Agios Pharmaceuticals (AGIO) 10-Q 29 Apr 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 23, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-36014
Entity Registrant Name	AGIOS PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-0662915
Entity Address, Address Line One	88 Sidney Street
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	649-8600
Title of 12(b) Security	Common Stock, Par Value $0.001 per share
Trading Symbol	AGIO
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		69,937,607
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Central Index Key	0001439222
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,888,025	$ 127,436
Marketable securities	447,578	445,493
Prepaid expenses and other current assets	19,511	15,889
Current assets of discontinued operations	0	47,859
Total current assets	2,355,114	636,677
Marketable securities	21,598	97,608
Operating lease assets	82,244	84,661
Property and equipment, net	28,976	30,815
Financing lease assets	502	590
Non-current assets of discontinued operations	0	2,601
Total assets	2,488,434	852,952
Current liabilities:
Accounts payable	51,224	17,724
Accrued expenses	23,601	30,801
Operating lease liabilities	7,988	7,093
Financing lease liabilities	321	317
Income tax payable	13,370	0
Current liabilities of discontinued operations	0	38,459
Total current liabilities	96,504	94,394
Operating lease liabilities, net of current portion	95,052	97,458
Financing lease liabilities, net of current portion	248	331
Non-current liabilities of discontinued operations	0	261,269
Total liabilities	191,804	453,452
Stockholders’ equity:
Preferred stock, $0.001 par value; 25,000,000 shares authorized; no shares issued or outstanding at March 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value; 125,000,000 shares authorized; 69,812,205 and 69,293,920 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	70	69
Additional paid-in capital	2,265,713	2,242,801
Accumulated other comprehensive (loss) income	(3)	105
Retained earnings (Accumulated deficit)	30,850	(1,843,475)
Total stockholders’ equity	2,296,630	399,500
Total liabilities and stockholders’ equity	$ 2,488,434	$ 852,952

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	125,000,000	125,000,000
Common stock, shares issued (in shares)	69,812,205	69,293,920
Common stock, shares outstanding (in shares)	69,812,205	69,293,920

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cost and expenses:
Research and development	$ 57,667	$ 55,358
Selling, general and administrative	33,550	31,672
Total cost and expenses	91,217	87,030
Loss from operations	(91,217)	(87,030)
Interest income, net	340	2,936
Net loss from continuing operations	(90,877)	(84,094)
Net income from discontinued operations, net of tax	1,965,202	43,838
Net income (loss)	$ 1,874,325	$ (40,256)
Net loss from continuing operations per share - basic (in usd per share)	$ (1.31)	$ (1.23)
Net loss from continuing operations per share - diluted (in usd per share)	(1.31)	(1.23)
Net income from discontinued operations per share - basic (in usd per share)	28.26	0.64
Net income from discontinued operations per share - diluted (in usd per share)	28.26	0.64
Net income (loss) per share - basic (in usd per share)	26.95	(0.59)
Net income (loss) per share - diluted (in usd per share)	$ 26.95	$ (0.59)
Weighted-average number of common shares used in computing net income (loss) per share from continuing operations and discontinued operations and net income (loss) per share basic (in shares)	69,543,510	68,608,279
Weighted-average number of common shares used in computing net income (loss) per share from continuing operations and discontinued operations and net income (loss) per share – diluted (in shares)	69,543,510	68,608,279

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,874,325	$ (40,256)
Other comprehensive loss
Unrealized loss on available-for-sale securities	(108)	(128)
Comprehensive income (loss)	$ 1,874,217	$ (40,384)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		68,401,105
Beginning balance at Dec. 31, 2019	$ 640,528	$ 68	$ 2,156,363	$ 202	$ (1,516,105)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under stock incentive plan and ESPP (in shares)		388,820
Common stock issued under stock incentive plan and ESPP	5,465	$ 1	5,464
Stock-based compensation expense	15,670		15,670
Other comprehensive loss	(128)			(128)
Net income (loss)	(40,256)				(40,256)
Disposition of oncology business	4,020		4,020
Ending balance (in shares) at Mar. 31, 2020		68,789,925
Ending balance at Mar. 31, 2020	625,299	$ 69	2,181,517	74	(1,556,361)
Beginning balance (in shares) at Dec. 31, 2020		69,293,920
Beginning balance at Dec. 31, 2020	$ 399,500	$ 69	2,242,801	105	(1,843,475)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under stock incentive plan and ESPP (in shares)	122,422	518,285
Common stock issued under stock incentive plan and ESPP	$ 7,347	$ 1	7,346
Stock-based compensation expense	14,854		14,854
Other comprehensive loss	(108)			(108)
Net income (loss)	1,874,325				1,874,325
Disposition of oncology business	712		712
Ending balance (in shares) at Mar. 31, 2021		69,812,205
Ending balance at Mar. 31, 2021	$ 2,296,630	$ 70	$ 2,265,713	$ (3)	$ 30,850

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities
Net income (loss)	$ 1,874,325	$ (40,256)
Less: Net Income from discontinued operations	1,965,202	43,838
Net loss from continuing operations	(90,877)	(84,094)
Adjustments to reconcile net loss from continuing operations to net cash used in operating activities:
Depreciation and amortization	2,479	2,474
Stock-based compensation expense	14,854	15,670
Net amortization of premium (accretion of discount) on marketable securities	1,664	126
Non-cash operating lease expense	2,417	2,203
Changes in operating assets and liabilities:
Prepaid expenses and other current and non-current assets	(3,621)	(1,076)
Accounts payable	(2,941)	(883)
Accrued expenses and other current liabilities	(12,697)	(10,972)
Operating lease liabilities	(1,504)	(2,229)
Net cash used in operating activities - continuing operations	(90,226)	(78,781)
Net cash used in operating activities - discontinued operations	(30,523)	(26,577)
Net cash used in operating activities	(120,749)	(105,358)
Investing activities
Purchases of marketable securities	(61,863)	(54,911)
Proceeds from maturities and sales of marketable securities	134,016	167,501
Purchases of property and equipment	(1,012)	(4,196)
Net cash provided by investing activities - continuing operations	71,141	108,394
Net cash provided by (used in) investing activities - discontinued operations	1,802,936	(259)
Net cash provided by investing activities	1,874,077	108,135
Financing activities
Payments on financing lease obligations	(86)	(80)
Net proceeds from stock option exercises and employee stock purchase plan	7,347	5,465
Net cash provided by financing activities - continuing operations	7,261	5,385
Net cash provided by financing activities - discontinued operations	0	0
Net cash provided by financing activities	7,261	5,385
Net change in cash and cash equivalents	1,760,589	8,162
Cash and cash equivalents at beginning of the period	127,436	80,931
Cash and cash equivalents at end of the period	1,888,025	89,093
Supplemental disclosure of non-cash investing and financing transactions
Additions to property and equipment in accounts payable and accrued expenses	6	5,444
Operating lease liabilities arising from obtaining operating lease assets	$ 0	$ 0

