CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Series A, B, C and D Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balances at Dec. 31, 2020	$ 132,040	$ 3	$ 29	$ 409,722	$ (277,707)	$ (7)
Balances, Shares at Dec. 31, 2020		3,218,287	29,260,247
Issuance of common stock upon the exercise of stock options	370			370
Issuance of common stock upon the exercise of stock options, shares			46,715
Issuance of common stock, net of financing/offering costs and net of issuance costs	4,123		$ 1	4,122
Issuance of common stock and preferred stock, net of financing/offering costs, shares			257,185
Conversion of convertible preferred stock to common stock, shares		(135)	135,000
Premium for commitment to sell common stock	(12,463)			(12,463)
Share-based compensation expense	4,172			4,172
Unrealized gain (loss) on available-for-sale securities	5					5
Net loss	(37,995)				(37,995)
Balances at Jun. 30, 2021	90,252	$ 3	$ 30	405,923	(315,702)	(2)
Balances, Shares at Jun. 30, 2021		3,218,152	29,699,147
Balances at Mar. 31, 2021	118,846	$ 3	$ 30	415,946	(297,130)	(3)
Balances, Shares at Mar. 31, 2021		3,218,152	29,663,946
Issuance of common stock upon the exercise of stock options	277			277
Issuance of common stock upon the exercise of stock options, shares			35,201
Premium for commitment to sell common stock	(12,463)			(12,463)
Share-based compensation expense	2,163			2,163
Unrealized gain (loss) on available-for-sale securities	1					1
Net loss	(18,572)				(18,572)
Balances at Jun. 30, 2021	90,252	$ 3	$ 30	405,923	(315,702)	(2)
Balances, Shares at Jun. 30, 2021		3,218,152	29,699,147
Balances at Dec. 31, 2021	88,289	$ 3	$ 32	455,719	(367,463)	(2)
Balances, Shares at Dec. 31, 2021		3,218,152	32,393,738
Issuance of common stock upon the exercise of stock options	$ 419			419
Issuance of common stock upon the exercise of stock options, shares	56,120		56,120
Issuance of common stock, net of financing/offering costs and net of issuance costs	$ 4,203		$ 1	4,202
Issuance of common stock and preferred stock, net of financing/offering costs, shares			737,619
Conversion of convertible preferred stock to common stock	1	$ (1)	$ 2
Conversion of convertible preferred stock to common stock, shares		(942,938)	1,880,000
Share-based compensation expense	4,520			4,520
Unrealized gain (loss) on available-for-sale securities	2					2
Net loss	(61,511)				(61,511)
Balances at Jun. 30, 2022	35,923	$ 2	$ 35	464,860	(428,974)
Balances, Shares at Jun. 30, 2022		2,275,214	35,067,477
Balances at Mar. 31, 2022	62,473	$ 3	$ 33	462,735	(400,292)	(6)
Balances, Shares at Mar. 31, 2022		3,218,152	32,755,559
Issuance of common stock upon the exercise of stock options	231			231
Issuance of common stock upon the exercise of stock options, shares			38,504
Issuance of common stock, net of financing/offering costs and net of issuance costs	577			577
Issuance of common stock and preferred stock, net of financing/offering costs, shares			393,414
Conversion of convertible preferred stock to common stock	1	$ (1)	$ 2
Conversion of convertible preferred stock to common stock, shares		942,938	1,880,000
Share-based compensation expense	1,317			1,317
Unrealized gain (loss) on available-for-sale securities	6					$ 6
Net loss	(28,682)				(28,682)
Balances at Jun. 30, 2022	$ 35,923	$ 2	$ 35	$ 464,860	$ (428,974)
Balances, Shares at Jun. 30, 2022		2,275,214	35,067,477