Amicus Therapeutics (FOLD) 10-Q9 May 242024 Q1 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2024	Apr. 25, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-33497
Entity Registrant Name	Amicus Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	71-0869350
Entity Address, Address Line One	47 Hulfish Street
Entity Address, City or Town	Princeton
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08542
City Area Code	(609)
Local Phone Number	662-2000
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	FOLD
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		296,198,963
Entity Central Index Key	0001178879
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 209,761	$ 246,994
Investments in marketable securities	29,842	39,206
Accounts receivable	76,433	87,632
Inventories	60,759	59,696
Prepaid expenses and other current assets	54,444	49,533
Total current assets	431,239	483,061
Operating lease right-of-use assets, net	23,003	26,312
Property and equipment, less accumulated depreciation of $26,563 and $25,429 at March 31, 2024 and December 31, 2023, respectively	32,421	31,667
Intangible assets, less accumulated amortization of $3,328 and $2,510 at March 31, 2024 and December 31, 2023, respectively	19,672	20,490
Goodwill	197,797	197,797
Other non-current assets	17,657	18,553
Total Assets	721,789	777,880
Current liabilities:
Accounts payable	9,210	15,120
Accrued expenses and other current liabilities	124,622	144,245
Operating lease liabilities	8,270	8,324
Total current liabilities	142,102	167,689
Long-term debt	388,391	387,858
Operating lease liabilities	47,831	48,877
Other non-current liabilities	12,771	13,282
Total liabilities	591,095	617,706
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value, 500,000,000 shares authorized, 296,159,417 and 293,594,209 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	2,922	2,918
Additional paid-in capital	2,853,550	2,836,018
Accumulated other comprehensive loss:
Foreign currency translation adjustment	6,847	5,429
Unrealized loss on available-for-sale securities	(203)	(188)
Warrants	71	71
Accumulated deficit	(2,732,493)	(2,684,074)
Total stockholders’ equity	130,694	160,174
Total Liabilities and Stockholders’ Equity	$ 721,789	$ 777,880

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Accumulated depreciation of property and equipment	$ 26,563	$ 25,429
Accumulated amortization of intangible assets	$ 3,328	$ 2,510
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	296,159,417	293,594,209
Common stock, shares outstanding (in shares)	296,159,417	293,594,209

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Net product sales	$ 110,403	$ 86,270
Cost of goods sold	13,567	6,942
Gross profit	96,836	79,328
Operating expenses:
Research and development	28,329	41,499
Selling, general, and administrative	88,029	73,957
Changes in fair value of contingent consideration payable	0	251
Restructuring charges	6,045	0
Depreciation and amortization	2,154	1,257
Total operating expenses	124,557	116,964
Loss from operations	(27,721)	(37,636)
Other expense:
Interest income	1,540	2,199
Interest expense	(12,436)	(11,844)
Other expense	(4,966)	(5,938)
Loss before income tax	(43,583)	(53,219)
Income tax (expense) benefit	(4,836)	287
Net loss attributable to common stockholders	$ (48,419)	$ (52,932)
Net loss attributable to common stockholders per common share - basic (in dollars per share)	$ (0.16)	$ (0.18)
Net loss attributable to common stockholders per common share — diluted (in dollars per share)	$ (0.16)	$ (0.18)
Weighted average common shares outstanding - basic (in shares)	302,903,009	291,336,750
Weighted average common shares outstanding - diluted (in shares)	302,903,009	291,336,750

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (48,419)	$ (52,932)
Other comprehensive gain, net of tax:
Foreign currency translation adjustment gain	1,418	5,446
Unrealized loss on available-for-sale securities	(15)	(85)
Other comprehensive gain	1,403	5,361
Comprehensive loss	$ (47,016)	$ (47,571)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Warrants	Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022		281,108,273
Beginning balance at Dec. 31, 2022	$ 123,047	$ 2,815	$ 2,664,744	$ 83	$ (12,105)	$ (2,532,490)
Increase (Decrease) in Stockholders' Equity
Stock options exercised, net (in shares)		384,108
Stock options exercised, net	2,655	$ 3	2,652
Vesting of restricted stock units, net of taxes (in shares)		1,612,975
Vesting of restricted stock units, net of taxes	(12,806)		(12,806)
Stock-based compensation	34,894		34,894
Issuance of shares in connection with at-the-market offering, net of issuance costs (in shares)		195,229
Issuance of shares in connection with at-the-market offering, net of issuance costs	2,354	$ 2	2,352
Unrealized loss on available-for-sale securities	(85)				(85)
Foreign currency translation adjustment	5,446				5,446
Net loss	(52,932)					(52,932)
Ending balance (in shares) at Mar. 31, 2023		283,300,585
Ending balance at Mar. 31, 2023	$ 102,573	$ 2,820	2,691,836	83	(6,744)	(2,585,422)
Beginning balance (in shares) at Dec. 31, 2023	293,594,209	293,594,209
Beginning balance at Dec. 31, 2023	$ 160,174	$ 2,918	2,836,018	71	5,241	(2,684,074)
Increase (Decrease) in Stockholders' Equity
Stock options exercised, net (in shares)	439,000	444,497
Stock options exercised, net	$ 3,454	$ 4	3,450
Vesting of restricted stock units, net of taxes (in shares)		2,120,711
Vesting of restricted stock units, net of taxes	(16,721)		(16,721)
Stock-based compensation	30,803		30,803
Unrealized loss on available-for-sale securities	(15)				(15)
Foreign currency translation adjustment	1,418				1,418
Net loss	$ (48,419)					(48,419)
Ending balance (in shares) at Mar. 31, 2024	296,159,417	296,159,417
Ending balance at Mar. 31, 2024	$ 130,694	$ 2,922	$ 2,853,550	$ 71	$ 6,644	$ (2,732,493)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating activities
Net loss	$ (48,419)	$ (52,932)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of debt discount and deferred financing	531	667
Depreciation and amortization	2,154	1,257
Stock-based compensation	30,803	34,894
Non-cash changes in the fair value of contingent consideration payable	0	251
Foreign currency remeasurement loss	1,736	5,885
Deferred taxes	0	(4,939)
Other	5,818	0
Changes in operating assets and liabilities:
Accounts receivable	9,557	(1,367)
Inventories	(1,678)	(3,158)
Prepaid expenses and other current assets	(5,340)	1,839
Accounts payable, accrued expenses, and other current liabilities	(24,483)	(72)
Other non-current assets and liabilities	(374)	(394)
Net cash used in operating activities	(29,695)	(18,069)
Investing activities
Sale and redemption of marketable securities	38,907	54,944
Purchases of marketable securities	(29,559)	(16,747)
Capital expenditures	(1,811)	(1,942)
Net cash provided by investing activities	7,537	36,255
Financing activities
Payment of finance leases	(42)	(28)
Withholding taxes paid on vested restricted stock units	(16,721)	(12,806)
Proceeds from stock options exercised, net	3,454	2,655
Proceeds from the issuance of shares in connection with at-the-market offering, net of issuance costs	0	2,354
Net cash used in financing activities	(13,309)	(7,825)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(1,816)	1,507
Net (decrease) increase in cash, cash equivalents, and restricted cash at the end of the period	(37,283)	11,868
Cash, cash equivalents, and restricted cash at the beginning of period	250,077	153,115
Cash, cash equivalents, and restricted cash at the end of period	212,794	164,983
Supplemental disclosures of cash flow information
Cash paid during the period for interest	11,801	11,361
Capital expenditures unpaid at the end of period	1,110	1,260
Cash paid for taxes	635	178
Tenant improvements paid through lease incentives	$ 52	$ 0

