CONDENSED STATEMENTS OF STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2020		29,471,854	29,967
Beginning 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 public offering, net (in shares)		18,400,000
Issuance of common stock, net	60,084	$ 19		60,065
Exercises of stock options (in shares)		110,146
Exercise of stock options	217			217
Stock-based compensation	670			670
Net loss	(27,358)				(27,358)
Ending balance (in shares) at Mar. 31, 2021		47,982,000	29,967
Ending balance at Mar. 31, 2021	$ 8,411	$ 48	$ (24)	296,468	(288,081)
Beginning balance (in shares) at Dec. 31, 2021	48,190,590	48,220,557	29,967
Beginning balance at Dec. 31, 2021	$ (93,034)	$ 48	$ (24)	298,736	(391,794)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in public offering, net (in shares)		500,000
Issuance of common stock, net	1,183	$ 1		1,182
Stock-based compensation	597			597
Net loss	$ (11,141)				(11,141)
Ending balance (in shares) at Mar. 31, 2022	48,690,590	48,720,557	29,967
Ending balance at Mar. 31, 2022	$ (102,395)	$ 49	$ (24)	$ 300,515	$ (402,935)