CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 35,848	$ 31,087
Restricted cash	62	0
Contract and other receivables	0	503
Prepaid materials, net	3,010	3,314
Prepaid expenses and other current assets	1,066	1,826
Total current assets	39,986	36,730
Property and equipment, net	277	472
Intangibles, net	89	125
Right of use asset	2,690	253
Other assets	0	24
Total assets	43,042	37,604
Current liabilities:
Accounts payable	586	535
Accrued liabilities	775	581
Accrued research and development expenses	2,347	1,097
Accrued compensation	1,427	1,743
Current portion of term loan, less debt issuance costs	4,668	4,652
Other current liabilities	1,657	2,970
Total current liabilities	11,460	11,578
Lease liability, less current portion	2,570	0
Total liabilities	14,030	11,578
Commitments and Contingencies	0	0
Stockholders’ equity:
Common stock, $0.001 par value; 400,000,000 shares and 200,000,000 authorized at September 30, 2021 and December 31, 2020, respectively; 87,047,832 and 67,432,712 shares issued and outstanding at September 30, 2021 (unaudited) and December 31, 2020, respectively	87	67
Additional paid-in capital	476,643	453,002
Accumulated deficit	(447,720)	(427,045)
Total stockholders’ equity	29,012	26,026
Total liabilities and stockholders’ equity	43,042	37,604
Class A-1 Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	0	0
Class A-2 Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	1	1
Class A-3 Convertible Preferred Stock
Stockholders’ equity:
Preferred stock	$ 1	$ 1