Description of Business

Description of Business	3 Months Ended
Description of Business	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Amicus Therapeutics, Inc. (the "Company") is a global, patient-dedicated biotechnology company focused on discovering, developing, and delivering novel medicines for rare diseases. The Company seeks to deliver the highest quality therapies that have the potential to obsolete current treatments, provide significant benefits to patients, and be first- or best-in-class. The Company's two marketed therapies are Galafold ® , the first oral monotherapy for people living with Fabry disease who have amenable genetic variants, and Pombiliti ® + Opfolda ® , a novel treatment designed to improve uptake of active enzyme into key disease relevant tissues for adults living with late-onset Pompe disease. Galafold ® (also referred to as "migalastat"), is approved in over 40 countries around the world, including the United States ("U.S."), European Union ("E.U."), United Kingdom ("U.K."), and Japan. Additionally, Galafold ® has been granted orphan drug designation in the U.S., E.U., U.K., Japan and several other countries. Pombiliti ® + Opfolda ® (also referred to as "cipaglucosidase alfa-atga/miglustat"), was approved in 2023 in the three largest Pompe markets: the U.S., the E.U., and the U.K. Multiple regulatory submissions and reimbursement processes with global health authorities are currently underway. Additionally, Pombiliti ® + Opfolda ® has been granted orphan drug designation in the U.S., E.U., U.K., Japan and several other countries. The Company had an accumulated deficit of $2.7 billion as of March 31, 2024 and anticipates incurring losses through the fiscal year ending December 31, 2024. The Company has historically funded its operations through stock offerings, product revenues, debt issuances, collaborations, and other financing arrangements. Based on its current operating model, the Company believes the current cash position, which includes expected revenues, is sufficient to fund the Company's operations and ongoing research programs for at least the next 12 months. Potential business development opportunities, pipeline expansion, and investment in manufacturing capabilities could impact the Company's long-term capital requirements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited Consolidated Financial Statements have been prepared in accordance with the U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10-01 of Regulation S-X. Accordingly, certain financial information that is normally included in annual financial statements prepared in accordance with U.S. GAAP, but that is not required for interim reporting purposes, has been omitted. In the opinion of management, the accompanying unaudited Consolidated Financial Statements reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company's interim financial information. Management has determined that the Company operates in one segment focused on the discovery, development, and commercialization of advanced therapies to treat a range of devastating rare and orphan diseases. The accompanying unaudited Consolidated Financial Statements and related notes should be read in conjunction with the Company's financial statements and related notes as contained in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2023. For a complete description of the Company's accounting policies, please refer to the Annual Report on Form 10-K for the fiscal year ended December 31, 2023. Consolidation The Consolidated Financial Statements include the accounts of the Company and its subsidiaries. Intercompany accounts and transactions are eliminated in consolidation. Foreign Currency Transactions The functional currency for most of the Company's foreign subsidiaries is their local currency. For non-U.S. subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the weighted average foreign exchange rates for the period. Adjustments resulting from the translation of the financial statements of the Company's foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in accumulated other comprehensive income, a separate component of stockholders' equity. Transactions which are not in the functional currency of the entity are remeasured into the functional currency with gains or losses resulting from the remeasurement recorded in other expense. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Cash, Cash Equivalents, Marketable Securities, and Restricted Cash The Company considers all highly liquid investments purchased with a maturity of three months or less at the date of acquisition to be cash equivalents. Marketable securities consist of fixed income investments with a maturity of greater than three months and other highly liquid investments that can be readily purchased or sold using established markets. These investments are classified as available-for-sale and are reported at fair value on the Company's Consolidated Balance Sheets. Unrealized holding gains and losses are reported within other comprehensive gain in the Company's Consolidated Statements of Comprehensive Loss. Fair value is based on available market information including quoted market prices, broker or dealer quotations, or other observable inputs. Restricted cash consists primarily of funds held to satisfy the requirements of certain agreements that are restricted in their use and is included as a component of other non-current assets on the Company's Consolidated Balance Sheets. Concentration of Credit Risk The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash, cash equivalents, 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 invests its marketable securities in high-quality commercial financial instruments. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on its cash, cash equivalents, or marketable securities. The Company's accounts receivable at March 31, 2024 have primarily arisen from Galafold ® sales in Europe, the U.S., and Japan. The Company periodically assesses the financial strength of its customers to establish allowances for anticipated losses, if any. For accounts receivable that have arisen from named patient sales, the payment terms are predetermined, and the Company evaluates the creditworthiness of each customer on a regular basis. As of March 31, 2024, the Company's allowance for doubtful accounts was $0.1 million. Revenue Recognition The Company has recorded revenue on sales where its products are available either on a commercial basis or through a reimbursed early access program. Product orders are generally received from distributors and pharmacies, with the ultimate payor often a government authority. The Company recognizes revenue when its performance obligation to its customers have been satisfied, which occurs at a point in time when the pharmacies or distributors obtain control of the products. The transaction price is determined based on fixed consideration in the Company's customer contracts and is recorded net of estimates for variable consideration, which primarily consist of third-party discounts and rebates. The identified variable consideration is recorded as a reduction of revenue at the time revenue from the sale is recognized. The Company recognizes revenue to the extent that it is probable that a significant revenue reversal will not occur in a future period. These estimates may differ from actual consideration received. The Company evaluates these estimates each reporting period to reflect known changes. The following table summarizes the Company's net product sales disaggregated by product: Three Months Ended March 31, (in thousands) 2024 2023 Galafold ® $ 99,359 $ 86,112 Pombiliti ® + Opfolda ® 11,044 158 Total net product sales $ 110,403 $ 86,270 The following table summarizes the Company's net product sales disaggregated by geographic area: Three Months Ended March 31, (in thousands) 2024 2023 U.S. $ 37,375 $ 28,831 Ex-U.S. 73,028 57,439 Total net product sales $ 110,403 $ 86,270 Inventories and Cost of Goods Sold Inventories are stated at the lower of cost and net realizable value, determined by the first-in, first-out method. Inventories are reviewed periodically to identify slow-moving or obsolete inventory based on projected sales activity as well as product shelf-life. In evaluating the recoverability of inventories produced, the probability that revenue will be obtained from the future sale of the related inventory is considered and inventory value is written down for inventory quantities in excess of expected requirements. Expired inventory is disposed of and the related costs are recognized as cost of goods sold in the Company's Consolidated Statements of Operations. Cost of goods sold includes the cost of inventory sold, manufacturing and supply chain costs, product shipping and handling costs, provisions for excess and obsolete inventory, as well as royalties payable. A portion of Pombiliti ® + Opfolda ® inventory was expensed as research and development costs prior to regulatory approval and as such, the cost of goods sold and related gross margins are not necessarily indicative of future costs of goods sold and gross margin. Recent Accounting Developments - Guidance Adopted in 2024 In November 2023, the Financial Accounting Standards Board ("FASB") issued the Accounting Standards Update ("ASU") No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The amendments expand reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments require, among other things, disclosure of the title and position of the chief operating decision maker and require that public entities with a single reportable segment provide all disclosures required by this update and existing segment disclosures in Topic 280. Annual disclosures are required for fiscal years beginning after December 15, 2023 and interim disclosures are required for periods within fiscal years beginning after December 15, 2024. Retrospective application is required unless it is impracticable, and early adoption is permitted. The Company adopted this guidance on January 1, 2024. This ASU applies to disclosure requirements only, and the Company will provide required annual disclosures as part of the 2024 Annual Report on Form 10-K and required interim disclosures as part of 2025 Quarterly Reports on Form 10-Q. Recent Accounting Developments - Guidance Not Yet Adopted In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): I mprovements to Income Tax Disclosures. The ASU requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, must be applied prospectively with an option to apply retrospectively, and early adoption is permitted. The adoption of this guidance is not expected to have a significant impact on the Company's consolidated financial statements.

