0000950170-22-007375 | 10-Q | XBRL Viewer

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Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2022	Apr. 29, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Trading Symbol	SRPT
Entity Registrant Name	Sarepta Therapeutics, Inc.
Entity Central Index Key	0000873303
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		87,500,961
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-14895
Entity Tax Identification Number	93-0797222
Entity Address, Address Line One	215 First Street
Entity Address, Address Line Two	Suite 415
Entity Address, State or Province	MA
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	02142
City Area Code	617
Local Phone Number	274-4000
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 1,233,877	$ 2,115,869
Short-term investments	779,548	0
Accounts receivable	178,194	152,990
Inventory	198,997	186,212
Other current assets	140,331	149,028
Total current assets	2,530,947	2,604,099
Property and equipment, net	187,248	191,156
Intangible assets, net	13,328	14,239
Right of use assets	45,982	45,531
Other non-current assets	278,649	292,949
Total assets	3,056,154	3,147,974
Current liabilities:
Accounts payable	54,007	76,741
Accrued expenses	293,908	271,697
Deferred revenue, current portion	89,244	89,244
Other current liabilities	17,803	15,051
Total current liabilities	454,962	452,733
Long-term debt	1,098,847	1,096,876
Lease liabilities, net of current portion	38,620	41,512
Deferred revenue, net of current portion	552,239	574,244
Contingent consideration	43,600	43,600
Other non-current liabilities	11,000	11,000
Total liabilities	2,199,268	2,219,965
Commitments and contingencies (Note 13)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 3,333,333 shares authorized; none issued and outstanding	0	0
Common stock, $0.0001 par value, 198,000,000 shares authorized; 87,495,607 and 87,126,974 issued and outstanding at March 31, 2022, and December 31, 2021, respectively	9	9
Additional paid-in capital	4,168,956	4,134,768
Accumulated other comprehensive loss, net of tax	(306)	(20)
Accumulated deficit	(3,311,773)	(3,206,748)
Total stockholders’ equity	856,886	928,009
Total liabilities and stockholders’ equity	$ 3,056,154	$ 3,147,974

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	3,333,333	3,333,333
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	198,000,000	198,000,000
Common stock, issued	87,495,607	87,126,974
Common stock, outstanding	87,495,607	87,126,974

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Products, net	$ 188,825	$ 124,926
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember
Collaboration	$ 22,005	$ 22,005
Total revenues	210,830	146,931
Cost and expenses:
Cost of sales (excluding amortization of in-licensed rights)	31,443	22,346
Research and development	194,250	195,149
Selling, general and administrative	71,840	71,131
Settlement and license charges	0	10,000
Amortization of in-licensed rights	178	170
Total cost and expenses	297,711	298,796
Operating loss	(86,881)	(151,865)
Other loss, net:
Other expense, net	(17,265)	(15,528)
Total other loss, net	(17,265)	(15,528)
Loss before income tax expense (benefit)	(104,146)	(167,393)
Income tax expense (benefit)	879	(143)
Net loss	(105,025)	(167,250)
Other comprehensive loss:
Unrealized losses on investments, net of tax	(286)	(6)
Total other comprehensive loss	(286)	(6)
Comprehensive loss	$ (105,311)	$ (167,256)
Net loss per share - basic and diluted	$ (1.20)	$ (2.10)
Weighted average number of shares of common stock used in computing basic and diluted net loss per share	87,253	79,454

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect of Accounting Change [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Cumulative Effect of Accounting Change [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Cumulative Effect of Accounting Change [Member]
Balance at Dec. 31, 2020	$ 761,759	$ (96,792)	$ 8	$ 3,609,877	$ (156,953)	$ 3	$ (2,848,129)	$ 60,161
Balance (in shares) at Dec. 31, 2020			79,374
Exercise of options for common stock	4,683			4,683
Exercise of options for common stock, shares			108
Vest of restricted stock units			204
Issuance of common stock under employee stock purchase plan	4,543			4,543
Issuance of common stock under employee stock purchase plan, shares			62
Stock-based compensation	28,508			28,508
Unrealized gains (losses) from available-for-sale securities, net of tax	(6)					(6)
Net loss	(167,250)						(167,250)
Balance at Mar. 31, 2021	535,445		$ 8	3,490,658		(3)	(2,955,218)
Balance (in shares) at Mar. 31, 2021			79,748
Balance at Dec. 31, 2021	928,009		$ 9	4,134,768		(20)	(3,206,748)
Balance (in shares) at Dec. 31, 2021			87,127
Exercise of options for common stock	997			997
Exercise of options for common stock, shares			18
Vest of restricted stock units			289
Issuance of common stock under employee stock purchase plan	3,993			3,993
Issuance of common stock under employee stock purchase plan, shares			62
Stock-based compensation	29,198			29,198
Unrealized gains (losses) from available-for-sale securities, net of tax	(286)					(286)
Net loss	(105,025)						(105,025)
Balance at Mar. 31, 2022	$ 856,886		$ 9	$ 4,168,956		$ (306)	$ (3,311,773)
Balance (in shares) at Mar. 31, 2022			87,496

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (105,025)	$ (167,250)
Adjustments to reconcile net loss to cash flows from operating activities:
Depreciation and amortization	10,719	8,930
Reduction in the carrying amounts of the right of use assets	3,655	2,220
Non-cash interest expense	1,957	1,816
Stock-based compensation	29,198	28,508
Other	1,838	2,692
Changes in operating assets and liabilities, net:
Net increase in accounts receivable	(25,204)	(16,863)
Net increase in inventory	(4,687)	(8,372)
Net decrease (increase) in other assets	13,401	34,915
Net decrease in deferred revenue	(22,005)	(22,005)
Net decrease in accounts payable, accrued expenses, lease liabilities and other liabilities	(5,022)	(44,962)
Net cash used in operating activities	(101,175)	(180,371)
Cash flows from investing activities:
Purchase of property and equipment	(5,551)	(21,149)
Purchase of available-for-sale securities	(779,770)	(29,989)
Maturity and sale of available-for-sale securities		210,000
Other	(486)	(2,196)
Net cash (used in) provided by investing activities	(785,807)	156,666
Cash flows from financing activities:
Proceeds from exercise of stock options and purchase of stock under the Employee Stock Purchase Program	4,990	9,226
Taxes paid related to net share settlement of equity awards		6,333
Net cash provided by financing activities	4,990	2,893
Decrease in cash, cash equivalents and restricted cash	(881,992)	(20,812)
Cash, cash equivalents and restricted cash:
Beginning of period	2,125,523	1,511,713
End of period	1,243,531	1,490,901
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	1,233,877	1,481,836
Restricted cash in other assets	9,654	9,065
Total cash, cash equivalents and restricted cash	1,243,531	1,490,901
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	11,688	11,688
Supplemental schedule of non-cash investing activities and financing activities:
Intangible assets and property and equipment included in accounts payable and accrued expenses	4,415	5,729
Lease liabilities arising from obtaining right of use assets	4,106	901
Lease liabilities terminated	$ 0	$ 19,967

ORGANIZATION AND NATURE OF BUSINESS

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

ORGANIZATION AND NATURE OF BUSINESS

1. ORGANIZATION AND NATURE OF BUSINESS

Sarepta Therapeutics, Inc. (together with its wholly-owned subsidiaries, “Sarepta” or the “Company”) is a commercial-stage biopharmaceutical company focused on helping patients through the discovery and development of unique RNA-targeted therapeutics, gene therapy and other genetic therapeutic modalities for the treatment of rare diseases. Applying its proprietary, highly-differentiated and innovative technologies, and through collaborations with its strategic partners, the Company is developing potential therapeutic candidates for a broad range of diseases and disorders, including Duchenne muscular dystrophy (“Duchenne”), Limb-girdle muscular dystrophies (“LGMDs”) and other neuromuscular and central nervous system (“CNS”) disorders.

