CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 76,057	$ 34,871
Restricted cash	364	364
Marketable securities	143,230	148,851
Interest and other receivables	4,254	1,763
Prepaid and other current assets	3,470	1,357
Total current assets	227,375	187,206
Noncurrent marketable securities		28,651
Property and equipment, net	641	650
Operating leases, right-of-use assets	4,442	4,727
Deposits and other assets	5,703	4,800
Total assets	238,161	226,034
Current liabilities:
Accounts payable	4,521	6,687
Accrued compensation and benefits	5,613	8,099
Operating lease liabilities	913	901
Debt	5,162
Accrued liabilities	30,670	29,834
Total current liabilities	46,879	45,521
Noncurrent operating lease liabilities	3,977	4,267
Noncurrent debt	45,258	49,830
Commitments and contingencies
Stockholders' equity:
Common stock	378	324
Additional paid-in capital	1,472,407	1,398,006
Accumulated deficit	(1,329,956)	(1,271,741)
Accumulated other comprehensive loss	(782)	(173)
Total stockholders' equity	142,047	126,416
Total liabilities and stockholders' equity	$ 238,161	$ 226,034