Cash, Cash Equivalents, Marketa

Cash, Cash Equivalents, Marketable Securities, and Restricted Cash	3 Months Ended
	Mar. 31, 2024
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Cash, Cash Equivalents, Marketable Securities, and Restricted Cash	Cash, Cash Equivalents, Marketable Securities, and Restricted Cash As of March 31, 2024, the Company held $209.8 million in cash and cash equivalents and $29.8 million of marketable securities which are reported at fair value on the Company's Consolidated Balance Sheets. Unrealized holding gains and losses are generally reported within other comprehensive gain in the Consolidated Statements of Comprehensive Loss. If a decline in the fair value of a marketable security below the Company's cost basis is determined to be other-than-temporary or if an available-for-sale debt security’s fair value is determined to be less than the amortized cost and the Company intends or is more than likely to sell the security before recovery and it is not considered a credit loss such security is written down to its estimated fair value as a new cost basis and the amount of the write-down is included in the Consolidated Statements of Operations as an impairment charge. If the unrealized loss of an available-for-sale debt security is determined to be a result of credit loss, the Company would recognize an allowance and the corresponding credit loss would be included in the Consolidated Statements of Operations. The Company regularly invests excess operating cash in deposits with major financial institutions, money market funds, notes issued by the U.S. government, as well as fixed income investments and U.S. bond funds, both of which can be readily purchased and sold using established markets. The Company believes that the market risk arising from its holdings of these financial instruments is mitigated as, in accordance with Company policy, securities are of high credit rating. Investments that have original maturities greater than three months but less than one year are classified as current. Cash, cash equivalents and marketable securities are classified as current unless mentioned otherwise below and consisted of the following: As of March 31, 2024 (in thousands) Cost Gross Gross Fair Cash and cash equivalents $ 209,761 $ — $ — $ 209,761 Commercial paper 25,718 — (4) 25,714 U.S. government agency bonds 3,978 — (1) 3,977 Money market 100 — — 100 Certificates of deposit 51 — — 51 $ 239,608 $ — $ (5) $ 239,603 Included in cash and cash equivalents $ 209,761 $ — $ — $ 209,761 Included in marketable securities 29,847 — (5) 29,842 Total cash, cash equivalents, and marketable securities $ 239,608 $ — $ (5) $ 239,603 As of December 31, 2023 (in thousands) Cost Gross Gross Fair Cash and cash equivalents $ 246,994 $ — $ — $ 246,994 Commercial paper 14,651 12 — 14,663 Treasury bill 12,944 2 — 12,946 U.S. government agency bonds 11,450 — (4) 11,446 Money market 100 — — 100 Certificate of deposit 51 — — 51 $ 286,190 $ 14 $ (4) $ 286,200 Included in cash and cash equivalents $ 246,994 $ — $ — $ 246,994 Included in marketable securities 39,196 14 (4) 39,206 Total cash, cash equivalents, and marketable securities $ 286,190 $ 14 $ (4) $ 286,200 For both the three months ended March 31, 2024 and March 31, 2023, there were no realized gains or losses. The cost of securities sold is based on the specific identification method. Unrealized loss positions in the marketable securities as of March 31, 2024 reflect temporary impairments and are not a result of credit loss. Additionally, as these positions have been in a loss position for less than twelve months and the Company does not intend to sell these securities before recovery, the losses are recognized as a component of other comprehensive gain. The fair value of these marketable securities in unrealized loss positions are $29.7 million and $11.4 million as of March 31, 2024 and December 31, 2023, respectively. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows. As of March 31, (in thousands) 2024 2023 Cash and cash equivalents $ 209,761 $ 160,602 Restricted cash 3,033 4,381 Cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows $ 212,794 $ 164,983

Inventories

Inventories	3 Months Ended
Inventories	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventories	Inventories The following table summarizes the components of the Company’s inventories for each of the periods indicated: (in thousands) March 31, 2024 December 31, 2023 Raw materials $ 31,613 $ 30,230 Work-in-process 22,146 22,597 Finished goods 7,000 6,869 Total inventories $ 60,759 $ 59,696 The Company's reserve for inventory was $2.9 million and $0.5 million as of March 31, 2024 and December 31, 2023, respectively.