Overview and Basis of Presentat

Overview and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	Overview and Basis of Presentation References to Agios Throughout this Quarterly Report on Form 10-Q, “we,” “us,” and “our,” and similar expressions, except where the context requires otherwise, refer to Agios Pharmaceuticals, Inc. and its consolidated subsidiaries, and “our Board of Directors” refers to the board of directors of Agios Pharmaceuticals, Inc. Overview We are a biopharmaceutical company committed to transforming patients’ lives through scientific leadership in the field of cellular metabolism and adjacent areas of biology, with the goal of creating differentiated, small molecule medicines for genetically defined diseases, or GDDs, and, prior to the completion of the sale of our oncology business to Servier Pharmaceuticals LLC, or Servier, as described below, hematologic malignancies and solid tumors. To address our focus areas, we take a systems biology approach to deeply understand disease states, drive the discovery and validation of novel therapeutic targets, and define patient selection strategies, thereby increasing the probability that our experimental medicines will have the desired therapeutic effect. We are located in Cambridge, Massachusetts. Sale of our Oncology Business to Servier On March 31, 2021, we completed the sale of our oncology business to Servier. We entered into a Purchase and Sale Agreement, or the Purchase Agreement, with Servier on December 20, 2020. The transaction included the sale of our oncology business, including TIBSOVO®, our clinical-stage product candidates vorasidenib, AG-270 and AG-636, and our oncology research programs for a payment of approximately $1.8 billion in cash at the closing, subject to certain adjustments, and a payment of $200 million in cash, if, prior to January 1, 2027, vorasidenib is granted new drug application, or NDA, approval from the U.S. Food and Drug Administration, or FDA, with an approved label that permits vorasidenib’s use as a single agent for the adjuvant treatment of patients with Grade 2 glioma that have an isocitrate dehydrogenase 1 or 2 mutation (and, to the extent required by such approval, the vorasidenib companion diagnostic test is granted an FDA premarket approval), as well as a royalty of 5% of U.S. net sales of TIBSOVO® from the close of the transaction through loss of exclusivity, and a royalty of 15% of U.S. net sales of vorasidenib from the first commercial sale of vorasidenib through loss of exclusivity. Servier also acquired our co-commercialization rights for Bristol Myers Squibb’s IDHIFA® and the right to receive a $25.0 million potential milestone payment under our prior collaboration agreement with Celgene Corporation, and following the sale Servier will conduct certain clinical development activities within the IDHIFA® development program. Basis of presentation The condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations, comprehensive income (loss) and stockholders' equity for the three months ended March 31, 2021 and 2020, and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of our management, reflect all adjustments, which include only normal recurring adjustments, necessary to fairly state our financial position as of March 31, 2021, our results of operations and stockholders' equity for the three months ended March 31, 2021 and 2020, and cash flows for the three months ended March 31, 2021 and 2020. The financial data and the other financial information disclosed in these notes to the condensed consolidated financial statements related to the three-month periods are also unaudited. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any other future annual or interim period. The condensed consolidated balance sheet data as of December 31, 2020 was derived from our audited financial statements, but does not include all disclosures required by U.S. generally accepted accounting principles, or U.S. GAAP. The condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2020 that was filed with the Securities and Exchange Commission, or the SEC, on February 25, 2021. In late March 2021, our oncology business met all the conditions to be classified as held for sale and, because we consider the disposal of the oncology business to be a strategic shift that will have a major effect on our operations and financial results, represented a discontinued operation. All assets and liabilities associated with our oncology business were therefore classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets for the periods presented. Further, all historical operating results for our oncology business are reflected within discontinued operations in the condensed consolidated statements of operations for all periods presented. For additional information, see Note 3, Discontinued Operations. Our condensed consolidated financial statements include our accounts and the accounts of our wholly owned subsidiaries. All intercompany transactions have been eliminated in consolidation. The condensed consolidated financial statements have been prepared in conformity with U.S. GAAP. Reclassifications Certain amounts in prior periods have been reclassified to reflect the impact of the discontinued operations treatment of the oncology business in order to conform to the current period presentation. Use of estimates The preparation of our condensed consolidated financial statements requires us to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, equity, revenues and expenses and related disclosure of contingent assets and liabilities. On an ongoing basis we evaluate our estimates, judgments and methodologies. We base our estimates on historical experience and on various other assumptions that we believe are reasonable, the results of which form the basis for making judgments about the carrying values of assets, liabilities and equity and the amount of revenues and expenses. The full extent to which the COVID-19 pandemic will directly or indirectly impact our business, results of operations and financial condition, including sales, expenses, reserves and allowances, clinical trials, research and development costs and employee-related amounts, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain the pandemic or treat COVID-19, as well as the economic impact on local, regional, national and international customers and markets. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods. Actual results may differ from these estimates. Liquidity On March 31, 2021 we completed the sale of our oncology business to Servier, and received approximately $1.8 billion in cash at closing. In connection with the sale, on March 25, 2021, we announced that our board of directors authorized the repurchase of up to $1.2 billion of our outstanding shares. We expect to conduct the share repurchases over the next 12—18 months, including executing a meaningful portion of the planned repurchases by the end of 2021 through a combination of 10b5-1 plans, open market purchases and privately negotiated block sales. As of March 31, 2021, we had cash, cash equivalents and marketable securities of $2.4 billion. Although we have incurred recurring losses and expect to continue to incur losses for the foreseeable future, we expect our cash, cash equivalents and marketable securities will be sufficient to fund current operations for at least the next twelve months from the issuance date of these financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Discontinued Operations We accounted for the sale of our oncology business in accordance with Accounting Standards Codification, ASC, 205 Discontinued Operations and Accounting Standards Update, ASU, No. 2014-08, Reporting of Discontinued Operations and Disclosures of Disposals of Components of an Entity . We followed the held-for-sale criteria as defined in ASC 306 and ASC 205. ASC 205 requires that a component of an entity that has been disposed of or is classified as held for sale and has operations and cash flows that can be clearly distinguished from the rest of the entity be reported as assets held for sale and discontinued operations. In the period a component of an entity has been disposed of or classified as held for sale, the results of operations for the periods presented are reclassified into separate line items in the unaudited condensed consolidated statements of operations. Assets and liabilities are also reclassified into separate line items on the related condensed consolidated balance sheets for the periods presented. The statements of cash flows for the periods presented are also reclassified to reflect the results of discontinued operations as separate line items. ASU 2014-08 requires that only a disposal of a component of an entity, or a group of components of an entity, that represents a strategic shift that has, or will have, a major effect on the reporting entity’s operations and financial results be reported in the financial statements as discontinued operations. ASU 2014-08 also provides guidance on the financial statement presentations and disclosures of discontinued operations. Due to the sale of the oncology business during the first quarter of 2021, see Note 3, Discontinued Operations , in accordance with ASC 205, Discontinued Operations , we have classified the results of the oncology business as discontinued operations in our unaudited condensed consolidated statements of operations and cash flows for all periods presented. All assets and liabilities associated with our oncology business were therefore classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets for the periods presented. All amounts included in the notes to the unaudited condensed consolidated financial statements relate to continuing operations unless otherwise noted. There have been no other material changes to the significant accounting policies previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2020. Recent accounting pronouncements Other accounting standards that have been issued by the Financial Accounting Standards Board or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on our financial statements upon adoption.

