Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Revenue-supply agreement	$ 8,000	$ 0
Operating expenses
Research and development	7,216,000	4,486,000
General and administrative	1,437,000	1,453,000
Total operating expenses	8,653,000	5,939,000
Loss from operations	(8,645,000)	(5,939,000)
Other income (expense):
Interest income	5,000	14,000
Change in fair value of warrant derivative liability	574,000	(1,637,000)
Total other income (expense)	579,000	(1,623,000)
Net loss	(8,066,000)	(7,562,000)
Net loss attributable to common shareholders	(8,066,000)	(7,562,000)
Net loss attributable to common shareholders	$ (8,066,000)	$ (7,562,000)
Net (loss) income per common share attributable to common stockholders, basic (in dollars per share)	$ (0.26)	$ (0.25)
Net (loss) income per common share attributable to common stockholders, diluted (in dollars per share)	$ (0.26)	$ (0.25)
Weighted-average shares outstanding, basic (in shares)	30,833,779	30,819,578
Weighted-average shares outstanding, diluted (in shares)	30,833,779	30,819,578
Net loss	$ (8,066,000)	$ (7,562,000)
Other comprehensive loss:
Foreign currency translation adjustment	0	(3,000)
Comprehensive loss	$ (8,066,000)	$ (7,565,000)