Debt

Debt	3 Months Ended
Debt	Mar. 31, 2024
Debt Disclosure [Abstract]
Debt	Debt The following table summarizes the Company's debt for each of the periods indicated: (in thousands) March 31, 2024 December 31, 2023 Senior Secured Term Loan due 2029: Principal $ 400,000 $ 400,000 Less: debt discount (1) (9,230) (9,652) Less: deferred financing (1) (2,379) (2,490) Net carrying value of Long-term debt $ 388,391 $ 387,858 ______________________________ (1) Included in the Company's Consolidated Balance Sheets within long-term debt and amortized to interest expense over the remaining life of the Senior Secured Term Loan due 2029 using the effective interest rate method. Interest Expense The following table sets forth interest expense recognized related to the Company's debt for the three months ended March 31, 2024 and 2023, respectively: Three Months Ended March 31, (in thousands) 2024 2023 Contractual interest expense $ 11,974 $ 11,230 Amortization of debt discount $ 422 $ 381 Amortization of deferred financing $ 109 $ 286

Restructuring

Restructuring	3 Months Ended
Restructuring	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In the first quarter of 2024, restructuring charges are primarily related to an initiative to reduce operating costs by abandoning one of the Company's leases that it no longer believes is necessary to conduct its operations. The associated liabilities are recorded in accrued expenses and other current liabilities in the Company’s Consolidated Balance Sheets. Total charges incurred are summarized as follows: (in thousands) Other Facility and Non-Lease Costs Accelerated Depreciation Total Balance as of December 31, 2023 $ — $ — $ — Restructuring charges 3,201 2,844 6,045 Non-cash items — (2,844) (2,844) Cash settled (310) — (310) Balance as of March 31, 2024 $ 2,891 $ — $ 2,891

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
Stock-Based Compensation	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Amended and Restated 2007 Equity Incentive Plan (the "Plan") provides for the granting of restricted stock units and options to purchase common stock in the Company to employees, directors, advisors, and consultants at a price to be determined by the Board of Directors. The Plan is intended to encourage ownership of stock by employees and consultants of the Company and to provide additional incentives for them to promote the success of the business. The Board of Directors, or its committee, is responsible for determining the individuals to be granted options, the number of options each individual will receive, the option price per share, and the exercise period of each option. Stock Option Grants The fair value of the stock options granted were estimated on the date of grant using a Black-Scholes option pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Expected stock price volatility 57.2 % 59.3 % Risk free interest rate 4.0 % 3.9 % Expected life of options (years) 5.6 5.5 Expected annual dividend per share $ — $ — A summary of the Company's stock options for the three months ended March 31, 2024 were as follows: Number of Weighted Average Exercise Weighted Average Remaining Aggregate (in thousands) (in millions) Options outstanding, December 31, 2023 23,002 $ 11.69 Granted 4,033 $ 14.23 Exercised (439) $ 7.86 Forfeited (271) $ 12.56 Expired (20) $ 17.28 Options outstanding, March 31, 2024 26,305 $ 12.13 6.4 $ 23.9 Vested and unvested expected to vest, March 31, 2024 24,409 $ 12.08 6.2 $ 23.5 Exercisable at March 31, 2024 15,979 $ 11.60 4.9 $ 22.3 As of March 31, 2024, the total unrecognized compensation cost related to non-vested stock options granted was $52.5 million and is expected to be recognized over a weighted average period of three years. Restricted Stock Units and Performance-Based Restricted Stock Units (collectively "RSUs") RSUs awarded under the Plan are generally subject to graded vesting and are contingent on an employee's continued service. RSUs are generally subject to forfeiture if employment terminates prior to the release of vesting restrictions. The Company expenses the cost of the RSUs, which is determined to be the fair market value of the shares of common stock underlying the RSUs at the date of grant, ratably over the period during which the vesting restrictions lapse. A summary of non-vested RSU activity under the Plan for the three months ended March 31, 2024 is as follows: Number of Weighted Weighted Aggregate (in thousands) (in millions) Non-vested units as of December 31, 2023 10,033 $ 13.37 Granted 3,251 $ 15.35 Vested (3,332) $ 13.49 Forfeited (393) $ 14.66 Non-vested units as of March 31, 2024 9,559 $ 13.92 2.5 $ 112.6 As of March 31, 2024, there was $77.7 million of total unrecognized compensation cost related to unvested RSUs with service-based vesting conditions. These costs are expected to be recognized over a weighted average period of three years. Compensation Expense Related to Equity Awards The following table summarizes information related to compensation expense recognized in the Company's Consolidated Statements of Operations related to the equity awards: Three Months Ended March 31, (in thousands) 2024 2023 Research and development expense $ 4,871 $ 8,490 Selling, general, and administrative expense 25,932 26,404 Total equity compensation expense $ 30,803 $ 34,894

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value	3 Months Ended
Assets and Liabilities Measured at Fair Value	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value	Assets and Liabilities Measured at Fair Value The Company's financial assets and liabilities are measured at fair value and classified within the fair value hierarchy, which is defined as follows: Level 1 — Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 — Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3 — Inputs that are unobservable for the asset or liability. A summary of the fair value of the Company's recurring assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of March 31, 2024 are identified in the following tables: (in thousands) Level 1 Level 2 Total Assets: Commercial paper $ — $ 25,714 $ 25,714 U.S. government agency bonds — 3,977 3,977 Money market 7,201 — 7,201 $ 7,201 $ 29,691 $ 36,892 (in thousands) Level 1 Level 2 Total Liabilities: Deferred compensation plan liability $ 7,101 $ — $ 7,101 $ 7,101 $ — $ 7,101 A summary of the fair value of the Company's recurring assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2023 are identified in the following tables: (in thousands) Level 1 Level 2 Total Assets: Commercial paper $ — $ 14,663 $ 14,663 Treasury bill — 12,946 12,946 U.S. government agency bonds — 11,446 11,446 Money market 7,631 — 7,631 $ 7,631 $ 39,055 $ 46,686 (in thousands) Level 1 Level 2 Total Liabilities: Deferred compensation plan liability 7,531 — 7,531 $ 7,531 $ — $ 7,531 Deferred compensation plan liability is recorded as a component of other non-current liabilities on the Company's Consolidated Balance Sheets. The Company did not have any Level 3 assets or liabilities as of March 31, 2024 or December 31, 2023. Cash, Money Market Funds, and Marketable Securities

