Blueprint Medicines (BPMC) 10-Q 2 May 24 2024 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - $ / shares	3 Months Ended
	Mar. 31, 2024	Apr. 30, 2024
Cover [Abstract]
Entity Central Index Key	0001597264
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-37359
Entity Registrant Name	BLUEPRINT MEDICINES CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-3632015
Entity Address, Address Line One	45 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	374-7580
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	BPMC
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 Listing, Par Value Per Share	$ 0.001
Entity Common Stock, Shares Outstanding		62,616,902
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 113,326	$ 71,286
Marketable securities	534,575	639,355
Accounts receivable	60,047	42,827
Inventory	30,940	21,223
Prepaid expenses and other current assets	37,714	33,702
Total current assets	776,602	808,393
Marketable securities	87,703	56,530
Property and equipment, net	41,947	41,959
Operating lease right-of-use assets, net	71,222	73,691
Restricted cash	10,634	10,238
Equity investment	27,789	27,789
Other assets	22,578	30,650
Total assets	1,038,475	1,049,250
Current liabilities:
Accounts payable	4,926	4,710
Accrued expenses	107,277	127,992
Current portion of operating lease liabilities	12,240	11,933
Current portion of deferred revenue	7,251	812
Current portion of liabilities related to the sale of future royalties and revenues	44,729	39,198
Current portion of term loan	30,180	30,278
Total current liabilities	206,603	214,923
Operating lease liabilities, net of current portion	78,489	81,751
Deferred revenue, net of current portion	4,635	4,792
Liabilities related to the sale of future royalties and revenues, net of current portion	223,090	402,427
Term loan, net of current portion	209,205	208,535
Other long-term liabilities	5,766	6,213
Total liabilities	727,788	918,641
Commitments and Contingencies (Note 16)
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.001 par value; 120,000,000 shares authorized; 62,594,247 and 61,147,236 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	63	61
Additional paid-in capital	2,565,277	2,473,985
Accumulated other comprehensive loss	(3,847)	(3,495)
Accumulated deficit	(2,250,806)	(2,339,942)
Total stockholders' equity	310,687	130,609
Total liabilities and stockholders' equity	$ 1,038,475	$ 1,049,250

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Preferred Stock Disclosures
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common Stock Disclosures
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	62,594,247	61,147,236
Common Stock, shares outstanding (in shares)	62,594,247	61,147,236

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues:
Revenue	$ 96,116	$ 63,287
Cost and operating expenses:
Cost of sales	3,191	3,175
Research and development	88,191	112,073
Selling, general and administrative	83,557	70,950
Collaboration loss sharing		1,296
Total cost and operating expenses	174,939	187,494
Other income (expense):
Interest expense, net	(5,895)	(5,819)
Other income, net	376	986
Debt extinguishment gain	173,658
Total other income (expense), net	168,139	(4,833)
Income (loss) before income taxes	89,316	(129,040)
Income tax expense	180	520
Net income (loss)	89,136	(129,560)
Other comprehensive income (loss):
Unrealized gains (losses) on available-for-sale investments	(564)	5,819
Currency translation adjustments	212	22
Comprehensive income (loss)	$ 88,784	$ (123,719)
Net income (loss) per share - basic (in dollars per share)	$ 1.45	$ (2.15)
Net income (loss) per share - diluted (in dollars per share)	$ 1.40	$ (2.15)
Weighted-average number of common shares used in net income (loss) per share - basic (in shares)	61,580	60,126
Weighted-average number of common shares used in net income (loss) per share - diluted (in shares)	63,802	60,126
Product revenue, net
Revenues:
Revenue	$ 92,525	$ 39,069
Collaboration and License
Revenues:
Revenue	$ 3,591	$ 24,218

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2022	$ 60	$ 2,358,018	$ (10,443)	$ (1,832,958)	$ 514,677
Beginning Balance (in shares) at Dec. 31, 2022	59,958,919
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plan (in shares)	457,416
At-the-market offerings, net of issuance costs (in shares)					0
Stock-based compensation expense		23,340			$ 23,340
Other comprehensive income (loss)			5,841		5,841
Net income (loss)				(129,560)	(129,560)
Ending Balance at Mar. 31, 2023	$ 60	2,381,358	(4,602)	(1,962,518)	414,298
Ending Balance (in shares) at Mar. 31, 2023	60,416,335
Beginning Balance at Dec. 31, 2023	$ 61	2,473,985	(3,495)	(2,339,942)	$ 130,609
Beginning Balance (in shares) at Dec. 31, 2023	61,147,236				61,147,236
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plan	$ 1	17,900			$ 17,901
Issuance of common stock under stock plan (in shares)	902,292
At-the-market offerings, net of issuance costs	$ 1	48,935			$ 48,936
At-the-market offerings, net of issuance costs (in shares)	544,719				544,719
Stock-based compensation expense		24,457			$ 24,457
Other comprehensive income (loss)			(352)		(352)
Net income (loss)				89,136	89,136
Ending Balance at Mar. 31, 2024	$ 63	$ 2,565,277	$ (3,847)	$ (2,250,806)	$ 310,687
Ending Balance (in shares) at Mar. 31, 2024	62,594,247				62,594,247

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net income (loss)	$ 89,136	$ (129,560)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,810	3,684
Non-cash lease expense	2,404	2,202
Stock-based compensation	24,225	23,196
Non-cash interest expense	793	4,635
Net (accretion of discount) amortization of premium on investments	(5,193)	(2,380)
Non-cash debt extinguishment gain	(173,658)
Other	(827)	1,683
Changes in assets and liabilities:
Accounts receivable	(17,339)	(4,949)
Inventory	2,696	78
Prepaid expenses and other current assets	1,016	15,640
Other assets	(4,332)	(417)
Accounts payable	313	7,806
Accrued expenses	(25,826)	(23,686)
Other long-term liabilities		(7,238)
Deferred revenue	3,158	(11,099)
Operating lease liabilities	(2,889)	(2,556)
Net cash used in operating activities	(101,513)	(122,961)
Cash flows from investing activities
Purchases of property and equipment	(1,104)	(2,584)
Purchases of investments	(200,165)	(132,875)
Maturities of investments	278,400	308,250
Net cash provided by investing activities	77,131	172,791
Cash flows from financing activities
Proceeds from at-the-market offerings, net of issuance costs	48,936
Net proceeds from stock option exercises and employee stock purchase plan	18,396
Principal payments for financing arrangements	(369)
Net cash provided by financing activities	66,963
Net increase in cash, cash equivalents, and restricted cash	42,581	49,830
Cash, cash equivalents and restricted cash at beginning of period	81,524	124,904
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(145)	197
Cash, cash equivalents and restricted cash at end of period	123,960	174,931
Supplemental cash flow information
Cash paid for interest	14,280	7,084
Property and equipment purchases unpaid at period end	1,834
Cash paid for taxes, net	$ 520	$ 311

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Nature of Business	1. Nature of Business Blueprint Medicines Corporation (the Company), a Delaware corporation incorporated on October 14, 2008, is a global fully-integrated biopharmaceutical company that invents life-changing medicines in two core focus areas: allergy/inflammation and oncology/hematology. The Company’s approach targets the root causes of disease, using deep scientific knowledge in the Company’s core focus areas and drug discovery expertise across multiple therapeutic modalities. The Company has a track record of success with two approved medicines, including AYVAKIT®/AYVAKYT® (avapritinib), which the Company is bringing to patients living with systemic mastocytosis (SM) and PDGFRA Exon 18 mutant GIST in the U.S. and Europe. Leveraging the Company’s established research, development, and commercial capability and infrastructure, the Company now aims to significantly scale its impact by advancing a board pipeline of programs ranging from early science to advanced clinical trials in mast cell diseases including SM and chronic urticaria, breast cancer and other solid tumors. As of March 31, 2024, the Company had cash, cash equivalents and marketable securities of $735.6 million. Based on the Company’s current operating plans, the Company anticipates that its existing cash, cash equivalents and marketable securities will be sufficient to enable it to fund its current operations for at least the next twelve months from the issuance of the financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Summary of Significant Accounting Policies and Recent Accounting Pronouncements	2. Summary of Significant Accounting Policies and Recent Accounting Pronouncements Basis of Presentation The unaudited interim condensed consolidated financial statements of the Company included herein have been prepared in accordance with accounting principles generally accepted in the U.S. (GAAP) as found in the Accounting Standards Codification (ASC), Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB) and the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these financial statements should be read in conjunction with the financial statements as of and for the year ended December 31, 2023 and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 15, 2024 (2023 Annual Report on Form 10-K). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements, and updated, as necessary, in this report. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of March 31, 2024, the results of its operations for the three months ended March 31, 2024 and 2023, stockholder’s equity for the three months ended March 31, 2024 and 2023 and cash flows for three months ended March 31, 2024 and 2023. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2024 are not necessarily indicative of the results for the year ending December 31, 2024 or for any future period. The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Blueprint Medicines Security Corporation, which is a Massachusetts subsidiary created to buy, sell and hold securities, Blueprint Medicines (Switzerland) GmbH, Blueprint Medicines (Netherlands) B.V., Blueprint Medicines (UK) Ltd., Blueprint Medicines (Germany) GmbH, Blueprint Medicines (Spain) S.L., Blueprint Medicines (France) SAS, and Blueprint Medicines (Italy) S.r.L. All intercompany transactions and balances have been eliminated. ​ Use of Estimates The preparation of financial statements in conformity with GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Management considers many factors in selecting appropriate financial accounting policies and in developing the estimates and assumptions that are used in the preparation of the financial statements. Management must apply significant judgment in this process. Management’s estimation process often may yield a range of potentially reasonable estimates and management must select an amount that falls within that range of reasonable estimates. Estimates are used in the following areas, among others: revenue recognition, inventory, operating lease right-of-use assets, operating lease liabilities, stock-based compensation expense, accrued expenses, liabilities related to the sale of future royalties and future revenues, equity investment, and income taxes. Actual results may differ from these estimates. Significant Accounting Policies The significant accounting policies used in preparation of these condensed consolidated financial statements for the three months ended March 31, 2024 are consistent with those discussed in Note 2 to the consolidated financial statements in the 2023 Annual Report on Form 10-K, with the exception of the below new policy. Modification of debt instruments New Accounting Pronouncements ​ Reclassification ​

