Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Revenue	$ 0	$ 0	$ 0	$ 0
Operating expenses:
Research and development	5,433	3,853	11,326	8,169
General and administrative	2,608	2,156	5,136	4,829
Total operating expenses	8,041	6,009	16,462	12,998
Loss from operations	(8,041)	(6,009)	(16,462)	(12,998)
Interest income	49	19	70	33
Other income (expense), net	0	304	(22)	304
Net loss	$ (7,992)	$ (5,686)	$ (16,414)	$ (12,661)
Net loss per share - basic	$ (0.09)	$ (0.06)	$ (0.18)	$ (0.15)
Net loss per share - diluted	$ (0.09)	$ (0.06)	$ (0.18)	$ (0.15)
Weighted average common shares outstanding - basic	90,823,597	90,458,550	90,749,011	86,941,002
Weighted average common shares outstanding - diluted	90,823,597	90,458,550	90,749,011	86,941,002
Comprehensive loss:
Net loss	$ (7,992)	$ (5,686)	$ (16,414)	$ (12,661)
Other comprehensive loss:
Unrealized gain (loss) on investments, net of tax of $0	(26)	13	(88)	8
Total other comprehensive income (loss)	(26)	13	(88)	8
Total comprehensive loss	$ (8,018)	$ (5,673)	$ (16,502)	$ (12,653)