan. In April 2022, the Company’s Board of Directors approved a reduction in the total number of shares of common stock that may be issued under the 2020 Inducement Stock Incentive Plan to 1,300,000 shares. In December 2022, the Company’s Board of Directors approved an additional 1,700,000 shares of common stock that may be issued under the 2020 Inducement Stock Inventive Plan. As of December 31, 2022, awards for 1,820,565 shares of common stock are available for issuance under the 2020 Inducement Stock Incentive Plan. The Board of Directors has the authority to select the individuals to whom options are granted and determine the terms of each option, including (i) the number of shares of common stock subject to the option; (ii) the date on which the option becomes exercisable; (iii) the option exercise price, which, in the case of incentive stock options, must be at least 100% (110% in the case of incentive stock options granted to a stockholder owning in excess of 10% of the Company’s stock) of the fair market value of the common stock as of the date of grant; and (iv) the duration of the option (which, in the case of incentive stock options, may not exceed ten years). Options typically vest over a four-year period. Inducement stock option awards Pursuant to the Nasdaq inducement grant exception, during the year ended December 31, 2022, the Company issued options to purchase an aggregate of 104,385 shares of common stock to certain new hire employees at a weighted-average exercise price of $42.02 per share under the 2020 Inducement Stock Incentive Plan. Additionally, during the year ended December 31, 2022, the Company issued 43,800 restricted stock units under the 2020 Inducement Stock Incentive Plan. An aggregate of 237,700 of options and 26,336 of restricted stock units previously granted as inducement awards were forfeited during the year ended December 31, 2022 in connection with employee separations from the Company. Stock option activity ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ average ​ ​ Aggregate ​ ​ ​ ​ average ​ remaining ​ ​ intrinsic ​ ​ Number of ​ exercise ​ contractual ​ ​ value(in ​ ​ options ​ price ​ term ​ ​ thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 31, 2019 11,043,939 ​ $ 31.67 ​ ​ Granted 2,777,975 ​ $ 51.06 ​ ​ Exercised (3,268,452) ​ $ 24.25 ​ ​ Forfeited (889,785) ​ $ 42.14 ​ ​ Outstanding at December 31, 2020 9,663,677 ​ $ 38.72 ​ ​ Granted 2,487,234 ​ $ 61.36 ​ ​ Exercised (635,871) ​ $ 28.01 ​ ​ Forfeited (742,458) ​ $ 52.04 ​ ​ Outstanding at December 31, 2021 10,772,582 ​ $ 43.66 ​ ​ Granted 1,685,435 ​ $ 38.55 ​ ​ Exercised (496,863) ​ $ 29.45 ​ ​ Forfeited/Cancelled (458,737) ​ $ 48.75 ​ ​ Outstanding at December 31, 2022 11,502,417 ​ $ 43.33 6.38 years ​ $ 38,330 Vested or Expected to vest at December 31, 2022 3,432,725 ​ $ 47.74 8.20 years ​ $ 1,694 Exercisable at December 31, 2022 7,774,274 ​ $ 41.23 5.49 years ​ $ 36,523 ​ The fair values of grants made in the years ended December 31, 2022, 2021 and 2020 were contemporaneously estimated on the date of grant using the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Risk-free interest rate 1.55% - 4.57% 0.51% - 1.24% 0.34% - 1.45% Expected volatility 54% - 74% 74% - 89% 87% - 89% Expected term 5.5 years 5.5 years 5.75 years ​ The Company assumed no expected dividends for all grants. The weighted average grant date fair value of options granted during the years ended December 31, 2022, 2021 and 2020 was $23.54, $43.05, and $36.94 per share, respectively. Restricted Stock Awards and Restricted Stock Units restricted stock awards, which has been determined based upon the market value of the Company’s shares on the grant date, is expensed over the vesting period. The following table summarizes information on the Company’s restricted stock awards and units: ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted Stock Awards and Units ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant ​ ​ Number of ​ Date ​ Shares Fair Value Unvested at December 31, 2021 ​ 1,519,831 ​ $ 55.43 Granted 1,686,467 ​ ​ 38.37 Vested (504,851) ​ ​ 50.15 Forfeited (185,111) ​ ​ 46.67 Unvested at December 31, 2022 2,516,336 ​ $ 45.67 ​ Employee Stock Purchase Plan The Company recorded share-based compensation expense in the statement of operations related to incentive stock options, nonstatutory stock options, restricted stock awards, restricted stock units and the ESPP as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2022 2021 2020 Research and development ​ $ 55,869 ​ $ 53,632 ​ $ 38,716 Selling, general and administrative ​ 54,464 ​ 49,881 ​ 31,609 Total ​ $ 110,333 ​ $ 103,513 ​ $ 70,325 ​ As of December 31, 2022, there was approximately $176.1 million of total unrecognized compensation cost related to unvested share-based compensation arrangements granted under the Company’s Plans. This cost is expected to be recognized as compensation expense over the weighted average remaining service period of approximately 2.19 years.

Other comprehensive income (los

Other comprehensive income (loss) and accumulated other comprehensive items	12 Months Ended
	Dec. 31, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income (loss) and accumulated other comprehensive items	12. Other comprehensive income (loss) and accumulated other comprehensive items Other comprehensive income (loss) includes changes in equity that are excluded from net loss, such as unrealized gains and losses on marketable securities. The following table summarizes other comprehensive income (loss) and the changes in accumulated other comprehensive items, by component, for the years ended December 31, 2022, 2021, and 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ Total ​ ​ Gains (Losses) ​ ​ ​ ​ Accumulated ​ ​ On ​ Foreign ​ Other ​ ​ Marketable ​ Currency ​ Comprehensive ​ ​ Securities, net of tax ​ Translation ​ Items Balance at December 31, 2019 ​ $ 755 ​ $ (11,339) ​ $ (10,584) Other comprehensive income (loss) before reclassifications ​ 479 ​ (51,518) ​ (51,039) Amounts reclassified from other comprehensive items ​ 666 ​ — ​ 666 Other comprehensive income (loss) ​ 1,145 ​ (51,518) ​ (50,373) Balance at December 31, 2020 ​ $ 1,900 ​ $ (62,857) ​ $ (60,957) Other comprehensive (loss) income before reclassifications ​ (3,279) ​ 39,177 ​ 35,898 Amounts reclassified from other comprehensive items ​ 777 ​ — ​ 777 Other comprehensive (loss) income ​ (2,502) ​ 39,177 ​ 36,675 Balance at December 31, 2021 ​ $ (602) ​ $ (23,680) ​ $ (24,282) Other comprehensive income before reclassifications ​ 4,072 ​ 28,970 ​ 33,042 Amounts reclassified from other comprehensive items ​ (3,964) ​ — ​ (3,964) Other comprehensive income ​ 108 ​ 28,970 ​ 29,078 Balance at December 31, 2022 ​ $ (494) ​ $ 5,290 ​ $ 4,796 ​ Reclassified amounts from other comprehensive items were determined using the actual realized gains and losses from the sales of marketable securities.

Revenue recognition

Revenue recognition	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue recognition	13. Revenue recognition Net product sales During the years ended December 31, 2022, 2021, and 2020, net product sales in the United States were $218.3 million, $187.3 million, and $139.0 million, respectively, consisting solely of sales of Emflaza, and net product sales outside of the United States were $316.9 million, $241.6 million, and $194.4 million respectively, consisting of sales of Translarna, Tegsedi, Waylivra, and Upstaza. Translarna net product revenues made up $288.6 million, $236.0 million, and $191.9 million of the net product sales outside the United States for the years ended December 31, 2022, 2021, and 2020, respectively. During the year ended December 31, 2022, two countries, the United States and Russia, accounted for at least 10% of the Company’s net product sales, representing $218.3 million and $59.7 million of the net product sales, respectively. During the years ended December 31, 2021 and 2020, only the United States accounted for at least 10% of the Company’s net product sales. For the years ended December 31, 2022, 2021, and 2020, two of the Company’s distributors each accounted for over 10% of the Company’s net product sales. As of December 31, 2022, the Company has a contract liabilities balance of $1.4 million relating to the production of plasmid DNA and AAV vectors for gene therapy applications for external customers. As of December 31, 2021, the Company did not have a contract liabilities balance. The Company did not have any contract assets for the years ended December 31, 2022 and 2021. For the year ended December 31, 2022, the Company did not recognize any revenue related to the amounts included in the contract liability balance at the beginning of the period. For the year ended December 31, 2021, the Company recognized revenues of $4.0 million related to amounts included in contract liability balance at the beginning of the period, which related to Translarna net product revenue. The Company has not made significant changes to the judgments made in applying ASC Topic 606 for the years ended December 31, 2022 and 2021. Remaining performance obligations Remaining performance obligations represent the transaction price for goods the Company has yet to provide. As of December 31, 2022, the aggregate amount of transaction price allocated to remaining performance obligations related to plasmid DNA and AAV vector production for external customers is $1.4 million. The Company expects to recognize revenue over the next one year Collaboration revenue and Royalty revenue In November 2011, the Company and the Spinal Muscular Atrophy Foundation (“SMA Foundation”) entered into a licensing and collaboration agreement with F. Hoffman-La Roche Ltd and Hoffman- La Roche Inc. (collectively, “Roche”). Under the terms of the SMA License Agreement, Roche acquired an exclusive worldwide license to the Company’s SMA program. Under the agreement, the Company is eligible to receive additional payments from Roche if specified events are achieved with respect to each licensed product, including up to $135.0 million in research and development event milestones, up to $325.0 million in sales milestones upon achievement of certain sales events, and up to double digit royalties on worldwide annual net sales of a commercial product. For the years ended December 31, 2022, 2021, and 2020, the Company recognized revenue related to the licensing and collaboration agreement with Roche of $50.1 million, $55.0 million, and $42.6 million, respectively. The below summarizes the milestone achievements associated with the Company’s SMA program during the years ended December 31, 2022, 2021, and 2020. The SMA program currently has one approved product, Evrysdi, which was approved in August 2020 by the FDA for the treatment of SMA in adults and children two months and older. The first commercial sale of Evrysdi in the United States was made in August 2020. This event triggered a $20.0 million milestone payment to the Company from Roche. In August 2020, the EMA accepted the MAA filed by Roche for Evrysdi for the treatment of SMA, which triggered a $15.0 million milestone payment to the Company from Roche. In October 2020, Chugai, a subsidiary of Roche, filed an NDA in Japan for Evrysdi for the treatment of SMA, which triggered a $7.5 million milestone payment to the Company from Roche. Under ASC Topic 606, the acceptance of the NDA filing resolved the uncertainty of whether the milestone was probable of being achieved. The Company recorded these three milestone payments as collaboration revenue for the year ended December 31, 2020. The first commercial sale of Evrysdi in the EU was made in March 2021. This event triggered a $20.0 million milestone payment to the Company from Roche. The first commercial sale in Japan was made in August 2021, which was the final research and development milestone received by the Company. This event triggered a $10.0 million payment to the Company from Roche. In December 2021, the Company recorded its first sales milestone of $25.0 million for the achievement of $500.0 million in worldwide annual net sales from Evrysdi. The Company recorded these three milestone payments as collaboration revenue for the year ended December 31, 2021. In September 2022, the Company recognized a sales milestone of $50.0 million for the achievement of $750.0 million in worldwide annual net sales from Evrysdi, which is recorded on the balance sheet within prepaid expenses and other current assets as of December 31, 2022. The remaining potential sales milestones as of December 31, 2022 is $250.0 million upon achievement of certain sales events. As of December 31, 2022, the Company does not have any remaining research and development milestones that can be received. In addition to research and development and sales milestones, the Company is eligible to receive up to double-digit royalties on worldwide annual net sales of a commercial product under the SMA License Agreement. For the years ended December 31, 2022, 2021, and 2020 the Company has recognized $113.5 million, $54.6 million, and $4.8 million of royalty revenue related to Evrysdi, respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income taxes	14. Income taxes The loss from operations before tax benefit (expense) consisted of the following for the years ended December 31, 2022, 2021, and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Domestic ​ $ (591,126) ​ $ (487,726) ​ $ (452,475) Foreign ​ 3,639 ​ (30,614) ​ 49,543 Total ​ $ (587,487) ​ $ (518,340) ​ $ (402,932) ​ The Income Tax Provision consisted of the following for the years ended December 31, 2022, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Current: ​ ​ ​ U.S. Federal ​ $ — ​ $ — ​ $ — U.S. State and Local ​ (4,224) ​ (3,844) ​ (24,984) Foreign ​ (1,582) ​ (1,340) ​ (4,372) Deferred: ​ ​ ​ ​ U.S. Federal ​ 23,689 ​ — ​ — U.S. State and Local ​ 10,587 ​ (377) ​ (5,872) Foreign ​ — ​ — ​ — Total tax benefit (expense) ​ $ 28,470 ​ $ (5,561) ​ $ (35,228) ​ A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 2020 Federal income tax provision at statutory rate ​ 21.00 % 21.00 % 21.00 % State income tax provision, net of federal benefit ​ 3.07 (0.74) (3.31) Permanent differences ​ (1.83) (4.06) (6.66) Research and development ​ 5.89 4.50 4.93 Change in valuation allowances ​ (23.36) (29.03) (26.40) Change in deferred tax assets ​ (0.10) 12.05 2.93 Foreign tax rate differential ​ (0.17) 0.01 0.72 Tax rate change ​ 0.34 0.01 (1.46) (Accrual) Release of uncertain tax positions ​ — ​ (4.78) ​ (0.61) ​ Other ​ — (0.03) 0.12 Effective income tax rate ​ 4.84 % (1.07) % (8.74) % ​ Accounting for income taxes under U.S. GAAP requires that individual tax-paying entities of the company offset all deferred tax liabilities and assets within each particular tax jurisdiction and present them as a noncurrent deferred tax liability or asset. Amounts in different tax jurisdictions cannot be offset against each other. The noncurrent deferred income tax asset is recorded within deposits and other assets on the balance sheet. The amount of deferred income taxes are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 Assets: ​ ​ Noncurrent deferred income taxes ​ $ — ​ $ — Liabilities: ​ ​ Noncurrent deferred income taxes ​ (102,834) ​ (137,110) Deferred income taxes - net ​ $ (102,834) ​ $ (137,110) ​ The significant components of the Company’s deferred tax assets and liabilities at December 31, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 Deferred tax assets: ​ ​ Accrued expense ​ $ 2,124 ​ $ 8,208 Amortization ​ 52,532 ​ 87,998 Federal tax credits ​ 174,802 ​ 142,595 State tax credits ​ 9,787 ​ 8,054 Federal net operating losses ​ 69,957 ​ 76,589 State net operating losses ​ 10,316 ​ 9,159 Foreign net operating losses ​ 4,837 ​ 3,316 Capitalized research and development costs ​ 110,219 ​ 241 Share based compensation and other ​ 27,054 ​ 15,273 Liability for sale of future royalties ​ ​ 185,589 ​ ​ 148,503 Noncash interest expense ​ ​ 30,160 ​ ​ 26,040 Other comprehensive loss ​ (719) ​ 143 Total gross deferred tax assets ​ 676,658 ​ 526,119 Less valuation allowance ​ (672,172) ​ (525,570) Total deferred tax assets, net of valuation allowance ​ $ 4,486 ​ $ 549 Deferred tax liabilities: ​ ​ Depreciation ​ $ (4,486) ​ $ (549) Indefinite lived intangible ​ (102,834) ​ (137,110) Total gross deferred tax liabilities ​ (107,320) ​ (137,659) Net deferred tax assets (liabilities) ​ $ (102,834) ​ $ (137,110) ​ For the year ended December 31, 2022, the Company generated taxable income in the U.S. of $61.6 million. The Company has not recorded any federal income tax provision after considering the federal NOL, section 250 deduction, available general business credits, and foreign tax credits. The Company recorded a state income tax provision of $4.2 million which is primarily attributable to state income taxes paid in the current year. At December 31, 2022 and 2021, the Company recorded a valuation allowance against its net deferred tax assets of $672.2 million and $525.6 million, respectively. The change in the valuation allowance during the years ended December 31, 2022 and 2021 was $146.6 million and $146.0 million, respectively. A valuation allowance has been recorded since, in the judgment of management, these assets are not more likely than not to be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during periods in which those temporary differences and carryforwards become deductible or are utilized. As of December 31, 2022, the Company had $333.1 million and $164.9 million of federal and state net operating loss carryforwards, respectively. The Company recorded a deferred tax liability in conjunction with the Agilis Merger of $122.0 million in 2018, related to the tax basis difference in the IPRD indefinite-lived intangibles acquired. The Company’s policy is to record a deferred tax liability related to acquired IPR&D which may eventually be realized either upon amortization of the asset when the research is completed, and a product is successfully launched or the write-off of the asset if it is abandoned or unsuccessful. In July 2022, the Company received EMEA approval for a portion of the IPR&D assets, and thus, began the amortization of the intangible. As of December 31, 2022, research and development credit carryforward for federal purposes is $29.0 million. In addition, the Orphan Drug Credit Carryover available as of December 31, 2022 is $145.8 million. The Company’s federal credit carryforwards could begin to expire in 2023 if not otherwise utilized as projected. As a result of U.S. tax reform legislation, federal net operating losses generated in 2018 carryforward indefinitely. State net operating loss carryforwards begin to expire in 2037. Sections 382 and 383 of the Internal Revenue Code of 1986 subject the future utilization of net operating losses and certain other tax attributes, such as research and development tax credits, to an annual limitation in the event of certain ownership changes, as defined. The Company has undergone an ownership change and has determined that a “change in ownership” as defined by IRC Section 382 of the Internal Revenue Code of 1986, as amended, and the rules and regulations promulgated thereunder, did occur in June of 2013. Accordingly, about $231.5 million of the Company’s NOL carryforwards are limited and the Company can only use $16.7 million for the first five years from the ownership change and $5.7 million per year going forward. Therefore, $169.2 million of the NOL’s will be freed up over the next 10 years and $62.3 million are expected to expire unused which are not included in the deferred tax assets listed above. At December 31, 2020, the Company utilized $364.1 million of NOLs of which $97.7 million was the section 382 NOL. The Company did not utilize any NOLs in the year ended December 31, 2021. At December 31, 2022, the Company utilized $49.3 million of NOLs of which $11.4 million is section 382 NOL. At December 31, 2022, there is $333.1 million available for immediate use and an additional $5.7 million will free up in 2023. The income tax benefit (expense) for the years ended December 31, 2022 and 2021 differed from the amounts computed by applying the U.S. federal income tax rate of 21% to loss before tax expense as a result of the IPR&D assets becoming partially amortizable in 2022, foreign taxes, the impact of temporary difference, including the updated section 174, the impact of permanent differences, including “global intangible low-taxed income” (“GILTI”), tax credits generated, true up of net operating loss carryforwards, and increase in the Company’s valuation allowance. Under the 2017 Tax Cuts and Jobs Act, the ability to currently deduct qualifying research and experimental costs under section 174, as well as software development costs, are eliminated for tax years beginning after December 31, 2021. Under the new rule, these costs must be capitalized and amortized over a five-year or fifteen-year period, depending on whether the research is conducted in the U.S. or abroad, respectively. The rule became effective for the Company during the year, and resulted in an increased current taxable income of the Company by $450.1 million for the tax year ended December 31, 2022. The Company applies the elements of FASB ASC 740-10 regarding accounting for uncertainty in income taxes. This clarifies the accounting for uncertainty in income taxes recognized in financial statements and required impact of a tax position to be recognized in the financial statements if that position is more likely than not of being sustained by the taxing authority. As of December 31, 2022, the Company recorded unrecognized tax benefits in the amount of $27.2 million including interest and penalties through 2022. The Company’s policy is to recognize interest and penalties related to tax matters within the income tax provision. Tax years beginning in 2014 are generally subject to examination by taxing authorities, although net operating losses from all years are subject to examinations and adjustments for at least three years following the year in which the attributes are used. The Company is currently under a wage tax audit in Germany for tax years 2018 through 2021. Although the outcome of tax audits is always uncertain, the company does not expect any adjustment to result for these years as of December 31, 2022. For all years through December 31, 2016, the Company generated research credits but has not conducted a study to document the qualified activities. This study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance. As a result of U.S. tax reform legislation, distributions of profits from non-U.S. subsidiaries are not expected to cause a significant incremental U.S. tax impact in the future. However, distributions may be subject to non-U.S. withholding taxes if profits are distributed from certain jurisdictions. As of December 31, 2022, for purposes of ASC 740-10-25-3, the Company had $65.1 million of undistributed earnings from non-U.S. subsidiaries that it intends to reinvest permanently in its non-U.S. operations. As these ASC 740-10-25-3 earnings are considered permanently reinvested, no tax provision has been accrued. It is not feasible to estimate the amount of tax that might be payable on the eventual remittance of such earnings. Unrecognized Tax Benefits A reconciliation of the gross amount of unrecognized tax benefits, excluding accrued interest and penalties, is as follows: ​ ​ ​ ​ Unrecognized Tax Benefits Balance at December 31, 2021 ​ 27,217 Additions based on tax positions related to the current year — Balance at December 31, 2022 $ 27,217 ​ Uncertain tax positions, for which management's assessment is that there is a more than 50% probability of sustaining the position upon challenge by a taxing authority based upon its technical merits, are subject to certain recognition and measurement criteria. The nature of the uncertain tax positions is often very complex and subject to change, and the amounts at issue can be substantial. The Company develops its cumulative probability assessment of the measurement of uncertain tax positions using internal experience, judgment, and assistance from professional advisors. The Company re-evaluates these uncertain tax positions on a quarterly basis based on a number of factors including, but not limited to, changes in facts or circumstances, changes in tax law, and effectively settled issues under audit and new audit activity. Any change in these factors could result in the recognition of a tax benefit or an additional charge to the tax provision. For the year ended December 31, 2022, the Company did not record any unrecognized tax benefits. While it is reasonably possible that a further change in the unrecognized tax benefits may occur within the next twelve months, the Company is unable to estimate the amount of any such change. The Company records penalties and tax-related interest expense on unrecognized tax benefits as a component of the provision for income taxes in the accompanying consolidated statement of operations. The Company has not recorded any interest and penalties related to uncertain tax positions for the year ended December 31, 2022, in the accompanying consolidated balance sheet. Future changes in the Company’s unrecognized tax benefits will affect the Company’s annual effective tax rate.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	15. Commitments and contingencies Under various agreements, the Company will be required to pay royalties and milestone payments upon the successful development and commercialization of products. The Company has entered into funding agreements with The Wellcome Trust Limited (“Wellcome Trust”) for the research and development of small molecule compounds in connection with its oncology and antibacterial programs. As the Company has discontinued development under its antibacterial program, it no longer expects that milestone and royalty payments from the Company to Wellcome Trust will apply under that agreement, resulting in a change to the total amount of development and regulatory milestone payments the Company may become obligated to pay for this program. Under the oncology platform funding agreement, to the extent that the Company develops and commercializes certain program intellectual property on a for-profit basis itself or in collaboration with a partner (provided the Company retains overall control of worldwide commercialization), the Company may become obligated to pay to Wellcome Trust development and regulatory milestone payments and single-digit royalties on sales of any research program product. The Company’s obligation to pay such royalties would continue on a country-by-country basis until the longer of the expiration of the last patent in the program intellectual property in such country covering the research program product and the expiration of market exclusivity of such product in such country. The Company made the first development milestone payment of $0.8 million to Wellcome Trust under the oncology platform funding agreement during the second quarter of 2016. During the year ended December 31, 2022, the Company incurred $2.5 million of development milestones in connection with the enrollment of patients in the registration-directed Phase 2/3 trial of unesbulin for the treatment of LMS, which is recorded in other long-term liabilities on the balance sheet and will be payable upon the earlier to occur of the first dose administered to the last patient enrolled in the study or the termination of dosing of all patients in the study. Additional milestone payments of up to an aggregate of $14.5 million may become payable by the Company to Wellcome Trust under this agreement. The Company has also entered into a collaboration agreement with the SMA Foundation. The Company may become obligated to pay the SMA Foundation single-digit royalties on worldwide net product sales of any collaboration product that is successfully developed and subsequently commercialized or, with respect to collaboration products the Company outlicenses, including Evrysdi, a specified percentage of certain payments the Company receives from its licensee. The Company is not obligated to make such payments unless and until annual sales of a collaboration product exceed a designated threshold. Since inception, the SMA Foundation has earned $28.5 million, $24.5 million which was paid and $4.0 million which was accrued as of December 31, 2022. The Company’s obligation to make such payments would end upon its payment to the SMA Foundation of an aggregate of $52.5 million. Pursuant to the asset purchase agreement ("Asset Purchase Agreement") between the Company and Marathon Pharmaceuticals, LLC (now known as Complete Pharma Holdings, LLC) (“Marathon”), Marathon is entitled to receive contingent payments from the Company based on annual net sales of Emflaza up to a specified aggregate maximum amount over the expected commercial life of the asset. In addition, Marathon received a $50.0 million sales-based milestone during the year ended December 31, 2022. Pursuant to the Agilis Merger Agreement with Agilis, Agilis equityholders were previously entitled to receive contingent consideration payments from the Company based on (i) the achievement of certain development milestones up to an aggregate maximum amount of $60.0 million, (ii) the achievement of certain regulatory approval milestones together with a milestone payment following the receipt of a priority review voucher up to an aggregate maximum amount of $535.0 million, (iii) the achievement of certain net sales milestones up to an aggregate maximum amount of $150.0 million, and (iv) a percentage of annual net sales for Friedreich Ataxia and Angelman Syndrome during specified terms, ranging from 2%-6%. The Company was required to pay $40.0 million of the development milestone payments upon the passing of the second anniversary of the closing of the Agilis Merger, regardless of whether the applicable milestones have been achieved. Pursuant to the terms of the Rights Exchange Agreement, the Participating Rightholders canceled and forfeited their rights under the Agilis Merger Agreement to receive (i) $174.0 million, in the aggregate, of potential milestone payments based on the achievement of certain regulatory milestones and (ii) $37.6 million, in the aggregate, of $40.0 million in development milestone payments that would have been due upon the passing of the second anniversary of the closing of the Agilis Merger, regardless of whether the milestones are achieved. The Rights Exchange Agreement has no effect on the Agilis Merger Agreement other than to provide for the cancellation and forfeiture of the Participating Rightholders’ rights to receive $211.6 million, in the aggregate, of the milestone payments described above. As a result, all other rights and obligations under the Agilis Merger Agreement remain in effect pursuant to their terms, including the Company’s obligation to pay up to an aggregate maximum amount of $20.0 million upon the achievement of certain development milestones (representing the remaining portion of potential development milestone payments for which rights were not canceled and forfeited pursuant to the Rights Exchange Agreement while excluding the remaining $2.4 million milestone payment that was due and paid upon the passing of the second anniversary of the closing of the Agilis Merger), up to an aggregate maximum amount of $361.0 million upon the achievement of certain regulatory milestones (representing the remaining portion of potential regulatory milestone payments for which rights were not canceled and forfeited pursuant to the Rights Exchange Agreement), up to a maximum aggregate amount of $150.0 million upon the achievement of certain net sales milestones and a percentage of annual net sales for Friedreich ataxia and Angelman syndrome during specified terms, ranging from 2% to 6%, pursuant to the terms of the Agilis Merger Agreement. In July 2022, the European Commission approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA. As a result of such approval, the Company paid the former equityholders of Agilis $50.0 million in accordance with the terms of the Agilis Merger Agreement in the year ended December 31, 2022. On October 25, 2019, the Company completed the acquisition of substantially all of the assets of BioElectron Technology Corporation (“BioElectron”), a Delaware corporation, including certain compounds that the Company has begun to develop as part of its Bio-e platform, pursuant to an asset purchase agreement by and between the Company and BioElectron, dated October 1, 2019 (the “BioElectron Asset Purchase Agreement”). BioElectron was a private company with a pipeline focused on inflammatory and central nervous system (CNS) disorders. The lead program, vatiquinone, is in late stage development for CNS disorders with substantial unmet need and significant commercial opportunity that are complementary to PTC’s existing pipeline. Subject to the terms and conditions of the BioElectron Asset Purchase Agreement, BioElectron may become entitled to receive contingent milestone payments of up to $200.0 million (in cash or in shares of the Company’s common stock, as determined by the Company) from the Company based on the achievement of certain regulatory and net sales milestones. Subject to the terms and conditions of the BioElectron Asset Purchase Agreement, BioElectron may also become entitled to receive contingent payments based on a percentage of net sales of certain products. Subject to the terms and conditions of the Censa Merger Agreement, former Censa securityholders may become entitled to receive contingent payments from the Company based on (i) the achievement of certain development and regulatory milestones up to an aggregate maximum amount of $217.5 million for sepiapterin’s two most advanced programs and receipt of a priority review voucher from the FDA as set forth in the Censa Merger Agreement, (ii) $109.0 million in development and regulatory milestones for each additional indication of sepiapterin, (iii) the achievement of certain net sales milestones up to an aggregate maximum amount of $160.0 million, (iv) a percentage of annual net sales during specified terms, ranging from single to low double digits of the applicable net sales threshold amount, and (v) any sublicense fees paid to the Company in consideration of any sublicense of Censa’s intellectual property to commercialize sepiapterin, on a country-by-country basis, which contingent payment will equal to a mid-double digit percentage of any such sublicense fees. Pursuant to the Censa Merger Agreement, the Company has the option to pay the initial $30.0 million development milestone, for the completion of enrollment of a Phase 3 clinical trial for sepiapterin for PKU, if achieved, in cash or shares of the Company’s common stock. ​ The Company also has the Tegsedi-Waylivra Agreement for the commercialization of Tegsedi and Waylivra, and products containing those compounds in countries in Latin America and the Caribbean. Akcea is entitled to receive royalty payments subject to certain terms set forth in the Tegsedi-Waylivra Agreement. The Company has employment agreements with certain employees which require the funding of a specific level of payments, if certain events, such as a change in control or termination without cause, occur. Additionally, the Company has royalty payments associated with Translarna, Emflaza, and Upstaza net product revenue, payable quarterly or annually in accordance with the terms of the related agreements. From time to time in the ordinary course of its business, the Company is subject to claims, legal proceedings and disputes. The Company is not currently aware of any material legal proceedings against it.