The Company's products in the U.S., EXONDYS 51 (eteplirsen) Injection (“EXONDYS 51”), VYONDYS 53 (golodirsen) Injection (“VYONDYS 53”) and AMONDYS 45 (casimersen) Injection (“AMONDYS 45”), were granted accelerated approval by the U.S. Food and Drug Administration (the “FDA”) on September 19, 2016, December 12, 2019 and February 25, 2021, respectively. Indicated for the treatment of Duchenne in patients who have a confirmed mutation of the dystrophin gene that is amenable to exon 51, exon 53 and exon 45 skipping, respectively, EXONDYS 51, VYONDYS 53 and AMONDYS 45 use the Company’s phosphorodiamidate morpholino oligomer (“PMO”) chemistry and exon-skipping technology to skip exon 51, exon 53 and exon 45 of the dystrophin gene. Exon skipping is intended to promote the production of an internally truncated but functional dystrophin protein.

As of March 31, 2022, the Company had approximately $2,023.1 million of cash, cash equivalents, restricted cash and investments, consisting of $1,233.9 million of cash and cash equivalents, $779.5 million of short-term investments and $9.7 million of long-term restricted cash. The Company believes that its balance of cash, cash equivalents, restricted cash and investments as of the date of the issuance of this report is sufficient to fund its current operational plan for at least the next twelve months, though it may pursue raising additional cash resources through public or private debt and equity financings, seek funded research and development arrangements and additional government contracts and establish collaborations with or license its technology to other companies.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”), reflect the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions between and among its consolidated subsidiaries have been eliminated. Management has determined that the Company operates in one segment: discovering, developing, manufacturing and delivering therapies to patients with rare diseases.

In the opinion of the Company’s management, all adjustments of a normal recurring nature necessary for a fair presentation have been reflected. 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. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes for the year ended December 31, 2021 which are contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the U.S. Securities and Exchange Commission on March 1, 2022. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the full year.

Estimates and Uncertainties

The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist of accounts receivable from customers, cash held at financial institutions and cash equivalents and investments.

As of March 31, 2022, the majority of the Company’s accounts receivable arose from product sales in the U.S. and all customers have standard payment terms that generally require payment within 60 to 91 days. Outside of the U.S., the majority of the Company’s customers have payment terms ranging between 45 and 150 days. Three individual customers accounted for 48%, 36% and 8% of net product revenues for the three months ended March 31, 2022 and 49%, 40% and 7% of net product revenues for the three months ended March 31, 2021. Three individual customers accounted for 41%, 39% and 8% of accounts receivable from product sales as of March 31, 2022 and 41%, 41% and 10% of accounts receivable from product sales as of December 31, 2021. The Company monitors the financial performance and creditworthiness of its customers so that it can properly assess and respond to changes in its customers’ credit profile. As of March 31, 2022, the Company believes that such customers are of high credit quality.

As of March 31, 2022, the Company’s cash was concentrated at three financial institutions in the U.S., which potentially exposes the Company to credit risks. However, the Company does not believe that there is significant risk of non-performance by the financial institutions. The Company also purchases commercial paper, government and government agency bonds, corporate bonds and certificates of deposit issued by highly rated corporations, financial institutions and governments and limits the amount of credit exposure to any one issuer. These amounts may at times exceed federally insured limits. The Company has not experienced any credit losses related to these financial instruments and does not believe to be exposed to any significant credit risk related to these instruments.

Significant Accounting Policies

For details about the Company’s accounting policies, please read Note 2, Summary of Significant Accounting Policies and Recent Accounting Pronouncements of the Annual Report on Form 10-K for the year ended December 31, 2021.

There have not been any material changes to the Company’s accounting policies through March 31, 2022.

LICENSE AND COLLABORATION AGREEMENTS

3 Months Ended

Mar. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

LICENSE AND COLLABORATION AGREEMENTS

3. LICENSE AND COLLABORATION AGREEMENTS

F. Hoffman-La Roche Ltd.

For both of the three months ended March 31, 2022 and 2021, the Company recognized $22.0 million of collaboration revenue associated with the license, collaboration and option agreement (the “Roche Agreement”) with F. Hoffman-La Roche Ltd. (“Roche”). As of March 31, 2022, the Company has total deferred revenue of $641.5 million associated with the Roche Agreement, of which $89.2 million is classified as current. The portion of deferred revenue related to the separate material rights for the options to acquire ex-U.S. rights to certain Duchenne-specific programs was $485.0 million as of March 31, 2022 and December 31, 2021.

The costs associated with co-development activities performed under the Roche Agreement are included in operating expenses, with any reimbursement of costs by Roche reflected as a reduction of such expenses when the related expense is incurred. For the three months ended March 31, 2022 and 2021, costs reimbursable by Roche and reflected as a reduction to operating expenses were $17.7 million and $13.4 million, respectively. As of March 31, 2022, there was $17.7 million of collaboration receivable included in other current assets.

Research and Option Agreements

The Company has research and option agreements with third parties in order to develop various technologies and biologics that may be used in the administration of the Company’s genetic therapeutics. The agreements generally provide for research services related to pre-clinical development programs and options to license the technology for clinical development. Prior to the options under these agreements being executed, the Company may be required to make up to $11.0 million in research milestone payments. Under these agreements, there are $187.1 million in potential option payments to be made by the Company upon the determination to exercise the options. Additionally, if the options for each agreement are executed, the Company would incur additional contingent obligations and may be required to make development, regulatory, and sales milestone payments and tiered royalty payments based on the sales of the developed products upon commercialization. As of March 31, 2022, the Company has not exercised any options nor have any additional research milestone payments become probable of occurring.

Milestone Obligations

The Company has license and collaboration agreements in place for which it could be obligated to pay, in addition to the payment of up-front fees upon execution of the agreements, certain milestone payments as a product candidate proceeds from the submission of an investigational new drug application through approval for commercial sale and beyond. As of March 31, 2022, the Company may be obligated to make up to $4.0 billion in future development, regulatory, commercial and up-front royalty milestone payments associated with its license and collaboration agreements. These obligations exclude potential future option and milestone payments for options that have yet to be exercised within agreements entered into by the Company as of March 31, 2022, which are discussed above. For the three months ended March 31, 2022 and 2021, the Company recognized up-front, development milestone

and settlement expenses of less than $0.1 million and $14.0 million, respectively, as research and development expense in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss.

FAIR VALUE MEASUREMENTS

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

. FAIR VALUE MEASUREMENTS

The Company has certain financial assets and liabilities that are recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.

•

Level 1 — quoted prices for identical instruments in active markets;

•

Level 2 — quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and

•

Level 3 — valuations derived from valuation techniques in which one or more significant value drivers are unobservable.

During the three months ended March 31, 2022, there were no transfers between Levels 1, 2 and 3. The tables below present information about the Company’s financial assets and liabilities that are measured and carried at fair value and indicate the level within the fair value hierarchy of valuation techniques it utilizes to determine such fair value:


	Fair Value Measurement as of March 31, 2022
	Total		Level 1		Level 2		Level 3
	(in thousands)
Assets
Money market funds	$	606,498	$	606,498	$	—	$	—
Commercial paper		145,335		—		145,335		—
Government and government agency bonds		602,288		54,856		547,432		—
Corporate bonds		187,232		—		187,232		—
Strategic equity investments		33,394		982		—		32,412
Certificates of deposit		24,381		—		24,381		—
Total assets	$	1,599,128	$	662,336	$	904,380	$	32,412

Liabilities
Contingent consideration	$	43,600	$	—	$	—	$	43,600
Total liabilities	$	43,600	$	—	$	—	$	43,600


	Fair Value Measurement as of December 31, 2021
	Total		Level 1		Level 2		Level 3
	(in thousands)
Assets
Money market funds	$	1,562,358	$	1,562,358	$	—	$	—
Strategic equity investments		34,892		2,480		—		32,412
Certificates of deposit		250		250		—		—
Total assets	$	1,597,500	$	1,565,088	$	—	$	32,412

Liabilities
Contingent consideration	$	43,600	$	—	$	—	$	43,600
Total liabilities	$	43,600	$	—	$	—	$	43,600

The Company’s assets with fair value categorized as Level 1 within the fair value hierarchy include money market funds, the Company’s strategic investment in Lysogene S.A. and certain government and government agency bonds.