Discontinued Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On March 31, 2021, we completed the sale of our oncology business to Servier. We have determined the sale of the oncology business represents a strategic shift that will have a major effect on our business and therefore met the criteria for classification as discontinued operations at March 31, 2021. Accordingly, the oncology business is reported as discontinued operations in accordance with ASC 205-20, Discontinued Operations . The related assets and liabilities of the oncology business are classified as assets and liabilities of discontinued operations in the condensed consolidated balance sheets and the results of operations from the oncology business as discontinued operations in the condensed consolidated statements of operations. Applicable amounts in prior years have been recast to conform to this discontinued operations presentation. We recognized a gain on the sale of the oncology business upon closing. The following table presents the assets and liabilities of the discontinued operations as of December 31, 2020: (in thousands) December 31, 2020 Assets Current assets: Accounts receivable, net $ 21,328 Collaboration receivable – related party 2,123 Collaboration receivable – other 1,948 Inventory 14,698 Prepaid expenses and other current assets 7,762 Total current assets of discontinued operations 47,859 Other non-current assets 2,601 Total assets of discontinued operations $ 50,460 Liabilities Current liabilities: Accounts payable $ 9,120 Accrued expenses 29,339 Total current liabilities of discontinued operations 38,459 Liability related to the sale of future revenue, net of debt issuance costs 261,269 Total liabilities of discontinued operations $ 299,728 The following table presents the net liabilities transferred for the sale oncology business for the quarter ended March 31, 2021: (in thousands) March 31, 2021 Assets Current assets: Accounts receivable, net $ 25,386 Collaboration receivable – related party 2,253 Collaboration receivable – other 2,438 Inventory 16,190 Prepaid expenses and other current assets 7,125 Total current assets of discontinued operations 53,392 Other non-current assets 2,234 Total assets of discontinued operations $ 55,626 Liabilities Current liabilities: Accounts payable $ 4,245 Accrued expenses 30,288 Total current liabilities of discontinued operations 34,533 Liability related to the sale of future revenue, net of debt issuance costs 264,281 Total liabilities of discontinued operations 298,814 Net liabilities distributed to Servier $ (243,188) The following table presents the gain on the sale for the quarter ended March 31, 2021: (in thousands) March 31, 2021 Cash proceeds $ 1,802,936 Less: transaction and insurance costs (53,573) Less: net liabilities distributed (243,188) Gain on sale, pre-tax 1,992,551 Income tax (12,867) Gain on sale, net of tax $ 1,979,684 The following table presents the financial results of the discontinued operations: Three Months Ended March 31, (in thousands) 2021 2020 Revenues: Product revenue, net $ 36,909 $ 22,674 Collaboration revenue – related party 1,350 60,097 Collaboration revenue – other 491 993 Royalty revenue – related party 2,659 3,334 Total revenue 41,409 87,098 Cost and expenses: Cost of sales 706 533 Research and development 41,357 35,897 Selling, general and administrative 8,131 6,830 Total cost and expenses 50,194 43,260 (Loss) income from discontinued operations (8,785) 43,838 Non-cash interest expense for the sale of future revenue (5,697) — Gain on the sale of the oncology business 1,992,551 — Income from discontinued operations, pre-tax 1,978,069 43,838 Income tax expense (12,867) — Net income from discontinued operations $ 1,965,202 $ 43,838 In accordance with ASC 205-20, only expenses specifically identifiable and related to a business to be disposed may be presented in discontinued operations. As such, the research and development, marketing, selling and general and administrative expenses in discontinued operations include corporate costs incurred directly to solely support our oncology business. Pursuant to the Purchase Agreement, we have also entered into a Transition Services Agreement with Servier, through which we will provide transitional services related to discovery, clinical development, technical operations, commercial and G&A related activities for periods ranging from one month to approximately one year after March 31, 2021. The milestone payment for approval of vorasidenib and royalty payments related to vorasidenib and TIBSOVO® represent contingent consideration. Contingent consideration has been accounted for as a gain contingency in accordance with ASC 450, Contingencies , and will be recognized in earnings in the period when realizable.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We record cash equivalents and marketable securities at fair value. ASC 820, Fair Value Measurements and Disclosures , establishes a fair value hierarchy for those instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and our own assumptions (unobservable inputs). The hierarchy consists of three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, directly or indirectly, for substantially the full term of the asset or liability. Level 3 – Unobservable inputs that reflect our own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date. The following table summarizes our cash equivalents and marketable securities measured at fair value on a recurring basis as of March 31, 2021: (In thousands) Level 1 Level 2 Level 3 Total Cash equivalents $ 55,058 $ — $ — $ 55,058 Total cash equivalents 55,058 — — 55,058 Marketable securities: U.S. Treasuries — 121,759 — 121,759 Government securities — 101,285 — 101,285 Corporate debt securities — 246,132 — 246,132 Total marketable securities — 469,176 — 469,176 Total cash equivalents and marketable securities $ 55,058 $ 469,176 $ — $ 524,234 Cash equivalents and marketable securities have been initially valued at the transaction price and subsequently, at the end of each reporting period, valued utilizing third-party pricing services or other observable market data. The pricing services utilize industry standard valuation models, including both income and market-based approaches, and observable market inputs to determine value. After completing our validation procedures, we did not adjust or override any fair value measurements provided by the pricing services as of March 31, 2021. There have been no changes to the valuation methods during the three months ended March 31, 2021. We have no financial assets or liabilities that were classified as Level 3 at any point during the three months ended March 31, 2021.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities Our marketable securities are classified as available-for-sale pursuant to ASC 320, Investments – Debt and Equity Securities , and are recorded at fair value. Unrealized gains are included as a component of accumulated other comprehensive (loss) income in the condensed consolidated balance sheets and statements of stockholders’ equity and a component of total comprehensive loss in the condensed consolidated statements of comprehensive income (loss), until realized. Unrealized losses are evaluated for impairment under ASC 326, Financial Instruments - Credit Losses , to determine if the impairment is credit-related or noncredit-related. Credit-related impairment is recognized as an allowance on the balance sheet with a corresponding adjustment to earnings, and noncredit-related impairment is recognized in other comprehensive income, net of taxes. Realized gains and losses are included in investment income on a specific-identification basis. There were no material realized gains or losses on marketable securities for the three months ended March 31, 2021 or 2020. Marketable securities at March 31, 2021 consisted of the following: (In thousands) Amortized Unrealized Unrealized Fair Current: U.S. Treasuries $ 111,508 $ 34 $ (7) $ 111,535 Government securities 96,481 19 — 96,500 Corporate debt securities 239,590 34 (81) 239,543 Total Current 447,579 87 (88) 447,578 Non-current: U.S. Treasuries 10,227 — (3) 10,224 Government securities 4,779 6 — 4,785 Corporate debt securities 6,594 — (5) 6,589 Total Non-current 21,600 6 (8) 21,598 Total marketable securities $ 469,179 $ 93 $ (96) $ 469,176 Marketable securities at December 31, 2020 consisted of the following: (In thousands) Amortized Unrealized Unrealized Fair Current: U.S. Treasuries $ 113,559 $ 134 $ (21) $ 113,672 Government securities 108,263 37 (8) 108,292 Corporate debt securities 223,461 140 (72) 223,529 Total Current 445,283 311 (101) 445,493 Non-current: U.S. Treasuries 15,147 — (10) 15,137 Government securities 26,831 8 — 26,839 Corporate debt securities 55,735 2 (105) 55,632 Total Non-current 97,713 10 (115) 97,608 Total marketable securities $ 542,996 $ 321 $ (216) $ 543,101 As of March 31, 2021 and December 31, 2020, we held both current and non-current investments. Investments classified as current have maturities of less than one year. Investments classified as non-current are those that: (i) have a maturity of greater than one year, and (ii) we do not intend to liquidate within the next twelve months, although these funds are available for use and, therefore, are classified as available-for-sale. As of March 31, 2021 and December 31, 2020, we held 78 and 87 debt securities, respectively, that were in an unrealized loss position for less than one year. We did not record an allowance for credit losses as of March 31, 2021 and December 31, 2020 related to these securities. The aggregate fair value of debt securities in an unrealized loss position at March 31, 2021 and December 31, 2020 was $248.3 million and $299.0 million, respectively. There were no individual securities that were in a significant unrealized loss position as of March 31, 2021 and December 31, 2020. We regularly review the securities in an unrealized loss position and evaluate the current expected credit loss by considering factors such as historical experience, market data, issuer-specific factors, and current economic conditions. We do not consider these marketable securities to be impaired as of March 31, 2021 and December 31, 2020.