Geographic information

Geographic information	12 Months Ended
	Dec. 31, 2022
Segments, Geographical Areas [Abstract]
Geographic information	16. Geographic information The Company views its operations and manages its business in one operating segment. The following table presents financial information based on the geographic location of the facilities of the Company as of and for the years ended: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2022 ​ United States Non-US Total Total assets ​ $ 1,473,770 ​ $ 231,849 ​ $ 1,705,619 Fixed assets, net ​ $ 71,754 ​ $ 836 ​ $ 72,590 Revenue ​ $ 498,567 ​ $ 200,234 ​ $ 698,801 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ United States Non-US Total Total assets ​ $ 1,744,225 ​ $ 193,831 ​ $ 1,938,056 Fixed assets, net ​ $ 51,626 ​ $ 959 ​ $ 52,585 Revenue ​ $ 297,005 ​ $ 241,588 ​ $ 538,593 ​

401(k) plan

401(k) plan	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
401(k) plan	17. 401(k) plan The Company maintains a 401(k) plan for its employees. Employee contributions are voluntary. The Company may match employee contributions in amounts to be determined at the Company’s sole discretion. The Company provided an 100% matching contribution for up to the first 6% of each contributing employee’s base salary contributions for the years ended December 31, 2022, 2021 and 2020, respectively. The Company made matching contributions to the 401(k) plan and recorded expense of approximately $8.4 million, $6.6 million, and $5.3 million for the years ended December 31, 2022, 2021 and 2020, respectively.

Intangible assets and goodwill

Intangible assets and goodwill	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets and goodwill	18. Intangible assets and goodwill Definite-lived intangibles Definite lived intangible assets consisted of the following at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Reclass from ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Definite lived ​ ​ December 31, ​ ​ ​ ​ ​ Indefinite Lived to ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets, gross ​ 2021 ​ Additions ​ Definite Lived ​ Impairment ​ translation ​ 2022 Emflaza ​ $ 291,875 ​ $ 128,378 ​ $ — ​ $ — ​ $ — ​ $ 420,253 Waylivra ​ ​ 9,904 ​ ​ — ​ ​ — ​ ​ — ​ ​ (588) ​ ​ 9,316 Tegsedi ​ ​ 4,060 ​ ​ 3,240 ​ ​ — ​ ​ — ​ ​ (191) ​ ​ 7,109 Upstaza ​ ​ — ​ ​ — ​ ​ 89,550 ​ ​ — ​ ​ — ​ ​ 89,550 Total definite lived intangibles, gross ​ $ 305,839 ​ $ 131,618 ​ $ 89,550 ​ $ — ​ $ (779) ​ $ 526,228 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Definite lived ​ ​ December 31, ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets, accumulated amortization ​ 2021 ​ Amortization ​ translation ​ 2022 Emflaza ​ $ (154,594) ​ $ (111,429) ​ $ — ​ $ (266,023) Waylivra ​ ​ (1,821) ​ ​ (1,020) ​ ​ 90 ​ ​ (2,751) Tegsedi ​ ​ (1,083) ​ ​ (685) ​ ​ 59 ​ ​ (1,709) Upstaza ​ ​ — ​ ​ (3,420) ​ ​ — ​ ​ (3,420) Total definite lived intangibles, accumulated amortization ​ $ (157,498) ​ $ (116,554) ​ $ 149 ​ $ (273,903) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total definite lived intangibles, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 252,325 ​ Marathon is entitled to receive contingent payments from the Company based on annual net sales of Emflaza beginning in 2018, up to a specified aggregate maximum amount over the expected commercial life of the asset. In accordance with the guidance for an asset acquisition, the Company records the milestone payment when it becomes payable to Marathon and increase the cost basis for the Emflaza rights intangible asset. For the year ended December 31, 2022, milestone payments of $128.4 million were recorded, which included a $50.0 million sales-based milestone. These payments are being amortized over the remaining useful life of the Emflaza rights asset on a straight line basis. As of December 31, 2022, a milestone payable to Marathon of $32.8 million was recorded on the balance sheet within accounts payable and accrued expenses. Akcea is also entitled to receive royalty payments subject to certain terms set forth in the Tegsedi-Waylivra Agreement related to sales of Waylivra and Tegsedi. In accordance with the guidance for an asset acquisition, the Company records royalty payments when they become payable to Akcea and increase the cost basis for the Waylivra and Tegsedi intangible assets, respectively. For the year ended December 31, 2022, royalty payments of $3.2 million were recorded for Tegsedi. As of December 31, 2022, a royalty payable of $0.5 million for Tegsedi was recorded on the balance sheet within accounts payable and accrued expenses. For the years ended December 31, 2022, 2021, and 2020, the Company recognized amortization expense of $116.6 million, $54.8 million, and $36.9 million respectively, related to the Emflaza rights, Waylivra, Tegsedi, and Upstaza intangible assets. The estimated future amortization of the Emflaza rights, Waylivra, Tegsedi, and Upstaza intangible assets is expected to be as follows: ​ ​ ​ ​ ​ ​ As of December 31, 2022 2023 ​ $ 142,324 2024 ​ 30,609 2025 ​ 9,352 2026 ​ 9,352 2027 and thereafter ​ 60,688 Total ​ $ 252,325 ​ The weighted average remaining amortization period of the definite-lived intangibles as of December 31, 2022 is 4.9 years. Indefinite-lived intangibles Indefinite lived intangible assets consisted of the following at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Reclass from ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Indefinite lived ​ ​ December 31, ​ ​ ​ ​ ​ Indefinite Lived to ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets ​ 2021 ​ Additions ​ Definite Lived ​ Impairment ​ translation ​ 2022 Upstaza ​ $ 358,700 ​ $ — ​ $ (89,550) ​ $ (33,384) ​ $ — ​ $ 235,766 PTC-FA ​ ​ 112,500 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 112,500 PTC-AS ​ ​ 105,300 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 105,300 Total indefinite lived intangibles ​ $ 576,500 ​ $ — ​ $ (89,550) ​ $ (33,384) ​ $ — ​ $ 453,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total intangible assets, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 705,891 ​ ​ In connection with the acquisition of the Company’s gene therapy platform from Agilis, the Company acquired rights to Upstaza, for the treatment of AADC deficiency. AADC deficiency is a rare CNS disorder arising from reductions in the enzyme AADC that result from mutations in the dopa decarboxylase gene. The gene therapy platform also includes PTC-FA, an asset targeting Friedreich ataxia, a rare and life-shortening neurodegenerative disease caused by a single defect in the FXN gene which causes reduced production of the frataxin protein. Additionally, the gene therapy platform includes two other programs targeting CNS disorders, including PTC-AS for Angelman syndrome, a rare, genetic, neurological disorder characterized by severe developmental delays. In accordance with the acquisition method of accounting, the Company allocated the acquisition cost for the Agilis Merger to the underlying assets acquired and liabilities assumed, based upon the estimated fair values of those assets and liabilities at the date of acquisition. The Company classified the fair value of the acquired IPR&D as indefinite lived intangible assets until the successful completion or abandonment of the associated research and development efforts. The value allocated to the indefinite lived intangible assets was $576.5 million. With the approval of Upstaza by the European Commission in July 2022, $89.6 million was reclassified from indefinite lived intangible assets to definite lived intangible assets. The Company performed an annual test for its indefinite-lived intangible assets as of October 1, 2022. In the fourth quarter of 2022, the Company recorded a partial impairment on the Upstaza indefinite lived intangible asset of $33.4 million, which is recorded as intangible asset impairment in the statement of operations. The impairment was related to a decrease in projected cash flows due to refinements in current market assumptions and the timing of patient treatments. To calculate the impairment amount, the Company utilized a discounted cash flow model under the income method, which primarily utilized Level 3 fair value inputs. The discount rate utilized in the discounted cash flow model was 15%, and the weighted average probability of success was 88%. As of December 31, 2022, the remaining balance of the Upstaza indefinite lived intangible asset is $235.8 million. No impairments were identified for the Company’s additional gene therapy portfolio pertaining to PTC-FA and PTC-AS. Goodwill As a result of the Agilis Merger on August 23, 2018, the Company recorded $82.3 million of goodwill. There have been no changes to the balance of goodwill since the date of the Agilis Merger. Accordingly, the goodwill balance as of December 31, 2022 and 2021 was $82.3 million. The Company performed an annual impairment test for goodwill as of October 1, 2022. The Company’s single reporting unit had a negative carrying value and thus the Company determined there was no impairment of goodwill.

