CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating expenses:
Research and development	$ 31,737	$ 23,818
General and administrative	6,615	6,361
Total operating expenses	38,352	30,179
Total operating loss	(38,352)	(30,179)
Other income (expense):
Interest income	52	3
Interest expense	(1,033)	(489)
Change in fair value of derivatives	557	138
Total other income (expense)	(424)	(348)
Net loss	(38,776)	(30,527)
Preferred stock dividends	(97)	(171)
Net loss applicable to common stockholders	$ (38,873)	$ (30,698)
Net loss per common share - basic (in dollars per share)	$ (0.65)	$ (0.52)
Net loss per common share - diluted (in dollars per share)	$ (0.65)	$ (0.52)
Weighted average common and potential common shares outstanding - basic (in shares)	59,391	58,527
Weighted average common and potential common shares outstanding - diluted (in shares)	59,391	58,527