Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 92,046	$ 72,037
Short-term marketable securities	154,724	211,548
Accounts receivable	1,103	1,877
Prepaid expenses and other current assets	3,123	3,143
Total current assets	250,996	288,605
Restricted cash	106	106
Long-term marketable securities	121,293	0
Property and equipment, net	4,763	4,271
Right-of-use assets	3,898	5,205
Other non-current assets	291	82
Total assets	381,347	298,269
Current liabilities
Accounts payable	2,100	953
Accrued liabilities	12,320	8,516
Contract liability	29,040	27,613
Operating lease liabilities, current	1,699	1,540
Other current liabilities		18
Total current liabilities	45,159	38,640
Long-term contract liability	31,192	56,160
Long-term operating lease liabilities	3,482	5,183
Other non-current liabilities		12
Total liabilities	79,833	99,995
Commitments and contingencies (Note 6)
Stockholders’ equity
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of December 31, 2021 and December 31, 2020; no shares issued and outstanding as of December 31, 2021 and December 31, 2020
Common stock, $0.0001 par value, 300,000,000 shares authorized as of December 31, 2021 and December 31, 2020; 38,533,045 and 29,537,216 shares issued and outstanding as of December 31, 2021 and December 31, 2020	4	3
Additional paid-in capital	478,970	325,250
Accumulated other comprehensive (loss) income	(712)	7
Accumulated deficit	(176,748)	(126,986)
Total stockholders’ equity	301,514	198,274
Total liabilities and stockholders’ equity	$ 381,347	$ 298,269