Basic and Diluted Net Loss per

Basic and Diluted Net Loss per Common Share	3 Months Ended
Basic and Diluted Net Loss per Common Share	Mar. 31, 2024
Earnings Per Share [Abstract]
Basic and Diluted Net Loss per Common Share	Basic and Diluted Net Loss per Common Share The following table provides a reconciliation of the numerator and denominator used in computing basic and diluted net loss attributable to common stockholders per common share: Three Months Ended March 31, (in thousands, except per share amounts) 2024 2023 Numerator: Net loss attributable to common stockholders $ (48,419) $ (52,932) Denominator: Weighted average common shares outstanding — basic and diluted 302,903,009 291,336,750 Dilutive common stock equivalents would include the dilutive effect of outstanding common stock options and unvested RSUs. Potentially dilutive common stock equivalents were excluded from the diluted earnings per share denominator for all periods because of their anti-dilutive effect. Weighted average common shares outstanding includes outstanding pre-funded warrants with an exercise price of $0.01. The table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method: As of March 31, (in thousands) 2024 2023 Options to purchase common stock 26,305 23,437 Unvested restricted stock units 9,559 9,430 Total number of potentially issuable shares 35,864 32,867

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (48,419)	$ (52,932)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Consolidated Financial Statements have been prepared in accordance with the U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10-01 of Regulation S-X. Accordingly, certain financial information that is normally included in annual financial statements prepared in accordance with U.S. GAAP, but that is not required for interim reporting purposes, has been omitted. In the opinion of management, the accompanying unaudited Consolidated Financial Statements reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company's interim financial information. Management has determined that the Company operates in one segment focused on the discovery, development, and commercialization of advanced therapies to treat a range of devastating rare and orphan diseases.
Consolidation	Consolidation The Consolidated Financial Statements include the accounts of the Company and its subsidiaries. Intercompany accounts and transactions are eliminated in consolidation.
Foreign Currency Transactions	Foreign Currency Transactions The functional currency for most of the Company's foreign subsidiaries is their local currency. For non-U.S. subsidiaries that transact in a functional currency other than the U.S. dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date. Income and expense items are translated at the weighted average foreign exchange rates for the period. Adjustments resulting from the translation of the financial statements of the Company's foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in accumulated other comprehensive income, a separate component of stockholders' equity. Transactions which are not in the functional currency of the entity are remeasured into the functional currency with gains or losses resulting from the remeasurement recorded in other expense.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Cash, Cash Equivalents, Marketable Securities, and Restricted Cash	Cash, Cash Equivalents, Marketable Securities, and Restricted Cash The Company considers all highly liquid investments purchased with a maturity of three months or less at the date of acquisition to be cash equivalents. Marketable securities consist of fixed income investments with a maturity of greater than three months and other highly liquid investments that can be readily purchased or sold using established markets. These investments are classified as available-for-sale and are reported at fair value on the Company's Consolidated Balance Sheets. Unrealized holding gains and losses are reported within other comprehensive gain in the Company's Consolidated Statements of Comprehensive Loss. Fair value is based on available market information including quoted market prices, broker or dealer quotations, or other observable inputs.
Concentration of Credit Risk	Concentration of Credit Risk The Company's financial instruments that are exposed to concentration of credit risk consist primarily of cash, cash equivalents, 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 invests its marketable securities in high-quality commercial financial instruments. The Company has not recognized any losses from credit risks on such accounts during any of the periods presented. The Company believes it is not exposed to significant credit risk on its cash, cash equivalents, or marketable securities. The Company's accounts receivable at March 31, 2024 have primarily arisen from Galafold ®
Revenue Recognition	Revenue Recognition The Company has recorded revenue on sales where its products are available either on a commercial basis or through a reimbursed early access program. Product orders are generally received from distributors and pharmacies, with the ultimate payor often a government authority. The Company recognizes revenue when its performance obligation to its customers have been satisfied, which occurs at a point in time when the pharmacies or distributors obtain control of the products. The transaction price is determined based on fixed consideration in the Company's customer contracts and is recorded net of estimates for variable consideration, which primarily consist of third-party discounts and rebates. The identified variable consideration is recorded as a reduction of revenue at the time revenue from the sale is recognized. The Company recognizes revenue to the extent that it is probable that a significant revenue reversal will not occur in a future period. These estimates may differ from actual consideration received. The Company evaluates these estimates each reporting period to reflect known changes.
Inventories and Cost of Goods Sold	Inventories and Cost of Goods Sold Inventories are stated at the lower of cost and net realizable value, determined by the first-in, first-out method. Inventories are reviewed periodically to identify slow-moving or obsolete inventory based on projected sales activity as well as product shelf-life. In evaluating the recoverability of inventories produced, the probability that revenue will be obtained from the future sale of the related inventory is considered and inventory value is written down for inventory quantities in excess of expected requirements. Expired inventory is disposed of and the related costs are recognized as cost of goods sold in the Company's Consolidated Statements of Operations. Cost of goods sold includes the cost of inventory sold, manufacturing and supply chain costs, product shipping and handling costs, provisions for excess and obsolete inventory, as well as royalties payable. A portion of Pombiliti ® + Opfolda ®
Recent Accounting Developments	Recent Accounting Developments - Guidance Adopted in 2024 In November 2023, the Financial Accounting Standards Board ("FASB") issued the Accounting Standards Update ("ASU") No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The amendments expand reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments require, among other things, disclosure of the title and position of the chief operating decision maker and require that public entities with a single reportable segment provide all disclosures required by this update and existing segment disclosures in Topic 280. Annual disclosures are required for fiscal years beginning after December 15, 2023 and interim disclosures are required for periods within fiscal years beginning after December 15, 2024. Retrospective application is required unless it is impracticable, and early adoption is permitted. The Company adopted this guidance on January 1, 2024. This ASU applies to disclosure requirements only, and the Company will provide required annual disclosures as part of the 2024 Annual Report on Form 10-K and required interim disclosures as part of 2025 Quarterly Reports on Form 10-Q. Recent Accounting Developments - Guidance Not Yet Adopted In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): I mprovements to Income Tax Disclosures. The ASU requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, must be applied prospectively with an option to apply retrospectively, and early adoption is permitted. The adoption of this guidance is not expected to have a significant impact on the Company's consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
Summary of Significant Accounting Policies (Tables)	Mar. 31, 2024
Accounting Policies [Abstract]
Schedule of Revenue Disaggregated by Geographical Area	The following table summarizes the Company's net product sales disaggregated by product: Three Months Ended March 31, (in thousands) 2024 2023 Galafold ® $ 99,359 $ 86,112 Pombiliti ® + Opfolda ® 11,044 158 Total net product sales $ 110,403 $ 86,270 The following table summarizes the Company's net product sales disaggregated by geographic area: Three Months Ended March 31, (in thousands) 2024 2023 U.S. $ 37,375 $ 28,831 Ex-U.S. 73,028 57,439 Total net product sales $ 110,403 $ 86,270

