CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Collaboration revenue	$ 0	$ 2,911	$ 4	$ 2,911
Operating expenses:
Research and development	3,656	7,893	15,346	19,411
General and administrative	3,578	3,282	9,791	10,217
Gain on lease modification	0	0	(245)	(133)
Restructuring costs	419	0	419	0
Property and equipment and right-of-use assets impairment	1,011	0	1,011	0
Total operating expenses	8,664	11,175	26,322	29,495
Loss from operations	(8,664)	(8,264)	(26,318)	(26,584)
Other income (expense):
Interest Expense	0	(841)	(1,921)	(2,266)
Other income, net	188	254	942	279
Other income (expense), net	188	(587)	(979)	(1,987)
Net loss	$ (8,476)	$ (8,851)	$ (27,297)	$ (28,571)
Earnings per share, Basic	$ (0.04)	$ (0.04)	$ (0.11)	$ (0.13)
Earnings per share, Diluted	$ (0.04)	$ (0.04)	$ (0.11)	$ (0.13)
Weighted Average Number Of Shares Outstanding Basic	240,046,026	215,098,995	239,842,327	215,015,377
Weighted Average Number Of Diluted Shares Outstanding	240,046,026	215,098,995	239,842,327	215,015,377