CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	At The Market	Public Offering	Common Stock	Common Stock At The Market	Common Stock Public Offering	Additional Paid-In Capital	Additional Paid-In Capital At The Market	Additional Paid-In Capital Public Offering	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 104,179			$ 2			$ 319,196			$ (177)	$ (214,842)
Beginning balance, shares at Dec. 31, 2020				24,773,361
Proceeds from issuance of common stock, net of issuance costs		$ 1,180						$ 1,180
Proceeds from issuance of common stock, net of issuance costs, shares					57,100
Proceeds from issuances of common stock under employee stock plans	121						121
Proceeds from issuances of common stock under employee stock plans, shares				31,620
Stock-based compensation	2,687						2,687
Foreign currency translation gain (loss)	38									38
Unrealized loss on marketable securities	(50)									(50)
Net loss	(16,514)										(16,514)
Ending balance at Mar. 31, 2021	91,641			$ 2			323,184			(189)	(231,356)
Ending balance, shares at Mar. 31, 2021				24,862,081
Beginning balance at Dec. 31, 2020	104,179			$ 2			319,196			(177)	(214,842)
Beginning balance, shares at Dec. 31, 2020				24,773,361
Foreign currency translation gain (loss)	108
Unrealized loss on marketable securities	(68)
Net loss	(32,624)
Ending balance at Jun. 30, 2021	217,579			$ 3			465,179			(137)	(247,466)
Ending balance, shares at Jun. 30, 2021				29,475,921
Beginning balance at Mar. 31, 2021	91,641			$ 2			323,184			(189)	(231,356)
Beginning balance, shares at Mar. 31, 2021				24,862,081
Proceeds from issuance of common stock, net of issuance costs		$ 3,510	$ 134,582			$ 1		$ 3,510	$ 134,581
Proceeds from issuance of common stock, net of issuance costs, shares					157,871	4,356,060
Proceeds from issuances of common stock under employee stock plans	1,016						1,016
Proceeds from issuances of common stock under employee stock plans, shares				99,909
Stock-based compensation	2,888						2,888
Foreign currency translation gain (loss)	70									70
Unrealized loss on marketable securities	(18)									(18)
Net loss	(16,110)										(16,110)
Ending balance at Jun. 30, 2021	217,579			$ 3			465,179			(137)	(247,466)
Ending balance, shares at Jun. 30, 2021				29,475,921
Beginning balance at Dec. 31, 2021	186,380			$ 3			470,629			(206)	(284,046)
Beginning balance, shares at Dec. 31, 2021				29,555,119
Proceeds from issuances of common stock under employee stock plans	132						132
Proceeds from issuances of common stock under employee stock plans, shares				37,640
Stock-based compensation	2,702						2,702
Foreign currency translation gain (loss)	(201)									(201)
Unrealized loss on marketable securities	(710)									(710)
Net loss	(20,468)										(20,468)
Ending balance at Mar. 31, 2022	167,835			$ 3			473,463			(1,117)	(304,514)
Ending balance, shares at Mar. 31, 2022				29,592,759
Beginning balance at Dec. 31, 2021	186,380			$ 3			470,629			(206)	(284,046)
Beginning balance, shares at Dec. 31, 2021				29,555,119
Foreign currency translation gain (loss)	349
Unrealized loss on marketable securities	(888)
Net loss	(39,652)
Ending balance at Jun. 30, 2022	202,133			$ 3			526,573			(745)	(323,698)
Ending balance, shares at Jun. 30, 2022				29,649,457
Beginning balance at Mar. 31, 2022	167,835			$ 3			473,463			(1,117)	(304,514)
Beginning balance, shares at Mar. 31, 2022				29,592,759
Proceeds from sale of pre-funded warrants in private placement, net of issuance costs	49,784						49,784
Proceeds from issuances of common stock under employee stock plans	654						654
Proceeds from issuances of common stock under employee stock plans, shares				56,698
Stock-based compensation	2,672						2,672
Foreign currency translation gain (loss)	550									550
Unrealized loss on marketable securities	(178)									(178)
Net loss	(19,184)										(19,184)
Ending balance at Jun. 30, 2022	$ 202,133			$ 3			$ 526,573			$ (745)	$ (323,698)
Ending balance, shares at Jun. 30, 2022				29,649,457