Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 34,817	$ 44,347
Short-term investments		2,504
Accounts receivable, net	564	1,818
Prepaid and other current assets	1,322	2,807
Total current assets	36,703	51,476
Other assets, noncurrent	472	472
Right-of-use assets	2,242	2,744
Property and equipment, net	857	970
Total assets	40,274	55,662
Current liabilities:
Accounts payable	4,706	6,419
Accrued compensation	2,137	1,467
Deferred revenue		230
Other accrued liabilities	4,438	4,072
Operating lease liability	1,909	1,977
Total current liabilities	13,190	14,165
Operating lease liability, noncurrent		408
Total liabilities	13,190	14,573
Commitments and Contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized; zero shares issued and outstanding
Common stock, $0.001 par value, 100,000,000 shares authorized; 31,477,053 and 31,409,707 shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	31	31
Additional paid-in capital	444,283	443,752
Accumulated deficit	(417,230)	(402,694)
Total stockholders’ equity	27,084	41,089
Total liabilities and stockholders’ equity	$ 40,274	$ 55,662