CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	At-The-Market Offering	Public Offering	Common Stock	Common Stock At-The-Market Offering	Common Stock Public Offering	Additional Paid-in Capital	Additional Paid-in Capital At-The-Market Offering	Additional Paid-in Capital Public Offering	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 14,567			$ 2			$ 302,655			$ (288,090)
Beginning balance, shares at Dec. 31, 2020				18,787,579
Exercise of options to purchase common stock	316						316
Exercise of options to purchase common stock, shares				46,807
Stock-based compensation	2,273						2,273
Issuance of common stock upon offering, net of issuance costs			$ 61,868						$ 61,868
Issuance of common stock upon offering, net of issuance costs, shares						3,162,500
Issuance costs related to common stock			$ (560)
Net loss	(10,308)									(10,308)
Ending balance at Mar. 31, 2021	68,716			$ 2			367,112			(298,398)
Ending balance, shares at Mar. 31, 2021				21,996,886
Beginning balance at Dec. 31, 2020	14,567			$ 2			302,655			(288,090)
Beginning balance, shares at Dec. 31, 2020				18,787,579
Net loss	(32,117)
Ending balance at Jun. 30, 2021	51,864			$ 2			372,069			(320,207)
Ending balance, shares at Jun. 30, 2021				22,272,975
Beginning balance at Mar. 31, 2021	68,716			$ 2			367,112			(298,398)
Beginning balance, shares at Mar. 31, 2021				21,996,886
Exercise of options to purchase common stock	2,454						2,454
Exercise of options to purchase common stock, shares				276,089
Stock-based compensation	2,690						2,690
Issuance costs related to common stock	(187)						(187)
Net loss	(21,809)									(21,809)
Ending balance at Jun. 30, 2021	51,864			$ 2			372,069			(320,207)
Ending balance, shares at Jun. 30, 2021				22,272,975
Beginning balance at Dec. 31, 2021	53,505			$ 2			378,750			(325,247)
Beginning balance, shares at Dec. 31, 2021				22,383,830
Stock-based compensation	2,349						2,349
Issuance of common stock upon offering, net of issuance costs		$ 553						$ 553
Issuance of common stock upon offering, net of issuance costs, shares					110,037
Issuance costs related to common stock		(17)
Net loss	(8,028)						0			(8,028)
Ending balance at Mar. 31, 2022	48,379			$ 2			381,652			(333,275)
Ending balance, shares at Mar. 31, 2022				22,493,867
Beginning balance at Dec. 31, 2021	53,505			$ 2			378,750			(325,247)
Beginning balance, shares at Dec. 31, 2021				22,383,830
Issuance of common stock upon offering, net of issuance costs		$ 600
Issuance of common stock upon offering, net of issuance costs, shares		110,037
Net loss	(14,803)
Ending balance at Jun. 30, 2022	44,398			$ 2			384,446			(340,050)
Ending balance, shares at Jun. 30, 2022				22,545,531
Beginning balance at Mar. 31, 2022	48,379			$ 2			381,652			(333,275)
Beginning balance, shares at Mar. 31, 2022				22,493,867
Common stock issued under Employee Stock Purchase Plan (ESPP)	126						126
Common stock issued under Employee Stock Purchase Plan (ESPP), shares				51,664
Stock-based compensation	2,668						2,668
Net loss	(6,775)									(6,775)
Ending balance at Jun. 30, 2022	$ 44,398			$ 2			$ 384,446			$ (340,050)
Ending balance, shares at Jun. 30, 2022				22,545,531