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	Leases Our building leases are comprised of office and laboratory space under non-cancelable operating leases. These lease agreements have remaining lease terms of seven years and contain various clauses for renewal at our option. The renewal options were not included in the calculation of the operating lease assets and the operating lease liabilities as the renewal options are not reasonably certain of being exercised. The lease agreements do not contain residual value guarantees. The components of lease expense and other information related to leases were as follows: Three Months Ended (In millions) 2021 2020 Operating lease costs $ 3.8 $ 3.8 Cash paid for amounts included in the measurement of operating lease liabilities $ 3.6 $ 3.9 We have not entered into any material short-term leases or financing leases as of March 31, 2021. As of March 31, 2021, undiscounted minimum rental commitments under non-cancelable leases, for each of the next five years and total thereafter were as follows: (In thousands) Remaining 2021 $ 9,640 2022 16,773 2023 18,126 2024 18,660 2025 19,507 Thereafter 44,385 Undiscounted minimum rental commitments $ 127,091 Interest (24,051) Operating lease liabilities $ 103,040

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following: (In thousands) March 31, December 31, Accrued compensation $ 7,348 $ 20,345 Accrued research and development costs 5,335 5,444 Accrued professional fees 2,486 2,897 Accrued other 8,432 2,115 Total accrued expenses $ 23,601 $ 30,801

Share-Based Payments

Share-Based Payments	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Payments	Share-Based Payments 2013 Stock Incentive Plan In June 2013, our Board of Directors adopted and, in July 2013 our stockholders approved, the 2013 Stock Incentive Plan, or the 2013 Plan. The 2013 Plan became effective upon the closing of our initial public offering and provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock units, or RSUs, performance-based share units, or PSUs, and other stock-based awards to employees, non-employees and non-employee directors. Following the adoption of the 2013 Plan, we granted no further stock options or other awards under the 2007 Stock Incentive Plan, or the 2007 Plan. Any options or awards outstanding under the 2007 Plan at the time of adoption of the 2013 Plan remain outstanding and effective. As of March 31, 2021, the total number of shares reserved under the 2007 Plan and the 2013 Plan was 12,082,101, and we had 4,382,070 shares available for future issuance under the 2013 Plan. Stock options The following table presents stock option activity for the three months ended March 31, 2021: Number of Weighted-Average Exercise Price Outstanding at December 31, 2020 6,143,046 $ 58.46 Granted 872,672 56.17 Exercised (122,422) 41.06 Forfeited/Expired (711,343) 56.04 Outstanding at March 31, 2021 6,181,953 $ 58.76 Exercisable at March 31, 2021 4,050,765 $ 61.02 Vested and expected to vest at March 31, 2021 6,181,953 $ 58.76 At March 31, 2021, there was approximately $67.9 million of total unrecognized compensation expense related to unvested stock option awards, which we expect to recognize over a weighted-average period of approximately 2.7 years. Restricted stock units The following table presents RSU activity for the three months ended March 31, 2021: Number of Weighted-Average Grant Date Fair Value Unvested shares at December 31, 2020 1,284,378 $ 50.78 Granted 701,314 56.08 Vested (336,462) 58.16 Forfeited (386,136) 52.15 Unvested shares at March 31, 2021 1,263,094 $ 51.34 As of March 31, 2021, there was approximately $54.6 million of total unrecognized compensation expense related to RSUs, which we expect to recognize over a weighted-average period of approximately 2.2 years. Performance-based stock units The following table presents PSU activity for the three months ended March 31, 2021: Number of Weighted-Average Grant Date Fair Value Unvested shares at December 31, 2020 142,229 $ 54.28 Granted 121,000 56.68 Vested — — Forfeited (10,850) 61.93 Unvested shares at March 31, 2021 252,379 $ 55.10 Stock-based compensation expense associated with these PSUs is recognized if the underlying performance condition is considered probable of achievement using our management’s best estimates. As of March 31, 2021, there was no unrecognized compensation expense related to PSUs with performance-based vesting criteria that are considered probable of achievement, and $13.9 million of total unrecognized compensation expense related to PSUs with performance-based vesting criteria that are considered not probable of achievement. Market-based stock units The following table presents market-based stock unit, or MSU, activity for the three months ended March 31, 2021: Number of Weighted-Average Unvested shares at December 31, 2020 42,695 $ 41.50 Granted — — Unvested shares at March 31, 2021 42,695 $ 41.50 The fair value of MSUs are estimated using a Monte Carlo simulation model. Assumptions and estimates utilized in the model include the risk-free interest rate, dividend yield, expected stock volatility and the estimated period to achievement of the market condition. As of March 31, 2021, there was no remaining unrecognized compensation expense related to MSUs. 2013 Employee Stock Purchase Plan In June 2013, our Board of Directors adopted, and in July 2013 our stockholders approved, the 2013 Employee Stock Purchase Plan, or the 2013 ESPP. We issued and sold 59,401 and 62,694 shares of common stock during the three months ended March 31, 2021 and 2020, respectively, under the 2013 ESPP. The 2013 ESPP provides participating employees with the opportunity to purchase up to an aggregate of 1,345,454 shares of our common stock. As of March 31, 2021, we had 921,043 shares of common stock available for future issuance under the 2013 ESPP. Stock-based compensation expense Stock-based compensation expense by award type included within the condensed consolidated statements of operations is as follows: Three Months Ended (In thousands) 2021 2020 Stock options $ 8,396 $ 9,309 Restricted stock units 6,205 4,459 Performance-based stock units — 1,335 Employee stock purchase plan 253 297 Other stock awards — 270 Total stock-based compensation expense $ 14,854 $ 15,670 Expenses related to stock options and stock-based awards were allocated as follows in the condensed consolidated statements of operations: Three Months Ended (In thousands) 2021 2020 Research and development expense $ 6,973 $ 6,999 Selling, general and administrative expense 7,881 8,671 Total stock-based compensation expense $ 14,854 $ 15,670

