Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (138,834)	$ (235,582)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Stock-based compensation expense	28,602	25,818
Depreciation expense	1,931	1,879
Net amortization of premiums and discounts on investments	1,227	701
Acquired in-process research and development		123,000
Loss on initial consolidation of variable interest entity		11,855
Change in fair value of contingent consideration liabilities	(4,395)
Changes in assets and liabilities:
Accounts receivable	115	74,801
Contract asset	(227)	3,462
Prepaid expenses and other current assets	478	4,964
Operating lease assets and liabilities, net	73	186
Other assets		22
Accounts payable	(4,611)	(867)
Accrued expenses and other liabilities	9,540	8,261
Deferred revenue	(165)
Net cash (used in) provided by operating activities	(106,266)	18,500
Cash flows from investing activities:
Purchases of property and equipment	(4,651)	(855)
Purchases of investments	(151,945)	(646,239)
Proceeds from maturities of investments	87,600	464,673
Cash paid for acquisition of ZebiAI, net of cash acquired		(25,132)
Net cash used in investing activities	(68,996)	(207,553)
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options	1,742	3,176
Proceeds from issuance of common stock under ESPP	1,137
Net cash provided by financing activities	2,879	3,176
Net decrease in cash, cash equivalents and restricted cash	(172,383)	(185,877)
Cash, cash equivalents and restricted cash at beginning of period	282,697	448,524
Cash, cash equivalents and restricted cash at end of period	110,314	262,647
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment additions included in accounts payable and accrued expenses	$ 669	1,077
Reclassification of restricted stock liability to additional paid-in capital		3
Assets obtained in asset acquisition of ZebiAI		662
Liabilities assumed in asset acquisition of ZebiAI		2,330
Fair value of equity issued in asset acquisition of ZebiAI		$ 62,990