Financing Arrangements

Financing Arrangements	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Financing Arrangements	3. Financing Arrangements ​ Royalty Pharma Purchase and Sale Agreement On June 30, 2022, the Company entered into a purchase and sale agreement (Royalty Purchase Agreement) with Royalty Pharma Investments 2019 ICAV (Royalty Pharma). Pursuant to the Royalty Purchase Agreement, the Company received an upfront payment of $175.0 million in consideration for the Company’s rights to receive royalty payments on the net sales of GAVRETO worldwide, excluding the CStone Territory (as defined below) and the U.S., under the terms of the Roche pralsetinib collaboration agreement. Despite selling all rights to receive royalties on GAVRETO net sales of the underlying territories to Royalty Pharma, the Company maintained its involvement in the global co-development of pralsetinib with Roche and was therefore involved in the generation of these future royalties. Due to the Company’s significant continued involvement, any royalties and development and commercialization milestones earned pertaining to the underlying territory under the Roche pralsetinib collaboration agreement were recognized as collaboration revenue on the consolidated statements of operations and comprehensive income (loss) throughout the contract term of the Roche pralsetinib collaboration agreement. The net proceeds received from the transaction were recorded as a liability related to sale of future royalties and revenues on the consolidated balance sheet on June 30, 2022. In February 2023, the Company received written notice from Roche of their election to terminate for convenience the Roche pralsetinib collaboration agreement. The termination became effective February 2024 and the Company regained commercialization and development rights to GAVRETO from Roche worldwide excluding the CStone Territory. In January 2024, the Company decided to discontinue global development and marketing of GAVRETO in territories excluding the U.S. and the CStone Territory following the termination of the Roche pralsetinib collaboration. In connection with and effective upon the termination of the Roche pralsetinib collaboration agreement, on February 22, 2024 (the Royalty Pharma Termination Date), Royalty Pharma and the Company agreed to terminate the Royalty Purchase Agreement (Royalty Pharma Termination Agreement). Following the termination of the Royalty Purchase Agreement, the Company has no outstanding obligations under the Royalty Purchase Agreement, other than the remaining royalty payment obligation related to GAVRETO net sales through the termination effective date . The Company has no material outstanding obligations under the Royalty Pharma Termination Agreement and it was accounted for as a debt extinguishment under ASC 470-50 as the terms and conditions of the Royalty Purchase Agreement had undergone a substantial modification and the modified terms are considered substantially different. As a result, during the three months ended March 31, 2024, the Company recorded a debt extinguishment gain of $173.7 million as other income in the unaudited condensed consolidated statements of operations and comprehensive income (loss). As of March 31, 2024, the net carrying value of liability related to these agreements was $0.9 million, which was determined based on the fair value of the remaining cash flow associated with anticipated future payments outlined in the Royalty Pharma Termination Agreement. Financing Arrangements with Sixth Street Partners ​ ​ Sixth Street Partners Purchase and Sale Agreement ​ Pursuant to the Future Revenue Purchase Agreement, the Company received gross proceeds of $250.0 million in exchange for future royalty payments at a rate of 9.75% on up to $900 million each year of (i) aggregate worldwide annual net product sales of AYVAKIT/AYVAKYT (avapritinib) and (ii), if it is approved, aggregate worldwide annual net product sales of BLU-263 (elenestinib), but excluding sales in Greater China, subject to a cumulative cap of 1.45 times the upfront invested capital or a total of $362.5 million. In the event that certain revenue targets are not achieved by specified dates, the royalty rate and cumulative cap shall be increased to 15% and 1.85 times the invested capital (or $462.5 million), respectively. ​ The Company continues to own the research, development, manufacturing and commercialization of AYVAKIT/AYVAKYT and if it is approved, elenestinib, and has significant continuing involvement in the generation of the cash flows under the Future Revenue Purchase Agreement. Therefore, the Company continues to account for any revenue earned from worldwide product sales of AYVAKIT/AYVAKYT and, if it is approved, elenestinib, on its consolidated statements of operations and comprehensive income (loss). Net proceeds received from the transaction were recorded as a liability related to sale of future royalties and revenues on the consolidated balance sheet. The Company accretes the $250.0 million, net of transaction costs of $5.4 million, to the total of these future payments as interest expense using the effective interest method over the estimated life of the arrangement. ​ As payments are made to Sixth Street Partners, the balance of the liability is effectively repaid over the life of the Future Revenue Purchase Agreement. In order to determine the amortization of the liability, the Company estimates the total amount of future revenue payments to be paid to Sixth Street Partners over the life of the arrangement. The exact amount of repayment is likely to change each reporting period. A significant increase or decrease in worldwide product sales of AYVAKIT/AYVAKYT and, if it is approved, elenestinib, will materially impact the liability related to this arrangement, interest expense and the time period for repayment. The Company periodically assesses the expected payments to Sixth Street Partners and prospectively adjusts the amortization of the liability related to this arrangement for material changes in such payments. As of March 31, 2024, the Company’s estimate of this total interest expense resulted in an effective annual interest rate of 10.8%. These estimates contain assumptions that impact the amount recorded and the interest expense that will be recognized in future periods. ​ As of March 31, 2024, the net carrying value of the liability related to this arrangement was $266.9 million. The following table shows the activity within the liability account (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Beginning Balance at January 1 ​ $ 266,670 ​ $ 254,328 Interest expense recognized ​ ​ 7,096 ​ ​ 7,089 Payments ​ ​ (6,875) ​ ​ (2,883) Carrying value as of March 31 ​ $ 266,891 ​ $ 258,534 ​ Sixth Street Partners Term Loan ​ ​ As part of the Financing Agreement with Sixth Street Partners, the Company received gross proceeds of $150.0 million in July 2022 and incurred an aggregate of $12.2 million of debt discounts and transaction costs. In August 2023, the Company received the first tranche of the senior secured delayed draw term loan facility in the amount of $100.0 million in gross proceeds and incurred $2.1 million of transaction costs. Debt discounts and transaction costs have been recorded as a reduction to the carrying amount of the debt on the Company’s consolidated balance sheet and are amortized as additional interest expenses using the effective interest rate method over the period from issuance through maturity. In addition, the Company may at any time request an incremental term loan in an amount not to exceed $260.0 million on terms to be agreed and subject to the consent of Sixth Street Partners providing such incremental term loan. As of March 31, 2024, the Company’s estimate of the total interest expense resulted in an effective annual interest rate of 13.2%. The carrying amount of the debt as of March 31, 2024 is subject to variable interest rates, which are based on current market rates, and as such, approximates fair value ​ The following table shows the activity within the liability account (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Beginning Balance at January 1 ​ $ 238,813 ​ $ 139,083 Interest expense recognized ​ ​ 7,977 ​ ​ 4,630 Payments ​ ​ (7,405) ​ ​ (4,201) Carrying value as of March 31 ​ $ 239,385 ​ $ 139,512 ​ indebtedness. The Financing Agreement also requires the Company to maintain a consolidated liquidity of at least (i) $50.0 million during the period commencing from the date on which the term loans are funded to the date which is the day before the next term loans are funded and (ii) $80.0 million for each day thereafter. As of March 31, 2024, the Company was in compliance with the applicable terms and conditions of the covenants under the Financing Agreement.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Marketable Securities	4. Marketable Securities Marketable securities consisted of the following at March 31, 2024 and December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Unrealized Unrealized Fair March 31, 2024 Cost Gain ​ Losses ​ Value Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ $ 120,099 ​ $ 4 ​ $ (343) ​ $ 119,760 U.S. treasury obligations ​ ​ 502,933 ​ ​ 93 ​ ​ (508) ​ ​ 502,518 Total ​ $ 623,032 ​ $ 97 ​ $ (851) ​ $ 622,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Unrealized Unrealized Fair December 31, 2023 Cost Gain ​ Losses ​ Value Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ $ 170,194 ​ $ 27 ​ $ (418) ​ $ 169,803 U.S. treasury obligations ​ ​ 525,880 ​ ​ 588 ​ ​ (386) ​ ​ 526,082 Total ​ $ 696,074 ​ $ 615 ​ $ (804) ​ $ 695,885 ​ The following table summarizes the amortized cost basis and estimated fair value of the Company’s available-for-sale securities by contractual maturity as of March 31, 2024 and December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ Amortized Fair Amortized Fair ​ Cost value Cost value Within one year $ 535,195 $ 534,575 $ 639,881 $ 639,355 After one through five years ​ 87,837 ​ 87,703 ​ 56,193 ​ 56,530 Total $ 623,032 $ 622,278 $ 696,074 $ 695,885 ​ ​ As of March 31, 2024 and December 31, 2023, the Company held 84 and 62 debt securities, respectively, that were in an unrealized loss position. The following table summarizes the estimated fair value and the aggregate unrealized loss of the Company’s available-for-sale securities that are in loss position as of March 31, 2024 and December 31, 2023 by the length of time the security has been in loss position (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ ​ Fair Unrealized Fair Unrealized ​ ​ value ​ losses ​ value ​ losses Debt securities in unrealized loss position for 12 months or less ​ $ 439,535 ​ $ (690) ​ $ 267,917 $ (550) Debt securities in unrealized loss position for more than 12 months ​ ​ 54,782 ​ ​ (161) ​ ​ 64,659 ​ (254) Total debt securities ​ $ 494,317 ​ $ (851) ​ $ 332,576 $ (804) ​ The Company has the intent and ability to hold its debt securities until recovery of amortized cost basis. As a result, the Company did not recognize any differences between the fair value and amortized cost basis as a loss in its condensed consolidated statements of operations and comprehensive income (loss) for the three months ended March 31, 2024 and 2023. The Company did not record any credit-related impairments for its available-for-sale securities for the three months ended March 31, 2024 and 2023. ​ The following table summarizes the proceeds from maturities of debt securities during the three months ended March 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 2023 Proceeds from maturities of debt securities ​ $ 278,400 ​ $ 308,250 ​ ​ The Company did no t realize any gains or losses from maturities of debt securities for the three months ended March 31, 2024 and 2023.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments The following table summarizes the Company’s cash equivalents and marketable securities measured at fair value on a recurring basis as of March 31, 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Active Observable Unobservable ​ ​ March 31, ​ Markets ​ Inputs ​ Inputs Description ​ 2024 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 100,072 ​ $ 100,072 ​ $ — ​ $ — Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ ​ 119,760 ​ ​ — ​ ​ 119,760 ​ ​ — U.S. treasury obligations ​ ​ 502,518 ​ ​ 502,518 ​ ​ — ​ ​ — Total ​ $ 722,350 ​ $ 602,590 ​ $ 119,760 ​ $ — ​ The following table summarizes the Company’s cash equivalents and marketable securities measured at fair value on a recurring basis as of December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Active Observable Unobservable ​ ​ December 31, ​ Markets ​ Inputs ​ Inputs Description ​ 2023 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 55,412 ​ $ 55,412 ​ $ — ​ $ — Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ ​ 169,803 ​ ​ ​ ​ ​ 169,803 ​ ​ — U.S. treasury obligations ​ ​ 526,082 ​ ​ 526,082 ​ ​ — ​ ​ — Total ​ $ 751,297 ​ $ 581,494 ​ $ 169,803 ​ $ —

Product Revenue

Product Revenue	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Product Revenue	6. Product Revenue The Company generates product revenue from the sales of AYVAKIT/AYVAKYT in the U.S. and Europe. 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2024 2023 United States ​ $ 83,136 ​ $ 34,927 Rest of World ​ ​ 9,389 ​ ​ 4,142 Total product revenue ​ $ 92,525 ​ $ 39,069 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 ​ 2023 Customer 1 ​ 39 % ​ 44 % Customer 2 ​ * % ​ 10 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 Customer 1 ​ 35 % ​ 34 % Customer 2 ​ 11 % ​ 11 % Customer 3 ​ 10 % ​ 10 % Customer 4 ​ * % ​ 10 % * Indicates the customer’s share is under 10%. The following table summarizes activity in each of the product revenue allowance and reserve categories for the three months ended March 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 ​ 2023 Beginning balance at January 1 $ 19,274 ​ $ 9,788 Provision related to sales in the current period 16,926 ​ ​ 8,502 Adjustment related to prior periods sales (309) ​ ​ (228) Credits and payments made (12,488) ​ ​ (4,773) Ending balance at March 31 $ 23,403 ​ $ 13,289 The total reserves that are included in the Company’s unaudited condensed consolidated balance sheets as of March 31, 2024 and December 31, 2023, are summarized as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2024 ​ 2023 Reduction of accounts receivable, net $ 2,640 ​ $ 1,809 Component of accrued expenses ​ 20,763 ​ ​ 17,465 Total revenue-related reserves $ 23,403 ​ $ 19,274

Inventory

Inventory	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Inventory	7. Inventory Capitalized inventory consists of the following at March 31, 2024 and December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 Raw materials ​ $ 3,069 ​ $ 3,147 Work in process ​ ​ 30,777 ​ ​ 29,132 Finished goods ​ 3,001 ​ 4,823 Total ​ $ 36,847 ​ $ 37,102 ​ Balance sheet classification ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 Inventory ​ $ 30,940 ​ $ 21,223 Other assets ​ 5,907 ​ 15,879 Total ​ $ 36,847 ​ $ 37,102 ​ Inventory amounts written down as a result of excess, obsolescence, unmarketability or other reasons are charged to cost of sales. The Company recognized an insignificant write-down and write-down of $1.5 million for the three months ended March 31, 2024 and 2023, respectively. Long-term inventory, which consists of work in process, is included in other assets in the unaudited condensed consolidated balance sheets.

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Restricted Cash	8. Restricted Cash The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Company's condensed consolidated balance sheets for the three months ended March 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ Cash and cash equivalents ​ $ 113,326 ​ $ 169,724 ​ Restricted cash ​ ​ 10,634 ​ ​ 5,207 ​ Total cash, cash equivalents, and restricted cash shown in condensed consolidated statements of cash flows ​ $ 123,960 ​ $ 174,931 ​ ​ As of March 31, 2024 and December 31, 2023, $10.6 million and $10.2 million, respectively, of the Company’s cash is restricted by a financial institution primarily related to funds held to satisfy the requirements of certain government agreements and the security deposits for the lease agreements for the Company’s office and laboratory spaces.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Accrued Expenses	9. Accrued Expenses Accrued expenses as of March 31, 2024 and December 31, 2023 consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2024 2023 Research, development and commercial contract costs ​ $ 39,612 ​ $ 49,354 Employee compensation ​ ​ 20,006 ​ ​ 43,434 Accrued professional fees ​ 19,852 ​ 12,522 Revenue-related reserves ​ ​ 20,763 ​ ​ 17,465 Other ​ ​ 7,044 ​ ​ 5,217 Total ​ $ 107,277 ​ $ 127,992

