Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 108,428	$ 72,037
Short-term marketable securities	156,123	211,548
Accounts receivable	1,018	1,877
Prepaid expenses and other current assets	3,394	3,143
Total current assets	268,963	288,605
Restricted cash	106	106
Long-term marketable securities	121,217
Property and equipment, net	4,707	4,271
Right-of-use assets	4,234	5,205
Other non-current assets	217	82
Total assets	399,444	298,269
Current liabilities
Accounts payable	2,152	953
Accrued liabilities	11,892	8,516
Contract liability	22,935	27,613
Lease liabilities	1,658	1,540
Other current liabilities		18
Total current liabilities	38,637	38,640
Long-term contract liability	39,248	56,160
Long-term lease liabilities	3,924	5,183
Other non-current liabilities	6	12
Total liabilities	81,815	99,995
Commitments and contingencies (Note 5)
Stockholders’ equity
Preferred stock, $0.0001 par value, 10,000,000 shares authorized as of September 30, 2021 and December 31, 2020; no shares issued and outstanding as of September 30, 2021 and December 31, 2020
Common stock, $0.0001 par value, 300,000,000 shares authorized as of September 30, 2021 and December 31, 2020; 38,463,086 and 29,537,216 shares issued and outstanding as of September 30, 2021 and December 31, 2020	4	3
Additional paid-in capital	476,211	325,250
Accumulated other comprehensive income	(50)	7
Accumulated deficit	(158,536)	(126,986)
Total stockholders’ equity	317,629	198,274
Total liabilities and stockholders’ equity	$ 399,444	$ 298,269