The Company's assets with fair value categorized as Level 2 within the fair value hierarchy consist of commercial paper, certain government and government agency bonds, corporate bonds and certificates of deposit. These assets have been initially valued at the transaction price and subsequently valued at the end of each reporting period utilizing third-party pricing services. The pricing services use observable market inputs to determine value, which primarily consist of reportable trades. Certain of the government and government agency bonds, commercial paper and corporate bonds, with original maturities of less than three months, are presented as cash equivalents on the unaudited condensed consolidated balance sheets as of March 31, 2022.

The Company’s assets with fair value categorized as Level 3 within the fair value hierarchy consist of a strategic investment in Series A preferred stock of Lacerta Therapeutics, Inc. (“Lacerta”) and strategic investments in two other private biotechnology companies. For more information related to Lacerta, please read Note 3, License and Collaboration Agreements of the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The fair value of the Lacerta investment was initially based on a cost approach corroborated by the Black-Scholes option pricing model. The most significant assumptions in the option pricing model include historical volatility of similar public companies, estimated term through Lacerta’s potential exit and a risk-free rate based on certain U.S. Treasury rates. The investments in the other two private companies are recorded at fair value at the time of purchase as measured by their respective investment cost. At the end of each reporting period, the fair value of the Company's strategic investments will be adjusted if the issuers are to issue similar or identical equity securities or when there is a triggering event for impairment. There were no valuation measurement events related to the fair value of the strategic investments during the three months ended March 31, 2022 and 2021, as no impairment indicators were identified nor were similar securities issued.

The Company’s contingent consideration liability with fair value categorized as Level 3 within the fair value hierarchy relates to the regulatory-related contingent payments to Myonexus Therapeutics, Inc. (“Myonexus”) selling shareholders as well as to two academic institutions under separate license agreements that meet the definition of a derivative. For more information related to Myonexus, please read Note 3, License and Collaboration Agreements of the Company’s Annual Report on Form 10-K for the year ended December 31, 2021. The contingent consideration liability was estimated using an income approach based on the probability-weighted expected cash flows that incorporated industry-based probability adjusted assumptions relating to the achievement of the milestone and thus the likelihood of making the payments. This fair value measurement was based upon significant inputs not observable in the market and therefore represented a Level 3 measurement. Significant changes which increase or decrease the probabilities of achieving the milestone or shorten or lengthen the time required to achieve the milestone would result in a corresponding increase or decrease in the fair value of the liability. At the end of each reporting period, the fair value is adjusted to reflect the most current assumptions through earnings.

For the three months ended March 31, 2022 and 2021, there have been no changes to the fair value of the contingent consideration liability. As of March 31, 2022, the contingent consideration was recorded as a non-current liability on the Company's unaudited consolidated balance sheets.

The fair value of the senior notes due on November 15, 2024 (the “2024 Notes”) is based on open market trades and is classified as Level 1 in the fair value hierarchy. As of March 31, 2022 and December 31, 2021, the fair value of the 2024 Notes was approximately $749.3 million and $846.1 million, respectively. The fair value of the December 13, 2019 term loan (the “December 2019 Term Loan”) is classified as Level 2 in the fair value hierarchy and is determined using a discounted cash flow analysis with market interest rates adjusted for credit risk as a significant input. As of March 31, 2022 and December 31, 2021, the fair value of the December 2019 Term Loan was approximately $569.4 million and $576.1 million, respectively. The carrying values of the 2024 Notes and December 2019 Term Loan were $564.2 million and $534.6 million as of March 31, 2022 and $563.7 million and $533.2 million as of December 31, 2021, respectively.

The carrying amounts reported in the unaudited condensed consolidated balance sheets for cash and cash equivalents, accounts receivable and accounts payable approximated fair value because of the short-term maturity of these financial instruments.

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES

3 Months Ended

Mar. 31, 2022

Cash and Cash Equivalents [Abstract]

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES

. CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES

The following table summarizes the Company’s financial assets with maturities of less than 90 days from the date of purchase included in cash equivalents in the unaudited condensed consolidated balance sheets for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Money market funds	$	606,498	$	1,562,358
Commercial paper		17,772		—
Government and government agency bonds		132,059		—
Corporate bonds		29,857		—
Total	$	786,186	$	1,562,358

It is the Company’s policy to mitigate credit risk in its financial assets by maintaining a well-diversified portfolio that limits the amount of exposure as to maturity and investment type. The weighted average maturity of the Company's available-for-sale securities as of March 31, 2022 was approximately four months. The Company did not hold any available-for-sale securities as of December 31, 2021.

The following tables summarize the Company’s cash, cash equivalents and short-term investments as of the periods indicated:


	As of March 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Cash and money market funds	$	1,054,189	$	—	$	—		$	1,054,189
Commercial paper		145,335		—		—			145,335
Government and government agency bonds		602,480		13		(205	)		602,288
Corporate bonds		187,326		21		(115	)		187,232
Certificates of deposit		24,381		—		—			24,381
Total cash, cash equivalents and investments	$	2,013,711	$	34	$	(320	)	$	2,013,425
As reported:
Cash and cash equivalents	$	1,233,891	$	2	$	(16	)	$	1,233,877
Short-term investments		779,820		32		(304	)		779,548
Total cash, cash equivalents and investments	$	2,013,711	$	34	$	(320	)	$	2,013,425


	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Cash and money market funds	$	2,115,869	$	—	$	—	$	2,115,869
Total cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869
As reported:
Cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869
Total cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869

ACCOUNTS RECEIVABLE AND RESERVES FOR PRODUCT SALES

3 Months Ended

Mar. 31, 2022

Receivables, Net, Current [Abstract]

ACCOUNTS RECEIVABLE AND RESERVES FOR PRODUCT SALES

. ACCOUNTS RECEIVABLE AND RESERVES FOR PRODUCT SALES

As of March 31, 2022 and December 31, 2021, the Company's accounts receivable were $178.2 million and $153.0 million, respectively, both of which were related to products sales receivable, net of discounts and allowances.

The following tables summarize an analysis of the change in reserves for discounts and allowances for each of the periods indicated:


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2021	$	799		$	60,506		$	2,798		$	6,363		$	70,466
Provision		2,437			24,140			2,950			9,211			38,738
Payments/credits		(2,906	)		(16,563	)		(2,645	)		(4,182	)		(26,296	)
Balance, as of March 31, 2022	$	330		$	68,083		$	3,103		$	11,392		$	82,908


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2020	$	2,281		$	41,771		$	1,949		$	4,969		$	50,970
Provision		2,085			14,907			1,844			3,191			22,027
Payments/credits		(3,969	)		(9,108	)		(1,432	)		(2,619	)		(17,128	)
Balance, as of March 31, 2021	$	397		$	47,570		$	2,361		$	5,541		$	55,869

The following table summarizes the total reserves included in the Company’s unaudited condensed consolidated balance sheets for the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Reduction to accounts receivable	$	13,935	$	8,321
Component of accrued expenses		68,973		62,145
Total reserves	$	82,908	$	70,466

INVENTORY

3 Months Ended

Mar. 31, 2022

Inventory Disclosure [Abstract]

INVENTORY

7. INVENTORY

The following table summarizes the components of the Company’s inventory for the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Raw materials	$	41,271	$	58,822
Work in progress		245,273		230,194
Finished goods		33,876		26,717
Total inventory	$	320,420	$	315,733

There were no material inventory reserves as of March 31, 2022 or December 31, 2021. Non-current inventory, which consists of raw materials and work in progress inventory, is included in other non-current assets in the Company's unaudited condensed consolidated balance sheets. Non-current inventory is anticipated to be consumed beyond our normal operating cycle.

