Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
OPERATING ACTIVITIES:
Net loss	$ (266,759)	$ (283,255)	$ (269,476)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and impairment of long-lived assets	17,391	24,557	15,625
Stock-based compensation expense	37,678	35,533	38,337
Change in the estimated fair value of contingent consideration	(638)	(40,773)	(3,364)
Change in the estimated fair value of success payment liabilities	(8,243)	(8,208)	(81,518)
Non-cash expense for operating lease right-of-use assets	9,681	13,265	12,106
Other non-cash items, net	(11,078)	(13,312)	(9,302)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(3,513)	8,143	(5,988)
Operating lease right-of-use assets and liabilities	9,341	10,959	1,562
Accounts payable	1,377	1,027	1,058
Accrued expenses and other liabilities	(8,390)	(1,518)	10,910
Net cash used in operating activities	(223,153)	(253,582)	(290,050)
INVESTING ACTIVITIES:
Purchases of marketable securities	(226,064)	(157,744)	(78,688)
Proceeds from maturities of marketable securities	276,947	349,788	310,126
Purchases of property and equipment	(33,430)	(20,032)	(20,876)
Net cash provided by investing activities	17,453	172,012	210,562
FINANCING ACTIVITIES:
Proceeds from employee stock purchase plan and exercise of stock options	11,005	4,626	4,312
Proceeds from issuance of common stock from equity financings, net	181,000	27,020	601
Proceeds from tenant improvement loan, net	7,744
Net cash provided by financing activities	199,749	31,646	4,913
Net decrease in cash, cash equivalents, and restricted cash	(5,951)	(49,924)	(74,575)
Cash, cash equivalents, and restricted cash at beginning of period	137,349	187,273	261,848
Cash, cash equivalents, and restricted cash at end of period	131,398	137,349	187,273
RECONCILITION OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	127,566	133,517	176,765
Restricted cash	3,832	3,832	6,100
Long-term restricted cash			4,408
Total cash, cash equivalents, and restricted cash	131,398	137,349	187,273
SUPPLEMENTAL CASH FLOW INFORMATION:
Operating lease right-of-use assets obtained in exchange for lease obligations		8,984	21,073
Purchases of property and equipment included in accounts payable and accrued liabilities		9,471	1,234
Cash received for tenant improvement allowances	7,509	12,547	2,014
Derecognition of operating lease right-of-use asset for lease termination		$ (14,204)
Derecognition of operating lease right-of-use asset for lease modification	$ (7,261)		$ (12,801)