Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
License revenues	$ 439,000		$ 3,570,000
Type of Revenue Extensible List	us-gaap:GrantMember	us-gaap:GrantMember	us-gaap:GrantMember	us-gaap:GrantMember
Operating expenses:
Research and development	$ 32,995,000	$ 20,487,000	$ 61,247,000	$ 38,071,000
General and administrative	10,489,000	5,602,000	19,195,000	10,936,000
Total operating expenses	43,484,000	26,089,000	80,442,000	49,007,000
Loss from operations	(43,045,000)	(26,089,000)	(76,872,000)	(49,007,000)
Other income (expense):
Interest income	720,000	23,000	913,000	53,000
Other expense, net	(81,000)	(29,000)	(64,000)	(42,000)
Change in valuation of derivative asset	31,000		31,000
Total other expense, net	670,000	(6,000)	880,000	11,000
Loss before equity method investment	(42,375,000)	(26,095,000)	(75,992,000)	(48,996,000)
Loss on equity method investment	0	0	(1,010,000)	0
Net loss	$ (42,375,000)	$ (26,095,000)	$ (77,002,000)	$ (48,996,000)
Net loss per share:
Net loss per share - basic	$ (0.81)	$ (0.70)	$ (1.54)	$ (1.40)
Net loss per share - diluted	$ (0.81)	$ (0.70)	$ (1.54)	$ (1.40)
Weighted average shares - basic	52,522	37,061	50,130	35,048
Weighted average shares - diluted	52,522	37,061	50,130	35,048
Other comprehensive income (loss):
Unrealized loss on investment securities	$ (1,427,000)	$ (9,000)	$ (3,237,000)	$ (15,000)
Comprehensive loss	$ (43,802,000)	$ (26,104,000)	$ (80,239,000)	$ (49,011,000)