Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Consolidated Statements of Operations and Comprehensive Loss [Abstract]
Grant revenue	$ 31,000		$ 31,000
Operating expenses
Research and development	2,648,000	$ 3,076,000	5,398,000	$ 5,137,000
General and administrative	1,973,000	2,082,000	4,144,000	3,462,000
Loss from operations	4,590,000	5,158,000	9,511,000	8,599,000
Other income (expense)
Interest income	22,000	28,000	24,000	76,000
Interest expense	(142,000)	(230,000)	(301,000)	(536,000)
Other income (expense)		4,000		4,000
Change in fair value of derivative liabilities		1,157,000		1,117,000
Total other income (expense), net	(120,000)	959,000	(277,000)	661,000
Net loss	$ (4,710,000)	$ (4,199,000)	$ (9,788,000)	$ (7,938,000)
Per share information:
Net loss per share, basic and diluted (in dollars per share)	$ (0.26)	$ (0.56)	$ (0.68)	$ (1.30)
Weighted average shares outstanding, basic and diluted	18,347,051	7,505,097	14,399,399	6,086,816
Net loss per share, diluted	$ (0.26)	$ (0.69)	$ (0.68)	$ (1.38)
Weighted average shares outstanding, diluted	18,347,051	7,720,977	14,399,399	6,452,413