Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 29,033	$ 30,436
Accounts receivable	123	10,000
Prepaid expenses	439	921
Other current assets	394	779
Total current assets	29,989	42,136
Property and equipment, net	321	238
Operating lease right-of-use asset	276	369
Restricted cash	160	160
Total assets	30,746	42,903
Current liabilities:
Accounts payable	2,644	941
Accrued liabilities	2,354	3,312
Current portion of operating lease liabilities	395	387
Total current liabilities	5,393	4,640
Operating lease liabilities	105	288
Total liabilities	5,498	4,928
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized and no shares issued at June 30, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value; 200,000,000 and 100,000,000 shares authorized at June 30, 2022 and December 31, 2021, respectively; 60,150,442 and 59,722,930 shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively	60	60
Additional paid-in capital	296,136	293,406
Accumulated deficit	(270,948)	(255,491)
Total stockholders’ equity	25,248	37,975
Total liabilities and stockholders’ equity	$ 30,746	$ 42,903