STATEMENTS OF STOCKHOLDERS’ DEFICIT - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		28,796,371	29,967
Beginning balance at Dec. 31, 2019	$ 59,978	$ 29	$ (24)	$ 222,131	$ (162,158)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock warrants	7,925			7,925
Issuance of common stock in initial public offering, net (in shares)		561,848
Issuance of common stock in public offering, net	2,942	$ 19		2,942
Issuance of common stock through employee share purchase plan (in shares)		62,063
Issuance of common stock through employee stock purchase plan	186			186
Exercises of stock options (in shares)		51,572
Exercises of stock options	95			95
Stock-based compensation	2,237			2,237
Net loss	$ (98,565)				(98,565)
Ending balance (in shares) at Dec. 31, 2020	29,441,887	29,471,854	29,967
Ending balance at Dec. 31, 2020	$ (25,202)	$ 29	$ (24)	235,516	(260,723)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in initial public offering, net (in shares)		18,400,000
Issuance of common stock in public offering, net	60,241			60,222
Issuance of common stock through employee share purchase plan (in shares)		138,952
Issuance of common stock through employee stock purchase plan	336			336
Exercises of stock options (in shares)		209,751
Exercises of stock options	394			394
Stock-based compensation	2,268			2,268
Net loss	$ (131,071)				(131,071)
Ending balance (in shares) at Dec. 31, 2021	48,190,590	48,220,557	29,967
Ending balance at Dec. 31, 2021	$ (93,034)	$ 48	$ (24)	$ 298,736	$ (391,794)