CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Licensing revenue	$ 0	$ 0	$ 7,600,000	$ 0
Operating expenses:
Cost of licensing revenue	0	0	200,000	0
Research and development	4,541,000	2,367,000	12,281,000	6,511,000
General and administrative	2,436,000	2,125,000	8,794,000	6,312,000
Total operating expenses	6,977,000	4,492,000	21,275,000	12,823,000
Operating loss	(6,977,000)	(4,492,000)	(13,675,000)	(12,823,000)
Non-operating income (expense), net:
Change in fair value of warrant liability	30,000	6,000	(29,000)	25,000
Change in fair value of contingent consideration	(140,000)	13,000	(403,000)	(268,000)
Interest income	2,000	0	6,000	25,000
Total non-operating income (expense), net	(108,000)	19,000	(426,000)	(218,000)
Net loss	(7,085,000)	(4,473,000)	(14,101,000)	(13,041,000)
Deemed dividend arising from warrant modifications	0	0	0	(78,000)
Net loss attributable to common stockholders, basic	(7,085,000)	(4,473,000)	(14,101,000)	(13,119,000)
Net loss attributable to common stockholders, diluted	$ (7,085,000)	$ (4,473,000)	$ (14,101,000)	$ (13,119,000)
Per share information:
Net loss per common share attributable to common stockholders, basic (in dollars per share)	$ (0.45)	$ (0.53)	$ (0.92)	$ (1.83)
Net loss per common share attributable to common stockholders, diluted (in dollars per share)	$ (0.45)	$ (0.53)	$ (0.92)	$ (1.83)
Weighted-average common shares outstanding, basic (in shares)	15,874,076	8,418,038	15,344,210	7,174,859
Weighted-average common shares outstanding, diluted (in shares)	15,874,076	8,418,038	15,344,210	7,174,859