The following table summarizes the balance sheet classification of the Company's inventory for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Balance sheet classification
Inventory	$	198,997	$	186,212
Other non-current assets		121,423		129,521
Total inventory	$	320,420	$	315,733

OTHER ASSETS

3 Months Ended

Mar. 31, 2022

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

OTHER ASSETS

8. OTHER ASSETS

The following table summarizes the Company’s other current assets for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Manufacturing-related deposits and prepaids	$	86,431	$	93,656
Collaboration receivable		17,722		18,647
Prepaid clinical and pre-clinical expenses		9,975		12,667
Prepaid maintenance services		9,312		8,452
Prepaid insurance		3,331		5,282
Prepaid research expenses		2,772		3,082
Prepaid commercial expenses		2,119		831
Interest receivable		1,285		8
Prepaid income tax		376		1,100
Other		7,008		5,303
Total other current assets	$	140,331	$	149,028

The following table summarizes the Company’s other non-current assets for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Non-current inventory	$	121,423	$	129,521
Manufacturing-related deposits and prepaids		108,363		112,765
Strategic investments		33,394		34,892
Restricted cash and investments		9,654		9,904
Prepaid clinical expenses		2,080		2,007
Other		3,735		3,860
Total other non-current assets	$	278,649	$	292,949

ACCRUED EXPENSES

3 Months Ended

Mar. 31, 2022

Payables and Accruals [Abstract]

ACCRUED EXPENSES

9. ACCRUED EXPENSES

The following table summarizes the Company’s accrued expenses for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Accrued contract manufacturing costs	$	138,179	$	104,311
Product revenue related reserves		68,973		62,145
Accrued clinical and pre-clinical costs		34,554		25,955
Accrued employee compensation costs		19,177		48,299
Accrued royalties		12,980		11,965
Accrued professional fees		10,644		9,381
Accrued interest expense		3,182		1,045
Accrued collaboration cost sharing		2,263		2,887
Other		3,956		5,709
Total accrued expenses	$	293,908	$	271,697

STOCK-BASED COMPENSATION

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

10. STOCK-BASED COMPENSATION

The following table summarizes the Company’s stock awards granted for each of the periods indicated:


	For the Three Months Ended March 31,
	2022				2021
	Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value
Stock options		1,291,537	$	46.99		1,359,637	$	49.35
Restricted stock units*		712,435	$	79.98		689,367	$	87.14

*Included in 2022 restricted stock units (“RSUs”) are 38,500 shares with performance conditions which are related to regulatory approval of certain of the Company's product candidates. As of March 31, 2022, none of the performance conditions are probable of being achieved. If the performance milestones are achieved within the required time frame, the Company may recognize up to $3.1 million of stock-based compensation related to these grants. Stock options and the remaining RSUs granted during the periods presented in the table have only service-based criteria and vest over four years.

Stock-based Compensation Expense

For the three months ended March 31, 2022 and 2021, total stock-based compensation expense was $29.2 million and $28.5 million, respectively. The following table summarizes stock-based compensation expense by function included within the unaudited condensed consolidated statements of operations and comprehensive loss:


		For the Three Months Ended March 31,
		2022		2021
	(in thousands)
Research and development		$	13,068	$	11,126
Selling, general and administrative			16,130		17,382
Total stock-based compensation expense		$	29,198	$	28,508

The following table summarizes stock-based compensation expense by grant type included within the unaudited condensed consolidated statements of operations and comprehensive loss:


		For the Three Months Ended March 31,
		2022		2021
	(in thousands)
Stock options		$	16,406	$	17,019
Restricted stock awards/units			11,365		9,931
Employee stock purchase plan			1,427		1,558
Total stock-based compensation expense		$	29,198	$	28,508

OTHER LOSS, NET

3 Months Ended

Mar. 31, 2022

Other Income and Expenses [Abstract]

OTHER LOSS, NET

11. OTHER LOSS, NET

The following table summarizes other loss, net for the periods indicated:


		For the Three Months Ended March 31,
		2022			2021
	(in thousands)
Interest expense		$	(15,796	)	$	(15,651	)
Interest income			173			59
Other expense (income), net			(1,642	)		64
Total other loss, net		$	(17,265	)	$	(15,528	)

NET LOSS PER SHARE

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

NET LOSS PER SHARE

12. NET LOSS PER SHARE

Basic net loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding. Diluted net loss per share is computed by dividing net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding. For both the three months ended March 31, 2022 and 2021, there were no differences between basic and diluted net loss per share since the effect of common stock equivalents would be anti-dilutive due to the net loss position and, therefore, would be excluded from the diluted net loss per share calculation.


		For the Three Months Ended March 31,
		2022			2021
	(in thousands, except per share amounts)
Net loss		$	(105,025	)	$	(167,250	)
Weighted-average common shares outstanding - basic			87,253			79,454
Effect of dilutive securities*			—			—
Weighted-average common shares outstanding - diluted			87,253			79,454
Net loss per share - basic and diluted		$	(1.20	)	$	(2.10	)

* For the three months ended March 31, 2022 and 2021, stock options, RSAs, RSUs, and ESPP to purchase 11.3 million and 10.3 million shares of the Company’s common stock, respectively, were excluded from the diluted net loss per share calculation as their effect would have been anti-dilutive. The Company accounts for the effect of its 2024 Notes on diluted net earnings per share (“EPS”) using the if-converted method as this obligation may be settled in cash or shares at the Company’s option. The effect of potential share settlement is included in the diluted EPS calculation if the effect is more dilutive. During the three months ended March 31, 2022 and March 31, 2021, respectively, the inclusion of the potential share settlement of the 2024 Notes was anti-dilutive. Accordingly, the potential conversion of 7,763,552 shares has been excluded from the computation of diluted net loss per share as of March 31, 2022 and March 31, 2021, respectively.

COMMITMENTS AND CONTINGENCIES

3 Months Ended

Mar. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

. COMMITMENTS AND CONTINGENCIES

Manufacturing Obligations

The following table summarizes the aggregate non-cancelable contractual obligations arising from the Company’s manufacturing obligations:


	As of March 31, 2022
	(in thousands)
2022 (April-December)	$	651,791
2023		248,256
2024		136,740
2025		100,296
2026		54,720
Thereafter		109,440
Total manufacturing commitments*	$	1,301,243

* Total manufacturing commitments includes the Catalent Inc. manufacturing and supply agreement, for which the Company has right of use assets and lease liabilities recorded on the unaudited condensed consolidated balance sheets as of March 31, 2022. For more information, please read Note 21, Commitments and Contingencies of the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.

Additionally, should the Company obtain regulatory approval for any drug product candidate produced as a part of the Company’s manufacturing obligations above, additional minimum batch requirements with the respective manufacturing parties would be required.

Litigation

In the normal course of business, the Company from time to time is named as a party to various legal claims, actions and complaints, which have included or may include matters involving securities, employment, intellectual property, arising from the use of therapeutics utilizing its technology, or others. We record a loss contingency reserve for a legal proceeding when we consider the potential loss probable and we can reasonably estimate the amount of the loss or determine a probable range of loss. We provide disclosure when we consider a loss reasonably possible or when we determine that a loss in excess of a reserve is reasonably possible. We provide an estimate of such reasonably possible losses or an aggregate range of such reasonably possible losses, unless we believe that such an estimate cannot be made. The Company has not recorded any material accruals for loss contingencies and in management's opinion no material range of loss is estimable for the matters described below as of March 31, 2022.

On September 15, 2020, REGENXBIO INC. (“RegenX”) and the Trustees of the University of Pennsylvania filed a lawsuit against the Company and Sarepta Therapeutics Three, LLC (together, “Sarepta”), in the U.S. District Court for the District of Delaware. The plaintiffs assert patent infringement of U.S. Patent No. 10,526,617 (“the ‘617 Patent”) under 35 U.S.C.§§ 271(a)-(c) based on Sarepta’s alleged direct or indirect manufacture and use of the patented cultured host cell technology allegedly used to make adeno-associated virus (“AAV”) gene therapy products, including SRP-9001. Specifically, the Complaint essentially includes the allegation that Sarepta’s use, and the use by its contract manufacturers on its behalf, of a host cell containing a recombinant acid molecule that encodes a capsid protein having at least 95% amino acid identity to AAVrh10 infringes upon the ‘617 Patent asserted by RegenX. Plaintiffs seek injunctive relief, a judgment of infringement and willful infringement, an unspecified amount of damages that is no less than a reasonable royalty (treble damages), attorneys’ fees and costs, and such other relief as the court deems just and proper. On January 4, 2022, the Court denied Sarepta’s motion to dismiss the case pursuant to Federal Rule of Civil Procedure 12(b)(6) based on the Safe Harbor provision of non-infringement contained in 35 U.S.C. § 271(e)(1). Sarepta answered the Complaint on January 18, 2022, and a case schedule has been set with a trial commencing on January 29, 2024.