Loss per Share

Loss per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Loss per Share	Loss per Share Basic net loss per share is calculated by dividing net loss by the weighted-average shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting the weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury stock method. For purposes of the dilutive net loss per share calculation, stock options, RSUs, PSUs and MSUs for which the performance and market vesting conditions, respectively, have been deemed probable, and 2013 ESPP shares are considered to be common stock equivalents, while PSUs and MSUs with performance and market vesting conditions, respectively, that were not deemed probable as of March 31, 2021 are not considered to be common stock equivalents. We utilize the control number concept in the computation of diluted earnings per share to determine whether potential common stock equivalents are dilutive. The control number used is loss from continuing operations. The control number concept requires that the same number of potentially dilutive securities applied in computing diluted earnings per share from continuing operations be applied to all other categories of income or loss, regardless of their anti-dilutive effect on such categories. Since we had a net loss for continuing operations for all periods presented, no dilutive effect has been recognized in the calculation of income from discontinued operations per share. Basic and diluted net loss per share was the same for all periods presented. The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2021 2020 Stock options 6,181,953 6,749,373 Restricted stock units 1,263,094 1,290,875 Performance-based stock units — 78,920 Employee stock purchase plan shares 7,384 13,430 Total common stock equivalents 7,452,431 8,132,598

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesWe recorded a provision for income taxes of $12.9 million for the three months ended March 31, 2021 and no income tax provision for the three months ended March 31, 2020. The tax provision has been recorded within discontinued operations as it relates to the income tax impact on the sale of its oncology business to Servier. There is no income tax expense recorded in continuing operations for the three months ended March 31, 2021 and 2020, respectively.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On March 25, 2021, we announced that our board of directors authorized the repurchase of up to $1.2 billion of our outstanding shares of common stock, or the Repurchase Program, using the proceeds from the sale of our oncology business to Servier. On March 31, 2021, in connection with the Repurchase Program, we entered into a definitive share repurchase agreement with Bristol-Myers Squibb Company, or BMS, to repurchase 7,121,658 shares of our common stock held by certain subsidiaries of BMS for an aggregate purchase price of $344.5 million, or $48.3785 per share. This repurchase was completed on April 5, 2021. Further, on April 2, 2021, in connection with the Repurchase Program, we entered into a Rule 10b5-1 repurchase plan pursuant to which we may repurchase up to $600 million of shares of our common stock.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations, comprehensive income (loss) and stockholders' equity for the three months ended March 31, 2021 and 2020, and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual financial statements and, in the opinion of our management, reflect all adjustments, which include only normal recurring adjustments, necessary to fairly state our financial position as of March 31, 2021, our results of operations and stockholders' equity for the three months ended March 31, 2021 and 2020, and cash flows for the three months ended March 31, 2021 and 2020. The financial data and the other financial information disclosed in these notes to the condensed consolidated financial statements related to the three-month periods are also unaudited. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results to be expected for the year ending December 31, 2021 or for any other future annual or interim period. The condensed consolidated balance sheet data as of December 31, 2020 was derived from our audited financial statements, but does not include all disclosures required by U.S. generally accepted accounting principles, or U.S. GAAP. The condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2020 that was filed with the Securities and Exchange Commission, or the SEC, on February 25, 2021. In late March 2021, our oncology business met all the conditions to be classified as held for sale and, because we consider the disposal of the oncology business to be a strategic shift that will have a major effect on our operations and financial results, represented a discontinued operation. All assets and liabilities associated with our oncology business were therefore classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets for the periods presented. Further, all historical operating results for our oncology business are reflected within discontinued operations in the condensed consolidated statements of operations for all periods presented. For additional information, see Note 3, Discontinued Operations. Our condensed consolidated financial statements include our accounts and the accounts of our wholly owned subsidiaries. All intercompany transactions have been eliminated in consolidation. The condensed consolidated financial statements have been prepared in conformity with U.S. GAAP.
Reclassifications	Reclassifications Certain amounts in prior periods have been reclassified to reflect the impact of the discontinued operations treatment of the oncology business in order to conform to the current period presentation.
Use of Estimates	Use of estimates The preparation of our condensed consolidated financial statements requires us to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, equity, revenues and expenses and related disclosure of contingent assets and liabilities. On an ongoing basis we evaluate our estimates, judgments and methodologies. We base our estimates on historical experience and on various other assumptions that we believe are reasonable, the results of which form the basis for making judgments about the carrying values of assets, liabilities and equity and the amount of revenues and expenses. The full extent to which the COVID-19 pandemic will directly or indirectly impact our business, results of operations and financial condition, including sales, expenses, reserves and allowances, clinical trials, research and development costs and employee-related amounts, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain the pandemic or treat COVID-19, as well as the economic impact on local, regional, national and international customers and markets. We have made estimates of the impact of COVID-19 within our financial statements and there may be changes to those estimates in future periods. Actual results may differ from these estimates.
Discontinued Operations	Discontinued Operations We accounted for the sale of our oncology business in accordance with Accounting Standards Codification, ASC, 205 Discontinued Operations and Accounting Standards Update, ASU, No. 2014-08, Reporting of Discontinued Operations and Disclosures of Disposals of Components of an Entity . We followed the held-for-sale criteria as defined in ASC 306 and ASC 205. ASC 205 requires that a component of an entity that has been disposed of or is classified as held for sale and has operations and cash flows that can be clearly distinguished from the rest of the entity be reported as assets held for sale and discontinued operations. In the period a component of an entity has been disposed of or classified as held for sale, the results of operations for the periods presented are reclassified into separate line items in the unaudited condensed consolidated statements of operations. Assets and liabilities are also reclassified into separate line items on the related condensed consolidated balance sheets for the periods presented. The statements of cash flows for the periods presented are also reclassified to reflect the results of discontinued operations as separate line items. ASU 2014-08 requires that only a disposal of a component of an entity, or a group of components of an entity, that represents a strategic shift that has, or will have, a major effect on the reporting entity’s operations and financial results be reported in the financial statements as discontinued operations. ASU 2014-08 also provides guidance on the financial statement presentations and disclosures of discontinued operations. Due to the sale of the oncology business during the first quarter of 2021, see Note 3, Discontinued Operations , in accordance with ASC 205, Discontinued Operations , we have classified the results of the oncology business as discontinued operations in our unaudited condensed consolidated statements of operations and cash flows for all periods presented. All assets and liabilities associated with our oncology business were therefore classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets for the periods presented. All amounts included in the notes to the unaudited condensed consolidated financial statements relate to continuing operations unless otherwise noted.
Recent Accounting Pronouncements	Recent accounting pronouncements Other accounting standards that have been issued by the Financial Accounting Standards Board or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on our financial statements upon adoption.
Fair Value Measurements	We record cash equivalents and marketable securities at fair value. ASC 820, Fair Value Measurements and Disclosures , establishes a fair value hierarchy for those instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and our own assumptions (unobservable inputs). The hierarchy consists of three levels: Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, directly or indirectly, for substantially the full term of the asset or liability. Level 3 – Unobservable inputs that reflect our own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date.
Marketable Securities	Our marketable securities are classified as available-for-sale pursuant to ASC 320, Investments – Debt and Equity Securities , and are recorded at fair value. Unrealized gains are included as a component of accumulated other comprehensive (loss) income in the condensed consolidated balance sheets and statements of stockholders’ equity and a component of total comprehensive loss in the condensed consolidated statements of comprehensive income (loss), until realized. Unrealized losses are evaluated for impairment under ASC 326, Financial Instruments - Credit Losses
Loss per Share	Basic net loss per share is calculated by dividing net loss by the weighted-average shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting the weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury stock method. For purposes of the dilutive net loss per share calculation, stock options, RSUs, PSUs and MSUs for which the performance and market vesting conditions, respectively, have been deemed probable, and 2013 ESPP shares are considered to be common stock equivalents, while PSUs and MSUs with performance and market vesting conditions, respectively, that were not deemed probable as of March 31, 2021 are not considered to be common stock equivalents.

