Condensed Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (192,036)	$ (91,130)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	9,207	3,683
Depreciation and amortization	1,578	763
Non-cash lease expense	1,043	611
Changes in operating assets and liabilities:
Grants receivable	288	1,334
Prepaid expenses and other current assets	(281)	(295)
Prepaid research and development	12,014	(11,747)
Accounts payable	216	3,200
Accrued expenses and other liabilities	2,202	7,262
Lease liabilities	(104)	(796)
Other long term assets	(5,511)	91
Net cash used in operating activities	(171,384)	(87,024)
Investing activities
Purchase of property and equipment	(2,866)	(8,201)
Net cash used in investing activities	(2,866)	(8,201)
Financing activities
Proceeds from stock option exercises	1,444	16
Proceeds from stock issuances pursuant to employee stock purchase plan	439
Proceeds from initial public offering, net of issuance costs	232,546
Proceeds from the issuance of convertible preferred stock, net of issuance costs		248,189
Payment of deferred initial public offering costs		(1,451)
Net cash provided by financing activities	234,429	246,754
Net increase in cash, cash equivalents and restricted cash	60,179	151,529
Cash, cash equivalents and restricted cash at beginning of year	173,133	21,604
Cash, cash equivalent and restricted cash at end of year	233,312	173,133
Supplemental disclosure of noncash activities
Property and equipment purchases included in accounts payable and accrued expenses	127	140
Right-of-use assets obtained in exchange for operating lease liabilities	13,499	743
Remeasurement of operating lease right-of-use asset for lease modification	$ 342	417
Deferred initial public offering costs included in accounts payable and accrued expenses		$ 928