On July 13, 2021, Nippon Shinyaku Co., Ltd. (“Nippon Shinyaku” or “NS”) filed a lawsuit against the Company in the U.S. District Court for the District of Delaware. NS asserts a claim for breach of contract arising from Sarepta filing seven petitions for Inter Partes Review (“IPR Petitions”) with the Patent Trial and Appeal Board at the USPTO (PTAB Case Nos. IPR2021-01134, IPR2021-01135, IPR2021-01136, IPR2021-01137, IPR2021-01138, IPR2021-01139, IPR2021-01140) in which Sarepta is seeking to invalidate certain NS patents concerning exon 53 skipping technology (U.S. Patent Nos. 9,708,361, 10,385,092, 10,407,461, 10,487,106, 10,647,741, 10,662,217, and 10,683,322, respectively, and collectively the “NS Patents”). In addition, NS asserts claims for patent infringement and willful infringement of each of the NS Patents arising from Sarepta’s alleged activities concerning, including the sale of, its exon 53 skipping product, VYONDYS 53 (golodirsen). NS further seeks a determination of non-infringement by NS arising from NS’s alleged activities concerning, including the sale of, its exon 53 skipping product, Viltepso (viltolarsen) and invalidity of certain patents licensed to the Company from University of Western Australia (“UWA”) (U.S. Patent Nos. 9,994,851, 10,227,590, and 10,266,827, collectively the “UWA Patents”). NS is seeking legal fees and costs, an unspecified amount of monetary relief (treble damages) attributed to Sarepta’s alleged infringement, and such other relief as the court deems just and proper. NS filed a motion for preliminary injunction solely seeking Sarepta’s withdrawal of the IPR Petitions. The district court denied NS’ motion for preliminary injunction on September 24, 2021, and the U.S. Court of Appeals for the Federal Circuit reversed and remanded the district court on February 8, 2022. In January 2022, the PTAB granted institution of all claims of all NS Patents in response to Sarepta’s IPR Petitions and determined that Sarepta has demonstrated a reasonable likelihood of success in proving that the NS Patents are unpatentable. On December 27, 2021, the district court partially granted and denied the motion to dismiss by Sarepta and ordered NS to file a Second Amended Complaint (“SAC”), which it did on January 14, 2022. In the SAC, NS maintains all claims of the original complaint of July 13, 2021, except a determination of non-infringement of the UWA Patents. On January 28, 2022, Sarepta filed its answer to the SAC, with defenses and counterclaims against NS and NS Pharma Inc. that include infringement of the UWA Patents arising from their alleged activities concerning, including the sale of, its exon 53 skipping product, Viltepso (viltolarsen) and breach of contract. Sarepta is also seeking a determination of invalidity of the NS Patents. Sarepta is seeking an award of relief in its defenses to NS’ allegations, a judgment of breach of contract, a determination of invalidity of the NS Patents, a judgment of infringement and willful infringement of the UWA Patents, legal fees and costs, an unspecified amount of monetary relief (treble damages) attributed to NS’ alleged infringement, and such other relief as the court deems just and proper. Case scheduling in district court, including a trial date, will follow.

SUBSEQUENT EVENTS

3 Months Ended

Mar. 31, 2022

Subsequent Events [Abstract]

SUBSEQUENT EVENTS

14. SUBSEQUENT EVENTS

In June 2017, the Company granted its CEO 3,300,000 options with service and market conditions. These options have a five-year cliff vesting schedule. On April 19, 2022 (the “Effective Date”), the Company entered into an agreement with its CEO to modify the vesting conditions of the options. Under the agreement, one-third of the options vested on the Effective Date. Subject to the CEO’s continued service through each applicable vesting date and the compound annual growth rate (“CAGR”) of the Company's common stock exceeding that of the Nasdaq Biotech Index in varying percentages, the remaining two-thirds of the options shall vest in varying increments at any time between the Effective Date and June 26, 2025 (the “Measurement Period”) when (and if) the average of the closing price of the Company’s common stock during any consecutive 20 trading day period during the Measurement Period reaches certain pre-determined target stock prices. Additionally, the CEO is subject to a one-year post-exercise restriction to

sell, transfer or dispose shares acquired upon the exercise of the options after deduction of any shares withheld or sold to pay the applicable aggregate exercise price and/or withholding taxes. The Company is currently evaluating the impact that this modification will have on the consolidated financial statements. However, it expects that the modification will result in a significant increase in the Company’s stock-based compensation expense beginning on the Effective Date.

On April 22, 2022, the Company entered into a lease agreement for a 288,000 square feet research and development and manufacturing facility in Bedford, Massachusetts. Rent payments due over the 15-year term of the lease aggregate to $307.4 million. The Company has not yet completed its assessment of the lease agreement but expects the impact to result in a material increase to the Company's annual lease costs and recorded balances of right of use assets and lease liabilities.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”), reflect the accounts of the Company and its wholly-owned subsidiaries. All intercompany transactions between and among its consolidated subsidiaries have been eliminated. Management has determined that the Company operates in one segment: discovering, developing, manufacturing and delivering therapies to patients with rare diseases. In the opinion of the Company’s management, all adjustments of a normal recurring nature necessary for a fair presentation have been reflected. 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. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes for the year ended December 31, 2021 which are contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, filed with the U.S. Securities and Exchange Commission on March 1, 2022. The results for the three months ended March 31, 2022 are not necessarily indicative of the results to be expected for the full year.
Estimates and Uncertainties	Estimates and Uncertainties The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of accounts receivable from customers, cash held at financial institutions and cash equivalents and investments. As of March 31, 2022, the majority of the Company’s accounts receivable arose from product sales in the U.S. and all customers have standard payment terms that generally require payment within 60 to 91 days. Outside of the U.S., the majority of the Company’s customers have payment terms ranging between 45 and 150 days. Three individual customers accounted for 48%, 36% and 8% of net product revenues for the three months ended March 31, 2022 and 49%, 40% and 7% of net product revenues for the three months ended March 31, 2021. Three individual customers accounted for 41%, 39% and 8% of accounts receivable from product sales as of March 31, 2022 and 41%, 41% and 10% of accounts receivable from product sales as of December 31, 2021. The Company monitors the financial performance and creditworthiness of its customers so that it can properly assess and respond to changes in its customers’ credit profile. As of March 31, 2022, the Company believes that such customers are of high credit quality. As of March 31, 2022, the Company’s cash was concentrated at three financial institutions in the U.S., which potentially exposes the Company to credit risks. However, the Company does not believe that there is significant risk of non-performance by the financial institutions. The Company also purchases commercial paper, government and government agency bonds, corporate bonds and certificates of deposit issued by highly rated corporations, financial institutions and governments and limits the amount of credit exposure to any one issuer. These amounts may at times exceed federally insured limits. The Company has not experienced any credit losses related to these financial instruments and does not believe to be exposed to any significant credit risk related to these instruments.
Significant Accounting Policies	Significant Accounting Policies For details about the Company’s accounting policies, please read Note 2, Summary of Significant Accounting Policies and Recent Accounting Pronouncements of the Annual Report on Form 10-K for the year ended December 31, 2021. There have not been any material changes to the Company’s accounting policies through March 31, 2022.

FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured and Carried at Fair Value

The tables below present information about the Company’s financial assets and liabilities that are measured and carried at fair value and indicate the level within the fair value hierarchy of valuation techniques it utilizes to determine such fair value:


	Fair Value Measurement as of March 31, 2022
	Total		Level 1		Level 2		Level 3
	(in thousands)
Assets
Money market funds	$	606,498	$	606,498	$	—	$	—
Commercial paper		145,335		—		145,335		—
Government and government agency bonds		602,288		54,856		547,432		—
Corporate bonds		187,232		—		187,232		—
Strategic equity investments		33,394		982		—		32,412
Certificates of deposit		24,381		—		24,381		—
Total assets	$	1,599,128	$	662,336	$	904,380	$	32,412

Liabilities
Contingent consideration	$	43,600	$	—	$	—	$	43,600
Total liabilities	$	43,600	$	—	$	—	$	43,600


	Fair Value Measurement as of December 31, 2021
	Total		Level 1		Level 2		Level 3
	(in thousands)
Assets
Money market funds	$	1,562,358	$	1,562,358	$	—	$	—
Strategic equity investments		34,892		2,480		—		32,412
Certificates of deposit		250		250		—		—
Total assets	$	1,597,500	$	1,565,088	$	—	$	32,412

Liabilities
Contingent consideration	$	43,600	$	—	$	—	$	43,600
Total liabilities	$	43,600	$	—	$	—	$	43,600

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES (Tables)

3 Months Ended

Mar. 31, 2022

Cash and Cash Equivalents [Abstract]

Summary of Company Financial Assets with Maturities of Less Than 90 Days Included in Cash Equivalents


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Money market funds	$	606,498	$	1,562,358
Commercial paper		17,772		—
Government and government agency bonds		132,059		—
Corporate bonds		29,857		—
Total	$	786,186	$	1,562,358

Summary of Company Cash, Cash Equivalents and Short-Term Investments

The following tables summarize the Company’s cash, cash equivalents and short-term investments as of the periods indicated:


	As of March 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Cash and money market funds	$	1,054,189	$	—	$	—		$	1,054,189
Commercial paper		145,335		—		—			145,335
Government and government agency bonds		602,480		13		(205	)		602,288
Corporate bonds		187,326		21		(115	)		187,232
Certificates of deposit		24,381		—		—			24,381
Total cash, cash equivalents and investments	$	2,013,711	$	34	$	(320	)	$	2,013,425
As reported:
Cash and cash equivalents	$	1,233,891	$	2	$	(16	)	$	1,233,877
Short-term investments		779,820		32		(304	)		779,548
Total cash, cash equivalents and investments	$	2,013,711	$	34	$	(320	)	$	2,013,425


	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(in thousands)
Cash and money market funds	$	2,115,869	$	—	$	—	$	2,115,869
Total cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869
As reported:
Cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869
Total cash and cash equivalents	$	2,115,869	$	—	$	—	$	2,115,869

ACCOUNTS RECEIVABLE AND RESERVES FOR PRODUCT SALES (Tables)

3 Months Ended

Mar. 31, 2022

Receivables, Net, Current [Abstract]

Summary of Change in Reserves for Discounts and Allowances

The following tables summarize an analysis of the change in reserves for discounts and allowances for each of the periods indicated:


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2021	$	799		$	60,506		$	2,798		$	6,363		$	70,466
Provision		2,437			24,140			2,950			9,211			38,738
Payments/credits		(2,906	)		(16,563	)		(2,645	)		(4,182	)		(26,296	)
Balance, as of March 31, 2022	$	330		$	68,083		$	3,103		$	11,392		$	82,908


	Chargebacks			Rebates			Prompt Pay			Other Accruals			Total
	(in thousands)
Balance, as of December 31, 2020	$	2,281		$	41,771		$	1,949		$	4,969		$	50,970
Provision		2,085			14,907			1,844			3,191			22,027
Payments/credits		(3,969	)		(9,108	)		(1,432	)		(2,619	)		(17,128	)
Balance, as of March 31, 2021	$	397		$	47,570		$	2,361		$	5,541		$	55,869

Summary of Total Reserves Included in Consolidated Balance Sheets

The following table summarizes the total reserves included in the Company’s unaudited condensed consolidated balance sheets for the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Reduction to accounts receivable	$	13,935	$	8,321
Component of accrued expenses		68,973		62,145
Total reserves	$	82,908	$	70,466

INVENTORY (Tables)

3 Months Ended

Mar. 31, 2022

Inventory Disclosure [Abstract]

Summary of Components of Inventory

The following table summarizes the components of the Company’s inventory for the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Raw materials	$	41,271	$	58,822
Work in progress		245,273		230,194
Finished goods		33,876		26,717
Total inventory	$	320,420	$	315,733

Summary Of Inventory Balance Sheet Classification

The following table summarizes the balance sheet classification of the Company's inventory for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Balance sheet classification
Inventory	$	198,997	$	186,212
Other non-current assets		121,423		129,521
Total inventory	$	320,420	$	315,733

OTHER ASSETS (Tables)

3 Months Ended

Mar. 31, 2022

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Summary of Other Current Assets

The following table summarizes the Company’s other current assets for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Manufacturing-related deposits and prepaids	$	86,431	$	93,656
Collaboration receivable		17,722		18,647
Prepaid clinical and pre-clinical expenses		9,975		12,667
Prepaid maintenance services		9,312		8,452
Prepaid insurance		3,331		5,282
Prepaid research expenses		2,772		3,082
Prepaid commercial expenses		2,119		831
Interest receivable		1,285		8
Prepaid income tax		376		1,100
Other		7,008		5,303
Total other current assets	$	140,331	$	149,028

Summary of Other Non-current Assets

The following table summarizes the Company’s other non-current assets for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Non-current inventory	$	121,423	$	129,521
Manufacturing-related deposits and prepaids		108,363		112,765
Strategic investments		33,394		34,892
Restricted cash and investments		9,654		9,904
Prepaid clinical expenses		2,080		2,007
Other		3,735		3,860
Total other non-current assets	$	278,649	$	292,949

ACCRUED EXPENSES (Tables)

3 Months Ended

Mar. 31, 2022

Payables and Accruals [Abstract]

Summary of Accrued Expenses

The following table summarizes the Company’s accrued expenses for each of the periods indicated:


	As of March 31, 2022		As of December 31, 2021
	(in thousands)
Accrued contract manufacturing costs	$	138,179	$	104,311
Product revenue related reserves		68,973		62,145
Accrued clinical and pre-clinical costs		34,554		25,955
Accrued employee compensation costs		19,177		48,299
Accrued royalties		12,980		11,965
Accrued professional fees		10,644		9,381
Accrued interest expense		3,182		1,045
Accrued collaboration cost sharing		2,263		2,887
Other		3,956		5,709
Total accrued expenses	$	293,908	$	271,697

STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Summary of Stock Awards Granted

The following table summarizes the Company’s stock awards granted for each of the periods indicated:


	For the Three Months Ended March 31,
	2022				2021
	Grants		Weighted Average Grant Date Fair Value		Grants		Weighted Average Grant Date Fair Value
Stock options		1,291,537	$	46.99		1,359,637	$	49.35
Restricted stock units*		712,435	$	79.98		689,367	$	87.14

Summary of Stock-Based Compensation Expense by Function Included within Condensed Consolidated Statements of Operations and Comprehensive Loss

The following table summarizes stock-based compensation expense by function included within the unaudited condensed consolidated statements of operations and comprehensive loss:


		For the Three Months Ended March 31,
		2022		2021
	(in thousands)
Research and development		$	13,068	$	11,126
Selling, general and administrative			16,130		17,382
Total stock-based compensation expense		$	29,198	$	28,508

Summary of Stock-Based Compensation Expense by Grant Type Included within Consolidated Statements of Operations and Comprehensive Loss

The following table summarizes stock-based compensation expense by grant type included within the unaudited condensed consolidated statements of operations and comprehensive loss:


		For the Three Months Ended March 31,
		2022		2021
	(in thousands)
Stock options		$	16,406	$	17,019
Restricted stock awards/units			11,365		9,931
Employee stock purchase plan			1,427		1,558
Total stock-based compensation expense		$	29,198	$	28,508

OTHER LOSS, NET (Tables)

3 Months Ended

Mar. 31, 2022

Other Income and Expenses [Abstract]

Summary of Other Loss

The following table summarizes other loss, net for the periods indicated:


		For the Three Months Ended March 31,
		2022			2021
	(in thousands)
Interest expense		$	(15,796	)	$	(15,651	)
Interest income			173			59
Other expense (income), net			(1,642	)		64
Total other loss, net		$	(17,265	)	$	(15,528	)

NET LOSS PER SHARE (Tables)

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Basic and Diluted Net Loss Per Share

For both the three months ended March 31, 2022 and 2021, there were no differences between basic and diluted net loss per share since the effect of common stock equivalents would be anti-dilutive due to the net loss position and, therefore, would be excluded from the diluted net loss per share calculation.