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent events	19. Subsequent events In February 2023, the Company completed enrollment of its Phase 3 placebo-controlled clinical trial for sepiapterin for PKU. In connection with this event and in accordance with the Censa Merger Agreement, the Company is obligated to pay a $30.0 million development milestone to the former Censa securityholders, which the Company has the option to pay in cash or shares of its common stock.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. Certain prior period balances have been reclassified to conform to the current period presentation. These reclassifications did not have a material impact on the consolidated statements of operations, consolidated balance sheets, consolidated statements of cash flows, or notes to the consolidated financial statements.
Use of estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates in these consolidated financial statements have been made in connection with the calculation of net product sales, royalty revenue, certain accruals related to the Company’s research and development expenses, valuation procedures for liability for sale of future royalties, valuation procedures for the convertible notes, indefinite lived intangible assets annual impairment assessment, fair value of the contingent consideration, and the provision for or benefit from income taxes. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.
Restricted Cash	Restricted Cash Restricted cash included in deposits and other assets on the consolidated balance sheet relates to an unconditional, irrevocable and transferable letter of credit that was entered into during the twelve-month period ended December 31, 2019 in connection with obligations under a facility lease for the Company’s leased biologics manufacturing facility in Hopewell Township, New Jersey. The amount of the letter of credit is $7.5 million, is to be maintained for a term of not less than five years and has the potential to be reduced to $3.8 million if after five years the Company is not in default of its lease. Restricted cash also contains an unconditional, irrevocable and transferable letter of credit that was entered into during June 2022 in connection with obligations for the Company’s new facility lease in Warren, New Jersey. The amount of the letter of credit is $8.1 million and has the potential to be reduced to $4.1 million if after five years the Company is not in default of its lease. Both amounts are classified within deposits and other assets on the consolidated balance sheet due to the long-term nature of the letter of credit. Restricted cash also includes a bank guarantee of $0.5 million denominated in a foreign currency. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the consolidated balance sheet that sum to the total of the same amounts shown in the statement of cash flows: ​ ​ ​ ​ ​ ​ ​ ​ ​ End of ​ Beginning of ​ period- period- ​ December 31, December 31, ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 279,834 ​ $ 189,718 Restricted cash included in deposits and other assets ​ 16,091 ​ 7,500 Total Cash, cash equivalents and restricted cash per statement of cash flows ​ $ 295,925 ​ $ 197,218 ​
Consolidation	Consolidation The consolidated financial statements include the accounts of PTC Therapeutics, Inc. and its wholly owned subsidiaries. All inter-company accounts, transactions, and profits have been eliminated in consolidation.
Segment and geographic information	Segment and geographic information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating and reporting
Cash equivalents	Cash equivalents The Company considers all highly liquid investments with a maturity of 90 days or less at the time of purchase to be cash equivalents. Cash equivalents are carried at cost which approximates fair value due to their short-term nature.
Marketable securities	Marketable securities The Company’s marketable securities consists of both debt securities and equity investments. The Company considers its investments in debt securities with original maturities of greater than 90 days to be available for sale securities. Securities under this classification are recorded at fair value and unrealized gains and losses within accumulated other comprehensive income. The estimated fair value of the available for sale securities is determined based on quoted market prices or rates for similar instruments. In addition, the cost of debt securities in this category is adjusted for amortization of premium and accretion of discount to maturity. For available for sale debt securities in an unrealized loss position, the Company assesses whether it intends to sell or if it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value. If the criteria are not met, the Company evaluates whether the decline in fair value has resulted from a credit loss or other factors. In making this assessment, management considers, among other factors, the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized costs basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. For the years ended December 31, 2022 and 2021, no allowance was recorded for credit losses. Marketable securities that are equity investments are measured at fair value, as it is readily available, and as such are classified as Level 1 assets. Unrealized holding gains and losses for these equity investments are components of other (expense) income, net within the consolidated statement of operations.
Concentration of credit risk	Concentration of credit risk The Company’s financial instruments that are exposed to credit risks consist primarily of cash and cash equivalents, available-for-sale marketable securities and accounts receivable. The Company maintains its cash and cash equivalents in bank accounts, which, at times, exceed federally insured limits. The Company has not experienced any credit losses in these accounts and does not believe it is exposed to any significant credit risk on these funds. The Company’s investment policy includes guidelines on the quality of the financial institutions and financial instruments the Company is allowed to invest in, which the Company believes minimizes the exposure to concentration of credit risk. The Company is subject to credit risk from its accounts receivable related to its product sales. The payment terms are predetermined and the Company evaluates the creditworthiness of each customer or distributor on a regular basis. The Company reserves all uninsured amounts billed directly to a patient until the time of cash receipt as collectability is not reasonably assured at the time the product is received. To date, the Company has not incurred any material credit losses.
Fixed assets	Fixed assets Fixed assets are stated at cost. Depreciation is computed starting when the asset is placed into service on a straight-line basis over the estimated useful life of the related asset as follows: Leasehold improvements Lesser of useful life or lease term Computer equipment and software ​ 3 years Machinery and lab equipment ​ 7 years Furniture and fixtures ​ 7 years ​
Inventory and cost of product sales	Inventory and cost of product sales Inventory Inventories are stated at the lower of cost and net realizable value with cost determined on a first-in, first-out basis by product. The Company capitalizes inventory costs associated with products following regulatory approval when future commercialization is considered probable and the future economic benefit is expected to be realized. Products which may be used in clinical development programs are included in inventory and charged to research and development expense when the product enters the research and development process and no longer can be used for commercial purposes. Inventory used for marketing efforts are charged to selling, general and administrative expense. Amounts related to clinical development programs and marketing efforts are immaterial. The following table summarizes the components of the Company’s inventory for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 December 31, 2021 Raw materials ​ $ 1,078 ​ $ 1,418 Work in progress ​ 14,074 ​ 7,721 Finished goods ​ 6,656 ​ 6,717 Total inventory ​ $ 21,808 ​ $ 15,856 ​ The Company periodically reviews its inventories for excess amounts or obsolescence and writes down obsolete or otherwise unmarketable inventory to its estimated net realizable value. The Company recorded write downs of $1.7 million and $2.2 million for the years ended December 31, 2022 and 2021, respectively, primarily related to product approaching expiration. Additionally, though the Company’s product is subject to strict quality control and monitoring which it performs throughout the manufacturing processes, certain batches or units of product may not meet quality specifications resulting in a charge to cost of product sales. For the years ended December 31, 2022 and December 31, 2021, these amounts were immaterial. Cost of product sales Cost of product sales consists of the cost of inventory sold, manufacturing and supply chain costs, storage costs, amortization of the acquired intangible asset, royalty payments associated with net product sales, and royalty payments to collaborative partners associated with royalty revenues and collaboration revenue related to milestones. Production costs are expensed as cost of product sales when the related products are sold or royalty revenues and collaboration revenue milestones are earned.
Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Accumulated other comprehensive income (loss) consists of unrealized gains or losses on marketable securities and foreign currency translation adjustments.
Revenue recognition	Revenue recognition Net product revenue The Company’s net product revenue primarily consists of sales of Translarna in territories outside of the U.S. for the treatment of nmDMD and sales of Emflaza in the U.S. for the treatment of DMD. The Company recognizes revenue when its performance obligations with its customers have been satisfied. The Company’s performance obligations are to provide products based on customer orders from distributors, hospitals, specialty pharmacies or retail pharmacies. The performance obligations are satisfied at a point in time when the Company’s customer obtains control of the product, which is typically upon delivery. The Company invoices its customers after the products have been delivered and invoice payments are generally due within 30 to 90 days of the invoice date. The Company determines the transaction price based on fixed consideration in its contractual agreements. Contract liabilities arise in certain circumstances when consideration is due for goods the Company has yet to provide. As the Company has identified only one distinct performance obligation, the transaction price is allocated entirely to product sales. In determining the transaction price, a significant financing component does not exist since the timing from when the Company delivers product to when the customers pay for the product is typically less than one year. Customers in certain countries pay in advance of product delivery. In those instances, payment and delivery typically occur in the same month. The Company records product sales net of any variable consideration, which includes discounts, allowances, rebates related to Medicaid and other government pricing programs, and distribution fees. The Company uses the expected value or most likely amount method when estimating its variable consideration, unless discount or rebate terms are specified within contracts. The identified variable consideration is recorded as a reduction of revenue at the time revenues from product sales are recognized. These estimates for variable consideration are adjusted to reflect known changes in factors and may impact such estimates in the quarter those changes are known. Revenue recognized does not include amounts of variable consideration that are constrained. During the years ended December 31, 2022, 2021, and 2020, net product sales in the United States were $218.3 million, $187.3 million, and $139.0 million, respectively, consisting solely of sales of Emflaza, and net product sales outside of the United States were $316.9 million, $241.6 million, and $194.4 million respectively, consisting of sales of Translarna, Tegsedi, Waylivra, and Upstaza. Translarna net product revenues made up $288.6 million, $236.0 million, and $191.9 million of the net product sales outside of the United States for the years ended December 31, 2022, 2021, and 2020, respectively. During the year ended December 31, 2022, two countries, the United States and Russia, accounted for at least 10% of the Company’s net product sales, representing $218.3 million and $59.7 million of net product sales, respectively. During the years ended December 31, 2021 and 2020, only the United States accounted for at least 10% of the Company’s net product sales. In relation to customer contracts, the Company incurs costs to fulfill a contract but does not incur costs to obtain a contract. These costs to fulfill a contract do not meet the criteria for capitalization and are expensed as incurred. The Company considers any shipping and handling costs that are incurred after the customer has obtained control of the product as a cost to fulfill a promise. Shipping and handling costs associated with finished goods delivered to customers are recorded as a selling expense. Collaboration and royalty revenue The terms of these agreements typically include payments to the Company of one or more of the following: nonrefundable, upfront license fees; milestone payments; research funding and royalties on future product sales. In addition, the Company generates service revenue through agreements that generally provide for fees for research and development services and may include additional payments upon achievement of specified events. At the inception of a collaboration arrangement, the Company needs to first evaluate if the arrangement meets the criteria in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 808 “Collaborative Arrangements” to then determine if ASC Topic 606 is applicable by considering whether the collaborator meets the definition of a customer. If the criteria are met, the Company assesses the promises in the arrangement to identify distinct performance obligations. For licenses of intellectual property, the Company assesses, at contract inception, whether the intellectual property is distinct from other performance obligations identified in the arrangement. If the licensing of intellectual property is determined to be distinct, revenue is recognized for nonrefundable, upfront license fees when the license is transferred to the customer and the customer can use and benefit from the license. If the licensing of intellectual property is determined not to be distinct, then the license will be bundled with other promises in the arrangement into one distinct performance obligation. The Company needs to determine if the bundled performance obligation is satisfied over time or at a point in time. If the Company concludes that the nonrefundable, upfront license fees will be recognized over time, the Company will need to assess the appropriate method of measuring proportional performance. For milestone payments, the Company assesses, at contract inception, whether the development or sales-based milestones are considered probable of being achieved. If it is probable that a significant revenue reversal will occur, the Company will not record revenue until the uncertainty has been resolved. Milestone payments that are contingent upon regulatory approval are not considered probable of being achieved until the applicable regulatory approvals or other external conditions are obtained as such conditions are not within the Company’s control. If it is probable that a significant revenue reversal will not occur, the Company will estimate the milestone payments using the most likely amount method. The Company will re-assess the development and sales-based milestones each reporting period to determine the probability of achievement. The Company recognizes royalties from product sales at the later of when the related sales occur or when the performance obligation to which the royalty has been allocated has been satisfied. If it is probable that a significant revenue reversal will not occur, the Company will estimate the royalty payments using the most likely amount method. The Company recognizes revenue for reimbursements of research and development costs under collaboration agreements as the services are performed. The Company records these reimbursements as revenue and not as a reduction of research and development expenses as the Company has the risks and rewards as the principal in the research and development activities. For the years ended December 31, 2022, 2021, and 2020, the Company has recognized $50.1 million, $55.0 million, and $42.6 million of collaboration revenue, respectively, related to the SMA License Agreement with Roche. For the years ended December 31, 2022, 2021 and 2020, the Company has recognized $113.5 million, $54.6 million, and $4.8 million of royalty revenue, respectively, related to Evrysdi.
Allowance for doubtful accounts	Allowance for doubtful accounts The Company maintains an allowance for estimated losses resulting from the inability of its customers to make required payments. The Company estimates uncollectible amounts based upon current customer receivable balances, the age of customer receivable balances, the customer’s financial condition and current economic trends. The Company also assesses whether an allowance for expected credit losses may be required which includes a review of the Company’s receivables portfolio, which are pooled on a customer basis or country basis. In making its assessment of whether an allowance for credit losses is required, the Company considers its historical experience with customers, current balances, levels of delinquency, regulatory and legal environments, and other relevant current and future forecasted economic conditions
Liability for sale of future royalties	Liability for sale of future royalties On July 17, 2020, the Company, RPI Intermediate Finance Trust (“RPI”), and, for the limited purposes set forth in the agreement, Royalty Pharma PLC, entered into a Royalty Purchase Agreement (the “Royalty Purchase Agreement”). Pursuant to the Royalty Purchase Agreement, the Company sold to RPI 42.933% (the “Assigned Royalty Payment”) of the Company’s right to receive sales-based royalty payments (the “Royalty”) on worldwide net sales of Evrysdi and any other product developed pursuant to the License and Collaboration Agreement (the “License Agreement”), dated as of November 23, 2011, by and among the Company, Roche and, for the limited purposes set forth therein, the SMA Foundation under the SMA program. In consideration for the sale of the Assigned Royalty Payments, RPI paid the Company $650.0 million in cash consideration. The Company has retained a 57.067% interest in the Royalty and all economic rights to receive the remaining potential regulatory and sales milestone payments under the License Agreement, which remaining milestone payments equal $250.0 million in the aggregate as of December 31, 2022. The Royalty Purchase Agreement will terminate 60 days following the earlier of the date on which Roche is no longer obligated to make any payments of the Royalty pursuant to the License Agreement and the date on which RPI has received $1.3 billion in respect of the Assigned Royalty Payments. The cash consideration obtained pursuant to the Royalty Purchase Agreement is classified as debt and is recorded as “liability for sale of future royalties-current” and “liability for sale of future royalties-noncurrent” on the Company’s consolidated balance sheet based on the timing of the expected payments to be made to RPI. The fair value for the liability for sale of future royalties at the time of the transaction was based on the Company’s estimates of future royalties expected to be paid to RPI over the life of the arrangement, which was determined using forecasts from market data sources, which are considered Level 3 inputs. The liability is being amortized using the effective interest method over the life of the arrangement, in accordance with the respective guidance. The Company utilizes the prospective method to account for subsequent changes in the estimated future payments to be made to RPI. Refer to Note 8 for further details. ​
Leases	Leases The Company determines if an arrangement is a lease at inception. This determination generally depends on whether the arrangement conveys to the Company the right to control the use of an explicitly or implicitly identified fixed asset for a period of time in exchange for consideration. Control of an underlying asset is conveyed to the Company if the Company obtains the rights to direct the use of and to obtain substantially all of the economic benefits from using the underlying asset. The Company has lease agreements which include lease and non-lease components, which the Company accounts for as a single lease component for all leases. Operating and finance leases are classified as right of use ("ROU") assets, short term lease liabilities, and long term lease liabilities. Operating and finance lease ROU assets and lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. ROU assets are Variable lease payments associated with the Company’s leases are recognized when the event, activity, or circumstance in the lease agreement on which those payments are assessed occurs. Variable lease payments are presented in the Company’s consolidated statements of operations in the same line item as expense arising from fixed lease payments for operating leases. Leases with an initial term of 12 months or less are not recorded on the consolidated balance sheet and the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company applies this policy to all underlying asset categories. A lessee is required to discount its unpaid lease payments using the interest rate implicit in the lease or, if that rate cannot be readily determined, its incremental borrowing rate. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company gives consideration to its recent debt issuances as well as publicly available data for instruments with similar characteristics when calculating its incremental borrowing rates. The lease term for all of the Company’s leases includes the non-cancellable period of the lease plus any additional periods covered by either a Company option to extend (or not to terminate) the le
Research and development costs	Research and development costs Research and development expenses include the clinical development costs associated with the Company’s product development programs and research and development costs associated with the Company’s discovery programs. These expenses include internal research and development costs and the costs of research and development conducted on behalf of the Company by third parties, including sponsored university-based research agreements and clinical study vendors. All research and development costs are expensed as incurred. Costs incurred in obtaining technology licenses are charged immediately to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future uses. Advance payments made for goods and services that will be used in future research and development activities are deferred if the contracted party has not yet performed the related activities. The amount deferred is then recognized as expense when the research and development activities are performed. The short term deferred research and development advance payments were $2.4 million and $1.4 million and are classified as prepaid expenses and other current assets on the consolidated balance sheet as of December 31, 2022 and 2021, respectively. The long term deferred research and development advance payments were $3.9 million and $1.8 million and are classified as deposits and other assets on the consolidated balance sheet as of December 31, 2022 and 2021, respectively.
Fair value of financial instruments	Fair value of financial instruments The Company follows the fair value measurement rules, which provides guidance on the use of fair value in accounting and disclosure for assets and liabilities when such accounting and disclosure is called for by other accounting literature. These rules establish a fair value hierarchy for inputs to be used to measure fair value of financial assets and liabilities. This hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels: Level 1 (highest priority), Level 2, and Level 3 (lowest priority). ● Level 1—Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the balance sheet date. ● Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). ● Level 3—Inputs are unobservable and reflect the Company’s assumptions as to what market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available. Cash equivalents, marketable securities, and equity investments are reflected in the accompanying financial statements at fair value. The carrying amount of receivables and accounts payable and accrued expenses approximates fair value due to the short-term nature of those instruments.
Share-based compensation	Share-based compensation The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant date fair value of the award. Restricted stock awards are measured based on the fair market values of the underlying stock on the dates of grant. For service type awards, share-based compensation expense is recognized on a straight-line basis over the period during which the employee is required to provide service in exchange for the entire award. The fair value of options is calculated using the Black-Scholes option pricing model to determine the fair value of stock options on the date of grant based on key assumptions such as expected volatility and expected term. The Company estimates the expected volatility of options utilizing the Company’s historical stock volatility. The Company estimates the expected term of options utilizing the Company’s historical exercise data. The risk-free rate of the option is based on U.S. Government Securities Treasury Constant Maturities yields at the date of grant for a term similar to the expected term of the option. In connection with the adoption of FASB Accounting Standards Update (“ASU”) 2016-9, the Company made a policy election to continue its methodology for estimating its forfeiture rate.
Income Taxes	Income taxes On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act, referred to herein as the CARES Act, as a response to the economic uncertainty resulting from a strain of novel coronavirus, COVID-19. The CARES Act includes modifications for net operating loss carryovers and carrybacks, limitations of business interest expense for tax, immediate refund of alternative minimum tax (“AMT”) credit carryovers as well as a technical correction to the 2017 Tax Cuts and Jobs Act ("the 2017 Tax Act") for qualified improvement property. On December 27, 2020, the Coronavirus Response and Relief Supplemental Appropriations Act of 2021 – a $900 billion relief package to deliver the second round of economic stimulus for individuals, families, and businesses was signed into law. The bill provides relief through multiple measures and expands many of the provisions already put into place under the CARES Act. As of December 31, 2022, the Company expects that these provisions will not have a material impact. Tax provisions of the CARES Act also include the deferral of certain payroll taxes, relief for retaining employees, and other provisions. The relief for retaining employees was not material to the financial statements and there were no deferrals of certain payroll taxes as of December 31, 2022, which is no longer accrued in other current liabilities on the consolidated balance sheet. Additionally, the Organization for Economic Co-operation and Development, or OECD, the EC, and individual taxing jurisdictions where the Company and its affiliates do business have recently focused on issues related to the taxation of multinational corporations. The OECD has released its comprehensive plan to create an agreed set of international rules for fighting base erosion and profit shifting. In addition, the OECD, the EC, and individual counties are examining changes to how taxing rights should be allocated among countries considering the digital economy. As a result, the tax laws in the U.S. and other countries in which PTC and its affiliates do business could change on a prospective or retroactive basis and any such changes could materially adversely affect the Company’s business. On December 22, 2017, the U.S. government enacted the 2017 Tax Cuts and Jobs Act (“TCJA”), which significantly revised U.S. tax law by, among other provisions, lowering the U.S. federal statutory income tax rate to 21%, imposing a mandatory one-time transition tax on previously deferred foreign earnings, and eliminating or reducing certain income tax deductions. The Global Intangible Low-tax Income ("GILTI") provisions of the TCJA require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. The Company has elected to account for GILTI tax in the period in which it is incurred, and therefore has not provided any deferred tax impacts of GILTI in its consolidated financial statements for the period ended December 31, 2022. Starting in 2022, TCJA amendments to IRC Section 174 will no longer permit an immediate deduction for research and development (R&D) expenditures in the tax year that such costs are incurred. Instead, these IRC Section 174 development costs must now be capitalized and amortized over either a five- or 15-year period, depending on the location of the activities performed. The new amortization period begins with the midpoint of any taxable year that IRC Section 174 costs are first incurred, regardless of whether the expenditures were made prior to or after July 1 and runs until the midpoint of year five for activities conducted in the United States or year 15 in the case of development conducted on foreign soil. This tax law change resulted in an increased current taxable income of the Company by $450.1 million for the year ended December 31, 2022. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As a result of the reduction in the U.S. corporate income tax rate, the Company revalued its ending net deferred tax assets as of December 31, 2017. In the fourth quarter of 2018, the Company completed its analysis to determine the effect of the Tax Act and recorded no further adjustments. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and net operating loss and credit carryforwards. Deferred tax assets and liabilities are measured at rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the statement of operations in the period that includes the enactment date. A valuation allowance is recorded when it is not more likely than not that all or a portion of the net deferred tax assets will be realized. On August 23, 2018, the Company completed its acquisition of Agilis Biotherapeutics, Inc. (“Agilis”), pursuant to an Agreement and Plan of Merger, dated as of July 19, 2018 (the “Agilis Merger Agreement”), by and among the Company, Agility Merger Sub, Inc., a Delaware corporation and the Company’s wholly owned, indirect subsidiary, Agilis and, solely in its capacity as the representative, agent and attorney-in-fact of the equityholders of Agilis, Shareholder Representative Services LLC, (the “Agilis Merger”). The Company recorded a deferred tax liability in conjunction with the Agilis Merger of $122.0 million in 2018, related to the tax basis difference in the In-Process Research and Development, or IPR&D, indefinite-lived intangibles acquired. The Company’s policy is to record a deferred tax liability related to acquired IPR&D which may eventually be realized either upon amortization of the asset when the research is completed and a product is successfully launched or the write-off of the asset if it is abandoned or unsuccessful. In July 2022, the Company received EMEA approval for a portion of the IPR&D assets, and thus, began the amortization of the intangible.
Foreign currency	Foreign currency The functional currencies of the Company’s foreign subsidiaries primarily are the local currencies of the country in which the subsidiary operates. The Company also has an intercompany loan which is recorded on a non-U.S. subsidiary and was formally denominated in U.S. dollars and was remeasured into local currency using the exchange rate as of the balance sheet date. During the year ended December 31, 2022, the loan agreement was amended to change the denomination from U.S. dollars to local currency, and the Company recorded a non-cash realized foreign exchange loss of $16.9 million, which is recorded within other (expense) income, net on the consolidated statement of operations. The Company’s asset and liability accounts, including the intercompany loan, are translated using the current exchange rate as of the balance sheet date. Stockholders’ equity accounts are translated using historical rates at the balance sheet date. Revenue and expense accounts are translated using a weighted average exchange rate over the period ended on the balance sheet date. Adjustments resulting from the translation of the financial statements of the Company’s foreign subsidiaries into U.S. dollars are accumulated as a separate component of stockholders’ equity within other comprehensive income. Gains or losses resulting from transactions denominated in foreign currencies are included in other income or expense, within the consolidated statements of income.
Net (loss) income per share	Net (loss) income per share Basic net (loss) income per share is calculated by dividing the net (loss) income attributable to common stockholders by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net income per share is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method and the if-converted method. During periods in which the Company incurs net losses, both basic and diluted loss per share is calculated by dividing the net loss by the weighted average shares outstanding—potentially dilutive securities are excluded from the calculation because their effect would be anti-dilutive. Dilutive common stock equivalents are comprised of options and unvested restricted stock outstanding under the Company’s stock option plans.
Business combinations and asset acquisitions	Business combinations and asset acquisitions The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in ASU 2017-01, “Business Combinations”, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquiree and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, and non-controlling interest in the acquiree based on the fair value estimates as of the date of acquisition. In accordance with ASC 805, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired. The consideration for the Company’s business acquisitions may include future payments that are contingent upon the occurrence of a particular event or events. The obligations for such contingent consideration payments are recorded at fair value on the acquisition date. The contingent consideration obligations are then evaluated each reporting period. Changes in the fair value of contingent consideration, other than changes due to payments, are recognized as a gain or loss and recorded within the change in the fair value of deferred and contingent consideration in the consolidated statements of operations. If determined to be an asset acquisition, the Company accounts for the transaction under ASC 805-50, which requires the acquiring entity in an asset acquisition to recognize assets acquired and liabilities assumed based on the cost to the acquiring entity on a relative fair value basis, which includes transaction costs in addition to consideration given. No gain or loss is recognized as of the date of acquisition unless the fair value of noncash assets given as consideration differs from the assets’ carrying amounts on the acquiring entity’s books. Consideration transferred that is noncash will be measured based on either the cost (which will be measured based on the fair value of the consideration given) or the fair value of the assets acquired and liabilities assumed, whichever is more reliably measurable. Goodwill is not recognized in an asset acquisition and any excess consideration transferred over the fair value of the net assets acquired is allocated to the identifiable assets based on relative fair values. Contingent consideration payments in asset acquisitions are recognized when the contingency is resolved and the consideration is paid or becomes payable (unless the contingent consideration meets the definition of a derivative, in which case the amount becomes part of the basis in the asset acquired). Upon recognition of the contingent consideration payment, the amount is included in the cost of the acquired asset or group of assets.
Finite-lived intangible assets	Finite-lived intangible assets The Company records the fair value of purchased intangible assets with finite useful lives as of the transaction date of a business combination or asset acquisition. Purchased intangible assets with finite useful lives are amortized to their estimated residual values over their estimated useful lives.
Impairment of long-lived assets	Impairment of long-lived assets The Company monitors its long-lived assets and finite-lived intangibles for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. The Company believes that no impairment of long-lived assets exists as of December 31, 2022.
Indefinite-lived intangible assets	Indefinite-lived intangible assets Indefinite-lived intangible assets consist of IPR&D. IPR&D acquired directly in a transaction other than a business combination is capitalized if the projects will be further developed or have an alternative future use; otherwise they are expensed. The fair values of IPR&D projects and license agreement assets acquired in business combinations are capitalized. Several methods may be used to determine the estimated fair value of the IPR&D and license agreement asset acquired in a business combination. The Company utilizes the "income method” and uses estimated future net cash flows that are derived from projected sales revenues and estimated costs. These projections are based on factors such as relevant market size, patent protection, and expected pricing and industry trends. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. These assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are amortized over the remaining useful life or written off, as appropriate. Intangible assets with indefinite lives, including IPR&D, are tested for impairment if impairment indicators arise and, at a minimum, annually. However, an entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that an indefinite-lived intangible asset’s fair value is less than its carrying amount. Otherwise, no further impairment testing is required. The indefinite-lived intangible asset impairment test consists of a one-step analysis that compares the fair value of the intangible asset with its carrying amount. If the carrying amount of an intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. The Company considers many factors in evaluating whether the value of its intangible assets with indefinite lives may not be recoverable, including, but not limited to, expected growth rates, the cost of equity and debt capital, general economic conditions, the Company’s outlook and market performance of the Company’s industry and recent and forecasted financial performance. The Company performed an annual test for its indefinite-lived intangible assets as of October 1, 2022. In the fourth quarter of 2022, the Company recorded a partial impairment on the Upstaza indefinite lived intangible asset of $33.4 million, which is recorded as intangible asset impairment in the statement of operations. The impairment was related to a decrease in projected cash flows due to refinements in current market assumptions and the timing of patient treatments. To calculate the impairment amount, the Company utilized a discounted cash flow model under the income method, which primarily utilized Level 3 fair value inputs. Some of the more significant assumptions inherent in the development of the model included the estimated annual cash flows, particularly net revenues and operations costs, the appropriate discount rate to select in order to measure the risk inherent in the future cash flows, and the probability of success. Refer to Note 18 for further information regarding the Company’s intangible assets.
Goodwill	Goodwill Goodwill represents the amount of consideration paid in excess of the fair value of net assets acquired as a result of the Company’s business acquisitions accounted for using the acquisition method of accounting. Goodwill is not amortized and is subject to impairment testing at a reporting unit level on an annual basis or when a triggering event occurs that may indicate the carrying value of the goodwill is impaired. The Company reassess its reporting units as part of its annual segment review. As of December 31, 2022, the Company concluded that it continues to operate as one reporting unit. An entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that the fair value of the reporting unit is less than its carrying amount. The Company performed an annual test for goodwill as of October 1, 2022. The Company’s single reporting unit had a negative carrying value and thus the Company determined there was no impairment of goodwill.