Cash, Cash Equivalents, Marke_2

Cash, Cash Equivalents, Marketable Securities, and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2024
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Schedule of Cash, Cash Equivalents and Marketable Securities	Cash, cash equivalents and marketable securities are classified as current unless mentioned otherwise below and consisted of the following: As of March 31, 2024 (in thousands) Cost Gross Gross Fair Cash and cash equivalents $ 209,761 $ — $ — $ 209,761 Commercial paper 25,718 — (4) 25,714 U.S. government agency bonds 3,978 — (1) 3,977 Money market 100 — — 100 Certificates of deposit 51 — — 51 $ 239,608 $ — $ (5) $ 239,603 Included in cash and cash equivalents $ 209,761 $ — $ — $ 209,761 Included in marketable securities 29,847 — (5) 29,842 Total cash, cash equivalents, and marketable securities $ 239,608 $ — $ (5) $ 239,603 As of December 31, 2023 (in thousands) Cost Gross Gross Fair Cash and cash equivalents $ 246,994 $ — $ — $ 246,994 Commercial paper 14,651 12 — 14,663 Treasury bill 12,944 2 — 12,946 U.S. government agency bonds 11,450 — (4) 11,446 Money market 100 — — 100 Certificate of deposit 51 — — 51 $ 286,190 $ 14 $ (4) $ 286,200 Included in cash and cash equivalents $ 246,994 $ — $ — $ 246,994 Included in marketable securities 39,196 14 (4) 39,206 Total cash, cash equivalents, and marketable securities $ 286,190 $ 14 $ (4) $ 286,200
Schedule of Cash, Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows. As of March 31, (in thousands) 2024 2023 Cash and cash equivalents $ 209,761 $ 160,602 Restricted cash 3,033 4,381 Cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows $ 212,794 $ 164,983

Inventories (Tables)

Inventories (Tables)	3 Months Ended
Inventories (Tables)	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventories for the Period	The following table summarizes the components of the Company’s inventories for each of the periods indicated: (in thousands) March 31, 2024 December 31, 2023 Raw materials $ 31,613 $ 30,230 Work-in-process 22,146 22,597 Finished goods 7,000 6,869 Total inventories $ 60,759 $ 59,696

Debt (Tables)

Debt (Tables)	3 Months Ended
Debt (Tables)	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Liability Components of Long-Term Debt	The following table summarizes the Company's debt for each of the periods indicated: (in thousands) March 31, 2024 December 31, 2023 Senior Secured Term Loan due 2029: Principal $ 400,000 $ 400,000 Less: debt discount (1) (9,230) (9,652) Less: deferred financing (1) (2,379) (2,490) Net carrying value of Long-term debt $ 388,391 $ 387,858 ______________________________ (1) Included in the Company's Consolidated Balance Sheets within long-term debt and amortized to interest expense over the remaining life of the Senior Secured Term Loan due 2029 using the effective interest rate method.
Schedule of Components of Total Interest Expense	The following table sets forth interest expense recognized related to the Company's debt for the three months ended March 31, 2024 and 2023, respectively: Three Months Ended March 31, (in thousands) 2024 2023 Contractual interest expense $ 11,974 $ 11,230 Amortization of debt discount $ 422 $ 381 Amortization of deferred financing $ 109 $ 286

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
Restructuring (Tables)	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Schedule of Total Charges Incurred	Total charges incurred are summarized as follows: (in thousands) Other Facility and Non-Lease Costs Accelerated Depreciation Total Balance as of December 31, 2023 $ — $ — $ — Restructuring charges 3,201 2,844 6,045 Non-cash items — (2,844) (2,844) Cash settled (310) — (310) Balance as of March 31, 2024 $ 2,891 $ — $ 2,891

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
Stock-Based Compensation (Tables)	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Fair Value of Options	The fair value of the stock options granted were estimated on the date of grant using a Black-Scholes option pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2024 2023 Expected stock price volatility 57.2 % 59.3 % Risk free interest rate 4.0 % 3.9 % Expected life of options (years) 5.6 5.5 Expected annual dividend per share $ — $ —
Schedule of Stock Options Activity	A summary of the Company's stock options for the three months ended March 31, 2024 were as follows: Number of Weighted Average Exercise Weighted Average Remaining Aggregate (in thousands) (in millions) Options outstanding, December 31, 2023 23,002 $ 11.69 Granted 4,033 $ 14.23 Exercised (439) $ 7.86 Forfeited (271) $ 12.56 Expired (20) $ 17.28 Options outstanding, March 31, 2024 26,305 $ 12.13 6.4 $ 23.9 Vested and unvested expected to vest, March 31, 2024 24,409 $ 12.08 6.2 $ 23.5 Exercisable at March 31, 2024 15,979 $ 11.60 4.9 $ 22.3
Schedule of Non-Vested RSU Activity under the Plan	A summary of non-vested RSU activity under the Plan for the three months ended March 31, 2024 is as follows: Number of Weighted Weighted Aggregate (in thousands) (in millions) Non-vested units as of December 31, 2023 10,033 $ 13.37 Granted 3,251 $ 15.35 Vested (3,332) $ 13.49 Forfeited (393) $ 14.66 Non-vested units as of March 31, 2024 9,559 $ 13.92 2.5 $ 112.6
Schedule of Equity Compensation Expenses	The following table summarizes information related to compensation expense recognized in the Company's Consolidated Statements of Operations related to the equity awards: Three Months Ended March 31, (in thousands) 2024 2023 Research and development expense $ 4,871 $ 8,490 Selling, general, and administrative expense 25,932 26,404 Total equity compensation expense $ 30,803 $ 34,894