		For the Three Months Ended March 31,
		2022			2021
	(in thousands, except per share amounts)
Net loss		$	(105,025	)	$	(167,250	)
Weighted-average common shares outstanding - basic			87,253			79,454
Effect of dilutive securities*			—			—
Weighted-average common shares outstanding - diluted			87,253			79,454
Net loss per share - basic and diluted		$	(1.20	)	$	(2.10	)

COMMITMENTS AND CONTINGENCIES (Tables)

3 Months Ended

Mar. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

Summary of Aggregate Non-Cancelable Contractual Obligations Arising from Manufacturing Obligations

The following table summarizes the aggregate non-cancelable contractual obligations arising from the Company’s manufacturing obligations:


	As of March 31, 2022
	(in thousands)
2022 (April-December)	$	651,791
2023		248,256
2024		136,740
2025		100,296
2026		54,720
Thereafter		109,440
Total manufacturing commitments*	$	1,301,243

Organization and Nature of Business - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and investments	$ 2,023,100
Cash and cash equivalents	1,233,877	$ 2,115,869	$ 1,481,836
Short-term investments	779,548	0
Restricted cash and investments	$ 9,654	$ 9,904

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($) Segment	Mar. 31, 2021 USD ($)	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments \| Segment	1
Net loss \| $	$ (105,025)	$ (167,250)
Outside of U.S. [Member] \| Product Revenues [Member] \| Customer One [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	48.00%	49.00%
Outside of U.S. [Member] \| Product Revenues [Member] \| Customer Two [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	36.00%	40.00%
Outside of U.S. [Member] \| Product Revenues [Member] \| Customer Three [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	8.00%	7.00%
Outside of U.S. [Member] \| Accounts Receivable [Member] \| Customer One [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	41.00%		41.00%
Outside of U.S. [Member] \| Accounts Receivable [Member] \| Customer Two [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	39.00%		41.00%
Outside of U.S. [Member] \| Accounts Receivable [Member] \| Customer Three [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration of credit risk percentage	8.00%		10.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable payment term	60 days
Minimum [Member] \| Outside of U.S. [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable payment term	45 days
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable payment term	91 days
Maximum [Member] \| Outside of U.S. [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable payment term	150 days

License and Collaboration Agreements - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Product revenues, net	$ 188,825	$ 124,926
Settlement charge	0	10,000
Collaborative Arrangement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment for option exercise	187,100
Stock options exercised or expired			0
Development Milestone and Upfront Fee Recognized as Research and Development Expense	100	14,000
Collaborative Arrangement \| Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent research milestone payments	11,000
Development Milestone and Settlement Upfront Fee Recognized as Research and Development Expense	4,000,000
Collaborative Arrangement \| Roche Holding A.G. [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Product revenues, net	22,000	22,000
Deferred Revenue	641,500
Deferred Revenue, Current	89,200
Deferred Revenue Separate Material Options Right	485,000			$ 485,000
Research and development expense	17,700	$ 13,400
Collaboration Receivable	$ 17,700

Assets and Liabilities Measured and Carried at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 1,599,128	$ 1,597,500
Contingent consideration	43,600	43,600
Total liabilities	43,600	43,600
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	606,498	1,562,358
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	145,335
Government and Government Agency Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	602,288
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	187,232
Strategic Equity Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	33,394	34,892
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	24,381	250
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	662,336	1,565,088
Level 1 [Member] \| Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	606,498	1,562,358
Level 1 [Member] \| Government and Government Agency Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	54,856
Level 1 [Member] \| Strategic Equity Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	982	2,480
Level 1 [Member] \| Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		250
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	904,380
Level 2 [Member] \| Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	145,335
Level 2 [Member] \| Government and Government Agency Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	547,432
Level 2 [Member] \| Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	187,232
Level 2 [Member] \| Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	24,381
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	32,412	32,412
Contingent consideration	43,600	43,600
Total liabilities	43,600	43,600
Level 3 [Member] \| Strategic Equity Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 32,412	$ 32,412

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
2024 Convertible Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument Fair Value	$ 749.3	$ 846.1
Net carrying value	564.2	563.7
2019 Term Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument Fair Value	569.4	576.1
Net carrying value	$ 534.6	$ 533.2

- Definition

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

+ References + Details

Summary of Company Financial Assets with Maturities of Less Than 90 Days Included in Cash Equivalents (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash equivalents	$ 786,186	$ 1,562,358
Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash equivalents	606,498	1,562,358
Commercial Paper [Member]
Cash and Cash Equivalents [Line Items]
Cash equivalents	17,772
Government and Government Agency Bonds [Member]
Cash and Cash Equivalents [Line Items]
Cash equivalents	132,059
Corporate Bond [Member]
Cash and Cash Equivalents [Line Items]
Cash equivalents	$ 29,857

Cash, Cash Equivalents and Marketable Securities - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Weighted average maturity period of available-for-sale securities	4 months
Available for sale debt securities current, Fair value	$ 779,548	$ 0

Summary of Company Cash, Cash Equivalents and Short-term Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	$ 2,013,711
Cash and cash equivalents, Gross unrealized gains	2
Cash and cash equivalents, Gross unrealized losses	(16)
Cash and cash equivalents	1,233,877	$ 2,115,869	$ 1,481,836
Cash, cash equivalents and investments, Amortized cost	1,233,891	2,115,869
Cash, cash equivalents and investments, Gross unrealized gains	34
Cash, cash equivalents and investments, Gross unrealized losses	(320)
Cash, cash equivalents and investments, Fair value	2,013,425	2,115,869
Available for sale debt securities current, Amortized cost	779,820
Available for sale debt securities current, Gross unrealized gains	32
Available for sale debt securities current, Gross unrealized losses	(304)
Available for sale debt securities current, Fair value	779,548	0
Cash and Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, Amortized cost	1,054,189	2,115,869
Cash and cash equivalents	1,054,189	2,115,869
Commercial Paper [Member]
Cash and Cash Equivalents [Line Items]
Available for sale debt securities, Fair value	145,335
Cash and cash equivalents, Amortized cost	145,335
Government and Government Agency Bonds [Member]
Cash and Cash Equivalents [Line Items]
Available for sale debt securities, Gross unrealized gains	13
Available for sale debt securities, Gross unrealized losses	(205)
Available for sale debt securities, Fair value	602,288
Cash and cash equivalents, Amortized cost	602,480
Cash, cash equivalents and investments, Fair value		$ 2,115,869
Corporate Bond [Member]
Cash and Cash Equivalents [Line Items]
Available for sale debt securities, Gross unrealized gains	21
Available for sale debt securities, Gross unrealized losses	(115)
Available for sale debt securities, Fair value	187,232
Cash and cash equivalents, Amortized cost	187,326
Certificates of Deposit [Member]
Cash and Cash Equivalents [Line Items]
Available for sale debt securities, Fair value	24,381
Cash and cash equivalents, Amortized cost	$ 24,381

Accounts Receivable and Reserves for Product Sales (Additional Information) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Receivables, Net, Current [Abstract]
Product sales receivable, net of discounts and allowances	$ 178.2	$ 153.0

Summary of Change in Reserves for Discounts and Allowances (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	$ 70,466	$ 50,970
Provision	38,738	22,027
Payments/credits	(26,296)	(17,128)
Ending balance	82,908	55,869
Chargebacks [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	799	2,281
Provision	2,437	2,085
Payments/credits	(2,906)	(3,969)
Ending balance	330	397
Rebates [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	60,506	41,771
Provision	24,140	14,907
Payments/credits	(16,563)	(9,108)
Ending balance	68,083	47,570
Prompt Pay [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	2,798	1,949
Provision	2,950	1,844
Payments/credits	(2,645)	(1,432)
Ending balance	3,103	2,361
Other Accruals [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	6,363	4,969
Provision	9,211	3,191
Payments/credits	(4,182)	(2,619)
Ending balance	$ 11,392	$ 5,541