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Reconciliation of cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the consolidated balance sheet that sum to the total of the same amounts shown in the statement of cash flows: ​ ​ ​ ​ ​ ​ ​ ​ ​ End of ​ Beginning of ​ period- period- ​ December 31, December 31, ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 279,834 ​ $ 189,718 Restricted cash included in deposits and other assets ​ 16,091 ​ 7,500 Total Cash, cash equivalents and restricted cash per statement of cash flows ​ $ 295,925 ​ $ 197,218 ​
Schedule of estimated useful life of related assets	Leasehold improvements Lesser of useful life or lease term Computer equipment and software ​ 3 years Machinery and lab equipment ​ 7 years Furniture and fixtures ​ 7 years
Schedule of Inventory	The following table summarizes the components of the Company’s inventory for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 December 31, 2021 Raw materials ​ $ 1,078 ​ $ 1,418 Work in progress ​ 14,074 ​ 7,721 Finished goods ​ 6,656 ​ 6,717 Total inventory ​ $ 21,808 ​ $ 15,856 ​

Fair value of financial instr_2

Fair value of financial instruments and investments - (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities that are required to be measured at fair value on a recurring basis	The following represents the fair value using the hierarchy described in Note 2 for the Company’s financial assets and liabilities that are required to be measured at fair value on a recurring basis as of December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ ​ Quoted prices Significant ​ ​ ​ ​ ​ ​ in active other Significant ​ ​ ​ ​ markets for observable unobservable ​ ​ ​ ​ identical assets inputs inputs ​ Total (level 1) (level 2) (level 3) Marketable securities - available for sale ​ $ 22,610 ​ $ — ​ $ 22,610 ​ $ — Marketable securities - equity investments ​ $ 108,261 ​ $ 108,261 ​ $ — ​ $ — ClearPoint Equity Investments ​ $ 10,965 ​ $ 10,965 ​ $ — ​ $ — ClearPoint convertible debt security ​ $ 15,231 ​ $ — ​ $ 15,231 ​ $ — Contingent consideration payable- development and regulatory milestones ​ $ 82,500 ​ $ — ​ $ — ​ $ 82,500 Contingent consideration payable- net sales milestones and royalties ​ $ 81,500 ​ $ — ​ $ — ​ $ 81,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Quoted prices Significant ​ ​ ​ ​ ​ ​ in active other Significant ​ ​ ​ ​ markets for observable unobservable ​ ​ ​ ​ identical assets inputs inputs ​ Total (level 1) (level 2) (level 3) Marketable securities - available for sale ​ $ 376,685 ​ $ — ​ $ 376,685 ​ $ — Marketable securities - equity investments ​ $ 206,973 ​ $ 206,973 ​ $ — ​ $ — ClearPoint Equity Investments ​ $ 14,525 ​ $ 14,525 ​ $ — ​ $ — ClearPoint convertible debt security ​ $ 20,971 ​ $ — ​ $ 20,971 ​ $ — Contingent consideration payable- development and regulatory milestones ​ $ 139,300 ​ $ — ​ $ — ​ $ 139,300 Contingent consideration payable- net sales milestones and royalties ​ $ 100,600 ​ $ — ​ $ — ​ $ 100,600 ​
Summary of marketable securities accounted for as available-for-sale debt securities	The following is a summary of marketable securities accounted for as available for sale debt securities at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Amortized Gross Unrealized ​ ​ ​ ​ Cost Gains Losses Fair Value Commercial paper ​ $ 12,419 ​ $ 5 ​ $ — ​ $ 12,424 Corporate debt securities ​ 10,685 ​ ​ — ​ ​ (499) ​ ​ 10,186 Total ​ $ 23,104 ​ $ 5 ​ $ (499) ​ $ 22,610 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Amortized Gross Unrealized ​ ​ ​ ​ Cost Gains Losses Fair Value Commercial paper ​ $ 75,275 ​ $ 5 ​ $ (1) ​ $ 75,279 Corporate debt securities ​ 268,246 ​ ​ 81 ​ ​ (644) ​ 267,683 Asset-backed securities ​ 15,287 ​ ​ 16 ​ ​ (5) ​ 15,298 Government obligations ​ ​ 18,479 ​ ​ 5 ​ ​ (59) ​ ​ 18,425 Total ​ $ 377,287 ​ $ 107 ​ $ (709) ​ $ 376,685 ​
Summary of unrealized losses and fair values of available-for-sale debt securities in a continuous unrealized loss position	The unrealized losses and fair values of available for sale debt securities that have been in an unrealized loss position for a period of less than and greater than or equal to 12 months as of December 31, 2022 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Securities in an unrealized loss Securities in an unrealized loss ​ ​ ​ ​ ​ ​ position less than 12 months position greater than or equal to 12 months ​ Total ​ Unrealized losses Fair Value Unrealized losses Fair Value Unrealized losses Fair Value Corporate debt securities ​ $ — ​ ​ — ​ ​ (499) ​ ​ 10,186 ​ ​ (499) ​ $ 10,186 Total ​ $ — ​ $ — ​ $ (499) ​ $ 10,186 ​ $ (499) ​ $ 10,186 ​ The unrealized losses and fair values of available for sale debt securities that have been in an unrealized loss position for a period of less than and greater than or equal to 12 months as of December 31, 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Securities in an unrealized loss Securities in an unrealized loss ​ ​ ​ ​ ​ ​ position less than 12 months position greater than or equal to 12 months ​ Total ​ Unrealized losses Fair Value Unrealized losses Fair Value Unrealized losses Fair Value Commercial paper ​ $ (1) ​ ​ 12,992 ​ ​ — ​ ​ — ​ ​ (1) ​ $ 12,992 Corporate debt securities ​ ​ (608) ​ ​ 217,540 ​ ​ (36) ​ ​ 4,985 ​ ​ (644) ​ ​ 222,525 Asset-backed securities ​ (5) ​ ​ 10,786 ​ ​ — ​ ​ — ​ (5) ​ ​ 10,786 Government obligations ​ ​ (59) ​ ​ 15,483 ​ ​ — ​ ​ — ​ ​ (59) ​ ​ 15,483 Total ​ $ (673) ​ $ 256,801 ​ $ (36) ​ $ 4,985 ​ $ (709) ​ $ 261,786 ​
Schedule of marketable securities on the balance sheet	Available for sale debt securities on the balance sheet at December 31, 2022 and 2021 mature as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Less Than More Than ​ 12 Months 12 Months Commercial paper ​ $ 12,424 ​ $ — Corporate debt securities ​ — ​ 10,186 Total ​ $ 12,424 ​ $ 10,186 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Less Than More Than ​ 12 Months 12 Months Commercial paper ​ $ 75,279 ​ $ — Corporate debt securities ​ 131,606 ​ 136,077 Asset-backed securities ​ 8,724 ​ 6,574 Government obligations ​ ​ 6,002 ​ ​ 12,423 Total ​ $ 221,611 ​ $ 155,074 ​
Summary of changes in the fair value of the Company's Level 3 valuation for contingent consideration payable	The table presented below is a summary of changes in the fair value of the Company’s Level 3 valuation for the contingent consideration payables for the years ended December 31, 2022, and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration payable- ​ Contingent consideration payable- ​ ​ development and regulatory ​ net sales milestones and royalties ​ milestones - Agilis - Agilis Beginning balance as of December 31, 2020 ​ $ 139,200 ​ $ 101,200 Additions ​ — ​ — Change in fair value ​ 100 ​ (600) Payments ​ ​ — ​ ​ — Ending balance as of December 31, 2021 ​ $ 139,300 ​ $ 100,600 Additions ​ — ​ — Change in fair value ​ (6,800) ​ (19,100) Payments ​ (50,000) ​ — Ending balance as of December 31, 2022 ​ $ 82,500 ​ $ 81,500 ​ In July 2022, the European Commission approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA, which triggered a $50.0 million milestone payment to the former equityholders of Agilis in accordance with the terms of the Agilis Merger Agreement. In accordance with ASC 230, the portion of the $50.0 million milestone payment up to the acquisition date fair value of the contingent consideration liability is classified as a financing outflow and the amount paid in excess of the acquisition date fair value of that liability is classified as an operating outflow on the consolidated statements of cash flows. The following significant unobservable inputs were used in the valuation of the contingent consideration payables for the years ended December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Fair Value Valuation Technique Unobservable Input Range Contingent consideration payable- ​ $82,500 Probability-adjusted discounted cash flow Potential development and regulatory milestones ​ $0 - $331 million Contingent considerable payable- net sales ​ $81,500 Option-pricing model with Monte Carlo simulation Potential net sales milestones ​ $0 - $150 million ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Fair Value Valuation Technique Unobservable Input Range Contingent consideration payable- ​ $139,300 Probability-adjusted discounted cash flow Potential development and regulatory milestones ​ $0 - $381 million Contingent considerable payable- net sales ​ $100,600 Option-pricing model with Monte Carlo simulation Potential net sales milestones ​ $0 - $150 million ​

Fixed assets (Tables)

Fixed assets (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of fixed assets, net	Fixed assets, net were as follows at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 Leasehold improvements ​ $ 28,969 ​ $ 19,937 Computer equipment and software ​ 15,332 ​ 13,812 Machinery and lab equipment ​ ​ 47,496 ​ ​ 33,187 Furniture and fixtures ​ 3,812 ​ 3,805 Assets in process ​ 14,349 ​ 9,017 ​ ​ 109,958 ​ 79,758 Less accumulated depreciation ​ (37,368) ​ (27,173) Total ​ $ 72,590 ​ $ 52,585 ​

Leases - (Tables)