Collaboration and Other Agreeme

Collaboration and Other Agreements	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Collaboration and Other Agreements	10 . Collaboration and Other Agreements Rigel On February 22, 2024, the Company entered into an Asset Purchase Agreement with Rigel Pharmaceuticals, Inc. (“Rigel”) for Rigel to purchase certain assets from the Company comprising the U.S. rights to research, develop, manufacture and commercialize GAVRETO (pralsetinib). Such assets include, among other things, applicable intellectual property related to pralsetinib in the U.S, including patents, copyrights and trademarks, as well as clinical regulatory and commercial data and records. Simultaneously and in connection with entering into the Asset Purchase Agreement, the parties also entered into certain supporting agreements, including a customary transition agreement, (such agreements collectively, the Rigel agreement), pursuant to which, during a transition period, the Company will transition certain inventory and regulatory and distribution responsibility for pralsetinib to Rigel. This transition is anticipated to be completed in the third quarter of 2024. Under the terms of the Rigel agreement, the Company will receive a purchase price of $15.0 million, with $10.0 million payable upon first commercial sale of GAVRETO by Rigel and an additional $5.0 million payable on the earlier of (i) the first anniversary of the closing date of the transaction as a delayed purchase price, or (ii) the completion of certain transition activities. The Company is also eligible to receive up to $102.5 million in contingent specified regulatory and commercial milestone payments, in addition to tiered percentage royalties ranging from ten percent to 30 percent on annual net sales of GAVRETO in the U.S. The royalties will be payable until the later of (i) the expiration of the royalty term, as defined in the agreement, which begins on the date of the first commercial sale of GAVRETO in the U.S., (ii) the date of expiration of the last valid patent claim within the Company’s IP that covers GAVRETO in the U.S., and (iii) the expiration of the last regulatory exclusivity for GAVRETO in the U.S. Under the Rigel agreement, the Company has an obligation to provide compensation to Rigel in response to credit events arising from the transition activities as defined in the Rigel agreement. The Company determined that the Rigel agreement is a transaction with a customer and therefore accounted for the transaction in accordance with ASC 606. For the purpose of ASC 606, the transaction price, including variable considerations, of the Rigel agreement at the outset of the arrangement are fully constrained until key transition activities, including transfer of the new drug application (NDA), stipulated in the Rigel agreement have been completed based on the defined timeline. Therefore, no revenue was recognized in the condensed consolidated statement of operations during the three months ended March 31, 2024. IDRx In August 2022, the Company entered into a license agreement with IDRx, Inc. (IDRx), pursuant to which the Company granted IDRx an exclusive, worldwide, royalty-bearing license to exploit the Company’s internally discovered KIT exon 13 inhibitor IDRX-73 (IDRx License Agreement). IDRx is a clinical-stage biopharmaceutical company and a mong IDRx’s founders are Alexis Borisy, George Demetri, M.D., and Nicholas Lydon, Ph.D., who were each members of the Company’s board of directors at the time. Due to these relationships, the transaction with IDRx is a related party transaction. In connection with the IDRx License Agreement, the Company also entered into a stock purchase agreement with IDRx (IDRx Stock Purchase Agreement), pursuant to which the Company received 4,509,105 shares of IDRx’s Series A preferred stock with the right to receive additional shares of IDRx’s Series A preferred stock through an anti-dilution provision subject to a defined financing cap. In July 2023, the Company received 192,282 additional shares under the anti-dilution provision. The shares are restricted from reselling unless IDRx subsequently proposes a resale registered under the Securities Act or if an exemption from registration is otherwise available. The Company is also eligible to receive up to $217.5 million in contingent cash payments, including specified development, regulatory and sales-based milestone payments. In addition, IDRx is obligated to pay to the Company royalties on aggregate annual worldwide net sales of licensed products at tiered percentage rates up to low-teens, subject to adjustments in specified circumstances under the IDRx License Agreement. Unless earlier terminated, the IDRx License Agreement will expire on a country-by-country, licensed product-by-licensed product basis upon the latest of: (a) the expiration of the last valid claim within the licensed patents covering such licensed product in a such country, (b) the expiration of the regulatory exclusivity period for such licensed product in such country, or (c) the 10th anniversary of the first commercial sale of such licensed product in such country. Following the end of the term for any such licensed product and in such region by expiration, the license granted to IDRx will become exclusive, perpetual, irrevocable, fully paid-up and royalty-free. IDRx may terminate the IDRx License Agreement for convenience at any time upon at least twelve months ’ prior written notice to the Company. Either party may also terminate the IDRx License Agreement for material breach of the other party or for insolvency, and the Company may terminate the IDRx License Agreement for IDRx’s breach of the anti-dilution provision in the IDRx Stock Purchase Agreement. Upon termination of the license agreement in its entirety, all rights and obligations under the license agreement will terminate and revert back to the Company, and the Company has a license under certain intellectual property of IDRx to continue to exploit the compound and terminated product, subject to a royalty that will be negotiated at the time of termination. The Company considered the ASC 606 criteria for combining contracts and determined the IDRx License Agreement and the IDRx Stock Purchase Agreement should be combined into a single contract because they were negotiated and entered into in contemplation of one another. Therefore, the Company determined that the 4,509,105 shares of IDRx’s Series A preferred stock and the anti-dilution right to receive additional shares should be attributed to the transaction price of the IDRx License Agreement. The Company evaluated the IDRx License Agreement under ASC 606. The Company identified the following material promises under the agreement: (1) the exclusive license and (2) the initial know-how transfer. The Company determined that the exclusive license and the initial know-how transfer were not distinct from each other, as the exclusive license has limited value without the corresponding know-how transfer. As such, for the purposes of ASC 606, the Company determined that these two material promises, the exclusive license and the initial know-how transfer, should be combined into one distinct performance obligation. The Company concluded that the license is a functional intellectual property license. The Company determined that IDRx benefited from the license along with the initial know-how transfer at the time of grant, and therefore the related performance obligation is satisfied at a point in time. For the purposes of ASC 606, the transaction price of the IDRx License Agreement at the contract inception was determined to be $27.5 million and recorded as license revenue-related party on the consolidated statements of operations and comprehensive loss during 2022. The fair value was derived from IDRx’s most recent financing transaction with unrelated investors. All potential milestone payments that the Company is eligible to receive under the IDRx License Agreement have been excluded from the transaction price. The Company reevaluates the transaction price for inclusion of milestone payments and royalties at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, and if necessary, the Company adjusts its estimate of the transaction price, and any addition to the transaction price would be recognized as revenue when it becomes probable that inclusion would not lead to a significant revenue reversal. Additionally, the Company is entitled to sales milestones and royalties from the sales of the licensed products, and revenue are recognized when the related sales occur. The Company concluded the preferred stock investment should be accounted for as an equity investment as it is not mandatorily redeemable nor does the Company have the unilateral right to redeem the preferred stock, and the Company, along with its related parties, do not have a controlling financial interest in IDRx nor have the ability to influence the financial and operating policies through the ownership of preferred stock. IDRx’s preferred stock is not exchange-traded and does not have a readily determinable fair value. Therefore, the preferred stock investment is accounted for under the measurement alternative for equity investments that do not have a readily determinable fair value, which is at cost of $27.8 million including transaction costs of $0.3 million. As of March 31, 2024, the cost of the investment in IDRx’s preferred stock was $27.8 million and no adjustments have been recognized related to the preferred stock investment as a result of the application of the measurement alternative. No revenue was recorded under the IDRx License Agreement during the three months ended March 31, 2024 and 2023. VantAI Under the A&R Agreement, VantAI will be eligible to receive up to $1.67 billion in contingent payments including specified research, development, regulatory and commercialization milestones for all the target programs. The Company will be obligated to pay VantAI tiered percentage royalties on a licensed product-by-licensed product basis ranging from the mid-single digits on annual net sales of each licensed product in the applicable territory, subject to adjustment in specified circumstances. Under the 2022 Agreement, the Company paid Proteovant an upfront payment of $20.0 million in connection with the execution of the 2022 Agreement. This upfront payment was recorded as a prepaid asset on the Company’s consolidated balance sheet and was amortized as research and development expense over the expected research period because the Company concluded that Proteovant was providing the Company with research services throughout such period. The Company determined to continue to amortize the remaining prepaid asset balance as research and development expense over the expected research period of the A&R Agreement as VantAI continued to provide such research and development services. During the three months ended March 31, 2024 and 2023, the Company recorded research and development expense of $2.1 million and $1.3 million under the A&R Agreement and the 2022 Agreement, respectively. The Company reevaluates the expected research period at the end of each reporting period and prospectively adjusts the amortization of the asset for changes in the expected research period. Each research and development milestone payment is accrued and expensed when probable. Zai Lab In November 2021, the Company entered into a collaboration (the Zai Lab agreement) with Zai Lab (Shanghai) Co., Ltd., (Zai Lab) to develop and commercialize certain licensed products for the treatment of EGFR-driven non-small cell lung cancer in Greater China, including Mainland China, Hong Kong, Macau and Taiwan (collectively, the Zai Lab Territory). The collaboration aims to accelerate and expand global development of the licensed products, which currently include BLU-945 and BLU-525. In January 2024, the Company decided to discontinue further investment in the early clinical-stage therapies for EGFR-mutant NSCLC globally, which includes BLU-945 and BLU-525. Zai Lab retains its rights to BLU-945 and BLU-525 under the agreement. The Company retains exclusive rights to the licensed products outside the Zai Lab Territory. The decision to deprioritize the licensed products does not have an impact on the Company’s accounting treatment related to the Zai Lab agreement. Under the Zai Lab agreement, the Company received an upfront cash payment of $25.0 million and, in addition to the upfront payment received, the Company is eligible to receive up to $590.0 million in contingent payments, including specified development, regulatory and sales-based milestones and tiered percentage royalties on a licensed product-by-licensed product basis ranging from the low-teens to mid-teens on annual net sales of each licensed product in the Zai Lab Territory, subject to adjustment in specified circumstances. Zai Lab is responsible for costs related to clinical trials in the Zai Lab Territory, other than the specified shared services costs as defined in the Zai Lab agreement which are shared by the Company and Zai Lab. Pursuant to the terms of the Zai Lab agreement, Zai Lab is responsible for conducting all development and commercialization activities in the Zai Lab Territory related to the licensed drug candidates. In addition, under the Zai Lab agreement, each party has granted the other party specified intellectual property licenses to enable the other party to perform its obligations and exercise its rights under the Zai Lab agreement, including license grants to enable each party to conduct research, development and commercialization activities pursuant to the terms of the Zai Lab agreement. The Zai Lab agreement will continue on a licensed product-by-product and region-by-region basis until the later of (i) the 12 th second The Company evaluated the Zai Lab agreement to determine whether it is a collaborative arrangement in the scope of ASC 808. The Company concluded that the Zai Lab agreement is a collaborative agreement under ASC 808 as both parties are active participants in the clinical trials and are exposed to significant risks and rewards of those activities under the Zai Lab agreement. The Company determined that the Zai Lab agreement contained two material components: (i) licenses granted to Zai Lab to exploit and develop each licensed product in the Zai Lab Territory and related activities in the Zai Lab Territory, including manufacturing, and (ii) the parties’ participation in the global development of the licensed products. The Company used the criteria specified in ASC 606 to determine which of the components of the Zai Lab agreement are performance obligations with a customer and concluded that Zai Lab is the Company’s customer for the licenses and related activities in the Zai Lab Territory under ASC 606. The global development activities under the agreement does not present a transaction with a customer and the payments received by the Company for global development activities, including manufacturing, are accounted for as a reduction of related expenses. During the three months ended March 31, 2024, the Company did not record any reductions of expenses under the Zai Lab agreement and such reductions of expenses were insignificant during the three months ended March 31, 2023. The Company evaluated the Zai Lab Territory specific licenses and related activities under ASC 606 as these transactions are considered transactions with a customer and identified three material promises at the outset of the Zai Lab agreement, which consists of the following for each licensed product: (1) the exclusive license, (2) the initial know-how transfer and (3) manufacturing activities related to development and commercial supply of the licensed product in the Zai Lab Territory. The Company determined that the exclusive license and the initial know-how transfer were not distinct from each other, as the exclusive license has limited value without the corresponding know-how transfer. As such, for the purposes of ASC 606, the Company determined that these two material promises, the exclusive license and the initial know-how, should be combined into one distinct performance obligation. The Company further evaluated the material promise associated with manufacturing activities related to development and commercial supply of the licensed products in the Zai Lab Territory, given Zai Lab is not obligated to purchase any minimum amount or quantities of the development and commercial supply from the Company, the Company concluded that, for the purpose of ASC 606, the provision of manufacturing activities related to development and commercial supply of the licensed product in Zai Lab Territory was an option but not a performance obligation of the Company at the inception of the Zai Lab collaboration agreement and will be accounted for if and when exercised. The Company also concluded that there is no separate material right in connection with the development and commercial supply of the licensed product, as the expected pricing was not issued at a significant and incremental discount. Therefore, the manufacturing activities were excluded as performance obligation at the outset of the arrangement. The Company evaluated the license under ASC 606 and concluded that the license is a functional intellectual property license. The Company determined that Zai Lab benefited from the license along with the initial know-how transfer at the time of grant, and therefore the related performance obligation is satisfied at a point in time. Additionally, the Company is entitled to sales milestones and royalties from Zai Lab upon future sales of the licensed products in the Zai Lab Territory, and revenue will be recognized when the related sales occur. Costs that are incurred associated with Zai Lab Territory specific activities are reimbursable from Zai Lab and are recognized as revenue. During the three months ended March 31, 2024, the Company did not record any revenue under the Zai Lab agreement and revenue recorded during the three months ended March 31, 2023 under the Zai Lab agreement was insignificant. For the purposes of ASC 606, the transaction price of the Zai Lab agreement at the outset of the arrangement was determined to be $25.0 million, which consisted of the upfront cash payment. The other potential milestone payments that the Company is eligible to receive were excluded from the transaction price, as all milestone amounts were fully constrained based on the probability of achievement. The Company satisfied the performance obligation upon delivery of the licenses and initial know-how transfer, and recognized the upfront payment of $25.0 million as revenue in 2021. The Company reevaluates the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur, and if necessary, the Company adjusts its estimate of the transaction price, and any addition to the transaction price would be recognized as revenue when it becomes probable that inclusion would not lead to a significant revenue reversal. Roche – Pralsetinib Collaboration Under the Roche pralsetinib collaboration agreement, the Company received an upfront cash payment of $675.0 million. Through the collaboration termination effective date, the Company received an aggregate of $105.0 million in specified regulatory and commercialization milestones under the Roche pralsetinib collaboration agreement. The Company and Roche continued to perform their respective obligations under the Roche pralsetinib collaboration agreement through the collaboration termination effective date. In the U.S., the Company and Roche co-commercialized pralsetinib and shared responsibilities, profits and losses equally. In addition, the Company received tiered royalties ranging from high-teens to mid-twenties on annual net sales of pralsetinib outside the U.S., excluding the CStone Territory (the Roche Territory). The Company and Roche also co-developed pralsetinib globally in RET-altered solid tumors, including non-small cell lung cancer, medullary thyroid carcinoma and other thyroid cancers, as well as other solid tumors. The Company and Roche shared global development costs for pralsetinib at a rate of 45 percent for the Company and 55 percent for Roche. In connection with the Roche pralsetinib collaboration agreement, on July 13, 2020, the Company also entered into a stock purchase agreement with Roche Holdings, Inc. (Roche Holdings) pursuant to which the Company issued and sold an aggregate of 1,035,519 shares of common stock to Roche Holdings at a purchase price of $96.57 per share and received an aggregate of $100.0 million in the third quarter of 2020. The closing for a minority portion of the equity investment occurred following the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and other customary closing conditions. The Company considered the ASC 606 criteria for combining contracts and determined that the Roche pralsetinib collaboration agreement and stock purchase agreement should be combined into a single contract because they were negotiated and entered into in contemplation of one another. The Company accounted for the common stock issued to Roche Holdings based on the fair market value of the common stock on the dates of issuance. The fair market value of the common stock issued to Roche Holdings was $79.3 million, based on the closing price of the Company’s common stock on the dates of issuance, resulting in a $20.7 million premium. The Company determined that the premium paid by Roche Holdings for the common stock should be attributed to the transaction price of the Roche pralsetinib collaboration agreement. The Company determined that the Roche pralsetinib collaboration agreement contained four material components: (i) licenses granted to Roche to develop and commercialize pralsetinib worldwide, excluding the CStone Territory (pralsetinib license); (ii) the Roche Territory-specific commercialization activities for pralsetinib, including manufacturing (Roche Territory activities); (iii) the parties’ joint development activities for pralsetinib worldwide, excluding the CStone Territory; and (iv) the parties’ joint commercialization activities for pralsetinib in the U.S. The Company considered the guidance in ASC 606 to determine which of the components of the Roche pralsetinib collaboration agreement are performance obligations with a customer and concluded that the pralsetinib license and the Roche Territory activities are within the scope of ASC 606 because Roche is the Company’s customer in those transactions. The Company evaluated the Roche pralsetinib license under ASC 606 and concluded that the pralsetinib license is a functional intellectual property license and is a distinct performance obligation. The Company determined that Roche benefited from the pralsetinib license at the time of grant, and therefore the related performance obligation is satisfied at a point in time. The Company evaluated the Roche Territory activities under ASC 606 and identified one material promise associated with manufacturing activities related to development and commercial supply of pralsetinib in the Roche Territory for up to 24 months. Given that Roche was not obligated to purchase any minimum amount or quantities of the development and commercial supply from the Company, the Company concluded that, for the purpose of ASC 606, the provision of manufacturing activities related to development and commercial supply of pralsetinib in Roche Territory was an option but not a performance obligation of the Company at the inception of the Roche collaboration agreement and was accounted for when exercised. The Company also concluded that there was no separate material right in connection with the development and commercial supply of pralsetinib, as the expected pricing was not issued at a significant and incremental discount. Therefore, the manufacturing activities were excluded as performance obligations at the outset of the arrangement. Costs incurred associated with the Roche Territory activities were reimbursable from Roche and were recognized as revenue. For the purposes of ASC 606, the transaction price of the Roche pralsetinib collaboration agreement at the outset of the arrangement was determined to be $695.7 million, which consisted of the upfront cash payment of $675.0 million and the $20.7 million premium on the sale of common stock to Roche Holdings, which was allocated to the performance obligation related to the pralsetinib licenses. Through the collaboration termination effective date, the Company achieved an aggregate of $105.0 million in specified regulatory and commercialization milestones which were added to the estimated transaction price of the Roche pralsetinib collaboration agreement. Roche was the principal for recording product sales to customers in the U.S., and the Company recognized a portion of the profit as revenue and losses as collaboration loss sharing in its consolidated statements of operations and comprehensive income (loss). During the three months ended March 31, 2024, the Company recorded revenue of $1.4 million derived from profit sharing on Roche sales of GAVRETO in the U.S. through the collaboration termination effective date. During the three months ended March 31, 2023, the Company recorded a collaboration loss sharing expense of $1.3 million on Roche’s sales of GAVRETO in the U.S.. ​ Despite selling all rights to receive royalties on GAVRETO net sales of Roche Territory to Royalty Pharma in June 2022, given the Company’s significant continued involvement in the generation of future royalties through the collaboration termination effective date, the Company continued to record any royalties earned related to the Roche Territory activities under the Roche pralsetinib collaboration agreement as collaboration revenue on its consolidated statements of operations and comprehensive income (loss) through the collaboration termination effective date. For additional information, see Note 3 – Financing Arrangements ​ The following table summarizes revenue recognized under the Roche pralsetinib collaboration during the three months ended March 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2024 2023 Manufacturing and research and development services related to $ 324 $ 127 Royalty revenue ​ 198 ​ 437 GAVRETO profit share in the U.S. ​ ​ 1,416 ​ ​ — Total Roche pralsetinib collaboration revenue $ 1,938 $ 564 ​ For the parties’ participation in global development for pralsetinib and the U.S. commercialization activities for GAVRETO, the Company concluded that those activities and cost-sharing payments related to such activities are within the scope of ASC 808, as both parties are active participants in the development, manufacturing and commercialization activities and are exposed to significant risks and rewards of those activities under the Roche pralsetinib collaboration agreement. Payments to or reimbursements from Roche related to the global development activities are accounted for either as an increase or reduction of research and development expenses. The following table summarizes the amounts recognized as reductions to selling, general and administrative expenses related to the commercialization of GAVRETO in the U.S. and increases in research and development expenses related to global development activities for pralsetinib under the Roche pralsetinib collaboration during the three months ended March 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2024 2023 Reductions to selling, general and administrative expenses $ 980 $ 2,781 Increases in research and development expenses $ 1,421 $ 8,276 ​ ​ ​ Pursuant to the Roche transition agreement, the Company is obligated to reimburse Roche for wind-down costs associated with the marketing and commercialization activities occurred for Roche Territory until December 31, 2026. Additionally, the Company is obligated to reimburse Roche for any U.S. transition related costs that exceeds GAVRETO’s net sales in the U.S., and any remaining net profit are shared equally between the Company and Roche until December 31, 2025. The Company has concluded that such activities and associated payments to Roche are not within the scope of ASC 808 as only the Company are exposed to significant risks and awards associated with those activities. The Company records those wind-down costs and the net amount of U.S. transition costs reimbursable to Roche as selling, general, and administrative expenses when they are incurred. During the three months ended March 31, 2024, the net amount reimbursable to Roche for these wind-down and U.S. transition related costs was insignificant. The following table summarizes the assets and liabilities associated with the Roche pralsetinib agreements as of March 31, 2024 and December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 Other current assets $ 357 $ 361 Accrued expenses $ — $ 7,388 ​ Clementia In October 2019, the Company entered into a license agreement (the Clementia agreement) with Clementia Pharmaceuticals, Inc. (Clementia), a wholly-owned subsidiary of Ipsen S.A. Under the Clementia agreement, the Company granted an exclusive, worldwide, royalty-bearing license to Clementia to develop and commercialize BLU-782, the Company’s oral, highly selective investigational ALK2 inhibitor in Phase 1 clinical development for the treatment of fibrodysplasia ossificans progressiva (FOP), as well as specified other compounds related to the BLU-782 program. Under the Clementia agreement, the Company received an upfront cash payment of $25.0 million and through March 31, 2024, the Company has received an aggregate of $50.0 million in cash milestone payments. Subject to the terms of the Clementia agreement, in addition to the upfront and milestone payments received through March 31, 2024, the Company is eligible to receive up to $460.0 million in contingent payments, including specified development, regulatory and sales-based milestones for licensed products. In addition, Clementia is obligated to pay to the Company royalties on aggregate annual worldwide net sales of licensed products at tiered percentage rates ranging from the low- to mid-teens, subject to adjustment in specified circumstances under the Clementia agreement, and Clementia purchased specified manufacturing inventory from the Company for a total of $1.5 million. Unless earlier terminated in accordance with the terms of the Clementia agreement, the agreement will expire on a country-by-country, licensed product-by-licensed product basis on the date when no royalty payments are or will become due. Clementia may terminate the agreement at any time upon at least 12 months’ prior written notice to the Company. Either party may terminate the agreement for the other party’s uncured material breach or insolvency and in certain other circumstances agreed to by the parties. In certain termination circumstances, the Company is entitled to retain specified licenses to be able to continue to exploit the Clementia licensed products. The Company evaluated the Clementia agreement under ASC 606, as the agreement represented a transaction with a customer. The Company identified the following material promises under the agreement: (1) the exclusive license to develop, manufacture and commercialize BLU-782; (2) the technology transfer of BLU-782 program; (3) the transfer of existing manufacturing inventory; and (4) the transfer of in-process manufacturing inventory. In addition, the Company determined that the exclusive license and technology transfer were not distinct from each other, as the exclusive license has limited value without the corresponding technology transfer. As such, for the purposes of ASC 606, the Company determined that these four material promises, described above, should be combined into three performance obligations: (1) the exclusive license and the technology transfer; (2) the transfer of existing manufacturing inventory; and (3) the transfer of in-process manufacturing inventory. The Company determined that the transaction price at the outset of the arrangement was $46.5 million, which was allocated to the three performance obligations on a relative stand-alone selling price basis, and was recognized as revenue During the three months ended March 31, 2024 and 2023, no revenue was recognized from the Clementia agreement. All potential milestone payments that the Company is eligible to receive were

