Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues	$ 2,181	$ 675
Operating expenses:
Research and development	19,013	19,622
General and administrative	7,238	6,625
Total operating expenses	26,251	26,247
Operating loss	(24,070)	(25,572)
Other income (expense):
Interest income	503	642
Non-cash interest expense related to sale of future royalties	(804)	(178)
Other expense, net	(1)	(3)
Loss before income taxes	(24,372)	(25,111)
Provision for income taxes	45	29
Net loss	$ (24,417)	$ (25,140)
Net loss per share - basic and diluted (in dollars per share)	$ (0.14)	$ (0.19)
Shares used to compute net loss per share - basic and diluted (in shares)	168,811,095	135,213,196
Comprehensive loss:
Net loss	$ (24,417)	$ (25,140)
Unrealized (loss) gain on available-for-sale investments, net of tax	(9)	229
Comprehensive loss	(24,426)	(24,911)
Non Cash Royalty Revenue [Member]
Revenues	585	278
Government Contract [Member]
Revenues	1,596	0
Grant [Member]
Revenues	$ 0	$ 397