Leases - (Tables)	12 Months Ended
	Dec. 31, 2022
Leases
Schedule of lease costs	The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2022 ​ Year Ended December 31, 2021 ​ Year Ended December 31, 2020 Operating Lease Cost ​ ​ ​ ​ ​ ​ ​ ​ Fixed lease cost ​ $ 19,804 ​ $ 16,411 ​ $ 12,368 Variable lease cost ​ ​ 4,557 ​ ​ 4,361 ​ ​ 2,448 Short-term lease cost ​ ​ 808 ​ ​ 656 ​ ​ 450 Total operating lease cost ​ $ 25,169 ​ $ 21,428 ​ $ 15,266 ​ Supplemental lease term and discount rate information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 Weighted-average remaining lease terms - operating leases (years) 11.61 ​ ​ 10.87 ​ Weighted-average discount rate - operating leases ​ 8.61 % ​ 8.91 % Weighted-average remaining lease terms - finance lease (years) 10.01 ​ ​ 11.00 ​ Weighted-average discount rate - finance lease 7.80 % ​ 7.80 % ​
Schedule of supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 ​ 2020 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases $ 14,736 ​ $ 13,683 ​ $ 8,462 Financing cash flows from finance lease ​ 1,276 ​ ​ 2,224 ​ ​ 17,829 Operating cash flows from finance leases ​ 1,724 ​ ​ 776 ​ ​ 171 ​ ​ ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease obligations: ​ ​ ​ ​ ​ Operating leases $ 35,817 ​ $ 645 ​ $ 76,811 Finance lease ​ — ​ ​ — ​ ​ 41,382 ​
Schedule of future lease payments - Operating leases	Future minimum lease payments under non-cancelable leases as of December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Lease 2023 ​ $ 15,373 ​ $ 3,000 2024 ​ 18,456 ​ 3,000 2025 ​ 20,431 ​ 3,000 2026 ​ 19,985 ​ 3,000 2027 and thereafter ​ 193,792 ​ 18,000 Total lease payments ​ 268,037 ​ 30,000 Less: Imputed Interest expense ​ 157,807 ​ 8,325 Total ​ $ 110,230 ​ $ 21,675

Accounts payable and accrued _2

Accounts payable and accrued expenses - (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of components of accounts payable and accrued expenses	Accounts payable and accrued expenses at December 31, 2022 and 2021 consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 Employee compensation, benefits, and related accruals ​ $ 62,669 ​ $ 55,733 Income tax payable ​ ​ 4,712 ​ ​ 1,287 Consulting and contracted research ​ 38,882 ​ 26,434 Professional fees ​ 3,093 ​ 3,547 Sales allowance ​ 63,787 ​ 61,662 Sales rebates ​ 67,355 ​ 68,770 Royalties ​ ​ 40,546 ​ ​ 35,679 Accounts payable ​ 27,268 ​ 23,033 Other ​ 12,054 ​ 12,639 Total ​ $ 320,366 ​ $ 288,784

Debt - (Tables)

Debt - (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Instrument, Redemption [Line Items]
Summary of liability for sale of future royalties	The following table shows the activity within the “liability for sale of future royalties- current” and “liability for sale of future royalties- noncurrent” accounts for the year ended December 31, 2022: ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Liability for sale of future royalties- (current and noncurrent) ​ 2022 ​ Beginning balance as of December 31, 2021 ​ $ 733,985 ​ Less: Non-cash royalty revenue payable to RPI ​ ​ (48,738) ​ Plus: Non-cash interest expense recognized ​ ​ 72,639 ​ Ending balance ​ $ 757,886 ​ Effective interest rate as of December 31, 2022 ​ 8.7 % ​
1.50% Convertible senior notes due 2026
Debt Instrument, Redemption [Line Items]
Summary of convertible notes	The 2026 Convertible Notes consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, Liability component ​ 2022 ​ ​ 2021 Principal ​ $ 287,500 ​ $ 287,500 Less: Debt issuance costs ​ (4,456) ​ ​ (5,606) Net carrying amount ​ $ 283,044 ​ $ 281,894 ​
Summary of interest expense recognized related to debt	The following table sets forth total interest expense recognized related to the 2026 Convertible Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 ​ Contractual interest expense ​ $ 4,313 ​ $ 4,313 ​ Amortization of debt issuance costs ​ 1,150 ​ ​ 1,128 ​ Total ​ $ 5,463 ​ $ 5,441 ​ Effective interest rate ​ 1.9 % ​ 1.9 % ​
3.00% Convertible senior notes due 2022
Debt Instrument, Redemption [Line Items]
Summary of convertible notes	The 2022 Convertible Notes consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, Liability component ​ 2022 2021 Principal ​ $ 150,000 ​ $ 150,000 Less: Debt issuance costs ​ — ​ (460) Repayment of Convertible Notes ​ (150,000) ​ — Net carrying amount ​ $ — ​ $ 149,540 ​
Summary of interest expense recognized related to debt	The following table sets forth total interest expense recognized related to the 2022 Convertible Notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ December 31, ​ ​ 2022 2021 Contractual interest expense ​ $ 2,800 ​ $ 4,500 ​ Amortization of debt issuance costs ​ 460 ​ 720 ​ Total ​ $ 3,260 ​ $ 5,220 ​ Effective interest rate ​ 3.5 % 3.5 %
Senior Secured Term Loan Facility
Debt Instrument, Redemption [Line Items]
Summary of interest expense recognized related to debt	The following table sets forth total interest expense recognized related to the senior secured term loan: ​ ​ ​ ​ ​ ​ Year ended ​ December 31, ​ 2022 ​ Contractual interest expense $ 6,069 ​ Amortization of debt issuance costs 290 ​ Total $ 6,359 ​ Effective interest rate ​ 12.2 % ​

Net loss per share - (Tables)

Net loss per share - (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted net loss available to common stockholders	The following table sets forth the computation of basic and diluted net loss per share for common stockholders: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ ​ 2022 2021 2020 ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss ​ $ (559,017) $ (523,901) $ (438,160) Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator for basic and diluted net loss per share ​ 71,728,634 70,466,393 66,027,908 Net loss per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic and diluted ​ $ (7.79) * $ (7.43) * $ (6.64) * * For the years ended December 31, 2022, 2021, and 2020, the Company experienced a net loss and therefore did not report any dilutive share impact.
Schedule of historical dilutive common share equivalents outstanding	The following table shows historical dilutive common share equivalents outstanding, which are not included in the above historical calculation, as the effect of their inclusion is anti-dilutive during each period. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2022 2021 2020 Stock Options ​ 11,502,417 ​ 10,772,582 ​ 9,663,677 Unvested restricted stock awards and units 2,516,336 1,519,831 982,058 Total 14,018,753 12,292,413 10,645,735

Stock award plan - (Tables)

Stock award plan - (Tables)	12 Months Ended
	Dec. 31, 2022
Share-based Payment Arrangement [Abstract]
Summary of stock option activity	Stock option activity ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ average ​ ​ Aggregate ​ ​ ​ ​ average ​ remaining ​ ​ intrinsic ​ ​ Number of ​ exercise ​ contractual ​ ​ value(in ​ ​ options ​ price ​ term ​ ​ thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding at December 31, 2019 11,043,939 ​ $ 31.67 ​ ​ Granted 2,777,975 ​ $ 51.06 ​ ​ Exercised (3,268,452) ​ $ 24.25 ​ ​ Forfeited (889,785) ​ $ 42.14 ​ ​ Outstanding at December 31, 2020 9,663,677 ​ $ 38.72 ​ ​ Granted 2,487,234 ​ $ 61.36 ​ ​ Exercised (635,871) ​ $ 28.01 ​ ​ Forfeited (742,458) ​ $ 52.04 ​ ​ Outstanding at December 31, 2021 10,772,582 ​ $ 43.66 ​ ​ Granted 1,685,435 ​ $ 38.55 ​ ​ Exercised (496,863) ​ $ 29.45 ​ ​ Forfeited/Cancelled (458,737) ​ $ 48.75 ​ ​ Outstanding at December 31, 2022 11,502,417 ​ $ 43.33 6.38 years ​ $ 38,330 Vested or Expected to vest at December 31, 2022 3,432,725 ​ $ 47.74 8.20 years ​ $ 1,694 Exercisable at December 31, 2022 7,774,274 ​ $ 41.23 5.49 years ​ $ 36,523 ​
Schedule of assumptions used to estimate fair values of grants made on the date of grant	The fair values of grants made in the years ended December 31, 2022, 2021 and 2020 were contemporaneously estimated on the date of grant using the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Risk-free interest rate 1.55% - 4.57% 0.51% - 1.24% 0.34% - 1.45% Expected volatility 54% - 74% 74% - 89% 87% - 89% Expected term 5.5 years 5.5 years 5.75 years ​
Summary of information on the Company's restricted stock	The following table summarizes information on the Company’s restricted stock awards and units: ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted Stock Awards and Units ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ ​ Grant ​ ​ Number of ​ Date ​ Shares Fair Value Unvested at December 31, 2021 ​ 1,519,831 ​ $ 55.43 Granted 1,686,467 ​ ​ 38.37 Vested (504,851) ​ ​ 50.15 Forfeited (185,111) ​ ​ 46.67 Unvested at December 31, 2022 2,516,336 ​ $ 45.67 ​
Schedule of share-based compensation expense recorded in the statement of operations	The Company recorded share-based compensation expense in the statement of operations related to incentive stock options, nonstatutory stock options, restricted stock awards, restricted stock units and the ESPP as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2022 2021 2020 Research and development ​ $ 55,869 ​ $ 53,632 ​ $ 38,716 Selling, general and administrative ​ 54,464 ​ 49,881 ​ 31,609 Total ​ $ 110,333 ​ $ 103,513 ​ $ 70,325 ​

Other comprehensive income (l_2

Other comprehensive income (loss) and accumulated other comprehensive items - (Tables)	12 Months Ended
	Dec. 31, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Summary of other comprehensive income (loss) and the changes in accumulated other comprehensive items	The following table summarizes other comprehensive income (loss) and the changes in accumulated other comprehensive items, by component, for the years ended December 31, 2022, 2021, and 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ Total ​ ​ Gains (Losses) ​ ​ ​ ​ Accumulated ​ ​ On ​ Foreign ​ Other ​ ​ Marketable ​ Currency ​ Comprehensive ​ ​ Securities, net of tax ​ Translation ​ Items Balance at December 31, 2019 ​ $ 755 ​ $ (11,339) ​ $ (10,584) Other comprehensive income (loss) before reclassifications ​ 479 ​ (51,518) ​ (51,039) Amounts reclassified from other comprehensive items ​ 666 ​ — ​ 666 Other comprehensive income (loss) ​ 1,145 ​ (51,518) ​ (50,373) Balance at December 31, 2020 ​ $ 1,900 ​ $ (62,857) ​ $ (60,957) Other comprehensive (loss) income before reclassifications ​ (3,279) ​ 39,177 ​ 35,898 Amounts reclassified from other comprehensive items ​ 777 ​ — ​ 777 Other comprehensive (loss) income ​ (2,502) ​ 39,177 ​ 36,675 Balance at December 31, 2021 ​ $ (602) ​ $ (23,680) ​ $ (24,282) Other comprehensive income before reclassifications ​ 4,072 ​ 28,970 ​ 33,042 Amounts reclassified from other comprehensive items ​ (3,964) ​ — ​ (3,964) Other comprehensive income ​ 108 ​ 28,970 ​ 29,078 Balance at December 31, 2022 ​ $ (494) ​ $ 5,290 ​ $ 4,796 ​

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	The loss from operations before tax benefit (expense) consisted of the following for the years ended December 31, 2022, 2021, and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Domestic ​ $ (591,126) ​ $ (487,726) ​ $ (452,475) Foreign ​ 3,639 ​ (30,614) ​ 49,543 Total ​ $ (587,487) ​ $ (518,340) ​ $ (402,932) ​
Components of Income Tax Provision	The Income Tax Provision consisted of the following for the years ended December 31, 2022, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 2020 Current: ​ ​ ​ U.S. Federal ​ $ — ​ $ — ​ $ — U.S. State and Local ​ (4,224) ​ (3,844) ​ (24,984) Foreign ​ (1,582) ​ (1,340) ​ (4,372) Deferred: ​ ​ ​ ​ U.S. Federal ​ 23,689 ​ — ​ — U.S. State and Local ​ 10,587 ​ (377) ​ (5,872) Foreign ​ — ​ — ​ — Total tax benefit (expense) ​ $ 28,470 ​ $ (5,561) ​ $ (35,228) ​
Schedule of reconciliation of the U.S. statutory income tax rate to the Company's effective tax rate	A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 2020 Federal income tax provision at statutory rate ​ 21.00 % 21.00 % 21.00 % State income tax provision, net of federal benefit ​ 3.07 (0.74) (3.31) Permanent differences ​ (1.83) (4.06) (6.66) Research and development ​ 5.89 4.50 4.93 Change in valuation allowances ​ (23.36) (29.03) (26.40) Change in deferred tax assets ​ (0.10) 12.05 2.93 Foreign tax rate differential ​ (0.17) 0.01 0.72 Tax rate change ​ 0.34 0.01 (1.46) (Accrual) Release of uncertain tax positions ​ — ​ (4.78) ​ (0.61) ​ Other ​ — (0.03) 0.12 Effective income tax rate ​ 4.84 % (1.07) % (8.74) % ​
Schedule of significant components of the Company's deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 Assets: ​ ​ Noncurrent deferred income taxes ​ $ — ​ $ — Liabilities: ​ ​ Noncurrent deferred income taxes ​ (102,834) ​ (137,110) Deferred income taxes - net ​ $ (102,834) ​ $ (137,110) ​ The significant components of the Company’s deferred tax assets and liabilities at December 31, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 2021 Deferred tax assets: ​ ​ Accrued expense ​ $ 2,124 ​ $ 8,208 Amortization ​ 52,532 ​ 87,998 Federal tax credits ​ 174,802 ​ 142,595 State tax credits ​ 9,787 ​ 8,054 Federal net operating losses ​ 69,957 ​ 76,589 State net operating losses ​ 10,316 ​ 9,159 Foreign net operating losses ​ 4,837 ​ 3,316 Capitalized research and development costs ​ 110,219 ​ 241 Share based compensation and other ​ 27,054 ​ 15,273 Liability for sale of future royalties ​ ​ 185,589 ​ ​ 148,503 Noncash interest expense ​ ​ 30,160 ​ ​ 26,040 Other comprehensive loss ​ (719) ​ 143 Total gross deferred tax assets ​ 676,658 ​ 526,119 Less valuation allowance ​ (672,172) ​ (525,570) Total deferred tax assets, net of valuation allowance ​ $ 4,486 ​ $ 549 Deferred tax liabilities: ​ ​ Depreciation ​ $ (4,486) ​ $ (549) Indefinite lived intangible ​ (102,834) ​ (137,110) Total gross deferred tax liabilities ​ (107,320) ​ (137,659) Net deferred tax assets (liabilities) ​ $ (102,834) ​ $ (137,110) ​
Schedule of unrecognized tax benefits	A reconciliation of the gross amount of unrecognized tax benefits, excluding accrued interest and penalties, is as follows: ​ ​ ​ ​ Unrecognized Tax Benefits Balance at December 31, 2021 ​ 27,217 Additions based on tax positions related to the current year — Balance at December 31, 2022 $ 27,217 ​

Geographic information (Tables)

Geographic information (Tables)	12 Months Ended
	Dec. 31, 2022
Segments, Geographical Areas [Abstract]
Summary of financial information based on geographical location	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2022 ​ United States Non-US Total Total assets ​ $ 1,473,770 ​ $ 231,849 ​ $ 1,705,619 Fixed assets, net ​ $ 71,754 ​ $ 836 ​ $ 72,590 Revenue ​ $ 498,567 ​ $ 200,234 ​ $ 698,801 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ United States Non-US Total Total assets ​ $ 1,744,225 ​ $ 193,831 ​ $ 1,938,056 Fixed assets, net ​ $ 51,626 ​ $ 959 ​ $ 52,585 Revenue ​ $ 297,005 ​ $ 241,588 ​ $ 538,593

Intangible assets and goodwill

Intangible assets and goodwill - (Tables)	12 Months Ended
	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of definite lived intangible assets	Definite lived intangible assets consisted of the following at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Reclass from ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Definite lived ​ ​ December 31, ​ ​ ​ ​ ​ Indefinite Lived to ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets, gross ​ 2021 ​ Additions ​ Definite Lived ​ Impairment ​ translation ​ 2022 Emflaza ​ $ 291,875 ​ $ 128,378 ​ $ — ​ $ — ​ $ — ​ $ 420,253 Waylivra ​ ​ 9,904 ​ ​ — ​ ​ — ​ ​ — ​ ​ (588) ​ ​ 9,316 Tegsedi ​ ​ 4,060 ​ ​ 3,240 ​ ​ — ​ ​ — ​ ​ (191) ​ ​ 7,109 Upstaza ​ ​ — ​ ​ — ​ ​ 89,550 ​ ​ — ​ ​ — ​ ​ 89,550 Total definite lived intangibles, gross ​ $ 305,839 ​ $ 131,618 ​ $ 89,550 ​ $ — ​ $ (779) ​ $ 526,228 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Definite lived ​ ​ December 31, ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets, accumulated amortization ​ 2021 ​ Amortization ​ translation ​ 2022 Emflaza ​ $ (154,594) ​ $ (111,429) ​ $ — ​ $ (266,023) Waylivra ​ ​ (1,821) ​ ​ (1,020) ​ ​ 90 ​ ​ (2,751) Tegsedi ​ ​ (1,083) ​ ​ (685) ​ ​ 59 ​ ​ (1,709) Upstaza ​ ​ — ​ ​ (3,420) ​ ​ — ​ ​ (3,420) Total definite lived intangibles, accumulated amortization ​ $ (157,498) ​ $ (116,554) ​ $ 149 ​ $ (273,903) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total definite lived intangibles, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 252,325 ​
Schedule of estimated future amortization of intangible assets	The estimated future amortization of the Emflaza rights, Waylivra, Tegsedi, and Upstaza intangible assets is expected to be as follows: ​ ​ ​ ​ ​ ​ As of December 31, 2022 2023 ​ $ 142,324 2024 ​ 30,609 2025 ​ 9,352 2026 ​ 9,352 2027 and thereafter ​ 60,688 Total ​ $ 252,325 ​
Schedule of indefinite lived intangible assets	Indefinite lived intangible assets consisted of the following at December 31, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending Balance at ​ ​ ​ ​ ​ Reclass from ​ ​ ​ ​ ​ Foreign ​ ​ Ending Balance at Indefinite lived ​ ​ December 31, ​ ​ ​ ​ ​ Indefinite Lived to ​ ​ ​ ​ ​ currency ​ ​ December 31, intangibles assets ​ 2021 ​ Additions ​ Definite Lived ​ Impairment ​ translation ​ 2022 Upstaza ​ $ 358,700 ​ $ — ​ $ (89,550) ​ $ (33,384) ​ $ — ​ $ 235,766 PTC-FA ​ ​ 112,500 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 112,500 PTC-AS ​ ​ 105,300 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 105,300 Total indefinite lived intangibles ​ $ 576,500 ​ $ — ​ $ (89,550) ​ $ (33,384) ​ $ — ​ $ 453,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total intangible assets, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 705,891 ​

The Company (Details)

The Company (Details) - USD ($) $ in Thousands	Aug. 15, 2022	Aug. 15, 2015	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2019	Aug. 31, 2015
Long-term debt
Retained earnings (accumulated deficit)			$ (2,656,974)	$ (2,097,957)
Convertible debt | 1.50% Convertible senior notes due 2026
Long-term debt
Interest rate ( as a percent )					1.50%
Convertible debt | 3.00% Convertible senior notes due 2022
Long-term debt
Interest rate ( as a percent )	3%					3%
Repayment of convertible notes including accrued interest	$ 152,300	$ 152,300