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Stockholders' Equity	11. Stockholders’ Equity In February 2022, the Company entered into an at-the-market (ATM) Facility with Cowen, pursuant to which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock having an aggregate offering price of up to $300.0 million through Cowen as sales agent. During the three months ended March 31, 2024, the Company issued and sold 544,719 shares of its common stock under the ATM Facility and received net proceeds of $48.9 million. The Company did not issue any shares under the ATM Facility during the three months ended March 31, 2023.

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Stock-based Compensation	12. Stock-based Compensation 2015 Stock Option and Incentive Plan In 2015, the Company’s board of directors and stockholders approved the 2015 Stock Option and Incentive Plan (the 2015 Plan), which replaced the Company’s 2011 Stock Option and Grant Plan, as amended (the 2011 Plan). The 2015 Plan includes incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance-based restricted stock units, unrestricted stock, performance-based awards and cash- based awards. The Company initially reserved a total of 1,460,084 shares of common stock for the issuance of awards under the 2015 Plan. The 2015 Plan provides that the number of shares reserved and available for issuance under the 2015 Plan will be cumulatively increased on January 1 of each calendar year by 4% of the number of shares of common stock issued and outstanding on the immediately preceding December 31 or such lesser amount as specified by the compensation committee of the board of directors. For the calendar year beginning January 1, 2024, the number of shares reserved for issuance under the 2015 Plan was increased by 2,445,889 shares. In addition, the total number of shares reserved for issuance is subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. As of March 31, 2024, there were 5,388,122 shares available for future grant under the 2015 Plan. 2020 Inducement Plan In March 2020, the Company’s board of directors adopted the 2020 Inducement Plan (the Inducement Plan), pursuant to which the Company may grant, subject to the terms of the Inducement Plan and Nasdaq rules, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, and other stock-based awards. The Company initially reserved a total of 1,000,000 shares of common stock for the issuance of awards under the Inducement Plan. In June 2022, the Company’s board of directors approved the reservation of an additional 1,500,000 shares of common stock for the issuance of awards under the Inducement Plan. The number of shares reserved and available for issuance under the Inducement Plan can be increased at any time with the approval of the Company’s board of directors. The Inducement Plan permits the board of directors or a committee thereof to use the stock-based awards available under the Inducement Plan to attract key employees for the growth of the Company. As of March 31, 2024, there were 1,372,658 shares available for future grant under the Inducement Plan. Stock options The following table summarizes the stock option activity for the three months ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Shares Exercise Price Outstanding at December 31, 2023 6,658,444 ​ $ 66.48 Granted 968,539 ​ ​ 95.06 Exercised (325,771) ​ ​ 54.95 Canceled (34,246) ​ ​ 80.09 Outstanding at March 31, 2024 7,266,966 ​ $ 70.75 Exercisable at March 31, 2024 4,610,372 ​ $ 70.08 ​ As of March 31, 2024, the total unrecognized compensation expense related to unvested stock option awards was $101.3 million, which is expected to be recognized over a weighted-average period of approximately 2.88 years. Restricted stock units The following table summarizes the restricted stock units activity for the three months ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Shares Grant Date Fair Value Unvested shares at December 31, 2023 2,107,026 ​ $ 60.33 Granted 911,766 ​ 95.08 Vested (576,521) ​ 62.74 Forfeited (28,183) ​ 66.11 Unvested shares at March 31, 2024 2,414,088 ​ $ 72.82 ​ As of March 31, 2024, the total unrecognized compensation expense related to unvested restricted stock units was $162.0 million, which is expected to be recognized over a weighted-average period of approximately 2.95 years. Performance-based restricted stock units In 2023, the Company began granting performance-based restricted stock units (PSUs) that will settle in stock. PSUs awarded to employees have a third ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ Grant Date ​ Shares Grant Date Fair Value Unvested shares at December 31, 2023 52,500 ​ $ 59.32 Granted 90,000 ​ 135.84 Vested — ​ — Forfeited — ​ — Unvested shares at March 31, 2024 142,500 ​ $ 107.65 ​ 2015 Employee Stock Purchase Plan In 2015, the Company’s board of directors and stockholders approved the 2015 Employee Stock Purchase Plan (the 2015 ESPP), which became effective upon the closing of the Company’s initial public offering in May 2015. The Company initially reserved a total of 243,347 shares of common stock for issuance under the 2015 ESPP. The 2015 ESPP provides that the number of shares reserved and available for issuance under the 2015 ESPP will be cumulatively increased on January 1 of each calendar year by 1% of the number of shares of common stock issued and outstanding on the immediately preceding December 31 or such lesser amount as specified by the compensation committee of the board of directors. For the calendar year beginning January 1, 2024, the number of shares reserved for issuance under the 2015 ESPP was increased by 611,472 shares. ​ Stock-based compensation expense The Company recognized stock-based compensation expense of $24.2 million and $23.2 million for the three months ended March 31, 2024, and 2023, respectively. Stock-based compensation expense by award type included within the unaudited condensed consolidated statements of operations and comprehensive income (loss) was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2024 2023 Stock options ​ $ 9,573 ​ $ 10,861 Restricted stock units ​ ​ 13,836 ​ ​ 11,940 Performance-based restricted stock units ​ ​ 594 ​ ​ 87 Employee stock purchase plan ​ ​ 454 ​ ​ 452 Subtotal ​ ​ 24,457 ​ ​ 23,340 Capitalized stock-based compensation costs ​ ​ (232) ​ ​ (144) Stock-based compensation expense included in total cost and operating expenses ​ $ 24,225 ​ $ 23,196 ​ Stock-based compensation expense, that is included in operating expenses, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2024 2023 ​ Research and development ​ $ 10,875 $ 10,117 Selling, general and administrative ​ 13,350 ​ 13,079 ​ Total ​ $ 24,225 ​ $ 23,196 ​

