Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows used in operating activities:
Net loss	$ (109,054)	$ (134,232)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired inprocess research and development	3,000	7,000
Depreciation and amortization	2,733	874
Sharebased compensation	15,477	25,116
Amortization of premium and discount on marketable securities, net	1,206	2,235
Deferred rent		1,618
Changes in operating assets and liabilities:
Prepaid expenses and other current assets, and other assets	1,701	(66)
Prepaid research and development	310	2,026
Right of use assets and operating lease liabilities	478
Accounts payable	(4,979)	2,085
Accrued expenses and other current liabilities	(5,061)	(2,760)
Net cash used in operating activities	(94,189)	(96,104)
Cash flows provided by (used in) investing activities:
Purchases of marketable securities	(116,304)	(169,860)
Sales or maturities of marketable securities	149,661	145,974
Purchases of technology licenses	(3,000)	(7,500)
Purchases of property and equipment	(1,800)	(10,823)
Net cash provided by (used in) investing activities	28,557	(42,209)
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock, net of offering costs		165,805
Payment of offering costs		(338)
Proceeds from the exercise of stock options	128	229
Proceeds from the issuance of common stock under employee stock purchase plan	243	505
Payments for insurance premium financing	(1,136)
Net cash provided by (used in) financing activities	(765)	166,201
Net increase (decrease) in cash and cash equivalents	(66,397)	27,888
Cash and cash equivalents at beginning of year	128,965	135,002
Cash and cash equivalents at end of period	62,568	162,890
Supplemental disclosure of noncash investing and financing activities:
Unrealized gain (loss) on marketable securities	(1,055)	45
Property and equipment in accounts payable and accrued expenses and other current liabilities	45	2,254
Property and equipment in deferred rent		2,769
Vesting of early exercise option awards		$ 45
Right of use assets recognized upon the adoption of Topic 842	(20,375)
Operating lease liabilities recognized upon the adoption of Topic 842	$ 27,296