Summary of significant accoun_4

Summary of significant accounting policies - Narrative (Details) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	Jun. 30, 2022 USD ($)	Jul. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) segment country	Dec. 31, 2021 USD ($) country	Dec. 31, 2020 USD ($) country	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Letters of credit							$ 7,500
Number of operating segments | segment				1
Number of reporting units | segment				1
Allowance for credit loss			$ 0	$ 0	$ 0
Allowance for doubtful accounts receivable			300	300	100
Revenue				698,801	538,593	$ 380,766
Cash consideration received from Royalty Purchase Agreement		$ 650,000				650,000
State income tax provision				$ 4,224	$ 3,844	$ 24,984
Income taxes
Federal income tax statutory rate				21%	21%	21%
Deferred tax liability			107,320	$ 107,320	$ 137,659
Impairment of long-lived assets				0
Non cash realized foreign exchange loss				16,887
Increase in current taxable income resulting from the elimination of current deduction of qualifying R&D costs under Section 174.				450,100
Impairment of indefinite-lived intangibles excluding goodwill				33,384
Impairment of goodwill				0
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term for letter of credit (in years)							5 years
Indefinite-lived intangible assets
Income taxes
Impairment of indefinite-lived intangibles excluding goodwill				33,384
Indefinite-lived intangible assets | Upstaza
Income taxes
Impairment of indefinite-lived intangibles excluding goodwill			33,400	33,384
Agilis
Income taxes
Deferred tax liability								$ 122,000
Impairment of goodwill				0
Prepaids and other current assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred research and development advance payments, short-term			2,400	2,400	1,400
Deposits and other assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank guarantee			500	500
Deferred research and development advance payments, long-term			$ 3,900	3,900	1,800
Fifth Anniversary
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Letters of credit							$ 3,800
Term for letter of credit (in years)							5 years
Warren Premises
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Period after which letter of credit may be reduced if lease is not in default	5 years
Warren Premises | Deposits and other assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Letters of credit	$ 8,100
Warren Premises | Fifth Anniversary
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Letters of credit	$ 4,100
Non-US
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				200,234	241,588
United States
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				$ 498,567	$ 297,005
Net product revenue | Geographic concentration risk
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of countries exceeding 10% of net product sales | country				2	1	1
Percentage of net product sales threshold				10%	10%	10%
Net product revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				$ 535,228	$ 428,904	$ 333,401
Net product revenue | Non-US
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				316,900	241,600	194,400
Net product revenue | Net product revenue | Geographic concentration risk | Russia
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				59,700
Net product revenue | Net product revenue | Geographic concentration risk | United States
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				218,300
Emflaza | United States
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				218,300	187,300	139,000
Translarna | Non-US
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue				$ 288,600	$ 236,000	$ 191,900

Summary of significant accoun_5

Summary of significant accounting policies - Reconciliation of cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 279,834	$ 189,718
Restricted cash included in deposits and other assets	16,091	7,500
Total Cash, cash equivalents and restricted cash per statement of cash flows	$ 295,925	$ 197,218	$ 216,312	$ 295,528

Summary of significant accoun_6

Summary of significant accounting policies - Fixed Assets (Details)	12 Months Ended
	Dec. 31, 2022
Computer equipment and software
Fixed assets
Estimated useful life	3 years
Machinery and lab equipment
Fixed assets
Estimated useful life	7 years
Furniture, fixtures, machinery and lab equipment
Fixed assets
Estimated useful life	7 years

Summary of significant accoun_7

Summary of significant accounting policies - Inventory (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Raw materials	$ 1,078	$ 1,418
Work in progress	14,074	7,721
Finished goods	6,656	6,717
Total inventory	21,808	15,856
Inventory write-down	$ 1,700	$ 2,200

Summary of significant accoun_8

Summary of significant accounting policies - Collaboration and Royalty Revenue (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaboration and royalty revenue
Revenue			$ 698,801	$ 538,593	$ 380,766
Collaboration and grant revenue
Collaboration and royalty revenue
Revenue			50,052	55,046	42,579
Royalty revenue
Collaboration and royalty revenue
Revenue			113,521	54,643	4,786
SMA License Agreement | Collaboration and grant revenue
Collaboration and royalty revenue
Revenue			50,100	55,000	42,600
SMA License Agreement | Royalty revenue
Collaboration and royalty revenue
Revenue			113,500	$ 54,600	$ 4,800
SMA License Agreement | Sales Milestones
Collaboration and royalty revenue
Net sales milestone threshold achieved	$ 750,000		$ 500,000
SMA License Agreement | Sales Milestones | Prepaids and other current assets
Collaboration and royalty revenue
Milestone payments due	$ 50,000	$ 25,000

Summary of significant accoun_9

Summary of significant accounting policies - Liability for Sale of Future Royalties (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Jul. 17, 2020	Jul. 31, 2020	Dec. 31, 2020	Dec. 31, 2022
Assigned royalty payments
Cash consideration received from Royalty Purchase Agreement		$ 650,000	$ 650,000
Assigned royalty payment, retained percentage	57.067%
Remaining potential milestones that can be achieved				$ 250,000
Royalty Purchase Agreement
Assigned royalty payments
Cash consideration received from Royalty Purchase Agreement	$ 650,000
Royalty Purchase Agreement | Assigned Royalty Payments
Assigned royalty payments
Assigned royalty payment, percentage	42.933%
Royalty purchase agreement, termination period	60 days
Royalty purchase agreement, payment maximum	$ 1,300,000

Summary of significant accou_10

Summary of significant accounting policies - Adoption of ASU 2020-06 (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stockholders equity	$ (347,086)	$ 1,438	$ 481,982	$ 594,330
Long-term debt	571,722	281,894
Deferred tax valuation allowance	672,172	525,570
Cumulative Effect Adjustment
Stockholders equity			(120,440)
Additional paid-in capital
Stockholders equity	2,305,020	2,123,606	2,171,746	1,795,351
Additional paid-in capital | Cumulative Effect Adjustment
Stockholders equity			(175,236)
Accumulated deficit
Stockholders equity	$ (2,656,974)	$ (2,097,957)	(1,628,877)	$ (1,190,499)
Accumulated deficit | Cumulative Effect Adjustment
Stockholders equity			$ 54,796

Acquisitions - Censa Acquisitio

Acquisitions - Censa Acquisition (Details) - USD ($) $ in Thousands		12 Months Ended
	May 29, 2020	Dec. 31, 2020
Acquisitions
Issuance of common stock related to acquisition		$ 42,869
Censa [Member]
Acquisitions
Payments for asset acquisitions	$ 15,000
Payments for asset acquisitions, upfront payment	10,400
Payments for asset acquisitions, net assets	$ 4,600
Issuance of common stock related to acquisition (in shares)	845,364
Issuance of common stock related to acquisition	$ 42,900
Acquisition costs	700
Total consideration	58,600
Fair value of net assets acquired	4,600
Asset acquisition, cash and cash equivalents	3,800
Asset acquisition, other current assets	800
Asset acquisition, in-process research and development	$ 54,000
Censa [Member] | Research and development
Acquisitions
Asset acquisition, research and development expense		53,300
Censa [Member] | Selling, general and administrative
Acquisitions
Acquisition costs		$ 700

Acquisitions - BioElectron Acqu

Acquisitions - BioElectron Acquisition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Acquisitions
Research and development	$ 651,496	$ 540,684	$ 477,643
BioElectron | Maximum
Acquisitions
Development milestone payment obligations	$ 200,000

Fair value of financial instr_3

Fair value of financial instruments and investments - Marketable Securities (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity Investments
Purchase of equity investments			$ 100
Purchase of marketable securities - equity investments		$ 22,787	210,018
Net unrealized gain (loss) on equity investments		(7,992)	1,673
Redemption of marketable securities- equity investments		112,958	4,281
ClearPoint Convertible note
Purchase of convertible note		52,764	333,148	$ 1,439,665
Unrealized gain (loss) on convertible note		(5,740)	(8,281)	$ 19,252
Recurring basis
Equity Investments
Fair value of equity investment		108,261	206,973
Recurring basis | Quoted prices in active markets for identical assets (Level 1)
Equity Investments
Fair value of equity investment		108,261	206,973
Marketable securities - equity investments
Equity Investments
Net unrealized gain (loss) on equity investments		(8,000)	1,700
Redemption of marketable securities- equity investments		113,000	4,300
Unrealized foreign currency losses on equity investments		500	400
ClearPoint equity investment
Equity Investments
Net unrealized gain (loss) on equity investments		(3,500)	6,100
ClearPoint equity investment | Recurring basis | Quoted prices in active markets for identical assets (Level 1) | Deposits and Other Assets, Noncurrent
Equity Investments
Fair value of equity investment		11,000	14,500
ClearPoint convertible debt
ClearPoint Convertible note
Purchase of convertible note	$ 10,000
Conversion price - convertible note	$ 6
Term of convertible note	5 years
Unrealized gain (loss) on convertible note		(5,800)	8,300
ClearPoint convertible debt | Recurring basis | Significant other observable inputs (Level 2) | Deposits and Other Assets, Noncurrent
ClearPoint Convertible note
ClearPoint convertible debt security		$ 15,200	$ 21,000

Fair value of financial instr_4

Fair value of financial instruments and investments - Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financial assets and liabilities measured at fair value on recurring basis
Marketable securities - available for sale	$ 22,610	$ 376,685
Contingent consideration payable	164,000	239,900
Transfers from Level 1 to Level 2	0	0
Transfers from Level 2 to Level 1	0	0
Recurring basis
Financial assets and liabilities measured at fair value on recurring basis
Marketable securities - available for sale	22,610	376,685
Marketable securities - equity investments	108,261	206,973
ClearPoint Equity Investments	10,965	14,525
ClearPoint convertible debt security	15,231	20,971
Recurring basis | Quoted prices in active markets for identical assets (Level 1)
Financial assets and liabilities measured at fair value on recurring basis
Marketable securities - equity investments	108,261	206,973
ClearPoint Equity Investments	10,965	14,525
Recurring basis | Significant other observable inputs (Level 2)
Financial assets and liabilities measured at fair value on recurring basis
Marketable securities - available for sale	22,610	376,685
ClearPoint convertible debt security	15,231	20,971
Recurring basis | Development and Regulatory Milestones
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	82,500	139,300
Recurring basis | Development and Regulatory Milestones | Significant unobservable inputs (Level 3)
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	82,500	139,300
Recurring basis | Net Sales Milestones and Royalties
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	81,500	100,600
Recurring basis | Net Sales Milestones and Royalties | Significant unobservable inputs (Level 3)
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	$ 81,500	$ 100,600

Fair value of financial instr_5

Fair value of financial instruments and investments - Marketable Securities, Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 23,104	$ 377,287
Gross Unrealized, Gain	5	107
Gross Unrealized, Loss	(499)	(709)
Fair Value	22,610	376,685
Write downs of available for sale debt securities	0	0
Increase in allowance for credit losses	0	0
Realized gain (loss) from sale of marketable securities	4,000	800
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	12,419	75,275
Gross Unrealized, Gain	5	5
Gross Unrealized, Loss	0	(1)
Fair Value	12,424	75,279
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,685	268,246
Gross Unrealized, Gain	0	81
Gross Unrealized, Loss	(499)	(644)
Fair Value	$ 10,186	267,683
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		15,287
Gross Unrealized, Gain		16
Gross Unrealized, Loss		(5)
Fair Value		15,298
Government obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		18,479
Gross Unrealized, Gain		5
Gross Unrealized, Loss		(59)
Fair Value		$ 18,425

Fair value of financial instr_6

Fair value of financial instruments and investments - Available-for-sale securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Securities in an unrealized loss position less than 12 months - Unrealized losses		$ (673)
Securities in an unrealized loss position less than 12 months - Fair Value		256,801
Securities in an unrealized loss position greater than 12 months - Unrealized losses	$ (499)	(36)
Securities in an unrealized loss position greater than 12 months - Fair Value	10,186	4,985
Total - Unrealized losses	(499)	(709)
Total - Fair Value	10,186	261,786
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Securities in an unrealized loss position less than 12 months - Unrealized losses		(1)
Securities in an unrealized loss position less than 12 months - Fair Value		12,992
Total - Unrealized losses		(1)
Total - Fair Value		12,992
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Securities in an unrealized loss position less than 12 months - Unrealized losses		(608)
Securities in an unrealized loss position less than 12 months - Fair Value		217,540
Securities in an unrealized loss position greater than 12 months - Unrealized losses	(499)	(36)
Securities in an unrealized loss position greater than 12 months - Fair Value	10,186	4,985
Total - Unrealized losses	(499)	(644)
Total - Fair Value	$ 10,186	222,525
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Securities in an unrealized loss position less than 12 months - Unrealized losses		(5)
Securities in an unrealized loss position less than 12 months - Fair Value		10,786
Total - Unrealized losses		(5)
Total - Fair Value		10,786
Government obligations
Debt Securities, Available-for-sale [Line Items]
Securities in an unrealized loss position less than 12 months - Unrealized losses		(59)
Securities in an unrealized loss position less than 12 months - Fair Value		15,483
Total - Unrealized losses		(59)
Total - Fair Value		$ 15,483

Fair value of financial instr_7

Fair value of financial instruments and investments - Marketable Securities, Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Less Than 12 Months	$ 12,424	$ 221,611
Marketable securities, More Than 12 Months	10,186	155,074
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Less Than 12 Months	12,424	75,279
Marketable securities, More Than 12 Months	0
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Less Than 12 Months	0	131,606
Marketable securities, More Than 12 Months	$ 10,186	136,077
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Less Than 12 Months		8,724
Marketable securities, More Than 12 Months		6,574
Government obligations
Debt Securities, Available-for-sale [Line Items]
Marketable securities, Less Than 12 Months		6,002
Marketable securities, More Than 12 Months		$ 12,423

Fair value of financial instr_8

Fair value of financial instruments and investments - Convertible Notes and Rights Exchange Agreement (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2020	Aug. 15, 2022	Dec. 31, 2021	Apr. 29, 2020	Sep. 30, 2019	Aug. 31, 2015
Financial assets and liabilities measured at fair value on recurring basis
Payments on deferred consideration obligation	$ 40,400,000	$ 38,100,000
Issuance of common stock related to rights exchange		150,528,000
Contingent consideration payable	164,000,000			$ 239,900,000
3.00% Convertible senior notes due 2022 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Principal	150,000,000			150,000,000			$ 150,000,000
Interest rate ( as a percent )			3%				3%
1.50% Convertible senior notes due 2026 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Principal	287,500,000			287,500,000		$ 287,500,000
Interest rate ( as a percent )						1.50%
Significant other observable inputs (Level 2) | 3.00% Convertible senior notes due 2022 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Fair value of convertible notes	158,300,000
Significant other observable inputs (Level 2) | 1.50% Convertible senior notes due 2026 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Fair value of convertible notes	281,700,000			305,300,000
Development and Regulatory Milestones | Recurring basis
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	82,500,000			139,300,000
Development and Regulatory Milestones | Recurring basis | Significant unobservable inputs (Level 3)
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	82,500,000			139,300,000
Net Sales Milestones and Royalties | Recurring basis
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	81,500,000			100,600,000
Net Sales Milestones and Royalties | Recurring basis | Significant unobservable inputs (Level 3)
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable	$ 81,500,000			100,600,000
Agilis
Financial assets and liabilities measured at fair value on recurring basis
Net sales amount					$ 150,000,000
Agilis | Minimum
Financial assets and liabilities measured at fair value on recurring basis
Product sales (as a percent)	2%				2%
Agilis | Maximum
Financial assets and liabilities measured at fair value on recurring basis
Development milestone payment obligations	$ 60,000,000
Priority review voucher amount	535,000,000
Development milestone payment obligations, net of cancellation and forfeiture	20,000,000
Contingent liability, milestone, potential achievements, priority review voucher amount, net of cancellation and forfeiture	361,000,000
Net sales amount	$ 150,000,000
Product sales (as a percent)	6%				6%
Agilis | Development and Regulatory Milestones | Significant unobservable inputs (Level 3) | Commitments
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable- net sales milestones and royalties	$ 82,500,000	139,200,000		139,300,000
Agilis | Net Sales Milestones and Royalties | Significant unobservable inputs (Level 3) | Commitments
Financial assets and liabilities measured at fair value on recurring basis
Contingent consideration payable- net sales milestones and royalties	81,500,000	$ 101,200,000		$ 100,600,000
Non-collaborative Arrangement Transactions | Agilis
Financial assets and liabilities measured at fair value on recurring basis
Development milestone payment obligations	40,000,000
Rights Exchange Agreement
Financial assets and liabilities measured at fair value on recurring basis
Issuance of common stock related to rights exchange (in shares)		2,821,176
Issuance of common stock related to rights exchange		$ 150,500,000
Rights Exchange Agreement | Agilis
Financial assets and liabilities measured at fair value on recurring basis
Contingent liability, cancellation and forfeiture	$ 211,600,000

Fair value of financial instr_9

Fair value of financial instruments and investments - Summary of changes in the fair value of the Company's Level 3 valuation (Details) - Significant unobservable inputs (Level 3) - Agilis - Commitments - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Development and Regulatory Milestones
Changes in the fair value of warrant liability and SARs liability
Beginning Balance		$ 139,300	$ 139,200
Change in fair value		(6,800)	100
Payments	$ (50,000)	(50,000)
Ending Balance		82,500	139,300
Net Sales Milestones and Royalties
Changes in the fair value of warrant liability and SARs liability
Beginning Balance		100,600	101,200
Change in fair value		(19,100)	(600)
Ending Balance		$ 81,500	$ 100,600

Fair value of financial inst_10

Fair value of financial instruments and investments - Fair Value Liabilities Measured (Details) - Commitments $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Development and Regulatory Milestones | Significant unobservable inputs (Level 3) | Valuation Technique, Discounted Cash Flow | Probability of Success | Weighted Average
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.35
Development and Regulatory Milestones | Significant unobservable inputs (Level 3) | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Weighted Average
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.078
Net Sales Milestones and Royalties | Significant unobservable inputs (Level 3) | Valuation Technique, Option Pricing Model | Probability of Success | Weighted Average
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.50
Net Sales Milestones and Royalties | Significant unobservable inputs (Level 3) | Valuation Technique, Option Pricing Model | Measurement Input, Discount Rate | Weighted Average
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.115
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Development and Regulatory Milestone | Minimum
Fair Value Valuation Inputs
Potential milestones	$ 0	$ 0
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Development and Regulatory Milestone | Maximum
Fair Value Valuation Inputs
Potential milestones	$ 331,000	$ 381,000
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Probability of Success | Minimum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.25	0.25
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Probability of Success | Maximum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.92	0.94
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Minimum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.062	0.017
Agilis | Development and Regulatory Milestones | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Maximum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.083	0.047
Agilis | Development and Regulatory Milestones | Significant unobservable inputs (Level 3)
Fair Value Valuation Inputs
Fair value	$ 82,500	$ 139,300	$ 139,200
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Sales Milestones | Minimum
Fair Value Valuation Inputs
Potential milestones	0	0
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Sales Milestones | Maximum
Fair Value Valuation Inputs
Potential milestones	$ 150,000	$ 150,000
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Probability of Success | Minimum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.25	0.25
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Probability of Success | Maximum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	1	0.94
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Percentage of Sales for Royalties | Minimum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.02	0.02
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Percentage of Sales for Royalties | Maximum
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.06	0.06
Agilis | Net Sales Milestones and Royalties | Valuation Technique, Option Pricing Model | Measurement Input, Discount Rate
Fair Value Valuation Inputs
Rights Exchange Settlement measurement	0.115	0.110
Agilis | Net Sales Milestones and Royalties | Significant unobservable inputs (Level 3)
Fair Value Valuation Inputs
Fair value	$ 81,500	$ 100,600	$ 101,200

