Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (30,166)	$ (13,263)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	514	294
Non-cash lease expense	499	418
Amortization of premium on marketable securities	730	208
Stock-based compensation	4,203	670
Change in fair value of antidilution rights	0	(396)
Change in fair value of success payments liabilities	(1,677)	(382)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	1,149	(1,128)
Accounts payable	(5,105)	1,928
Accrued expenses and other liabilities	(3,131)	(3,047)
Operating lease liabilities	(523)	(443)
Net cash used in operating activities	(33,507)	(15,141)
Cash flows from investing activities:
Purchases of property and equipment	(2,908)	(1,070)
Purchases of marketable securities	0	(11,176)
Maturities of marketable securities	63,000	23,960
Net cash provided by investing activities	60,092	11,714
Cash flows from financing activities:
Proceeds from issuance of Series B convertible preferred stock, net	0	93,759
Proceeds from exercise of stock options	505	72
Net cash provided by financing activities	505	93,831
Increase in cash, cash equivalents and restricted cash	27,090	90,404
Cash, cash equivalents and restricted cash—beginning of period	69,567	9,456
Cash, cash equivalents and restricted cash—end of period	96,657	99,860
Supplemental disclosure of noncash investing and financing activities:
Property and equipment additions included in accounts payable and accrued expenses	2,017	528
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 0	$ 462