Assets and Liabilities Measur_2

Assets and Liabilities Measured at Fair Value (Tables)	3 Months Ended
Assets and Liabilities Measured at Fair Value (Tables)	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Subject to Fair Value Measurements	A summary of the fair value of the Company's recurring assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of March 31, 2024 are identified in the following tables: (in thousands) Level 1 Level 2 Total Assets: Commercial paper $ — $ 25,714 $ 25,714 U.S. government agency bonds — 3,977 3,977 Money market 7,201 — 7,201 $ 7,201 $ 29,691 $ 36,892 (in thousands) Level 1 Level 2 Total Liabilities: Deferred compensation plan liability $ 7,101 $ — $ 7,101 $ 7,101 $ — $ 7,101 A summary of the fair value of the Company's recurring assets and liabilities aggregated by the level in the fair value hierarchy within which those measurements fall as of December 31, 2023 are identified in the following tables: (in thousands) Level 1 Level 2 Total Assets: Commercial paper $ — $ 14,663 $ 14,663 Treasury bill — 12,946 12,946 U.S. government agency bonds — 11,446 11,446 Money market 7,631 — 7,631 $ 7,631 $ 39,055 $ 46,686 (in thousands) Level 1 Level 2 Total Liabilities: Deferred compensation plan liability 7,531 — 7,531 $ 7,531 $ — $ 7,531

Basic and Diluted Net Loss pe_2

Basic and Diluted Net Loss per Common Share (Tables)	3 Months Ended
Basic and Diluted Net Loss per Common Share (Tables)	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Reconciliation of the Numerator and Denominator Used in Computing Basic and Diluted Net Loss per Common Share	The following table provides a reconciliation of the numerator and denominator used in computing basic and diluted net loss attributable to common stockholders per common share: Three Months Ended March 31, (in thousands, except per share amounts) 2024 2023 Numerator: Net loss attributable to common stockholders $ (48,419) $ (52,932) Denominator: Weighted average common shares outstanding — basic and diluted 302,903,009 291,336,750
Schedule of Potential Shares of Common Stock that were Excluded from the Computation as they were Anti-Dilutive Using the Treasury Stock Method	The table below presents potential shares of common stock that were excluded from the computation as they were anti-dilutive using the treasury stock method: As of March 31, (in thousands) 2024 2023 Options to purchase common stock 26,305 23,437 Unvested restricted stock units 9,559 9,430 Total number of potentially issuable shares 35,864 32,867

Description of Business (Detail

Description of Business (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 2,732,493	$ 2,684,074

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) segment
Accounting Policies [Abstract]
Number of reportable segments	1
Number of operating segments	1
Allowance for doubtful accounts receivable \| $	$ 0.1

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Revenue by Product and Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Net product sales	$ 110,403	$ 86,270
U.S.
Disaggregation of Revenue [Line Items]
Net product sales	37,375	28,831
Ex-U.S.
Disaggregation of Revenue [Line Items]
Net product sales	73,028	57,439
Galafold
Disaggregation of Revenue [Line Items]
Net product sales	99,359	86,112
Pombiliti + Opfolda
Disaggregation of Revenue [Line Items]
Net product sales	$ 11,044	$ 158

Cash, Cash Equivalents, Marke_3

Cash, Cash Equivalents, Marketable Securities, and Restricted Cash - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Cash and cash equivalents	$ 209,761,000	$ 160,602,000	$ 246,994,000
Available-for-sale debt securities	29,842,000		39,206,000
Debt securities, realized gain (loss)	0	$ 0
Fair value of available-for-sale debt securities in unrealized loss positions	$ 29,700,000		$ 11,400,000

Cash, Cash Equivalents, Marke_4

Cash, Cash Equivalents, Marketable Securities, and Restricted Cash - Cash and Available for Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Cash, Money Market Funds, and Marketable Securities
Cash and cash equivalents	$ 209,761	$ 246,994	$ 160,602
Fair value, cash balances	209,761	246,994
Cost, available-for-sale securities	29,847	39,196
Gross unrealized gain, available-for-sale securities	0	14
Gross unrealized loss, available-for-sale securities	(5)	(4)
Fair value, available-for-sale debt securities	29,842	39,206
Cost, cash balances and available-for-sale securities	239,608	286,190
Gross unrealized gain, cash balances and available-for-sale securities	0	14
Gross unrealized loss, cash balances and available-for-sale securities	(5)	(4)
Fair value, cash balances and available-for-sale securities	239,603	286,200
Commercial paper
Cash, Money Market Funds, and Marketable Securities
Cost, available-for-sale securities	25,718	14,651
Gross unrealized gain, available-for-sale securities	0	12
Gross unrealized loss, available-for-sale securities	(4)	0
Fair value, available-for-sale debt securities	25,714	14,663
Treasury bill
Cash, Money Market Funds, and Marketable Securities
Cost, available-for-sale securities		12,944
Gross unrealized gain, available-for-sale securities		2
Gross unrealized loss, available-for-sale securities		0
Fair value, available-for-sale debt securities		12,946
U.S. government agency bonds
Cash, Money Market Funds, and Marketable Securities
Cost, available-for-sale securities	3,978	11,450
Gross unrealized gain, available-for-sale securities	0	0
Gross unrealized loss, available-for-sale securities	(1)	(4)
Fair value, available-for-sale debt securities	3,977	11,446
Money market
Cash, Money Market Funds, and Marketable Securities
Cost, available-for-sale securities	100	100
Gross unrealized gain, available-for-sale securities	0	0
Fair value, available-for-sale debt securities	100	100
Gross unrealized loss, cash balances and available-for-sale securities	0	0
Certificates of deposit
Cash, Money Market Funds, and Marketable Securities
Cost, available-for-sale securities	51	51
Gross unrealized gain, available-for-sale securities	0	0
Fair value, available-for-sale debt securities	51	51
Gross unrealized loss, cash balances and available-for-sale securities	$ 0	$ 0

Cash, Cash Equivalents, Marke_5

Cash, Cash Equivalents, Marketable Securities, and Restricted Cash - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Cash and cash equivalents	$ 209,761	$ 246,994	$ 160,602
Restricted cash	3,033		4,381
Cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$ 212,794	$ 250,077	$ 164,983	$ 153,115

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 31,613	$ 30,230
Work-in-process	22,146	22,597
Finished goods	7,000	6,869
Total inventories	$ 60,759	$ 59,696

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Reserve for inventory	$ 2.9	$ 0.5

Debt - Summary of Long Term Deb

Debt - Summary of Long Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Net carrying value of Long-term debt	$ 388,391	$ 387,858
Senior Loans \| Senior Secured Term Loan due 2029
Debt Instrument [Line Items]
Principal	400,000	400,000
Less: debt discount	(9,230)	(9,652)
Less: deferred financing	$ (2,379)	$ (2,490)

Debt - Interest Expense (Detail

Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Debt - Interest Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Debt Disclosure [Abstract]
Contractual interest expense	$ 11,974	$ 11,230
Amortization of debt discount	422	381
Amortization of deferred financing	$ 109	$ 286

