Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 110,334	$ 95,966
Short-term investments	62,614	104,378
Unbilled grant receivable		1,227
Prepaid expenses and other current assets	5,556	5,962
Total current assets	178,504	207,533
Restricted cash	631	420
Property and equipment, net	3,633	4,053
Operating lease right-of-use asset	1,105	1,263
Long-term investments		44,829
Other long-term assets	827	55
Total assets	184,700	258,153
Current liabilities:
Accounts payable	1,711	2,501
Accrued liabilities	16,553	8,604
Accrued legal settlement	10,000	10,000
Current operating lease liability	358	326
Total current liabilities	28,622	21,431
Operating lease liability, less current portion	1,314	1,585
Total liabilities	29,936	23,016
Stockholders' equity:
Common stock, $0.0001 par value; 900,000,000 shares authorized at September 30, 2023 and December 31, 2022, respectively; 38,054,583 and 37,877,387 shares issued and outstanding at September 30, 2023 and December 31,2022, respectively	4	4
Additional paid-in capital	437,359	428,623
Accumulated other comprehensive loss	(678)	(1,956)
Accumulated deficit	(281,921)	(191,534)
Total stockholders' equity	154,764	235,137
Total liabilities and stockholders' equity	$ 184,700	$ 258,153