Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (120,314)	$ (45,704)	$ (19,297)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,535	1,328	106
Non-cash research and development license expense in operating activity in cash flow	0	0	2,781
Non-cash lease expense	1,842		0
Amortization of premium on marketable securities	1,508	380	(72)
Stock-based compensation	7,072	850	446
Change in fair value of preferred stock tranche liabilities	0	(2,507)	4,883
Change in fair value of antidilution rights	25,574	5,359	982
Change in fair value of success payments liabilities	7,815	2,387	68
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(7,528)	(1,582)	(182)
Accounts payable	6,829	(1,898)	1,735
Accrued expenses and other liabilities	5,977	6,071	945
Success of payment liability	(6,250)	0	0
Operating lease liabilities	(1,940)		0
Deferred rent liability	0	51	163
Net cash used in operating activities	(77,880)	(35,265)	(7,442)
Cash flows from investing activities:
Purchases of property and equipment	(4,359)	(3,424)	(1,857)
Purchases of marketable securities	(371,494)	(98,484)	(22,001)
Maturities of marketable securities	136,755	50,781	11,100
Net cash used in investing activities	(239,098)	(51,127)	(12,758)
Cash flows from financing activities
Proceeds from issuance of Preferred Stock, net	93,759	92,616	18,040
Proceeds from initial public offering, net of underwriting discount	285,214		0
Shareholder loan given	0		(110)
Payment of initial public offering costs	(3,630)
Proceeds from exercise of stock options	966	11
Payments received on shareholder loan	0		24
Proceeds from purchase of shares through employee stock purchase plan	780
Net cash provided by financing activities	377,089	92,627	17,954
Increase (decrease) in cash, cash equivalents and restricted cash	60,111	6,235	(2,246)
Cash, cash equivalents and restricted cash—beginning of period	9,456	3,221	5,467
Cash, cash equivalents and restricted cash—end of period	69,567	9,456	3,221
Supplemental disclosure of noncash investing and finnacing activities:
Property and equipment additions included in accounts payable and accrued expenses	503	86	556
Issuance of preferred stock tranche liability			84
Settlement of tranche right liability	0	7,064
Conversion of convertible preferred stock to common stock upon closing of initial public offering	218,919
Settlement of derivative liability by issuing common stock	32,490	487	135
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 809