CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenues:
License fees and royalties	$ 73	$ 107	$ 196	$ 244
Operating expenses:
Research and development	20,606	21,937	42,705	43,050
General and administrative	7,443	7,059	14,142	14,537
Total operating expenses	28,049	28,996	56,847	57,587
Loss from operations	(27,976)	(28,889)	(56,651)	(57,343)
Interest income	330	136	442	309
Interest expense	(1,581)	(804)	(3,060)	(1,547)
Other income and (expense), net	1,110	(17)	1,054	1,183
Net loss	$ (28,117)	$ (29,574)	$ (58,215)	$ (57,398)
Basic net loss per share	$ (0.07)	$ (0.09)	$ (0.16)	$ (0.18)
Diluted net loss per share	$ (0.07)	$ (0.09)	$ (0.16)	$ (0.18)
Shares used in computing basic net loss per share	403,868,713	327,026,907	368,166,148	325,342,161
Shares used in computing diluted net loss per share	403,868,713	327,026,907	368,166,148	325,342,161