Discontinued Operations (Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Discontinued Operations	The following table presents the assets and liabilities of the discontinued operations as of December 31, 2020: (in thousands) December 31, 2020 Assets Current assets: Accounts receivable, net $ 21,328 Collaboration receivable – related party 2,123 Collaboration receivable – other 1,948 Inventory 14,698 Prepaid expenses and other current assets 7,762 Total current assets of discontinued operations 47,859 Other non-current assets 2,601 Total assets of discontinued operations $ 50,460 Liabilities Current liabilities: Accounts payable $ 9,120 Accrued expenses 29,339 Total current liabilities of discontinued operations 38,459 Liability related to the sale of future revenue, net of debt issuance costs 261,269 Total liabilities of discontinued operations $ 299,728 The following table presents the net liabilities transferred for the sale oncology business for the quarter ended March 31, 2021: (in thousands) March 31, 2021 Assets Current assets: Accounts receivable, net $ 25,386 Collaboration receivable – related party 2,253 Collaboration receivable – other 2,438 Inventory 16,190 Prepaid expenses and other current assets 7,125 Total current assets of discontinued operations 53,392 Other non-current assets 2,234 Total assets of discontinued operations $ 55,626 Liabilities Current liabilities: Accounts payable $ 4,245 Accrued expenses 30,288 Total current liabilities of discontinued operations 34,533 Liability related to the sale of future revenue, net of debt issuance costs 264,281 Total liabilities of discontinued operations 298,814 Net liabilities distributed to Servier $ (243,188) The following table presents the gain on the sale for the quarter ended March 31, 2021: (in thousands) March 31, 2021 Cash proceeds $ 1,802,936 Less: transaction and insurance costs (53,573) Less: net liabilities distributed (243,188) Gain on sale, pre-tax 1,992,551 Income tax (12,867) Gain on sale, net of tax $ 1,979,684 The following table presents the financial results of the discontinued operations: Three Months Ended March 31, (in thousands) 2021 2020 Revenues: Product revenue, net $ 36,909 $ 22,674 Collaboration revenue – related party 1,350 60,097 Collaboration revenue – other 491 993 Royalty revenue – related party 2,659 3,334 Total revenue 41,409 87,098 Cost and expenses: Cost of sales 706 533 Research and development 41,357 35,897 Selling, general and administrative 8,131 6,830 Total cost and expenses 50,194 43,260 (Loss) income from discontinued operations (8,785) 43,838 Non-cash interest expense for the sale of future revenue (5,697) — Gain on the sale of the oncology business 1,992,551 — Income from discontinued operations, pre-tax 1,978,069 43,838 Income tax expense (12,867) — Net income from discontinued operations $ 1,965,202 $ 43,838

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Cash Equivalents and Marketable Securities Measured at Fair Value on a Recurring Basis	The following table summarizes our cash equivalents and marketable securities measured at fair value on a recurring basis as of March 31, 2021: (In thousands) Level 1 Level 2 Level 3 Total Cash equivalents $ 55,058 $ — $ — $ 55,058 Total cash equivalents 55,058 — — 55,058 Marketable securities: U.S. Treasuries — 121,759 — 121,759 Government securities — 101,285 — 101,285 Corporate debt securities — 246,132 — 246,132 Total marketable securities — 469,176 — 469,176 Total cash equivalents and marketable securities $ 55,058 $ 469,176 $ — $ 524,234

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	Marketable securities at March 31, 2021 consisted of the following: (In thousands) Amortized Unrealized Unrealized Fair Current: U.S. Treasuries $ 111,508 $ 34 $ (7) $ 111,535 Government securities 96,481 19 — 96,500 Corporate debt securities 239,590 34 (81) 239,543 Total Current 447,579 87 (88) 447,578 Non-current: U.S. Treasuries 10,227 — (3) 10,224 Government securities 4,779 6 — 4,785 Corporate debt securities 6,594 — (5) 6,589 Total Non-current 21,600 6 (8) 21,598 Total marketable securities $ 469,179 $ 93 $ (96) $ 469,176 Marketable securities at December 31, 2020 consisted of the following: (In thousands) Amortized Unrealized Unrealized Fair Current: U.S. Treasuries $ 113,559 $ 134 $ (21) $ 113,672 Government securities 108,263 37 (8) 108,292 Corporate debt securities 223,461 140 (72) 223,529 Total Current 445,283 311 (101) 445,493 Non-current: U.S. Treasuries 15,147 — (10) 15,137 Government securities 26,831 8 — 26,839 Corporate debt securities 55,735 2 (105) 55,632 Total Non-current 97,713 10 (115) 97,608 Total marketable securities $ 542,996 $ 321 $ (216) $ 543,101

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Schedule of Components of Lease Expense and Other Information	The components of lease expense and other information related to leases were as follows: Three Months Ended (In millions) 2021 2020 Operating lease costs $ 3.8 $ 3.8 Cash paid for amounts included in the measurement of operating lease liabilities $ 3.6 $ 3.9
Schedule of Undiscounted Minimum Rental Commitments Under Non-cancelable Leases	As of March 31, 2021, undiscounted minimum rental commitments under non-cancelable leases, for each of the next five years and total thereafter were as follows: (In thousands) Remaining 2021 $ 9,640 2022 16,773 2023 18,126 2024 18,660 2025 19,507 Thereafter 44,385 Undiscounted minimum rental commitments $ 127,091 Interest (24,051) Operating lease liabilities $ 103,040

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following: (In thousands) March 31, December 31, Accrued compensation $ 7,348 $ 20,345 Accrued research and development costs 5,335 5,444 Accrued professional fees 2,486 2,897 Accrued other 8,432 2,115 Total accrued expenses $ 23,601 $ 30,801

Share-Based Payments (Tables)