Earnings (Loss) per Share

Earnings (Loss) per Share	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Earnings (Loss) per Share	13. Earnings (Loss) per Share Basic earnings per share (EPS) is calculated by dividing net income (loss) by the weighted average number of shares of common stock outstanding during the period. Diluted EPS is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period. For purposes of the diluted EPS calculation, the effect of stock options, unvested restricted stock units, PSUs and ESPP shares on the weighted average number of shares is calculated using the treasury stock method. In periods with reported net operating losses, all common stock equivalents are deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. The calculation of net income (loss) and the number of shares used to compute basic and diluted net income (loss) per share for are as follows (in thousands, except for per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2024 2023 ​ Net income (loss) - basic and diluted ​ $ 89,136 $ (129,560) Weighted average shares outstanding - basic ​ ​ 61,580 ​ ​ 60,126 ​ Effect of dilutive securities: ​ ​ ​ ​ ​ ​ ​ Stock options ​ ​ 1,165 ​ ​ — ​ Restricted stock units ​ ​ 985 ​ ​ — ​ Performance-based restricted stock units ​ ​ 72 ​ ​ — ​ Weighted average shares outstanding - diluted ​ ​ 63,802 ​ ​ 60,126 ​ Net income (loss) per share - basic ​ $ 1.45 ​ $ (2.15) ​ Net income (loss) per share - diluted ​ ​ 1.40 ​ ​ (2.15) ​ ​ The following table sets forth the potential shares excluded from the calculation of net income (loss) per share for the three months ended March 31, 2024 and 2023 because their inclusion would be anti-dilutive (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ 2024 2023 Stock options 2,126 ​ 7,189 Restricted stock units 372 ​ 2,198 Performance-based restricted stock units ​ 31 ​ 53 ESPP shares ​ 39 ​ 55 Total 2,568 9,495

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Income Taxes	14. Income Taxes The Company utilizes the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement carrying amounts and tax basis of assets and liabilities using enacted tax rates in effect for years in which the temporary differences are expected to reverse. The Company provides a valuation allowance when it is more likely than not that deferred tax assets will not be realized. The realization of deferred income tax assets is dependent on the generation of sufficient taxable income during future periods in which temporary differences are expected to reverse. Where the realization of such assets does not meet the more likely than not criterion, the Company applies a valuation allowance against the deferred income tax asset under consideration. The valuation allowance is reviewed periodically and if the assessment of the more likely than not criterion changes, the valuation allowance is adjusted accordingly. As of March 31, 2024, the Company has a full valuation allowance applied against its U.S. and foreign deferred tax assets. On June 30, 2022, the Company entered into a Royalty Purchase Agreement with Royalty Pharma and a Future Revenue Purchase Agreement with Sixth Street Partners. Pursuant to the agreements, the Company received gross proceeds of $175.0 million from Royalty Pharma in June 2022 and $250.0 million from Sixth Street Partners in July 2022 upon the transactions closing. The total cash consideration of $425.0 million, in its entirety, was considered taxable income for calendar year ended December 31, 2022. In connection with and effective upon the termination of the Roche collaboration agreement, on February 22, 2024, Royalty Pharma and the Company entered into a consent and agreement to terminate the Royalty Purchase Agreement. The Company accounted for the Royalty Pharma Termination Agreement as a debt extinguishment. As a result, during the three months ended March 31, 2024 the Company recorded $173.7 million as a debt extinguishment gain in its condensed consolidated financial statements. For additional information, see Note 3 , Financing Arrangements As of March 31, 2024, the Company expects to be in a taxable loss position for the calendar year ended December 31, 2024, and has recorded an income tax expense of $0.2 million for the three months ended March 31, 2024. The Company recorded an income tax provision despite forecasting a taxable loss due to state income tax and taxable income from the jurisdictions in which the Company is subject to tax. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. As of March 31, 2024, the Company did not have any gross unrecognized tax benefit.

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Leases	15. Leases The Company’s building leases are comprised of office and laboratory spaces under non-cancelable operating leases. The lease agreements contain various clauses for renewal at the Company’s option and only certain exercised renewal options were included in the calculation of the operating lease assets and the operating lease liabilities, as other renewal options were not reasonably certain of being exercised as of March 31, 2024. The lease agreements do not contain residual value guarantees. ​ L ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ March 31, Operating leases: 2024 ​ 2023 Lease cost $ 5,572 ​ $ 5,881 ​ The Company has not entered into any material short-term leases or financing leases as of March 31, 2024. Supplemental cash flow information related to leases for the three months ended March 31, 2024 and 2023 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ March 31, ​ 2024 ​ 2023 Cash paid for amounts included in the measurement of lease liabilities: $ 4,546 ​ $ 4,405 Lease liabilities arising from obtaining right-of-use assets: ​ ​ ​ ​ ​ Operating leases $ — ​ $ — ​ The weighted average remaining lease term and weighted average discount rate of the operating leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases Weighted average remaining lease term in years ​ ​ ​ ​ 5.6 Weighted average discount rate ​ ​ ​ ​ 7.4%

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Disclosure Text Block
Commitments and Contingencies	16. Commitments and Contingencies Purchase Commitments Associated with Clinical and Commercial Supply Agreements In connection with the commercialization of AYVAKIT/AYVAKYT, the Company has negotiated manufacturing agreements with certain vendors that require the Company to meet minimum purchase obligations on an annual basis. The Company also has unconditional purchase obligations related to certain clinical manufacturing agreements. The aggregate amount of future unconditional purchase obligations under these manufacturing agreements over the period of next five years is approximately $4.0 million as of March 31, 2024. Legal Proceedings The Company is not currently a party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses the costs related to its legal proceedings as they are incurred. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and senior management that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers of the Company. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has no t accrued any liabilities related to such obligations in its condensed consolidated financial statements as of March 31, 2024 or December 31, 2023.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2024
Policy Text Blocks
Basis of Presentation	Basis of Presentation The unaudited interim condensed consolidated financial statements of the Company included herein have been prepared in accordance with accounting principles generally accepted in the U.S. (GAAP) as found in the Accounting Standards Codification (ASC), Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB) and the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these financial statements should be read in conjunction with the financial statements as of and for the year ended December 31, 2023 and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 15, 2024 (2023 Annual Report on Form 10-K). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements, and updated, as necessary, in this report. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of March 31, 2024, the results of its operations for the three months ended March 31, 2024 and 2023, stockholder’s equity for the three months ended March 31, 2024 and 2023 and cash flows for three months ended March 31, 2024 and 2023. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2024 are not necessarily indicative of the results for the year ending December 31, 2024 or for any future period. The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Blueprint Medicines Security Corporation, which is a Massachusetts subsidiary created to buy, sell and hold securities, Blueprint Medicines (Switzerland) GmbH, Blueprint Medicines (Netherlands) B.V., Blueprint Medicines (UK) Ltd., Blueprint Medicines (Germany) GmbH, Blueprint Medicines (Spain) S.L., Blueprint Medicines (France) SAS, and Blueprint Medicines (Italy) S.r.L. All intercompany transactions and balances have been eliminated.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Management considers many factors in selecting appropriate financial accounting policies and in developing the estimates and assumptions that are used in the preparation of the financial statements. Management must apply significant judgment in this process. Management’s estimation process often may yield a range of potentially reasonable estimates and management must select an amount that falls within that range of reasonable estimates. Estimates are used in the following areas, among others: revenue recognition, inventory, operating lease right-of-use assets, operating lease liabilities, stock-based compensation expense, accrued expenses, liabilities related to the sale of future royalties and future revenues, equity investment, and income taxes. Actual results may differ from these estimates.
Significant Accounting Policies	Significant Accounting Policies The significant accounting policies used in preparation of these condensed consolidated financial statements for the three months ended March 31, 2024 are consistent with those discussed in Note 2 to the consolidated financial statements in the 2023 Annual Report on Form 10-K, with the exception of the below new policy. Modification of debt instruments
New Accounting Pronouncements	New Accounting Pronouncements
Reclassification	Reclassification ​

Financing Arrangements (Tables)

Financing Arrangements (Tables)	3 Months Ended
	Mar. 31, 2024
Sixth Street Partners, Future Revenue Purchase Agreement
Table Text Blocks
Schedule of activity within the liability account	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Beginning Balance at January 1 ​ $ 266,670 ​ $ 254,328 Interest expense recognized ​ ​ 7,096 ​ ​ 7,089 Payments ​ ​ (6,875) ​ ​ (2,883) Carrying value as of March 31 ​ $ 266,891 ​ $ 258,534 ​
Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facilities
Table Text Blocks
Schedule of activity within the liability account	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 2023 Beginning Balance at January 1 ​ $ 238,813 ​ $ 139,083 Interest expense recognized ​ ​ 7,977 ​ ​ 4,630 Payments ​ ​ (7,405) ​ ​ (4,201) Carrying value as of March 31 ​ $ 239,385 ​ $ 139,512

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of marketable securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Unrealized Unrealized Fair March 31, 2024 Cost Gain ​ Losses ​ Value Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ $ 120,099 ​ $ 4 ​ $ (343) ​ $ 119,760 U.S. treasury obligations ​ ​ 502,933 ​ ​ 93 ​ ​ (508) ​ ​ 502,518 Total ​ $ 623,032 ​ $ 97 ​ $ (851) ​ $ 622,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Unrealized Unrealized Fair December 31, 2023 Cost Gain ​ Losses ​ Value Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ $ 170,194 ​ $ 27 ​ $ (418) ​ $ 169,803 U.S. treasury obligations ​ ​ 525,880 ​ ​ 588 ​ ​ (386) ​ ​ 526,082 Total ​ $ 696,074 ​ $ 615 ​ $ (804) ​ $ 695,885
Summary of the fair value and the number of the available-for-sale securities by their maturities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ Amortized Fair Amortized Fair ​ Cost value Cost value Within one year $ 535,195 $ 534,575 $ 639,881 $ 639,355 After one through five years ​ 87,837 ​ 87,703 ​ 56,193 ​ 56,530 Total $ 623,032 $ 622,278 $ 696,074 $ 695,885
Summary of fair value and number of available-for-sale securities in loss positions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 December 31, 2023 ​ ​ Fair Unrealized Fair Unrealized ​ ​ value ​ losses ​ value ​ losses Debt securities in unrealized loss position for 12 months or less ​ $ 439,535 ​ $ (690) ​ $ 267,917 $ (550) Debt securities in unrealized loss position for more than 12 months ​ ​ 54,782 ​ ​ (161) ​ ​ 64,659 ​ (254) Total debt securities ​ $ 494,317 ​ $ (851) ​ $ 332,576 $ (804)
Summary of proceeds from maturities of debt securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 2023 Proceeds from maturities of debt securities ​ $ 278,400 ​ $ 308,250

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of financial instruments measured at fair value	The following table summarizes the Company’s cash equivalents and marketable securities measured at fair value on a recurring basis as of March 31, 2024 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Active Observable Unobservable ​ ​ March 31, ​ Markets ​ Inputs ​ Inputs Description ​ 2024 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 100,072 ​ $ 100,072 ​ $ — ​ $ — Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ ​ 119,760 ​ ​ — ​ ​ 119,760 ​ ​ — U.S. treasury obligations ​ ​ 502,518 ​ ​ 502,518 ​ ​ — ​ ​ — Total ​ $ 722,350 ​ $ 602,590 ​ $ 119,760 ​ $ — ​ The following table summarizes the Company’s cash equivalents and marketable securities measured at fair value on a recurring basis as of December 31, 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Active Observable Unobservable ​ ​ December 31, ​ Markets ​ Inputs ​ Inputs Description ​ 2023 ​ (Level 1) ​ (Level 2) ​ (Level 3) Cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds ​ $ 55,412 ​ $ 55,412 ​ $ — ​ $ — Marketable securities, available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government agency securities ​ ​ 169,803 ​ ​ ​ ​ ​ 169,803 ​ ​ — U.S. treasury obligations ​ ​ 526,082 ​ ​ 526,082 ​ ​ — ​ ​ — Total ​ $ 751,297 ​ $ 581,494 ​ $ 169,803 ​ $ —

Product Revenue (Tables)

Product Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedules of concentration of risk	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ 2024 ​ 2023 Customer 1 ​ 39 % ​ 44 % Customer 2 ​ * % ​ 10 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 Customer 1 ​ 35 % ​ 34 % Customer 2 ​ 11 % ​ 11 % Customer 3 ​ 10 % ​ 10 % Customer 4 ​ * % ​ 10 % * Indicates the customer’s share is under 10%.
Product revenue, net
Table Text Blocks
Summary of revenue recognized	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2024 2023 United States ​ $ 83,136 ​ $ 34,927 Rest of World ​ ​ 9,389 ​ ​ 4,142 Total product revenue ​ $ 92,525 ​ $ 39,069
Schedule of product revenue allowance and reserve categories	​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2024 ​ 2023 Beginning balance at January 1 $ 19,274 ​ $ 9,788 Provision related to sales in the current period 16,926 ​ ​ 8,502 Adjustment related to prior periods sales (309) ​ ​ (228) Credits and payments made (12,488) ​ ​ (4,773) Ending balance at March 31 $ 23,403 ​ $ 13,289 ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2024 ​ 2023 Reduction of accounts receivable, net $ 2,640 ​ $ 1,809 Component of accrued expenses ​ 20,763 ​ ​ 17,465 Total revenue-related reserves $ 23,403 ​ $ 19,274