Summary of Total Reserves Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Receivables, Net, Current [Abstract]
Reduction to accounts receivable	$ 13,935	$ 8,321
Component of accrued expenses	68,973	62,145
Total reserves	$ 82,908	$ 70,466	$ 55,869	$ 50,970

Inventory - Summary of Components of Inventory (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 41,271	$ 58,822
Work in progress	245,273	230,194
Finished goods	33,876	26,717
Total inventory	$ 320,420	$ 315,733

Inventory - Summarizes The Balance Sheet Classification (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Inventory	$ 198,997	$ 186,212
Other non-current assets	121,423	129,521
Total inventory	$ 320,420	$ 315,733

Summary of Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense and Other Assets, Current [Abstract]
Manufacturing-related deposits and prepaids	$ 86,431	$ 93,656
Collaboration receivable	17,722	18,647
Prepaid clinical and pre-clinical expenses	9,975	12,667
Prepaid maintenance services	9,312	8,452
Prepaid insurance	3,331	5,282
Prepaid research expenses	2,772	3,082
Prepaid commercial expenses	2,119	831
Interest receivable	1,285	8
Prepaid income tax	376	1,100
Other	7,008	5,303
Total other current assets	$ 140,331	$ 149,028

Summary of Other Non-current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Prepaid Expense and Other Assets, Noncurrent [Abstract]
Non-current inventory	$ 121,423	$ 129,521
Manufacturing-related deposits and prepaids	108,363	112,765
Strategic investments	33,394	34,892
Restricted cash and investments	9,654	9,904
Prepaid clinical expenses	2,080	2,007
Other	3,735	3,860
Total other non-current assets	$ 278,649	$ 292,949

Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued contract manufacturing costs	$ 138,179	$ 104,311
Product revenue related reserves	68,973	62,145
Accrued clinical and pre-clinical costs	34,554	25,955
Accrued employee compensation costs	19,177	48,299
Accrued royalties	12,980	11,965
Accrued professional fees	10,644	9,381
Accrued interest expense	3,182	1,045
Accrued collaboration cost sharing	2,263	2,887
Other	3,956	5,709
Total accrued expenses	$ 293,908	$ 271,697

Indebtedness - Additional Information (Detail) $ in Millions	Nov. 14, 2017	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Debt instrument, conversion rate	0.013621
2024 Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Fair Value		$ 749.3	$ 846.1

Indebtedness - Summary of Debt Facilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total carrying value of debt facilities	$ 1,098,847	$ 1,096,876
2024 Convertible Notes [Member]
Debt Instrument [Line Items]
Net carrying value	564,200	563,700
2019 Term Loan [Member]
Debt Instrument [Line Items]
Net carrying value	$ 534,600	$ 533,200

- Definition

+ References + Details

Summary of Stock Awards Granted (Detail) - $ / shares

1 Months Ended

3 Months Ended

Jun. 30, 2017

Mar. 31, 2022

Mar. 31, 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Grants, Stock options

3,300,000

Stock Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Grants, Stock options

1,291,537

1,359,637

Weighted Average Grant Date Fair Value, Stock options

$ 46.99

$ 49.35

Restricted Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Grants, Stock options

38,500

Grants, Restricted stock units and awards

^[1]

712,435

689,367

Weighted Average Grant Date Fair Value, Restricted stock units and awards

^[1]

$ 79.98

$ 87.14

[1]

Included in 2022 restricted stock units (“RSUs”) are 38,500 shares with performance conditions which are related to regulatory approval of certain of the Company's product candidates. As of March 31, 2022, none of the performance conditions are probable of being achieved. If the performance milestones are achieved within the required time frame, the Company may recognize up to $3.1 million of stock-based compensation related to these grants. Stock options and the remaining RSUs granted during the periods presented in the table have only service-based criteria and vest over four years.

Summary of Stock Awards Granted (Parenthetical) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2017	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options	3,300,000
Stock-based compensation Grants		$ 3.1
Share based compensation granted under plan vest period	5 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options		1,291,537	1,359,637
Share based compensation granted under plan vest period		4 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options		38,500
Share based compensation granted under plan vest period		4 years

Stock Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Stock-based compensation expense	$ 29,198	$ 28,508

Summary of Stock-Based Compensation Expense by Function Included within Condensed Consolidated Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 29,198	$ 28,508
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	13,068	11,126
Selling, General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 16,130	$ 17,382

Summary of Stock-Based Compensation Expense by Grant Type Included within Condensed Consolidated Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 29,198	$ 28,508
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	16,406	17,019
Restricted Stock Awards/Units (RSAs/RSUs) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	11,365	9,931
Employee Stock Purchase Plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 1,427	$ 1,558

Summary of Other Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
Summary of Other Loss (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2021
Nonoperating Income (Expense) [Abstract]
Interest expense	$ (15,796)	$ (15,651)
Interest income	173	59
Other expense (income), net	(1,642)	64
Total other loss, net	$ (17,265)	$ (15,528)

Basic and Diluted Net Loss Per Share (Detail) - USD ($)
$ / shares in Units, $ in Thousands

3 Months Ended

Mar. 31, 2022

Mar. 31, 2021

Earnings Per Share [Abstract]

Net loss

$ (105,025)

$ (167,250)

Weighted-average common shares outstanding - basic

87,253

79,454

Effect of dilutive securities*

^[1]

Weighted-average common shares outstanding - diluted

87,253

79,454

Net loss per share - basic and diluted

$ (1.20)

$ (2.10)

[1]

For the three months ended March 31, 2022 and 2021, stock options, RSAs, RSUs, and ESPP to purchase 11.3 million and 10.3 million shares of the Company’s common stock, respectively, were excluded from the diluted net loss per share calculation as their effect would have been anti-dilutive. The Company accounts for the effect of its 2024 Notes on diluted net earnings per share (“EPS”) using the if-converted method as this obligation may be settled in cash or shares at the Company’s option. The effect of potential share settlement is included in the diluted EPS calculation if the effect is more dilutive. During the three months ended March 31, 2022 and March 31, 2021, respectively, the inclusion of the potential share settlement of the 2024 Notes was anti-dilutive. Accordingly, the potential conversion of 7,763,552 shares has been excluded from the computation of diluted net loss per share as of March 31, 2022 and March 31, 2021, respectively.

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
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+ Details

Basic and Diluted Net Loss Per Share (Parenthetical) (Detail) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share	11,300,000	10,300,000
2024 Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of shares excluded from computation of diluted EPS	7,763,552

Summary of Aggregate Non-Cancelable Contractual Obligations Arising from Manufacturing Obligations (Detail) - Manufacturing Commitments Agreement [Member] - Catalent and Thermo [Member]
$ in Thousands

Mar. 31, 2022

USD ($)

Commitments And Contingencies [Line Items]

2022 (April - December)

$ 651,791

248,256

136,740

100,296

54,720

109,440

Total manufacturing commitments

$ 1,301,243

^[1]

[1]

Total manufacturing commitments includes the Catalent Inc. manufacturing and supply agreement, for which the Company has right of use assets and lease liabilities recorded on the unaudited condensed consolidated balance sheets as of March 31, 2022. For more information, please read Note 21, Commitments and Contingencies of the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.

Subsequent Events - Additional Information (Details) $ in Millions		1 Months Ended	38 Months Ended
	Apr. 22, 2022 USD ($) ft²	Jun. 30, 2017 shares	Jun. 26, 2025 Days
Subsequent Event [Line Items]
Stock options granted to CEO \| shares		3,300,000
Share based compensation granted under plan vest period		5 years
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of trading days \| Days			20
Accrued rent payment term	15 years
Future rent payment due \| $	$ 307.4
Subsequent Event [Member] \| Bedford, Massachusetts [Member]
Subsequent Event [Line Items]
Area of a facility used for research and development \| ft²	288,000