Share-Based Payments (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Company's Stock Option Activity	The following table presents stock option activity for the three months ended March 31, 2021: Number of Weighted-Average Exercise Price Outstanding at December 31, 2020 6,143,046 $ 58.46 Granted 872,672 56.17 Exercised (122,422) 41.06 Forfeited/Expired (711,343) 56.04 Outstanding at March 31, 2021 6,181,953 $ 58.76 Exercisable at March 31, 2021 4,050,765 $ 61.02 Vested and expected to vest at March 31, 2021 6,181,953 $ 58.76
Unvested Stock Unit Activity	The following table presents RSU activity for the three months ended March 31, 2021: Number of Weighted-Average Grant Date Fair Value Unvested shares at December 31, 2020 1,284,378 $ 50.78 Granted 701,314 56.08 Vested (336,462) 58.16 Forfeited (386,136) 52.15 Unvested shares at March 31, 2021 1,263,094 $ 51.34
Schedule of Performance-Based Units	The following table presents PSU activity for the three months ended March 31, 2021: Number of Weighted-Average Grant Date Fair Value Unvested shares at December 31, 2020 142,229 $ 54.28 Granted 121,000 56.68 Vested — — Forfeited (10,850) 61.93 Unvested shares at March 31, 2021 252,379 $ 55.10
Schedule of Market-Based Units Activity	The following table presents market-based stock unit, or MSU, activity for the three months ended March 31, 2021: Number of Weighted-Average Unvested shares at December 31, 2020 42,695 $ 41.50 Granted — — Unvested shares at March 31, 2021 42,695 $ 41.50
Schedule of Stock-Based Compensation Expense by Award Type Included Within the Condensed Consolidated Statements of Operations	Stock-based compensation expense by award type included within the condensed consolidated statements of operations is as follows: Three Months Ended (In thousands) 2021 2020 Stock options $ 8,396 $ 9,309 Restricted stock units 6,205 4,459 Performance-based stock units — 1,335 Employee stock purchase plan 253 297 Other stock awards — 270 Total stock-based compensation expense $ 14,854 $ 15,670
Schedule of Allocated Stock-Based Compensation Expense	Expenses related to stock options and stock-based awards were allocated as follows in the condensed consolidated statements of operations: Three Months Ended (In thousands) 2021 2020 Research and development expense $ 6,973 $ 6,999 Selling, general and administrative expense 7,881 8,671 Total stock-based compensation expense $ 14,854 $ 15,670

Loss per Share (Tables)

Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Common Stock Excluded from Calculation of Diluted Earnings Per Share	The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2021 2020 Stock options 6,181,953 6,749,373 Restricted stock units 1,263,094 1,290,875 Performance-based stock units — 78,920 Employee stock purchase plan shares 7,384 13,430 Total common stock equivalents 7,452,431 8,132,598

Overview and Basis of Present_2

Overview and Basis of Presentation (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 25, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash, cash equivalents, and marketable securities	$ 2,400,000
Repurchase Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock repurchase program, authorized amount		$ 1,200,000
Minimum | Repurchase Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Share repurchase period		12 months
Maximum | Repurchase Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Share repurchase period		18 months
2010 Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Milestone payment for achievement of specified ex-U.S. commercial milestone event	25,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds	1,802,936
Contingent milestone payment	$ 200,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | TIBSOVO | UNITED STATES
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent royalty payment	5.00%
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | Vorasidenib | UNITED STATES
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent royalty payment	15.00%

Discontinued Operations - Asset

Discontinued Operations - Assets and Liabilities of the Discontinued Operations (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Total current assets of discontinued operations	$ 0	$ 47,859
Current liabilities:
Total current liabilities of discontinued operations	0	38,459
Discontinued Operations, Disposed of by Sale | Agios Oncology Business
Current assets:
Accounts receivable, net	25,386	21,328
Collaboration receivable – related party	2,253	2,123
Collaboration receivable – other	2,438	1,948
Inventory	16,190	14,698
Prepaid expenses and other current assets	7,125	7,762
Total current assets of discontinued operations	53,392	47,859
Other non-current assets	2,234	2,601
Total assets of discontinued operations	55,626	50,460
Current liabilities:
Accounts payable	4,245	9,120
Accrued expenses	30,288	29,339
Total current liabilities of discontinued operations	34,533	38,459
Liability related to the sale of future revenue, net of debt issuance costs	264,281	261,269
Total liabilities of discontinued operations	298,814	$ 299,728
Net liabilities distributed to Servier	$ (243,188)

Discontinued Operations - Gain

Discontinued Operations - Gain on Sale (Details) - Discontinued Operations, Disposed of by Sale - Agios Oncology Business - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds	$ 1,802,936
Less: transaction and insurance costs	(53,573)
Less: net liabilities distributed	(243,188)	$ (243,188)
Gain on sale, pre-tax	1,992,551	$ 1,992,551	$ 0
Income tax	(12,867)
Gain on sale, net of tax	$ 1,979,684

Discontinued Operations - Finan

Discontinued Operations - Financial Results of the Discontinued Operations (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Cost and expenses:
Income tax expense		$ (12,900,000)	$ 0
Net income from discontinued operations, net of tax		1,965,202,000	43,838,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business
Revenues:
Total revenue		41,409,000	87,098,000
Cost and expenses:
Cost of sales		706,000	533,000
Research and development		41,357,000	35,897,000
Selling, general and administrative		8,131,000	6,830,000
Total cost and expenses		50,194,000	43,260,000
(Loss) income from discontinued operations		(8,785,000)	43,838,000
Non-cash interest expense for the sale of future revenue		(5,697,000)	0
Gain on the sale of the oncology business	$ 1,992,551,000	1,992,551,000	0
Income from discontinued operations, pre-tax		1,978,069,000	43,838,000
Income tax expense		(12,867,000)	0
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | Product revenue, net
Revenues:
Total revenue		36,909,000	22,674,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | Collaboration revenue – related party
Revenues:
Total revenue		1,350,000	60,097,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | Collaboration revenue – other
Revenues:
Total revenue		491,000	993,000
Discontinued Operations, Disposed of by Sale | Agios Oncology Business | Royalty revenue – related party
Revenues:
Total revenue		$ 2,659,000	$ 3,334,000

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) - Agios Oncology Business - Discontinued Operations, Disposed of by Sale	Mar. 31, 2021
Minimum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transitional services period	1 month
Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transitional services period	1 year

Fair Value Measurements - Cash

Fair Value Measurements - Cash Equivalents and Marketable Securities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	$ 469,176	$ 543,101
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	55,058
Total marketable securities	469,176
Total cash equivalents and marketable securities	524,234
Fair Value, Measurements, Recurring | Cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	55,058
Fair Value, Measurements, Recurring | U.S. Treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	121,759
Fair Value, Measurements, Recurring | Government securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	101,285
Fair Value, Measurements, Recurring | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	246,132
Fair Value, Measurements, Recurring | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	55,058
Total marketable securities	0
Total cash equivalents and marketable securities	55,058
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	55,058
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	0
Fair Value, Measurements, Recurring | Level 1 | Government securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	0
Fair Value, Measurements, Recurring | Level 1 | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	0
Total marketable securities	469,176
Total cash equivalents and marketable securities	469,176
Fair Value, Measurements, Recurring | Level 2 | Cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	0
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	121,759
Fair Value, Measurements, Recurring | Level 2 | Government securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	101,285
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	246,132
Fair Value, Measurements, Recurring | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	0
Total marketable securities	0
Total cash equivalents and marketable securities	0
Fair Value, Measurements, Recurring | Level 3 | Cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash equivalents	0
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasuries
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	0
Fair Value, Measurements, Recurring | Level 3 | Government securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	0
Fair Value, Measurements, Recurring | Level 3 | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total marketable securities	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	Mar. 31, 2021USD ($)
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets (liabilities)	$ 0

Marketable Securities - Additio

Marketable Securities - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)security	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)security
Investments, Debt and Equity Securities [Abstract]
Realized gain (loss) on marketable securities	$ 0	$ 0
Number of debt securities in unrealized loss position for less than one year | security	78		87
Allowance for credit losses	$ 0		$ 0
Aggregate fair value of debt securities in unrealized loss position	$ 248,300,000		$ 299,000,000
Number of debt securities in significant unrealized loss position | security	0		0