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of capitalized inventory	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 Raw materials ​ $ 3,069 ​ $ 3,147 Work in process ​ ​ 30,777 ​ ​ 29,132 Finished goods ​ 3,001 ​ 4,823 Total ​ $ 36,847 ​ $ 37,102 ​ Balance sheet classification ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 Inventory ​ $ 30,940 ​ $ 21,223 Other assets ​ 5,907 ​ 15,879 Total ​ $ 36,847 ​ $ 37,102

Restricted Cash (Tables)

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Reconciliation of cash, cash equivalents, and restricted cash	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ Cash and cash equivalents ​ $ 113,326 ​ $ 169,724 ​ Restricted cash ​ ​ 10,634 ​ ​ 5,207 ​ Total cash, cash equivalents, and restricted cash shown in condensed consolidated statements of cash flows ​ $ 123,960 ​ $ 174,931 ​

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2024 2023 Research, development and commercial contract costs ​ $ 39,612 ​ $ 49,354 Employee compensation ​ ​ 20,006 ​ ​ 43,434 Accrued professional fees ​ 19,852 ​ 12,522 Revenue-related reserves ​ ​ 20,763 ​ ​ 17,465 Other ​ ​ 7,044 ​ ​ 5,217 Total ​ $ 107,277 ​ $ 127,992

Collaboration and Other Agree_2

Collaboration and Other Agreements (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of amounts recognized as reductions to expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2024 2023 Reductions to selling, general and administrative expenses $ 980 $ 2,781 Increases in research and development expenses $ 1,421 $ 8,276
Roche, Collaboration (Pralsetnib) Agreement
Table Text Blocks
Summary of revenue recognized	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2024 2023 Manufacturing and research and development services related to $ 324 $ 127 Royalty revenue ​ 198 ​ 437 GAVRETO profit share in the U.S. ​ ​ 1,416 ​ ​ — Total Roche pralsetinib collaboration revenue $ 1,938 $ 564
Summary of contract assets and/or contract liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 Other current assets $ 357 $ 361 Accrued expenses $ — $ 7,388
C Stone | Collaboration revenue
Table Text Blocks
Summary of revenue recognized	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2024 2023 Manufacturing services and royalty revenue related to CStone territory-specific activities ​ $ 1,653 ​ $ 1,652
Summary of contract assets and/or contract liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2024 2023 Accounts receivable, net $ 1,937 $ — Contract liability ​ $ 3,762 ​ $ 604 Accrued expenses $ — $ 1,863

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Shares Exercise Price Outstanding at December 31, 2023 6,658,444 ​ $ 66.48 Granted 968,539 ​ ​ 95.06 Exercised (325,771) ​ ​ 54.95 Canceled (34,246) ​ ​ 80.09 Outstanding at March 31, 2024 7,266,966 ​ $ 70.75 Exercisable at March 31, 2024 4,610,372 ​ $ 70.08
Summary of restricted stock units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ Shares Grant Date Fair Value Unvested shares at December 31, 2023 2,107,026 ​ $ 60.33 Granted 911,766 ​ 95.08 Vested (576,521) ​ 62.74 Forfeited (28,183) ​ 66.11 Unvested shares at March 31, 2024 2,414,088 ​ $ 72.82
Summary of performance-based restricted stock units activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ Grant Date ​ Shares Grant Date Fair Value Unvested shares at December 31, 2023 52,500 ​ $ 59.32 Granted 90,000 ​ 135.84 Vested — ​ — Forfeited — ​ — Unvested shares at March 31, 2024 142,500 ​ $ 107.65
Summary of stock-based compensation expense, allocation by type of awards and recognition in statements of operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ 2024 2023 Stock options ​ $ 9,573 ​ $ 10,861 Restricted stock units ​ ​ 13,836 ​ ​ 11,940 Performance-based restricted stock units ​ ​ 594 ​ ​ 87 Employee stock purchase plan ​ ​ 454 ​ ​ 452 Subtotal ​ ​ 24,457 ​ ​ 23,340 Capitalized stock-based compensation costs ​ ​ (232) ​ ​ (144) Stock-based compensation expense included in total cost and operating expenses ​ $ 24,225 ​ $ 23,196 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2024 2023 ​ Research and development ​ $ 10,875 $ 10,117 Selling, general and administrative ​ 13,350 ​ 13,079 ​ Total ​ $ 24,225 ​ $ 23,196 ​

Earnings (Loss) per Share (Tabl

Earnings (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Schedule of net income (loss) and the number of shares used to compute basic and diluted net income (loss) per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, ​ ​ ​ 2024 2023 ​ Net income (loss) - basic and diluted ​ $ 89,136 $ (129,560) Weighted average shares outstanding - basic ​ ​ 61,580 ​ ​ 60,126 ​ Effect of dilutive securities: ​ ​ ​ ​ ​ ​ ​ Stock options ​ ​ 1,165 ​ ​ — ​ Restricted stock units ​ ​ 985 ​ ​ — ​ Performance-based restricted stock units ​ ​ 72 ​ ​ — ​ Weighted average shares outstanding - diluted ​ ​ 63,802 ​ ​ 60,126 ​ Net income (loss) per share - basic ​ $ 1.45 ​ $ (2.15) ​ Net income (loss) per share - diluted ​ ​ 1.40 ​ ​ (2.15) ​
Schedule of common stock equivalents excluded from calculation of diluted net loss per share applicable to common stockholders	​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ 2024 2023 Stock options 2,126 ​ 7,189 Restricted stock units 372 ​ 2,198 Performance-based restricted stock units ​ 31 ​ 53 ESPP shares ​ 39 ​ 55 Total 2,568 9,495

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Table Text Blocks
Summary of lease expenses and cash flow and weighted average information	​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ March 31, Operating leases: 2024 ​ 2023 Lease cost $ 5,572 ​ $ 5,881 ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ March 31, ​ 2024 ​ 2023 Cash paid for amounts included in the measurement of lease liabilities: $ 4,546 ​ $ 4,405 Lease liabilities arising from obtaining right-of-use assets: ​ ​ ​ ​ ​ Operating leases $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases Weighted average remaining lease term in years ​ ​ ​ ​ 5.6 Weighted average discount rate ​ ​ ​ ​ 7.4%

Nature of Business (Details)

Nature of Business (Details) $ in Millions	Mar. 31, 2024 USD ($)
Cash, cash equivalents and marketable securities
Cash, cash equivalents and marketable securities	$ 735.6

Financing Arrangements - Genera

Financing Arrangements - General Information (Details) $ in Millions		1 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Aug. 31, 2023 USD ($)	Jul. 31, 2022 USD ($) Transaction tranche	Dec. 31, 2022 USD ($)	Mar. 31, 2024
Sixth Street Partners, Financing Arrangements
Debt Financing
Debt instrument, transactions, number | Transaction			2
Sale of Future Royalties and Revenues
Gross Proceeds
Gross proceeds				$ 425
Sale of Future Royalties and Revenues | Royalty Pharma, Royalty Purchase Agreement
Debt Financing
Debt instrument, issuance date	Jun. 30, 2022
Gross Proceeds
Gross proceeds	$ 175
Sale of Future Royalties and Revenues | Sixth Street Partners, Future Revenue Purchase Agreement
Debt Financing
Debt instrument, face amount			$ 250
Transaction costs, gross			5.4
Gross Proceeds
Gross proceeds			250
Effective Interest Rate
Debt instrument, interest rate, effective percentage (as a percent)					10.80%
Loans Payable | Sixth Street Partners, Financing Agreement
Debt Financing
Debt instrument, face amount, potential amount			660
Debt instrument, covenants, consolidated liquidity, period commencing from date term loan funded to date day before next term loans funded			50
Debt instrument, covenants, consolidated liquidity, period commencing from date term loan funded to date day before next term loans funded, each day thereafter			$ 80
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facilities
Debt Financing
Debt instrument, maturity date			Jun. 30, 2028
Effective Interest Rate
Debt instrument, interest rate, effective percentage (as a percent)					13.20%
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facilities | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Financing
Debt instrument, basis spread on variable rate			6.50%
Debt instrument, variable rate floor			1%
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facilities | Base Rate
Debt Financing
Debt instrument, basis spread on variable rate			5.50%
Debt instrument, variable rate floor			2%
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facility
Debt Financing
Debt instrument, face amount			$ 150
Debt discounts and transaction costs			12.2
Gross Proceeds
Gross proceeds			150
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Delayed Draw Term Loan Facility
Debt Financing
Debt instrument, face amount, potential amount			$ 250
Debt instrument, tranches, number | tranche			2
Transaction costs, gross		$ 2.1
Gross Proceeds
Gross proceeds		$ 100
Secured Debt | Sixth Street Partners, Financing Agreement, Incremental Term Loan
Debt Financing
Debt instrument, face amount, potential amount			$ 260

Financing Arrangements - Debt E

Financing Arrangements - Debt Extinguishment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Feb. 22, 2022
Gain (Loss) on Extinguishment of Debt
Debt extinguishment gain	$ 173,658
Sale of Future Royalties and Revenues | Royalty Pharma, Royalty Purchase Agreement
Gain (Loss) on Extinguishment of Debt
Debt extinguishment gain	173,700
Long-term Debt
Debt reacquisition liability, current	900
Long-term debt	$ 0	$ 0

Financing Arrangements - Royalt

Financing Arrangements - Royalty and Sales Information (Details) - Sixth Street Partners $ in Millions	Jul. 31, 2022 USD ($)
Financing Arrangements
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, percentage rate (as a percent)	9.75%
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, amount, maximum	$ 900
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, cumulative cap of upfront invested capital, ratio	1.45
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, cumulative cap of upfront invested capital, amount	$ 362.5
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, cumulative cap of upfront invested capital, revenue targets not achieved, percentage increase (as a percent)	15%
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, cumulative cap of upfront invested capital, revenue targets not achieved, ratio	1.85
Purchase and sale agreement, royalties, future royalty payments, annual worldwide net product sales, cumulative cap of upfront invested capital, revenue targets not achieved, amount	$ 462.5

Financing Arrangements - Long-t

Financing Arrangements - Long-term Debt (Details) - Sale of Future Royalties and Revenues - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	Feb. 22, 2022
Royalty Pharma, Royalty Purchase Agreement
Long-term Debt
Long-term debt	$ 0				$ 0
Sixth Street Partners, Future Revenue Purchase Agreement
Long-term Debt
Long-term debt	$ 266,891	$ 266,670	$ 258,534	$ 254,328

Financing Arrangements - Roll F

Financing Arrangements - Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Sale of Future Royalties and Revenues | Sixth Street Partners, Future Revenue Purchase Agreement
Long-term Debt
Carrying value, beginning balance	$ 266,670	$ 254,328
Interest expense recognized	7,096	7,089
Payments	(6,875)	(2,883)
Carrying value, ending balance	266,891	258,534
Secured Debt | Sixth Street Partners, Financing Agreement, Senior Secured Term Loan Facilities
Long-term Debt
Carrying value, beginning balance	238,813	139,083
Interest expense recognized	7,977	4,630
Payments	(7,405)	(4,201)
Carrying value, ending balance	$ 239,385	$ 139,512

Marketable Securities - Tabular

Marketable Securities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Marketable securities, available-for-sale:
Amortized cost	$ 623,032	$ 696,074
Unrealized gain	97	615
Unrealized losses	(851)	(804)
Fair value	622,278	695,885
U.S. government agency securities
Marketable securities, available-for-sale:
Amortized cost	120,099	170,194
Unrealized gain	4	27
Unrealized losses	(343)	(418)
Fair value	119,760	169,803
U.S. Treasury obligations
Marketable securities, available-for-sale:
Amortized cost	502,933	525,880
Unrealized gain	93	588
Unrealized losses	(508)	(386)
Fair value	$ 502,518	$ 526,082

Marketable Securities - Maturit

Marketable Securities - Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Amortized cost
Within one year, amortized cost	$ 535,195	$ 639,881
After one through five years, amortized cost	87,837	56,193
Amortized cost	623,032	696,074
Fair value
Within one year, fair value	534,575	639,355
After one through five years, fair value	87,703	56,530
Investments, available-for-sale	$ 622,278	$ 695,885

Marketable Securities - Unreali

Marketable Securities - Unrealized Loss Positions - General Information (Details) - security	Mar. 31, 2024	Dec. 31, 2023
Unrealized loss position, number of positions
Number of held securities in an unrealized loss position	84	62

Marketable Securities - Unrea_2

Marketable Securities - Unrealized Loss Positions - Tabular Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Unrealized loss position, aggregate fair value
Unrealized loss position for less than 12 months, aggregate fair value	$ 439,535	$ 267,917
Unrealized loss position for more than 12 months, aggregate fair value	54,782	64,659
Unrealized loss position, aggregate fair value	494,317	332,576
Unrealized loss position
Unrealized loss position for less than 12 months	(690)	(550)
Unrealized loss position for more than 12 months	(161)	(254)
Total debt securities in unrealized loss position	$ (851)	$ (804)

Marketable Securities - Impairm

Marketable Securities - Impairment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Marketable Securities
Marketable debt securities, charges for credit-related impairments	$ 0	$ 0

Marketable Securities - Proceed

Marketable Securities - Proceeds from Maturities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Proceeds from the maturities of debt securities
Proceeds from the maturities of debt securities	$ 278,400	$ 308,250