Restructuring (Details)

Restructuring (Details) $ in Thousands	3 Months Ended
Restructuring (Details) $ in Thousands	Mar. 31, 2024 USD ($) lease	Mar. 31, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of leases abandoned \| lease	1
Restructuring Reserve [Roll Forward]
Balance	$ 0
Restructuring charges	6,045	$ 0
Non-cash items	(2,844)
Cash settled	(310)
Balance	2,891
Other Facility and Non-Lease Costs
Restructuring Reserve [Roll Forward]
Balance	0
Restructuring charges	3,201
Non-cash items	0
Cash settled	(310)
Balance	2,891
Accelerated Depreciation
Restructuring Reserve [Roll Forward]
Balance	0
Restructuring charges	2,844
Non-cash items	(2,844)
Cash settled	0
Balance	$ 0

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted-average Assumptions (Details) - Options to purchase common stock - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected stock price volatility	57.20%	59.30%
Risk free interest rate	4%	3.90%
Expected life of options (years)	5 years 7 months 6 days	5 years 6 months
Expected annual dividend per share (in dollars per share)	$ 0	$ 0

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) $ / shares shares
Number of Shares
Balance at the beginning of the period (in shares) \| shares	23,002
Options, granted (in shares) \| shares	4,033
Options, exercised (in shares) \| shares	(439)
Options, forfeited (in shares) \| shares	(271)
Options, expired (in shares) \| shares	(20)
Balance at the end of the period (in shares) \| shares	26,305
Vested and unvested expected to vest as of the end of the period (in shares) \| shares	24,409
Exercisable at the end of the period (in shares) \| shares	15,979
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share) \| $ / shares	$ 11.69
Options, granted (in dollars per share) \| $ / shares	14.23
Options, exercised (in dollars per share) \| $ / shares	7.86
Options, forfeited (in dollars per share) \| $ / shares	12.56
Options, expired (in dollars per share) \| $ / shares	17.28
Balance at the end of the period (in dollars per share) \| $ / shares	12.13
Vested and unvested expected to vest as of the end of the period (in dollars per share) \| $ / shares	12.08
Exercisable at the end of the period (in dollars per share) \| $ / shares	$ 11.60
Weighted Average Remaining Years and Aggregate Intrinsic Value
Balance at the end of the period	6 years 4 months 24 days
Vested and unvested expected to vest at the end of the period	6 years 2 months 12 days
Exercisable at the end of the period	4 years 10 months 24 days
Aggregate intrinsic value, options outstanding \| $	$ 23.9
Aggregate intrinsic value, vested and unvested expected to vest \| $	23.5
Aggregate intrinsic value of options exercisable \| $	$ 22.3

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs	$ 52.5
Unrecognized compensation costs, period for recognition (in years)	3 years
Unvested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs	$ 77.7
Unrecognized compensation costs, period for recognition (in years)	3 years

Stock-Based Compensation - RSUs

Stock-Based Compensation - RSUs and PBRSUs Summary (Details) - Unvested restricted stock units $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($) $ / shares shares
Number of Shares
Non-vested units as of the beginning of the period (in shares) \| shares	10,033
Granted (in shares) \| shares	3,251
Vested (in shares) \| shares	(3,332)
Forfeited (in shares) \| shares	(393)
Non-vested units as of the end of the period (in shares) \| shares	9,559
Weighted Average Grant Date Fair Value
Non-vested units as of the beginning of the period (in dollars per share) \| $ / shares	$ 13.37
Granted (in dollars per share) \| $ / shares	15.35
Vested (in dollars per share) \| $ / shares	13.49
Forfeited (in dollars per share) \| $ / shares	14.66
Non-vested units as of the end of the period (in dollars per share) \| $ / shares	$ 13.92
Weighted Average Remaining Years and Aggregate Intrinsic Value
Non-vested units, weighted average remaining years	2 years 6 months
Non-vested units, aggregate intrinsic value \| $	$ 112.6

Stock-Based Compensation - Expe

Stock-Based Compensation - Expense Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	$ 30,803	$ 34,894
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	4,871	8,490
Selling, general, and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total equity compensation expense	$ 25,932	$ 26,404

Assets and Liabilities Measur_3

Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Fair value of assets	$ 36,892	$ 46,686
Liabilities:
Deferred compensation plan liability	7,101	7,531
Fair value of liabilities	7,101	7,531
Commercial paper
Assets:
Fair value of assets	25,714	14,663
Treasury bill
Assets:
Fair value of assets		12,946
U.S. government agency bonds
Assets:
Fair value of assets	3,977	11,446
Money market
Assets:
Fair value of assets	7,201	7,631
Level 1
Assets:
Fair value of assets	7,201	7,631
Liabilities:
Deferred compensation plan liability	7,101	7,531
Fair value of liabilities	7,101	7,531
Level 1 \| Commercial paper
Assets:
Fair value of assets	0	0
Level 1 \| Treasury bill
Assets:
Fair value of assets		0
Level 1 \| U.S. government agency bonds
Assets:
Fair value of assets	0	0
Level 1 \| Money market
Assets:
Fair value of assets	7,201	7,631
Level 2
Assets:
Fair value of assets	29,691	39,055
Liabilities:
Deferred compensation plan liability	0	0
Fair value of liabilities	0	0
Level 2 \| Commercial paper
Assets:
Fair value of assets	25,714	14,663
Level 2 \| Treasury bill
Assets:
Fair value of assets		12,946
Level 2 \| U.S. government agency bonds
Assets:
Fair value of assets	3,977	11,446
Level 2 \| Money market
Assets:
Fair value of assets	$ 0	$ 0

Basic and Diluted Net Loss pe_3

Basic and Diluted Net Loss per Common Share (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net loss attributable to common stockholders	$ (48,419)	$ (52,932)
Denominator:
Weighted average common shares outstanding - basic (in shares)	302,903,009	291,336,750
Weighted average common shares outstanding - diluted (in shares)	302,903,009	291,336,750
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	35,864,000	32,867,000
Options to purchase common stock
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	26,305,000	23,437,000
Unvested restricted stock units
Antidilutive securities
Antidilutive securities excluded from computation of diluted earnings per share (in shares)	9,559,000	9,430,000

Basic and Diluted Net Loss pe_4

Basic and Diluted Net Loss per Common Share - Narrative (Details)	Mar. 31, 2024 $ / shares
Private Placement
Antidilutive securities
Warrants exercise price (in dollars per share)	$ 0.01