Condensed Unaudited Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses:
Research and development	$ 17,935,000	$ 18,841,000	$ 59,972,000	$ 45,311,000
General and administrative	6,648,000	6,643,000	21,688,000	17,930,000
Total operating expenses	24,583,000	25,484,000	81,660,000	63,241,000
Loss from operations	(24,583,000)	(25,484,000)	(81,660,000)	(63,241,000)
Interest income	42,000	33,000	184,000	437,000
Other expense, net	(10,000)	1,000	(13,000)	(6,000)
Loss before income tax benefit	(24,551,000)	(25,450,000)	(81,489,000)	(62,810,000)
Income tax benefit	0	0	0	3,695,000
Net loss	(24,551,000)	(25,450,000)	(81,489,000)	(59,115,000)
Comprehensive loss	$ (24,565,000)	$ (25,449,000)	$ (81,503,000)	$ (59,114,000)
Net loss per common share:
Basic (in dollars per share)	$ (0.23)	$ (0.27)	$ (0.84)	$ (0.87)
Diluted (in dollars per share)	$ (0.23)	$ (0.27)	$ (0.84)	$ (0.87)
Weighted average common shares outstanding:
Basic (in shares)	105,217	92,675	97,370	67,931
Diluted (in shares)	105,217	92,675	97,370	67,931