Marketable Securities - Realize

Marketable Securities - Realized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Realized gains (losses) from maturities of debt securities
Realized gains (losses) from maturities of debt securities	$ 0	$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value of Financial Instruments
Marketable securities, available-for-sale	$ 622,278	$ 695,885
U.S. government agency securities
Fair Value of Financial Instruments
Marketable securities, available-for-sale	119,760	169,803
U.S. Treasury obligations
Fair Value of Financial Instruments
Marketable securities, available-for-sale	502,518	526,082
Recurring
Fair Value of Financial Instruments
Total	722,350	751,297
Recurring | U.S. government agency securities
Fair Value of Financial Instruments
Marketable securities, available-for-sale	119,760	169,803
Recurring | U.S. Treasury obligations
Fair Value of Financial Instruments
Marketable securities, available-for-sale	502,518	526,082
Recurring | Money market funds
Fair Value of Financial Instruments
Cash equivalents	100,072	55,412
Recurring | Active Markets (Level 1)
Fair Value of Financial Instruments
Total	602,590	581,494
Recurring | Active Markets (Level 1) | U.S. Treasury obligations
Fair Value of Financial Instruments
Marketable securities, available-for-sale	502,518	526,082
Recurring | Active Markets (Level 1) | Money market funds
Fair Value of Financial Instruments
Cash equivalents	100,072	55,412
Recurring | Observable Inputs (Level 2)
Fair Value of Financial Instruments
Total	119,760	169,803
Recurring | Observable Inputs (Level 2) | U.S. government agency securities
Fair Value of Financial Instruments
Marketable securities, available-for-sale	$ 119,760	$ 169,803

Product Revenue - Product Reven

Product Revenue - Product Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Revenue	$ 96,116	$ 63,287
Product revenue, net
Revenues
Revenue	92,525	39,069
Product revenue, net | United States
Revenues
Revenue	83,136	34,927
Product revenue, net | Rest of World
Revenues
Revenue	$ 9,389	$ 4,142

Product Revenue - Concentration

Product Revenue - Concentration Risk (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer One
Concentration Risk
Concentration risk (as a percent)	39%	44%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer Two
Concentration Risk
Concentration risk (as a percent)		10%
Accounts Receivable, Net | Credit Concentration Risk | Customer One
Concentration Risk
Concentration risk (as a percent)	35%		34%
Accounts Receivable, Net | Credit Concentration Risk | Customer Two
Concentration Risk
Concentration risk (as a percent)	11%		11%
Accounts Receivable, Net | Credit Concentration Risk | Customer Three
Concentration Risk
Concentration risk (as a percent)	10%		10%
Accounts Receivable, Net | Credit Concentration Risk | Customer Four
Concentration Risk
Concentration risk (as a percent)			10%

Product Revenue - Product Rev_2

Product Revenue - Product Revenue Allowance and Reserve (Details) - Valuation Allowances and Reserves, Product Revenue - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Product revenue allowance and reserve
Beginning Balance	$ 19,274	$ 9,788
Provision related to sales in the current period	16,926	8,502
Adjustment related to prior periods sales	(309)	(228)
Credits and payments made	(12,488)	(4,773)
Ending Balance	$ 23,403	$ 13,289

Product Revenue - Revenue-relat

Product Revenue - Revenue-related Reserves (Details) - Valuation Allowances and Reserves, Product Revenue - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Product revenue allowance and reserve
Total revenue-related reserves	$ 23,403	$ 19,274	$ 13,289	$ 9,788
Accounts Receivable, Net
Product revenue allowance and reserve
Total revenue-related reserves	2,640	1,809
Accrued Expenses
Product revenue allowance and reserve
Total revenue-related reserves	$ 20,763	$ 17,465

Inventory - Capitalized (Detail

Inventory - Capitalized (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory
Raw materials	$ 3,069	$ 3,147
Work in process	30,777	29,132
Finished goods	3,001	4,823
Total	$ 36,847	$ 37,102

Inventory - Balance Sheet Class

Inventory - Balance Sheet Classification (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory
Inventory	$ 30,940	$ 21,223
Other assets	5,907	15,879
Total	$ 36,847	$ 37,102

Inventory - Write-down (Details

Inventory - Write-down (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Inventory
Inventory write-down	$ 1.5

Restricted Cash - Tabular Discl

Restricted Cash - Tabular Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Reconciliation of cash, cash equivalents, and restricted cash
Cash and cash equivalents	$ 113,326	$ 71,286	$ 169,724
Restricted cash	10,634	10,238	5,207
Total cash, cash equivalents, and restricted cash shown in condensed consolidated statements of cash flows	$ 123,960	$ 81,524	$ 174,931	$ 124,904

Restricted Cash - Additional In

Restricted Cash - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Restricted cash
Restricted cash	$ 10.6	$ 10.2

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued Expenses
Research, development and commercial contract costs	$ 39,612	$ 49,354
Employee compensation	20,006	43,434
Accrued professional fees	19,852	12,522
Revenue-related reserves	20,763	17,465
Other	7,044	5,217
Total	$ 107,277	$ 127,992

Collaboration and Other Agree_3

Collaboration and Other Agreements - General Information (Details) $ in Thousands

1 Months Ended

2 Months Ended

3 Months Ended

51 Months Ended

Oct. 15, 2019 USD ($)

Jun. 01, 2018 USD ($) item

Feb. 28, 2022 USD ($)

Oct. 31, 2019 USD ($)

Dec. 31, 2021 USD ($)

Mar. 31, 2024 USD ($) item

Mar. 31, 2023 USD ($)

Sep. 30, 2020 USD ($)

Mar. 31, 2024 USD ($) item

Feb. 22, 2024 USD ($)

Dec. 31, 2023 USD ($)

Nov. 08, 2021 USD ($)

Jul. 13, 2020

Collaboration and Other Agreements

Prepaid expenses and other current assets

$ 37,714

$ 37,714

$ 33,702

Research and development expense

88,191

$ 112,073

Collaborative Arrangement | IDRx, Inc. | Director

Collaboration and Other Agreements

Collaborative arrangement, milestones, potential contingent payments

$ 217,500

217,500

Collaborative arrangement, termination, counterparty written notice period

12 months

Collaborative Arrangement | VantAI

Collaboration and Other Agreements

Collaborative arrangement, upfront payment

$ 20,000

Collaborative arrangement, milestones, potential contingent payments

$ 1,670,000

$ 1,670,000

Research and development expense

$ 2,100

$ 1,300

Collaborative arrangement, jointly research and advance novel protein degrader therapies into development candidates, number | item

3

3

Collaborative Arrangement | Zai Lab (Shanghai) Co., Ltd.

Collaboration and Other Agreements

Collaborative arrangement, upfront payment, cash payment received

$ 25,000

Collaborative arrangement, milestones, contingent payments eligible to receive

$ 590,000

Collaborative arrangement, termination, counterparty written notice period, period from effective date

2 years

Collaborative arrangement, termination, counterparty written notice period, period from effective date, given after first commercial sale of licensed product in counterparty territory

12 months

Collaborative arrangement, termination, counterparty written notice period, period from effective date, given prior to first commercial sale of licensed product in counterparty territory

9 months

Collaborative Arrangement | Roche, Collaboration (Pralsetnib) Agreement

Collaboration and Other Agreements

Collaborative arrangement, upfront payment, cash payment received

$ 675,000

Collaborative arrangement, milestones, specified regulatory and commercialization milestones, achieved

$ 105,000

$ 105,000

Collaborative arrangement, percentage of global development costs shared, entity (as a percent)

45%

Collaborative arrangement, percentage of global development costs shared, counterparty (as a percent)

55%

Collaborative Arrangement | Clementia

Collaboration and Other Agreements

Collaborative arrangement, upfront payment, cash payment received

$ 25,000

Collaborative arrangement, milestones, cash payments received

$ 50,000

Collaborative arrangement, milestones, contingent payments eligible to receive

460,000

Collaborative arrangement, inventory purchased by counterparty

$ 1,500

Collaborative arrangement, termination, counterparty written notice period

12 months

Collaborative Arrangement | C Stone

Collaboration and Other Agreements

Collaborative arrangement, upfront payment, cash payment received

$ 40,000

Collaborative arrangement, milestones, contingent payments eligible to receive

$ 307,500

Collaborative arrangement, milestones, achieved

$ 38,500

$ 38,500

Collaborative arrangement, licensed product term from first commercial sale

12 years

Collaborative arrangement, license option rights, number | item

3

Collaborative arrangement, collaboration programs with exclusive commercialization rights, number | item

3

Arrangement Other than Collaborative, Asset Purchase Agreement | Rigel Pharmaceuticals, Inc.

Collaboration and Other Agreements

Asset purchase agreement, purchase price, receivable

$ 15,000

Asset purchase agreement, purchase price, receivable, payable upon first commercial sale

10,000

Asset purchase agreement, purchase price, receivable, additional contingent amount payable

5,000

Asset purchase agreement, contingent specified regulatory and commercial milestone payments

$ 102,500

Asset purchase agreement, tiered percentage royalties on annual net sales, low end of range (as a percent)

10%

Asset purchase agreement, tiered percentage royalties on annual net sales, high end of range (as a percent)

30%

Collaboration and Other Agree_4

Collaboration and Other Agreements - Transaction Price (Details) - Collaborative Arrangement - USD ($) $ in Millions				2 Months Ended	3 Months Ended
	Jul. 13, 2020	Oct. 15, 2019	Jun. 01, 2018	Dec. 31, 2021	Mar. 31, 2024
Zai Lab (Shanghai) Co., Ltd.
Collaboration and Other Agreements
Collaborative arrangement, transaction price				$ 25
Roche, Collaboration (Pralsetnib) Agreement
Collaboration and Other Agreements
Collaborative arrangement, transaction price	$ 695.7
Collaborative arrangement, transaction price, upfront payment	675
Collaborative arrangement, transaction price, stock issued, premium on sale of stock to counterparty	$ 20.7
Roche, Collaboration and License (Immunotherapy) Agreement
Collaboration and Other Agreements
Collaborative arrangement, transaction price					$ 64.7
Collaborative arrangement, transaction price, upfront payment					45
Collaborative arrangement, transaction price, aggregate research milestone achieved					25
Collaborative arrangement, transaction price, reduction, payment for certain clinical development costs					$ 5.3
Clementia
Collaboration and Other Agreements
Collaborative arrangement, transaction price		$ 46.5
C Stone
Collaboration and Other Agreements
Collaborative arrangement, transaction price			$ 40

Collaboration and Other Agree_5

Collaboration and Other Agreements - Equity Investment (Details) - USD ($) $ in Thousands		1 Months Ended
	Aug. 01, 2022	Jul. 31, 2023	Mar. 31, 2024	Dec. 31, 2023
Equity Investment
Equity investment			$ 27,789	$ 27,789
Collaborative Arrangement | IDRx, Inc. | Director
Equity Investment
Equity investment, license agreement, shares received (in shares)	4,509,105	192,282
Equity investment	$ 27,800		$ 27,800
Equity investment, transaction costs	$ 300

Collaboration and Other Agree_6

Collaboration and Other Agreements - Sale of Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jul. 13, 2020	Mar. 31, 2024	Mar. 31, 2023
Sale of Stock
Stock issued (in shares)		544,719	0
Issuance of common stock		$ 48,936
Private Placement
Sale of Stock
Stock issued (in shares)	1,035,519
Share price (in dollars per share)	$ 96.57
Purchase consideration	$ 100,000
Issuance of common stock	79,300
Share purchase consideration, premium	$ 20,700

Collaboration and Other Agree_7

Collaboration and Other Agreements - Revenue Recognized (Details) - USD ($) $ in Thousands		2 Months Ended	3 Months Ended		12 Months Ended		24 Months Ended
	Aug. 01, 2022	Feb. 22, 2024	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2020
Revenues
Revenue			$ 96,116	$ 63,287
Rigel Pharmaceuticals, Inc.
Revenues
Revenue			0
Collaboration and License
Revenues
Revenue			3,591	24,218
Collaboration and License | Zai Lab (Shanghai) Co., Ltd.
Revenues
Revenue			0		$ 25,000
Collaboration and License | Clementia
Revenues
Revenue			0	0			$ 46,500
Collaboration revenue | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue			1,938	564
Collaboration revenue | Roche, Collaboration and License (Immunotherapy) Agreement
Revenues
Revenue			0	22,000
Collaboration revenue | C Stone
Revenues
Revenue						$ 40,000
License milestone revenue | C Stone
Revenues
Revenue			0	0
Territory-specific activities, manufacturing services and royalty | C Stone
Revenues
Revenue			1,653	1,652
Territory-specific activities, manufacturing and research and development services | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue			324	127
Royalty | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue			198	437
GAVRETO profit share in the U.S. | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue		$ 1,400	1,416
License | IDRx, Inc. | Director
Revenues
Revenue	$ 27,500		$ 0	$ 0

Collaboration and Other Agree_8

Collaboration and Other Agreements - Collaboration Loss Sharing (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Collaboration and Other Agreements
Collaboration loss sharing	$ 1,296
Collaborative Arrangement | Roche, Collaboration (Pralsetnib) Agreement
Collaboration and Other Agreements
Collaboration loss sharing	$ 1,300

Collaboration and Other Agree_9

Collaboration and Other Agreements - Reduction in Expenses (Details) - Collaborative Arrangement - Roche, Collaboration (Pralsetnib) Agreement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Collaboration and Other Agreements
Collaborative arrangement, commercialization, reduction in selling, general and administrative expenses	$ 980	$ 2,781
Collaborative arrangement, global development activities, reductions to (increases in) research and development expenses	$ (1,421)	$ (8,276)

