Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 62,882	$ 21,228
Marketable securities	145,473	119,219
Prepaid expenses	2,570	2,733
Other current assets	729	1,631
Total current assets	211,654	144,811
Property and equipment, net	3,283	3,435
Operating lease right-of-use asset	2,714	3,314
Other assets	282	282
Total assets	217,933	151,842
Current liabilities:
Accounts payable	2,028	2,358
Accrued liabilities	4,985	3,021
Operating lease liabilities, current	1,199	1,042
Other liabilities, current		21
Total current liabilities	8,212	6,442
Operating lease liabilities, noncurrent	3,223	4,422
Debt, noncurrent	9,622
Total liabilities	21,057	10,864
Stockholders' equity:
Common stock, $0.001 par value, 125,000,000 shares authorized as of December 31, 2021 and 2020; 56,259,747 and 46,359,743 shares issued and outstanding as of December 31, 2021 and 2020, respectively	56	46
Preferred stock, $0.001 par value, 10,000,000 shares authorized, zero shares issued and outstanding as of December 31, 2021 and 2020
Additional paid-in capital	377,765	267,093
Accumulated other comprehensive loss	(291)	(137)
Accumulated deficit	(180,654)	(126,024)
Total stockholders' equity	196,876	140,978
Total liabilities and stockholders' equity	$ 217,933	$ 151,842