Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Common Stock IPO	Common Stock Market offering	Additional Paid-in Capital	Additional Paid-in Capital IPO	Additional Paid-in Capital Market offering	Accumulated Deficit	Accumulated Other Comprehensive Loss	Series A Redeemable Convertible Preferred Stock	Series B Redeemable Convertible Preferred Stock	Series C Redeemable Convertible Preferred Stock	Series D Redeemable Convertible Preferred Stock
Beginning balance at Dec. 31, 2018	$ (57,728)	$ 6			$ 1,339			$ (59,073)
Beginning balance, shares at Dec. 31, 2018										6,225,719	6,786,896	3,688,740
Beginning balance at Dec. 31, 2018										$ 24,967	$ 55,151	$ 37,692
Beginning balance, shares at Dec. 31, 2018		3,757,403
Issuance of preferred stock												$ 42,500
Issuance of preferred stock, net of issuance cost (in shares)												3,688,740
Exercise of stock options	322	$ 1			321
Exercise of stock options (in shares)		243,230
Issuance of common stock related to early exercised stock options		59,276
Vesting of early exercised stock options	122				122
Stock-based compensation expense	1,185				1,185
Net Loss	(50,274)							(50,274)
Ending balance at Dec. 31, 2019	(106,373)	$ 7			2,967			(109,347)
Ending balance, shares at Dec. 31, 2019										6,225,719	6,786,896	7,377,480
Ending balance at Dec. 31, 2019										$ 24,967	$ 55,151	$ 80,192
Ending balance, shares at Dec. 31, 2019		4,059,909
Conversion of preferred stock	270,190	$ 29			270,161					$ (24,967)	$ (55,151)	$ (80,192)	$ (109,879)
Conversion of preferred stock (in shares)										(6,225,719)	(6,786,896)	(7,377,480)	(8,220,242)
Conversion of preferred stock (in shares)		28,610,337
Conversion of common stock warrant		30,278
Conversion of preferred stock warrant		16,591
Warrant liability write-off	629				629
Issuance of common stock upon initial public offering or at-the-market offering, net of issuance costs	264,007		$ 18			$ 263,989
Issuance of common stock upon initial public offering or at-the-market offering, net of issuance costs (in shares)			17,968,750
Issuance of common stock under Employee Stock Purchase Plan	374				374
Issuance of common stock under Employee Stock Purchase Plan (in shares)		27,465
Issuance of preferred stock													$ 109,879
Issuance of preferred stock, net of issuance cost (in shares)													8,220,242
Exercise of stock options	635				635
Exercise of stock options (in shares)		343,444
Issuance of common stock related to early exercised stock options		14,819
Vesting of early exercised stock options	164				164
Stock-based compensation expense	5,434				5,434
Net Loss	(89,217)							(89,217)
Ending balance at Dec. 31, 2020	345,843	$ 54			544,353			(198,564)
Ending balance, shares at Dec. 31, 2020		51,071,593
Issuance of common stock upon initial public offering or at-the-market offering, net of issuance costs	13,847			$ 1			$ 13,846
Issuance of common stock upon initial public offering or at-the-market offering, net of issuance costs (in shares)				567,045
Issuance of common stock under Employee Stock Purchase Plan	888				888
Issuance of common stock under Employee Stock Purchase Plan (in shares)		62,546
Exercise of stock options	3,012				3,012
Exercise of stock options (in shares)		931,114
Issuance of common stock to LonzaLtd.	10,001	$ 1			10,000
Issuance of common stock to Lonza Ltd. (in shares)		399,680
Unrealized losses on investment	(241)								$ (241)
Vesting of early exercised stock options	16				16
Stock-based compensation expense	10,729				10,729
Net Loss	(100,077)							(100,077)
Ending balance at Dec. 31, 2021	$ 284,018	$ 56			$ 582,844			$ (298,641)	$ (241)
Ending balance, shares at Dec. 31, 2021		53,031,978