Collaboration and Other Agre_10

Collaboration and Other Agreements - Change in Contract with Customer, Liability (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Collaborative Arrangement | Roche, Collaboration and License (Immunotherapy) Agreement
Change in Contract with Customer, Liability
Amounts included in the contact liability at the beginning of the period	$ 15.8

Collaboration and Other Agre_11

Collaboration and Other Agreements - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Contract Assets
Accounts receivable, net	$ 60,047	$ 42,827
Contract Liabilities
Contract liabilities, current	7,251	812
Contract liabilities, noncurrent	4,635	4,792
Accrued expenses, current	39,612	49,354
Collaborative Arrangement | Roche, Collaboration (Pralsetnib) Agreement
Other Assets
Other current assets	357	361
Contract Liabilities
Accrued expenses		7,388
Collaborative Arrangement | Roche, Collaboration and License (Immunotherapy) Agreement
Contract Liabilities
Contract liabilities	0	0
Collaborative Arrangement | Clementia
Contract Liabilities
Contract liabilities	0	0
Collaborative Arrangement | C Stone
Contract Assets
Accounts receivable, net	1,937
Contract Liabilities
Contract liabilities	$ 3,762	604
Accrued expenses		$ 1,863

Collaboration and Other Agre_12

Collaboration and Other Agreements - Performance Obligations (Details) - Collaborative Arrangement	3 Months Ended
	Mar. 31, 2024 item component
IDRx, Inc. | Director
Performance Obligations
Collaborative arrangement, material promises, number	2
Collaborative arrangement, material promises, combined into distinct performance obligation, number	1
Zai Lab (Shanghai) Co., Ltd.
Performance Obligations
Collaborative arrangement, material promises, number	3
Collaborative arrangement, material promises, combined into distinct performance obligation, number	2
Collaborative arrangement, material components, number | component	2
Roche, Collaboration (Pralsetnib) Agreement
Performance Obligations
Collaborative arrangement, material promises, number	1
Collaborative arrangement, material promises, manufacturing activities, term	24 months
Collaborative arrangement, material components, number | component	4
Roche, Collaboration and License (Immunotherapy) Agreement
Performance Obligations
Revenue, performance obligation, performance obligations, number	1
Clementia
Performance Obligations
Collaborative arrangement, material promises, number	4
Revenue, performance obligation, performance obligations, number	3
C Stone
Performance Obligations
Collaborative arrangement, material promises, number	6
Collaborative arrangement, material components, number | component	2
Revenue, performance obligation, performance obligations, number	3

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Feb. 28, 2022
Proceeds from Issuance or Sale of Equity [Abstract]
At-the-market facility, aggregate offering price			$ 300,000
At-the-market offerings, net of issuance costs (in shares)	544,719	0
Proceeds from at-the-market offerings, net of issuance costs	$ 48,936

Stock-based Compensation - 2015

Stock-based Compensation - 2015 Stock Option and Incentive Plan (Details) - 2015 Stock Option and Incentive Plan - shares		3 Months Ended
	Jan. 01, 2024	Mar. 31, 2024	Apr. 08, 2015
Stock-based compensation
Initial shares of common stock authorized for issuance of stock awards (in shares)			1,460,084
Increase in number of shares available for grant (as a percent)		4%
Increase in number of shares available for grant (in shares)	2,445,889
Number of shares available for grant (in shares)		5,388,122

Stock-based Compensation - 2020

Stock-based Compensation - 2020 Inducement Plan (Details) - 2020 Inducement Plan - shares	1 Months Ended
	Jun. 30, 2022	Mar. 31, 2024	Mar. 31, 2020
Stock-based compensation
Initial shares of common stock authorized for issuance of stock awards (in shares)			1,000,000
Increase in number of shares available for grant (in shares)	1,500,000
Number of shares available for grant (in shares)		1,372,658

Stock-based Compensation - Stoc

Stock-based Compensation - Stock Options - Activity (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Shares
Outstanding at beginning of period (in shares) | shares	6,658,444
Granted (in shares) | shares	968,539
Exercised (in shares) | shares	(325,771)
Cancelled (in shares) | shares	(34,246)
Outstanding at end of period (in shares) | shares	7,266,966
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 66.48
Granted (in dollars per share) | $ / shares	95.06
Exercised (in dollars per share) | $ / shares	54.95
Cancelled (in dollars per share) | $ / shares	80.09
Outstanding at end of period (in dollars per share) | $ / shares	$ 70.75
Additional disclosures
Shares - Exercisable (in shares) | shares	4,610,372
Weighted-Average Exercise Price - Exercisable (in dollars per share) | $ / shares	$ 70.08

Stock-based Compensation - Perf

Stock-based Compensation - Performance-based Restricted Stock Units (Details) - Performance-based restricted stock units	3 Months Ended
	Mar. 31, 2024
Stock-based compensation
Award service period	3 years
Award vesting period	3 years
Performance metric, cumulative relative total shareholder return, period	3 years
Minimum
Stock-based compensation
Award grants, percentage of target (as a percent)	0%
Maximum
Stock-based compensation
Award grants, percentage of target (as a percent)	200%

Stock-based Compensation - Unve

Stock-based Compensation - Unvested Awards - Activity (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Restricted Stock Units
Shares
Unvested at beginning of period (in shares) | shares	2,107,026
Granted (in shares) | shares	911,766
Vested (in shares) | shares	(576,521)
Forfeited (in shares) | shares	(28,183)
Unvested at end of period (in shares) | shares	2,414,088
Weighted-Average Grant Date Fair Value
Unvested at beginning or period (in dollars per share) | $ / shares	$ 60.33
Granted (in dollars per share) | $ / shares	95.08
Vested (in dollars per share) | $ / shares	62.74
Forfeited (in dollars per share) | $ / shares	66.11
Unvested at end of period (in dollars per share) | $ / shares	$ 72.82
Performance-based restricted stock units
Shares
Unvested at beginning of period (in shares) | shares	52,500
Granted (in shares) | shares	90,000
Unvested at end of period (in shares) | shares	142,500
Weighted-Average Grant Date Fair Value
Unvested at beginning or period (in dollars per share) | $ / shares	$ 59.32
Granted (in dollars per share) | $ / shares	135.84
Unvested at end of period (in dollars per share) | $ / shares	$ 107.65

Stock-based Compensation - Unre

Stock-based Compensation - Unrecognized Compensation Costs (Details) $ in Millions	Mar. 31, 2024 USD ($)
Stock-based compensation
Total unrecognized compensation cost related to non-vested stock option awards	$ 101.3
Weighted-average period over which unrecognized compensation cost will be recognized	2 years 10 months 17 days
Restricted Stock Units
Stock-based compensation
Total unrecognized compensation cost related to non-vested stock awards	$ 162
Weighted-average period over which unrecognized compensation cost will be recognized	2 years 11 months 12 days
Performance-based restricted stock units
Stock-based compensation
Total unrecognized compensation cost related to non-vested stock awards	$ 13.9
Weighted-average period over which unrecognized compensation cost will be recognized	2 years 6 months 18 days

Stock-based Compensation - Empl

Stock-based Compensation - Employee Stock Purchase Plan (Details) - Employee Stock - shares	1 Months Ended
	May 31, 2015	Jan. 01, 2024
Stock-based compensation
Number of common shares reserved for future issuance (in shares)	243,347
Annual increase for common stock for issuance (as a percent)	1%
Increase of common shares reserved for future issuance (in shares)		611,472

Stock-based Compensation - St_2

Stock-based Compensation - Stock-based Compensation Expense - General Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Total stock based compensation expense
Stock-based compensation expense	$ 24,225	$ 23,196

Stock-based Compensation - St_3

Stock-based Compensation - Stock-based Compensation Expense - By Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Total stock based compensation expense
Subtotal	$ 24,457	$ 23,340
Capitalized stock-based compensation costs	(232)	(144)
Stock-based compensation expense included in total cost and operating expenses	24,225	23,196
Employee Stock Option
Total stock based compensation expense
Subtotal	9,573	10,861
Restricted Stock Units
Total stock based compensation expense
Subtotal	13,836	11,940
Performance-based restricted stock units
Total stock based compensation expense
Subtotal	594	87
Employee Stock
Total stock based compensation expense
Subtotal	$ 454	$ 452

Stock-based Compensation - St_4

Stock-based Compensation - Stock-based Compensation Expense - By Classification (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Total stock based compensation expense
Stock-based compensation expense	$ 24,225	$ 23,196
Research and Development
Total stock based compensation expense
Stock-based compensation expense	10,875	10,117
General and Administrative Expense
Total stock based compensation expense
Stock-based compensation expense	$ 13,350	$ 13,079

Earnings (loss) per Share - Net

Earnings (loss) per Share - Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net income (loss) - basic and diluted
Net Income (Loss)	$ 89,136	$ (129,560)
Net income (loss) - basic	89,136	(129,560)
Net income (loss) - diluted	$ 89,136	$ (129,560)
Weighted average shares outstanding
Weighted average shares outstanding - basic (in shares)	61,580	60,126
Effect of dilutive securities:
Weighted average shares outstanding - diluted (in shares)	63,802	60,126
Net income (loss) per share - basic
Net income (loss) per share - basic (in dollars per share)	$ 1.45	$ (2.15)
Net income (loss) per share - diluted
Net income (loss) per share - diluted (in dollars per share)	$ 1.40	$ (2.15)
Employee Stock Option
Effect of dilutive securities:
Effect of dilutive securities (in shares)	1,165
Restricted Stock Units
Effect of dilutive securities:
Effect of dilutive securities (in shares)	985
Performance-based restricted stock units
Effect of dilutive securities:
Effect of dilutive securities (in shares)	72

Earnings (Loss) per Share - Ant

Earnings (Loss) per Share - Anti-dilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive securities excluded from computation of earnings per share
Antidilutive securities excluded from computation of earnings per share	2,568	9,495
Employee Stock Option
Antidilutive securities excluded from computation of earnings per share
Antidilutive securities excluded from computation of earnings per share	2,126	7,189
Restricted Stock Units
Antidilutive securities excluded from computation of earnings per share
Antidilutive securities excluded from computation of earnings per share	372	2,198
Performance-based restricted stock units
Antidilutive securities excluded from computation of earnings per share
Antidilutive securities excluded from computation of earnings per share	31	53
Employee Stock
Antidilutive securities excluded from computation of earnings per share
Antidilutive securities excluded from computation of earnings per share	39	55

Income Taxes - Financing Arrang

Income Taxes - Financing Arrangements (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Jul. 31, 2022	Mar. 31, 2024	Dec. 31, 2022
Gain (Loss) on Extinguishment of Debt
Debt extinguishment gain			$ 173,658
Sale of Future Royalties and Revenues
Gross Proceeds
Gross proceeds				$ 425,000
Sale of Future Royalties and Revenues | Royalty Pharma, Royalty Purchase Agreement
Gross Proceeds
Gross proceeds	$ 175,000
Gain (Loss) on Extinguishment of Debt
Debt extinguishment gain			$ 173,700
Sale of Future Royalties and Revenues | Sixth Street Partners, Future Revenue Purchase Agreement
Gross Proceeds
Gross proceeds		$ 250,000

Income Taxes - Expense (Benefit

Income Taxes - Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income tax expense (benefit)
Income tax expense	$ 180	$ 520

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Unrecognized tax benefits
Unrecognized tax benefits	$ 0

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating leases:
Lease cost	$ 5,572	$ 5,881
Net lease cost	$ 5,572	$ 5,881

Leases - Cash Flow Information

Leases - Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases
Cash paid for amounts included in the measurement of lease liabilities, operating cash flows from operating leases	$ 4,546	$ 4,405

Leases - Weighted Average Remai

Leases - Weighted Average Remaining Lease-term and Weighted Average Discount Rate (Details)	Mar. 31, 2024
Leases
Weighted average remaining lease term in years	5 years 7 months 6 days
Weighted average discount rate	7.40%

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitments (Details) - Clinical Manufacturing Agreements $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Clinical and Commercial Supply Agreements
Unrecorded unconditional purchase obligation, term	5 years
Unrecorded unconditional purchase obligation, future minimum purchase obligations	$ 4

Commitments and Contingencies_2

Commitments and Contingencies - Indemnification Agreements (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Indemnification Agreement
Indemnification Agreements
Loss contingency accrual	$ 0	$ 0

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 89,136	$ (129,560)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Item 5. Other Information ​ ​ ​ ​ ​ ​ Name and Title Action Taken Type of Trading Arrangement Nature of Trading Arrangement Duration of Trading Arrangement Aggregate Number of Securities L. Becker Hewes ( Chief Medical Officer ) ​ Adoption ( March 1, 2024 ) Trading plan intended to satisfy the affirmative defense conditions of Securities Exchange Act Rule 10b5-1(c) Sale of the Company’s common stock pursuant to the terms of the trading plan March 1, 2024 – September 1, 2025 69,080 Debra Durso-Bumpus ( Chief People Officer ) Adoption ( March 13, 2024 ) Trading plan intended to satisfy the affirmative defense conditions of Securities Exchange Act Rule 10b5-1(c) Sale of the Company’s common stock pursuant to the terms of the trading plan March 13, 2024 – June 20, 2025 87,034 ​
L Becker Hewes
Trading Arrangements, by Individual
Name	L. Becker Hewes
Title	Chief Medical Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 1, 2024
Aggregate Available	69,080
Trd Arr Expiration Date	Sep. 24, 2024
Debra Durso-Bumpus
Trading Arrangements, by Individual
Name	Debra Durso-Bumpus
Title	Chief People Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 13, 2024
Aggregate Available	87,034
Trd Arr Expiration Date	Jun. 20, 2025