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 469,179	$ 542,996
Unrealized Gains	93	321
Unrealized Losses	(96)	(216)
Fair Value	469,176	543,101
Current:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	447,579	445,283
Unrealized Gains	87	311
Unrealized Losses	(88)	(101)
Fair Value	447,578	445,493
Current: | U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	111,508	113,559
Unrealized Gains	34	134
Unrealized Losses	(7)	(21)
Fair Value	111,535	113,672
Current: | Government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	96,481	108,263
Unrealized Gains	19	37
Unrealized Losses	0	(8)
Fair Value	96,500	108,292
Current: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	239,590	223,461
Unrealized Gains	34	140
Unrealized Losses	(81)	(72)
Fair Value	239,543	223,529
Non-current:
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	21,600	97,713
Unrealized Gains	6	10
Unrealized Losses	(8)	(115)
Fair Value	21,598	97,608
Non-current: | U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,227	15,147
Unrealized Gains	0	0
Unrealized Losses	(3)	(10)
Fair Value	10,224	15,137
Non-current: | Government securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,779	26,831
Unrealized Gains	6	8
Unrealized Losses	0	0
Fair Value	4,785	26,839
Non-current: | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,594	55,735
Unrealized Gains	0	2
Unrealized Losses	(5)	(105)
Fair Value	$ 6,589	$ 55,632

Leases - Additional Information

Leases - Additional Information (Details)	Mar. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Remaining lease terms	7 years
Weighted-average incremental borrowing rate	5.70%	5.70%
Weighted-average remaining lease term	6 years 10 months 24 days	7 years 2 months 12 days

Leases - Schedule of Lease Expe

Leases - Schedule of Lease Expense and Other Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating lease costs	$ 3.8	$ 3.8
Cash paid for amounts included in the measurement of operating lease liabilities	$ 3.6	$ 3.9

Leases - Schedule of Undiscount

Leases - Schedule of Undiscounted Minimum Rental Commitments Under Non-cancelable Leases (Details) $ in Thousands	Mar. 31, 2021USD ($)
Leases [Abstract]
Remaining 2021	$ 9,640
2022	16,773
2023	18,126
2024	18,660
2025	19,507
Thereafter	44,385
Undiscounted minimum rental commitments	127,091
Interest	(24,051)
Operating lease liabilities	$ 103,040

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued compensation	$ 7,348	$ 20,345
Accrued research and development costs	5,335	5,444
Accrued professional fees	2,486	2,897
Accrued other	8,432	2,115
Total accrued expenses	$ 23,601	$ 30,801

Share-Based Payments - Addition

Share-Based Payments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period to recognize compensation expense (in years)	2 years 2 months 12 days
Unrecognized compensation expense excluding options	$ 54,600,000
Performance-Based Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost not expected to be recognized	13,900,000
Market-Based Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense excluding options	$ 0
2007 Plan and 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance (in shares)	12,082,101
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)	4,382,070
Unrecognized compensation expense related to options	$ 67,900,000
2013 Stock Incentive Plan | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period to recognize compensation expense (in years)	2 years 8 months 12 days
2013 Stock Incentive Plan | Performance-Based Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense excluding options	$ 0
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance (in shares)	921,043
Shares issued under 2013 ESPP (in shares)	59,401	62,694
Opportunity to purchase of common stock (in shares)	1,345,454

Share-Based Payments - Summary

Share-Based Payments - Summary of Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Number of Stock Options
Outstanding, beginning balance (in shares) | shares	6,143,046
Granted (in shares) | shares	872,672
Exercised (in shares) | shares	(122,422)
Forfeited/expired (in shares) | shares	(711,343)
Outstanding, ending balance (in shares) | shares	6,181,953
Number of stock options, exercisable (in shares) | shares	4,050,765
Number of stock options, vested and expected to vest (in shares) | shares	6,181,953
Weighted-Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 58.46
Granted (in usd per share) | $ / shares	56.17
Exercised (in usd per share) | $ / shares	41.06
Forfeited/expired (in usd per share) | $ / shares	56.04
Outstanding, ending balance (in usd per share) | $ / shares	58.76
Weighted-average exercise price, exercisable (in usd per share) | $ / shares	61.02
Weighted-average exercise price, vested and expected to vest (in usd per share) | $ / shares	$ 58.76

Share-Based Payments - Summar_2

Share-Based Payments - Summary of Unvested RSUs Activity (Details) - Restricted stock units	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Number of Stock Units
Unvested shares beginning of period (in shares) | shares	1,284,378
Granted (in shares) | shares	701,314
Vested (in shares) | shares	(336,462)
Forfeited (in shares) | shares	(386,136)
Unvested shares end of period (in shares) | shares	1,263,094
Weighted-Average Grant Date Fair Value
Unvested shares beginning of period (in usd per share) | $ / shares	$ 50.78
Granted (in usd per share) | $ / shares	56.08
Vested (in usd per share) | $ / shares	58.16
Forfeited (in usd per share) | $ / shares	52.15
Unvested shares end of period (in usd per share) | $ / shares	$ 51.34

Share-Based Payments - Schedule

Share-Based Payments - Schedule of Performance-Based and Market- Based Units (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Performance-Based Stock Units
Number of Stock Units
Unvested shares beginning of period (in shares) | shares	142,229
Granted (in shares) | shares	121,000
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(10,850)
Unvested shares end of period (in shares) | shares	252,379
Weighted-Average Grant Date Fair Value
Unvested shares beginning of period (in usd per share) | $ / shares	$ 54.28
Granted (in usd per share) | $ / shares	56.68
Vested (in usd per share) | $ / shares	0
Forfeited (in usd per share) | $ / shares	61.93
Unvested shares end of period (in usd per share) | $ / shares	$ 55.10
Market-Based Stock Units
Number of Stock Units
Unvested shares beginning of period (in shares) | shares	42,695
Granted (in shares) | shares	0
Unvested shares end of period (in shares) | shares	42,695
Weighted-Average Grant Date Fair Value
Unvested shares beginning of period (in usd per share) | $ / shares	$ 41.50
Granted (in usd per share) | $ / shares	0
Unvested shares end of period (in usd per share) | $ / shares	$ 41.50

Share-Based Payments - Schedu_2

Share-Based Payments - Schedule of Stock-Based Compensation Expense by Award Type Included Within the Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 14,854	$ 15,670
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	8,396	9,309
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	6,205	4,459
Performance-Based Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	0	1,335
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	253	297
Other stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 0	$ 270

Share-Based Payments - Expenses

Share-Based Payments - Expenses Related to Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 14,854	$ 15,670
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	6,973	6,999
Selling, general and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7,881	$ 8,671

Loss per Share - Common Stock E

Loss per Share - Common Stock Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	7,452,431	8,132,598
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	6,181,953	6,749,373
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	1,263,094	1,290,875
Performance-based stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	0	78,920
Employee stock purchase plan shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents (in shares)	7,384	13,430

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Provision for income taxes recorded in discontinued operations	$ 12,900,000	$ 0
Provision for income taxes recorded in continuing operations	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 05, 2021	Apr. 02, 2021	Mar. 25, 2021
Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, authorized amount			$ 1,200,000
Repurchase Program | Subsequent Event
Subsequent Event [Line Items]
Shares repurchased (in shares)	7,121,658
Shares repurchased, aggregate purchase price	$ 344,500
Shares repurchased (in usd per share)	$ 48.3785
Rule 10b5-1 repurchase plan | Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program, authorized amount		$ 600,000