Fixed assets (Details)

Fixed assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fixed assets
Gross fixed assets	$ 109,958	$ 79,758
Less accumulated depreciation and amortization	(37,368)	(27,173)
Property, Plant and Equipment, Net, Total	72,590	52,585
Depreciation and amortization	12,300	9,400	$ 6,600
Leasehold improvements
Fixed assets
Gross fixed assets	28,969	19,937
Computer equipment and software
Fixed assets
Gross fixed assets	15,332	13,812
Machinery and lab equipment
Fixed assets
Gross fixed assets	47,496	33,187
Furniture and fixtures
Fixed assets
Gross fixed assets	3,812	3,805
Assets in process
Fixed assets
Gross fixed assets	$ 14,349	$ 9,017

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands		1 Months Ended	12 Months Ended
	Jul. 01, 2020 USD ($) ft² item	May 31, 2022 USD ($) ft² building period	Dec. 31, 2022 USD ($) ft² lease	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 19, 2020 USD ($)
Leases
Operating lease, expense			$ 25,200	$ 21,400	$ 15,300
Finance Lease, Liability			21,675
Finance lease liabilities- current			3,000	3,000
Finance lease liabilities- noncurrent			18,675	20,053
Aggregate rent, Initial term			268,037
Operating lease ROU assets			102,430	77,421
Operating Lease, Liability			110,230
Research and development			651,496	540,684	477,643
2023			15,373
MassBio
Leases
Finance lease cost			$ 1,600	$ 1,700
Finance Lease, Liability						$ 41,400
Finance lease ROU asset						$ 41,400
Finance lease, term of contract						12 years 6 months
Research and development					$ 41,400
Minimum
Leases
Operating lease, term of contract			1 year 2 months 12 days
Maximum
Leases
Operating lease, term of contract			16 years 4 months 24 days
Renewal term			15 years
Principal Office - NJ
Leases
Number of operating leases | lease			2
Lessee, Operating Lease, Existence of Option to Terminate [true false]			false
New Building | Minimum
Leases
Area of real estate property | ft²			75,000
Hopewell Campus
Leases
Operating lease, term of contract	15 years
Area of real estate property | ft²	220,500
Renewal term	10 years
Number of renewable terms | item	2
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Aggregate rent, Initial term	$ 111,500
Percent of market rate	95%
Warren Premises
Leases
Operating lease, term of contract		17 years
Number of buildings leased | building		2
Area of real estate property | ft²		360,000
Renewal term		5 years
Number of renewable terms | period		3
Lessee, Operating Lease, Existence of Option to Extend [true false]		true
Aggregate rent, Initial term		$ 163,000
Operating lease ROU assets		28,900
Operating Lease, Liability		$ 28,900
Base rent abatement period		3 years
Base rent abatement		$ 18,600
Aggregate rent net of base rate abatement, initial term		144,400
Allowance for lease improvements		36,200
Commitment to fund construction account		3,600
Payment due from lessor at issuance of temporary certificate of occupancy		$ 5,000

Leases - Lease costs (Details)

Leases - Lease costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases
Fixed lease cost	$ 19,804	$ 16,411	$ 12,368,000
Variable lease cost	4,557	4,361	2,448,000
Short-term lease cost	808	656	450,000
Total operating lease cost	$ 25,169	$ 21,428	$ 15,266,000

Leases - Balance sheet (Details

Leases - Balance sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Leases
Operating lease ROU assets	$ 102,430	$ 77,421
Operating lease liabilities- current	9,370	7,273
Operating lease liabilities- noncurrent	100,860	73,619
Total operating lease liability	110,230
Finance lease liabilities- current	3,000	3,000
Finance lease liabilities- noncurrent	18,675	$ 20,053
Total finance lease liability	$ 21,675

Leases - Supplemental lease ter

Leases - Supplemental lease terms (Details)	Dec. 31, 2022	Dec. 31, 2021
Leases
Weighted-average remaining lease terms - operating leases (years)	11 years 7 months 9 days	10 years 10 months 13 days
Weighted-average discount rate - operating leases	8.61%	8.91%
Weighted-average remaining lease terms - finance lease (years)	10 years 3 days	11 years
Weighted-average discount rate - finance lease	7.80%	7.80%

Leases - Cash flow (Details)

Leases - Cash flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Leases
Operating cash flows from operating leases	$ 14,736	$ 13,683	$ 8,462
Financing cash flows from finance lease	1,276	2,224	17,829
Operating cash flows from finance leases	1,724	776	171
Right-of-use assets obtained in exchange for operating lease obligations	$ 35,817	$ 645	76,811
Right-of-use assets obtained in exchange for finance lease obligations			$ 41,382

Leases - Lease payments (Detail

Leases - Lease payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Operating leases
2023	$ 15,373
2024	18,456
2025	20,431
2026	19,985
2027 and thereafter	193,792
Total lease payments	268,037
Less: Imputed Interest expense	157,807
Total	110,230
Finance leases
2023	3,000
2024	3,000
2025	3,000
2025	3,000
2027 and thereafter	18,000
Total lease payments	30,000
Less: Imputed Interest expense	8,325
Total	$ 21,675

Accounts payable and accrued _3

Accounts payable and accrued expenses - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Employee compensation, benefits, and related accruals	$ 62,669	$ 55,733
Income tax payable	4,712	1,287
Consulting and contracted research	38,882	26,434
Professional fees	3,093	3,547
Sales allowance	63,787	61,662
Sales rebates	67,355	68,770
Royalties	40,546	35,679
Accounts payable	27,268	23,033
Other	12,054	12,639
Accounts payable and accrued expenses	$ 320,366	$ 288,784

Debt - Liability for Sale of Fu

Debt - Liability for Sale of Future Royalties (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2020	Dec. 31, 2022	Dec. 31, 2020
Debt Disclosure [Abstract]
Proceeds from sale of future royalties	$ 650,000		$ 650,000
Beginning balance		$ 733,985
Less: Non-cash royalty revenue payable to RPI		(48,738)
Plus: non-cash interest expense recognized		72,639
Ending balance		$ 757,886
Effective interest rate of the liability component	11%	8.70%

Debt - Narrative (Details)

Debt - Narrative (Details)				1 Months Ended		12 Months Ended	18 Months Ended
	Aug. 15, 2022 USD ($)	Jan. 01, 2021 USD ($)	Aug. 15, 2015 USD ($)	Apr. 08, 2022 USD ($)	Sep. 30, 2019 USD ($) D $ / shares	Dec. 31, 2022 USD ($)	Mar. 14, 2022 USD ($)	Dec. 31, 2021 USD ($)	Aug. 31, 2015 USD ($)
Long-term debt
Long-term debt						$ 571,722,000		$ 281,894,000
Current portion of long-term debt								149,540,000
Additional paid-in capital						2,305,020,000		2,123,606,000
1.50% Convertible senior notes due 2026
Long-term debt
Term of the convertible notes					7 years
Net deferred tax liability in connection with convertible notes								25,300,000
Convertible debt | 1.50% Convertible senior notes due 2026
Long-term debt
Net carrying amount						283,044,000		281,894,000
Debt principal amount					$ 287,500,000	$ 287,500,000		287,500,000
Debt instrument additional amount available for repurchase					$ 37,500,000
Interest rate ( as a percent )					1.50%
Net proceeds from issuance of convertible notes					$ 279,300,000
Trading days, number | D					20
Consecutive trading days, period | D					30
Stock price trigger					130%
Business days, period					5 days
Consecutive trading-day period					5 days
Maximum product of the closing sale price of shares of the Company's common stock and the applicable conversion rate for such trading day					98%
Conversion ratio					19.0404
Conversion price per share (in dollars per share) | $ / shares					$ 52.52
Convertible instruments principal and unpaid interest payable upon events of default					100%
Minimum percentage of principal held by convertible debt instrument holders required to issue notice for declaration of principal and unpaid interest payable upon events of default					25%
Term of the convertible notes		7 years			7 years	3 years 8 months 12 days
Equity component of convertible notes, net					$ 123,000,000
Debt discount to be amortized		$ 0
Incremental interest rate per annum				0.50%			0.50%
Additional interest paid				$ 100,000			$ 2,100,000
Convertible debt | 1.50% Convertible senior notes due 2026 | Redemption on or after September 20, 2023
Long-term debt
Trading days, number | D					19
Consecutive trading days, period | D					30
Stock price trigger					130%
Redemption price as percent of principal amount					100%
Sinking fund					$ 0
Convertible debt | 3.00% Convertible senior notes due 2022
Long-term debt
Net carrying amount								149,540,000
Debt principal amount						$ 150,000,000		$ 150,000,000	$ 150,000,000
Interest rate ( as a percent )	3%								3%
Repayment of convertible notes including accrued interest	$ 152,300,000		$ 152,300,000
Cumulative Effect Adjustment | 1.50% Convertible senior notes due 2026
Long-term debt
Additional paid-in capital		(123,000,000)
Amortization of debt discount		$ 16,100,000

Debt - Senior Secured Term Loan

Debt - Senior Secured Term Loan (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 27, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2020
Interest expense
Amortization of debt issuance costs		$ 1,901	$ 1,848	$ 1,020
Effective interest rate		8.70%			11%
Blackstone Credit Agreement
Debt Facility
Maximum borrowing capacity	$ 950,000
Minimum consolidated liquidity covenant	100,000
Increased minimum consolidated liquidity covenant after consummation of acquisitions meeting specified thresholds	200,000
Committed Loan Facility
Debt Facility
Maximum borrowing capacity	$ 450,000
Fund draw term	18 months
Loan term	7 years
Committed Loan Facility | Adjusted Term SOFR
Debt Facility
Basis spread on variable rate	7.25%
Floor interest rate	1%
Committed Loan Facility | Base Rate
Debt Facility
Basis spread on variable rate	6.25%
Floor interest rate	2%
Senior Secured Term Loan Facility
Debt Facility
Principal	$ 300,000
Debt issuance costs capitalized		$ 11,600
Interest expense
Contractual interest expense		6,069
Amortization of debt issuance costs		290
Total		$ 6,359
Effective interest rate		12.20%
Committed Delayed Draw Term Loan Facility
Debt Facility
Maximum borrowing capacity	150,000
Uncommitted Incremental Facility
Debt Facility
Maximum borrowing capacity	$ 500,000

Debt - Convertible Notes (Detai

Debt - Convertible Notes (Details) - Convertible debt - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Sep. 30, 2019	Aug. 31, 2015
3.00% Convertible senior notes due 2022
Long-term debt
Principal	$ 150,000,000	$ 150,000,000			$ 150,000,000
Less: Debt issuance costs		(460,000)
Repayment of Convertible Notes	(150,000,000)
Net carrying amount		149,540,000
1.50% Convertible senior notes due 2026
Long-term debt
Principal	287,500,000	287,500,000		$ 287,500,000
Less: Debt issuance costs	(4,456,000)	(5,606,000)
Less: Debt discount, net			$ 0
Net carrying amount	$ 283,044,000	$ 281,894,000

Debt - Convertible Notes Intere

Debt - Convertible Notes Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2020
Long-term debt
Amortization of debt issuance costs	$ 1,901	$ 1,848	$ 1,020
Effective interest rate of the liability component	8.70%			11%
Convertible debt | 3.00% Convertible senior notes due 2022
Long-term debt
Contractual interest expense	$ 2,800	4,500
Amortization of debt issuance costs	460	720
Total	$ 3,260	$ 5,220
Effective interest rate of the liability component	3.50%	3.50%
Convertible debt | 1.50% Convertible senior notes due 2026
Long-term debt
Contractual interest expense	$ 4,313	$ 4,313
Amortization of debt issuance costs	1,150	1,128
Total	$ 5,463	$ 5,441
Effective interest rate of the liability component	1.90%	1.90%

Capital structure - Narrative (

Capital structure - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Oct. 27, 2022	Aug. 31, 2019	Dec. 31, 2022	Dec. 31, 2020	Dec. 31, 2021	Jun. 30, 2021
Common stock
Net consideration received on transaction				$ 28,100
Number of shares issued in transaction (in shares)			0	542,470
Price per share (in USD per share)				$ 53.37
Issuance of common stock related to rights exchange				$ 150,528
Issuance of common stock related to acquisition				$ 42,869
Common stock, authorized shares (in shares)			250,000,000	125,000,000	250,000,000	250,000,000
Maximum
Common stock
Aggregate value of remaining shares to be issued and sold			$ 93,000
Common stock
Common stock
Common stock, authorized shares (in shares)			250,000,000
Stock Purchase Agreement
Common stock
Net consideration received on transaction	$ 50,000
Number of shares issued in transaction (in shares)	1,095,290
Price per share (in USD per share)	$ 45.65
Number of days within which to register stock sale with the SEC per terms of the agreement	60 days
Period of time from the closing date that the entity agrees to keep the stock sale registration effective	6 months
Period of time from the closing date that the purchaser agrees not to resell or transfer entity's stock without written approval	90 days
Stock Purchase Agreement | Minimum
Common stock
Threshold percent of tender offer by a third party to purchase the Company's stock that would terminate the 'Standstill Restrictions' in effect under the stock purchase agreement	50%
Censa [Member]
Common stock
Issuance of common stock related to acquisition (in shares)				845,364
Issuance of common stock related to acquisition				$ 42,900
Rights Exchange Agreement
Common stock
Issuance of common stock related to rights exchange (in shares)				2,821,176
Issuance of common stock related to rights exchange				$ 150,500
Sales Agreement | Common stock | Maximum
Common stock
Net consideration received on transaction		$ 125,000

Net loss per share - Numerator

Net loss per share - Numerator and Denominator (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator
Net loss - Basic	$ (559,017)	$ (523,901)	$ (438,160)
Net loss - Diluted	$ (559,017)	$ (523,901)	$ (438,160)
Denominator
Basic	71,728,634	70,466,393	66,027,908
Diluted	71,728,634	70,466,393	66,027,908
Basic	$ (7.79)	$ (7.43)	$ (6.64)
Diluted	$ (7.79)	$ (7.43)	$ (6.64)

Net loss per share - Antidiluti

Net loss per share - Antidilutive (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net loss per share
Total shares excluded from calculation (in shares)	14,018,753	12,292,413	10,645,735
Stock Options
Net loss per share
Total shares excluded from calculation (in shares)	11,502,417	10,772,582	9,663,677
Restricted Stock and Restricted Stock Units [Member]
Net loss per share
Total shares excluded from calculation (in shares)	2,516,336	1,519,831	982,058

Stock award plan - Narrative (D

Stock award plan - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Jun. 08, 2022	Dec. 31, 2022	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Apr. 30, 2022	Jun. 30, 2021	May 31, 2021	Jan. 31, 2020
Stock option plan
Share-based compensation expense				$ 110,333	$ 103,513	$ 70,325
Unrecognized compensation cost		$ 176,100		$ 176,100
Weighted average remaining service period for recognition of unrecognized compensation cost				2 years 2 months 8 days
Stock option
Stock option plan
Granted (in shares)				1,685,435	2,487,234	2,777,975
Forfeited (in shares)				458,737	742,458	889,785
Expected dividend yield (as a percent)				0%	0%	0%
Weighted average grant date fair value (in dollars per share)				$ 23.54	$ 43.05	$ 36.94
Stock option | Maximum
Stock option plan
Vesting period				4 years
Employee Stock Purchase Plan
Stock option plan
Number of shares authorized (in shares)								2,000,000	1,000,000
Award requisite service period				6 months
Share-based compensation expense				$ 2,400
Employee Stock Purchase Plan | Minimum
Stock option plan
Purchase price of common stock, percent				85%
Employee stock purchase plan, voting percentage limit				5%
1998 Employee, Director, and Consultant Stock Option Plan, 2009 Equity and Long-term Incentive Plan, and 2013 Stock Incentive Plan
Stock option plan
Number of shares available for issuance		0		0
Amended 2013 LTIP
Stock option plan
Number of additional shares authorized (in shares)	8,475,000
Amended 2013 LTIP | Maximum
Stock option plan
Number of shares authorized (in shares)	16,724,212
2013 Long Term Incentive Plan
Stock option plan
Number of shares available for issuance		9,126,463		9,126,463
2020 Inducement Stock Incentive Plan
Stock option plan
Number of shares available for issuance		1,820,565		1,820,565
Number of additional shares authorized (in shares)			1,000,000
2020 Inducement Stock Incentive Plan | Maximum
Stock option plan
Number of shares authorized (in shares)										1,000,000
2020 Inducement Stock Incentive Plan | Common stock | Maximum
Stock option plan
Number of shares authorized (in shares)							1,300,000
Number of additional shares authorized (in shares)		1,700,000
2020 Inducement Stock Incentive Plan | Stock option
Stock option plan
Granted (in shares)					104,385
Forfeited (in shares)					237,700
Stockholder's specified ownership percentage		10%		10%
Expiration period				10 years
Granted (in dollars per share)					$ 42.02
2020 Inducement Stock Incentive Plan | Stock option | Minimum
Stock option plan
Stock options granted, exercise price as percentage of the fair market value of common stock at grant date		100%		100%
Stock options granted to stockholder with specified ownership percentage, exercise price as percentage of the fair market value of common stock at grant date		110%		110%
2020 Inducement Stock Incentive Plan | Restricted stock units
Stock option plan
Granted (in shares)					43,800
Forfeited (in shares)					26,336

Stock award plan - Stock Option

Stock award plan - Stock Option Activity (Details) - Stock option - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Number of options
Outstanding at the beginning of the period (in shares)	10,772,582	9,663,677	11,043,939
Granted (in shares)	1,685,435	2,487,234	2,777,975
Exercised (in shares)	(496,863)	(635,871)	(3,268,452)
Forfeited/Cancelled (in shares)	(458,737)	(742,458)	(889,785)
Outstanding at the end of the period (in shares)	11,502,417	10,772,582	9,663,677
Vested or Expected to vest at the end of the period (in shares)	3,432,725
Exercisable at the end of the period (in shares)	7,774,274
Weighted- average exercise price
Outstanding at the beginning of the period (in dollars per share)	$ 43.66	$ 38.72	$ 31.67
Granted (in dollars per share)	38.55	61.36	51.06
Exercised (in dollars per share)	29.45	28.01	24.25
Forfeited/Cancelled (in dollars per share)	48.75	52.04	42.14
Outstanding at the end of the period (in dollars per share)	43.33	$ 43.66	$ 38.72
Vested or Expected to vest at the end of the period (in dollars per share)	47.74
Exercisable at the end of the period (in dollars per share)	$ 41.23
Weighted- average remaining contractual term
Outstanding at the end of the period	6 years 4 months 17 days
Vested or Expected to vest at the end of the period	8 years 2 months 12 days
Exercisable at the end of the period	5 years 5 months 26 days
Aggregate intrinsic value (in thousands)
Outstanding at the end of the period (in dollars)	$ 38,330
Vested or Expected to vest at the end of the period (in dollars)	1,694
Exercisable at the end of the period (in dollars)	$ 36,523

Stock award plan - Assumptions

Stock award plan - Assumptions Used (Details) - Stock option	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Valuation assumptions
Expected term (in years)	5 years 6 months	5 years 6 months	5 years 9 months
Minimum
Valuation assumptions
Risk-free interest rate (as a percent)	1.55%	0.51%	0.34%
Expected volatility (as a percent)	54%	74%	87%
Maximum
Valuation assumptions
Risk-free interest rate (as a percent)	4.57%	1.24%	1.45%
Expected volatility (as a percent)	74%	89%	89%

