Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 95,966	$ 110,537
Short-term investments	104,378	143,222
Unbilled grant receivable	1,227	2,336
Prepaid expenses and other current assets	5,962	4,704
Total current assets	207,533	260,799
Restricted cash	420
Property and equipment, net	4,053	3,757
Operating lease right-of-use asset	1,263	1,460
Long-term investments	44,829	65,936
Other long-term assets	55	56
Total assets	258,153	332,008
Current liabilities:
Accounts payable	2,501	567
Accrued liabilities	8,604	8,437
Accrued legal settlement (Note 7)	10,000
Current operating lease liability	326	288
Total current liabilities	21,431	9,292
Operating lease liability, less current portion	1,585	1,632
Total liabilities	23,016	10,924
Stockholders' equity:
Common stock, $0.0001 par value; 900,000,000 shares authorized at December 31, 2022 and December 31, 2021, respectively; 37,877,387 and 37,379,077 shares issued and outstanding at December 31, 2022 and December 31, 2021, respectively	4	4
Additional paid-in capital	428,623	417,363
Accumulated other comprehensive loss	(1,956)	(388)
Accumulated deficit	(191,534)	(95,895)
Total stockholders' equity	235,137	321,084
Total liabilities and stockholders' equity	$ 258,153	$ 332,008