Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Total revenues	$ 0	$ 10,006
Operating expenses:
Research and development	17,794	15,347
General and administrative	10,022	8,814
Total operating expenses	27,816	24,161
Loss from operations	(27,816)	(14,155)
Other income (expense):
Interest and other income	864	233
Interest and other expense	(855)	(1,808)
Loss before income taxes	(27,807)	(15,730)
Income tax expense	(1)	0
Net loss and comprehensive net loss	$ (27,808)	$ (15,730)
Net loss per share, basic (in dollars per share)	$ (0.32)	$ (0.45)
Net loss per share, diluted (in dollars per share)	$ (0.32)	$ (0.45)
Weighted average shares used to compute basic net loss per share (in shares)	85,704,535	34,977,378
Weighted average shares used to compute diluted net loss per share (in shares)	85,704,535	34,977,378
Revenue, Product and Service [Extensible Enumeration]	Revenue Under Collaborations [Member]	Revenue Under Collaborations [Member]