Stock award plan - Restricted S

Stock award plan - Restricted Stock (Details) - Restricted stock awards and units	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Number of Shares
Balance at the beginning of the period (in shares) | shares	1,519,831
Granted (in shares) | shares	1,686,467
Vested (in shares) | shares	(504,851)
Forfeited (in shares) | shares	(185,111)
Balance at the end of the period (in shares) | shares	2,516,336
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 55.43
Granted (in dollars per share) | $ / shares	38.37
Vested (in dollars per share) | $ / shares	50.15
Forfeited (in dollars per share) | $ / shares	46.67
Balance at the end of the period (in dollars per share) | $ / shares	$ 45.67

Stock award plan - Share-based

Stock award plan - Share-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock option plan
Share-based compensation expense	$ 110,333	$ 103,513	$ 70,325
Unrecognized compensation cost	$ 176,100
Weighted average remaining service period for recognition of unrecognized compensation cost	2 years 2 months 8 days
Research and development
Stock option plan
Share-based compensation expense	$ 55,869	53,632	38,716
Selling, general and administrative
Stock option plan
Share-based compensation expense	$ 54,464	$ 49,881	$ 31,609

Other comprehensive income (l_3

Other comprehensive income (loss) and accumulated other comprehensive items (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other comprehensive income (loss)
Balance at the beginning of the period	$ 1,438	$ 481,982	$ 594,330
Balance at the end of the period	(347,086)	1,438	481,982
Unrealized Gains (Losses) On Marketable Securities, net of tax
Other comprehensive income (loss)
Balance at the beginning of the period	(602)	1,900	755
Other comprehensive income (loss) before reclassifications	4,072	(3,279)	479
Amounts reclassified from other comprehensive items	(3,964)	777	666
Other comprehensive income (loss)	108	(2,502)	1,145
Balance at the end of the period	(494)	(602)	1,900
Foreign Currency Translation
Other comprehensive income (loss)
Balance at the beginning of the period	(23,680)	(62,857)	(11,339)
Other comprehensive income (loss) before reclassifications	28,970	39,177	(51,518)
Other comprehensive income (loss)	28,970	39,177	(51,518)
Balance at the end of the period	5,290	(23,680)	(62,857)
AOCI Attributable to Parent
Other comprehensive income (loss)
Balance at the beginning of the period	(24,282)	(60,957)	(10,584)
Other comprehensive income (loss) before reclassifications	33,042	35,898	(51,039)
Amounts reclassified from other comprehensive items	(3,964)	777	666
Other comprehensive income (loss)	29,078	36,675	(50,373)
Balance at the end of the period	$ 4,796	$ (24,282)	$ (60,957)

Revenue recognition - Net Produ

Revenue recognition - Net Product Sales (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) segment country Distributor	Dec. 31, 2021 USD ($) country Distributor	Dec. 31, 2020 USD ($) Distributor country
Net product sales
Number of operating segments | segment	1
Revenue	$ 698,801	$ 538,593	$ 380,766
Contract with customer, liability	1,400	0
Contract with customer, assets	0	0
Performance obligations satisfied in period		4,000
United States
Net product sales
Revenue	498,567	297,005
Non-US
Net product sales
Revenue	$ 200,234	$ 241,588
Net product revenue | Geographic concentration risk
Net product sales
Number of countries exceeding 10% of net product sales | country	2	1	1
Percentage of net product sales threshold	10%	10%	10%
Net product revenue | Customer concentration risk
Net product sales
Number of distributors | Distributor	2	2	2
Percentage of net product sales threshold	10%	10%	10%
Net product revenue
Net product sales
Revenue	$ 535,228	$ 428,904	$ 333,401
Net product revenue | Non-US
Net product sales
Revenue	316,900	241,600	194,400
Net product revenue | Net product revenue | Geographic concentration risk | United States
Net product sales
Revenue	218,300
Net product revenue | Net product revenue | Geographic concentration risk | Russia
Net product sales
Revenue	59,700
Emflaza | United States
Net product sales
Revenue	218,300	187,300	139,000
Translarna | Non-US
Net product sales
Revenue	$ 288,600	$ 236,000	$ 191,900

Revenue recognition - Performan

Revenue recognition - Performance Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Remaining Performance Obligation
Remaining performance obligations	$ 0	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Remaining Performance Obligation
Remaining performance obligations	$ 1.4
Revenue, performance obligation, period	12 months

Revenue recognition - Collabora

Revenue recognition - Collaboration and Royalty Revenue (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) payment	Dec. 31, 2020 USD ($) payment	Aug. 31, 2021 USD ($)	Mar. 31, 2021 USD ($)	Oct. 31, 2020 USD ($)	Aug. 31, 2020 USD ($)	Nov. 30, 2011 USD ($)
Collaboration and royalty revenue
Remaining potential milestones that can be achieved			$ 250,000
Revenue			698,801	$ 538,593	$ 380,766
Collaboration revenue
Collaboration and royalty revenue
Revenue			50,052	55,046	42,579
Royalty revenue
Collaboration and royalty revenue
Revenue			113,521	54,643	4,786
SMA License Agreement | Collaboration revenue
Collaboration and royalty revenue
Revenue			50,100	55,000	42,600
SMA License Agreement | Royalty revenue
Collaboration and royalty revenue
Revenue			113,500	$ 54,600	$ 4,800
Research and Development and Sales Milestones | Collaboration revenue
Collaboration and royalty revenue
Number of milestone payments. | payment				3	3
Research And Development Event Milestones | SMA License Agreement
Collaboration and royalty revenue
Remaining potential milestones that can be achieved			0
Milestone payments received						$ 10,000	$ 20,000	$ 7,500
Research And Development Event Milestones, Period Payment 1 | SMA License Agreement
Collaboration and royalty revenue
Milestone payments received									$ 20,000
Research And Development Event Milestones, Period Payment 2 | SMA License Agreement
Collaboration and royalty revenue
Milestone payments received									$ 15,000
Sales Milestones | SMA License Agreement
Collaboration and royalty revenue
Remaining potential milestones that can be achieved			250,000
Net sales milestone threshold achieved	$ 750,000		$ 500,000
Sales Milestones | SMA License Agreement | Prepaids and other current assets
Collaboration and royalty revenue
Milestone payments due	$ 50,000	$ 25,000
Maximum | Research And Development Event Milestones | SMA License Agreement | Roche
Collaboration and royalty revenue
Remaining potential milestones that can be achieved										$ 135,000
Maximum | Sales Milestones | SMA License Agreement | Roche
Collaboration and royalty revenue
Remaining potential milestones that can be achieved										$ 325,000

Income taxes - Narrative (Detai

Income taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Operating loss carryforwards
Taxable income before consideration of NOL	$ 61,600
State income tax provision	4,224	$ 3,844	$ 24,984
Deferred tax valuation allowance	672,172	525,570
Valuation allowance, deferred tax asset, increase (decrease)	146,600	146,000
Deferred tax liability on indefinite-lived intangibles acquired	102,834	137,110
Orphan Drug Credit carryover	145,800
Net operating loss carryforwards utilized	$ 49,300	$ 0	$ 364,100
Federal income tax provision at statutory rate	21%	21%	21%
Uncertain tax position	$ 0
Increase in current taxable income resulting from the elimination of current deduction of qualifying R&D costs under Section 174.	450,100
Undistributed earnings from non-US subsidiaries	65,100
Undistributed earnings from non-US subsidiaries, tax	0
Unrecognized tax benefits	27,217	$ 27,217
Agilis
Operating loss carryforwards
Deferred tax liability on indefinite-lived intangibles acquired				$ 122,000
Federal
Operating loss carryforwards
Net operating loss carryforwards	333,100
Operating loss carryforwards limited by IRC Section 382	231,500
Research and development credit carryforwards	29,000
Operating loss carryforwards, not subject to expiration	169,200
Operating loss carryforwards, subject to expiration	62,300
Net operating loss carryforwards limited by IRC Section 382 utilized	11,400		$ 97,700
Operating loss carryforwards for immediate use	333,100
Operating loss carryforwards in next twelve months	5,700
Federal | First five years from ownership change
Operating loss carryforwards
Annual net operating loss carryforward available as limited by IRC Section 382	16,700
Federal | After five years
Operating loss carryforwards
Annual net operating loss carryforward available as limited by IRC Section 382	5,700
State
Operating loss carryforwards
Net operating loss carryforwards	$ 164,900

Income taxes - Loss from operat

Income taxes - Loss from operations before tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Domestic	$ (591,126)	$ (487,726)	$ (452,475)
Foreign	3,639	(30,614)	49,543
Loss before income tax expense	$ (587,487)	$ (518,340)	$ (402,932)

Income taxes - Provision for Ta

Income taxes - Provision for Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
U.S. Federal	$ 0	$ 0	$ 0
U.S. State and Local	(4,224)	(3,844)	(24,984)
Foreign	(1,582)	(1,340)	(4,372)
Deferred:
U.S. Federal	23,689	0	0
U.S. State and Local	10,587	(377)	(5,872)
Foreign	0	0	0
Total tax benefit (expense)	$ 28,470	$ (5,561)	$ (35,228)

Income taxes - Tax Rate Reconci

Income taxes - Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of the U.S. statutory income tax rate to the entity's effective tax rate
Federal income tax provision at statutory rate	21%	21%	21%
State income tax provision, net of federal benefit	3.07%	(0.74%)	(3.31%)
Permanent differences	(1.83%)	(4.06%)	(6.66%)
Research and development	5.89%	4.50%	4.93%
Change in valuation allowances	(23.36%)	(29.03%)	(26.40%)
Change in deferred tax assets	(0.10%)	12.05%	2.93%
Foreign tax rate differential	(0.17%)	0.01%	0.72%
Tax rate change	0.34%	0.01%	(1.46%)
(Accrual) release of uncertain tax positions		(4.78%)	(0.61%)
Other		(0.03%)	0.12%
Effective income tax rate	4.84%	(1.07%)	(8.74%)

Income taxes - Deferred Tax Ass

Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Accrued expense	$ 2,124	$ 8,208
Amortization	52,532	87,998
Federal tax credits	174,802	142,595
State tax credits	9,787	8,054
Federal net operating losses	69,957	76,589
State net operating losses	10,316	9,159
Foreign net operating losses	4,837	3,316
Capitalized research and development costs	110,219	241
Share based compensation and other	27,054	15,273
Liability for sale of future royalties	185,589	148,503
Noncash interest expense	30,160	26,040
Other comprehensive loss	(719)	143
Total gross deferred tax assets	676,658	526,119
Less valuation allowance	(672,172)	(525,570)
Total deferred tax assets, net of valuation allowance	4,486	549
Deferred tax liabilities:
Depreciation	(4,486)	(549)
Indefinite lived intangible	(102,834)	(137,110)
Total gross deferred tax liabilities	(107,320)	(137,659)
Net deferred tax assets (liabilities)	$ (102,834)	$ (137,110)

Income taxes - Unrecognized Tax

Income taxes - Unrecognized Tax Benefits (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Uncertain income tax benefits
Beginning Balance	$ 27,217
Ending Balance	$ 27,217

Commitments and contingencies -

Commitments and contingencies - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2022	Dec. 31, 2022	Jan. 31, 2023	Dec. 31, 2021	May 29, 2020	Apr. 29, 2020	Apr. 20, 2017	Jun. 30, 2016
Other Commitments
Accrued royalties		$ 40,546		$ 35,679
Wellcome Trust
Other Commitments
Development milestone payment obligations		2,500						$ 800
Wellcome Trust | Maximum
Other Commitments
Development milestone payments which the entity is obligated to pay		14,500
Censa
Other Commitments
Asset acquisition, milestone, amount					$ 217,500
Asset acquisition, development and regulatory milestones					109,000
Asset acquisition, net sales milestone					160,000
Asset acquisition, initial milestone					$ 30,000
Agilis Merger Agreement | Marathon
Other Commitments
Development milestone payment obligations							$ 50,000
SMA License Agreement | SMA Foundation
Other Commitments
Royalty expense		28,500
Royalty payments		24,500
Accrued royalties		4,000
SMA License Agreement | SMA Foundation | Maximum
Other Commitments
Potential royalty payments due on net product sales		52,500
Agilis
Other Commitments
Development milestone payments which the entity is obligated to pay		40,000
Net sales amount						$ 150,000
Milestone obligation payments made	$ 50,000
Development milestone obligation payments made		$ 2,400
Agilis | Minimum
Other Commitments
Product sales (as a percent)		2%				2%
Agilis | Maximum
Other Commitments
Development milestone payment obligations		$ 60,000
Priority review voucher amount		535,000
Net sales amount		$ 150,000
Product sales (as a percent)		6%				6%
Development milestone payment obligations, net of cancellation and forfeiture		$ 20,000
Contingent liability, milestone, potential achievements, priority review voucher amount, net of cancellation and forfeiture		361,000
Agilis | Agilis Merger Agreement
Other Commitments
Development milestone payment obligations		40,000
Agilis | Rights Exchange Agreement
Other Commitments
Contingent liability cancellation and forfeiture of potential milestone payments		174,000
Development milestone payment obligations, cancellation and forfeiture		37,600
Contingent liability, cancellation and forfeiture		211,600
BioElectron | Maximum
Other Commitments
Development milestone payment obligations		$ 200,000
Subsequent Event [Member] | Censa
Other Commitments
Development milestone payment obligations			$ 30,000

Geographic information (Details

Geographic information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment	1
Total assets	$ 1,705,619	$ 1,938,056
Fixed assets, net	72,590	52,585
Revenue	698,801	538,593	$ 380,766
United States
Segment Reporting Information [Line Items]
Total assets	1,473,770	1,744,225
Fixed assets, net	71,754	51,626
Revenue	498,567	297,005
Non-US
Segment Reporting Information [Line Items]
Total assets	231,849	193,831
Fixed assets, net	836	959
Revenue	$ 200,234	$ 241,588

401(k) plan (Details)

401(k) plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Matching contribution (as a percent of total salary)	100%	100%	100%
Percentage of employee's base salary, matched by employer	6%	6%	6%
Expense recorded	$ 8.4	$ 6.6	$ 5.3

Intangible assets and goodwil_2

Intangible assets and goodwill - Definite-lived Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Definite-lived intangible assets
Accrued royalties	$ 40,546	$ 35,679
Definite-lived intangibles
Amortization	(116,554)	(54,751)	$ (36,892)
Finite-Lived Intangible Assets, Net	$ 252,325
Weighted Average
Definite-lived intangible assets
Remaining amortization period	4 years 10 months 24 days
Emflaza asset acquisition
Definite-lived intangible assets
Milestone obligation payments recorded	$ 128,400
Emflaza asset acquisition | Accounts payable and accrued expenses
Definite-lived intangible assets
Milestone Payable	32,800
Emflaza asset acquisition | Sales Milestones
Definite-lived intangible assets
Milestone obligation payments recorded	50,000
Akcea | Tegsedi
Definite-lived intangible assets
Royalty payments	3,200
Akcea | Tegsedi | Accounts payable and accrued expenses
Definite-lived intangible assets
Accrued royalties	500
Definite-lived intangible assets
Definite-lived intangibles
Beginning balance - Definite-lived assets, Gross	305,839
Additions	131,618
Reclass from Indefinite Lived to Definite Lived	89,550
Foreign Currency Translation	(779)
Ending balance - Definite-lived assets, Gross	526,228	305,839
Beginning balance - Accumulated amortization	(157,498)
Amortization	(116,554)
Foreign Currency Translation - Accumulated amortization	149
Ending balance - Accumulated amortization	(273,903)	(157,498)
Finite-Lived Intangible Assets, Net	252,325
Definite-lived intangible assets | Emflaza
Definite-lived intangibles
Beginning balance - Definite-lived assets, Gross	291,875
Additions	128,378
Ending balance - Definite-lived assets, Gross	420,253	291,875
Beginning balance - Accumulated amortization	(154,594)
Amortization	(111,429)
Ending balance - Accumulated amortization	(266,023)	(154,594)
Definite-lived intangible assets | Waylivra
Definite-lived intangibles
Beginning balance - Definite-lived assets, Gross	9,904
Foreign Currency Translation	(588)
Ending balance - Definite-lived assets, Gross	9,316	9,904
Beginning balance - Accumulated amortization	(1,821)
Amortization	(1,020)
Foreign Currency Translation - Accumulated amortization	90
Ending balance - Accumulated amortization	(2,751)	(1,821)
Definite-lived intangible assets | Tegsedi
Definite-lived intangibles
Beginning balance - Definite-lived assets, Gross	4,060
Additions	3,240
Foreign Currency Translation	(191)
Ending balance - Definite-lived assets, Gross	7,109	4,060
Beginning balance - Accumulated amortization	(1,083)
Amortization	(685)
Foreign Currency Translation - Accumulated amortization	59
Ending balance - Accumulated amortization	(1,709)	$ (1,083)
Definite-lived intangible assets | Upstaza
Definite-lived intangibles
Reclass from Indefinite Lived to Definite Lived	89,550
Ending balance - Definite-lived assets, Gross	89,550
Amortization	(3,420)
Ending balance - Accumulated amortization	$ (3,420)

Intangible assets and goodwil_3

Intangible assets and goodwill - Future Amortization (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2023	$ 142,324
2024	30,609
2025	9,352
2026	9,352
2027 and thereafter	60,688
Total	$ 252,325

Intangible assets and goodwil_4

Intangible assets and goodwill - Indefinite-lived Intangibles (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Indefinite-lived intangibles
Impairment		$ (33,384)
Intangible assets, net	$ 705,891	705,891	$ 724,841
Indefinite-lived intangible assets
Indefinite-lived intangibles
Beginning Balance		576,500
Reclass from Indefinite-Lived to Definite-Lived		(89,550)
Impairment		(33,384)
Ending Balance	$ 453,566	$ 453,566
Indefinite-lived intangible assets | Significant unobservable inputs (Level 3) | Income Method | Discount Rate
Indefinite-lived intangibles
Indefinite-lived intangible asset, measurement input	0.15	0.15
Indefinite-lived intangible assets | Significant unobservable inputs (Level 3) | Income Method | Probability of success | Weighted Average
Indefinite-lived intangibles
Indefinite-lived intangible asset, measurement input	0.88	0.88
Indefinite-lived intangible assets | Upstaza
Indefinite-lived intangibles
Beginning Balance		$ 358,700
Reclass from Indefinite-Lived to Definite-Lived		(89,550)
Impairment	$ (33,400)	(33,384)
Ending Balance	235,766	235,766
Indefinite-lived intangible assets | PTC-FA
Indefinite-lived intangibles
Beginning Balance		112,500
Impairment		0
Ending Balance	112,500	112,500
Indefinite-lived intangible assets | PTC-AS
Indefinite-lived intangibles
Beginning Balance		105,300
Ending Balance	$ 105,300	$ 105,300

Intangible assets and goodwil_5

Intangible assets and goodwill - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2018
Goodwill
Goodwill	$ 82,341	$ 82,341
Impairment of goodwill	0
Agilis
Goodwill
Goodwill	82,300	$ 82,300	$ 82,300
Impairment of goodwill	$ 0

Subsequent events (Details)

Subsequent events (Details) $ in Millions	Jan. 31, 2023 USD ($)
Subsequent Event | Censa
Subsequent Event [Line Items]
Development milestone payment obligations	$ 30