Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 28,097	$ 38,320
Inventories	901	906
Prepaid expenses and other current assets	3,972	1,782
Total current assets	32,970	41,008
Restricted cash	540	1,960
Property and equipment, net	1,343	1,488
Right-of-use lease asset	3,955	4,224
Other assets	51
Total assets	38,859	48,680
Current liabilities:
Accounts payable, net	2,527	2,372
Accrued expenses and other current liabilities	4,695	5,461
Lease liability	954	899
Total current liabilities	8,176	8,732
Loans payable, net	14,176	13,430
Leases, net of current portion	4,946	5,436
Warrant liability	1,779	5,483
Total liabilities	29,077	33,081
Stockholders' equity:
Preferred stock-$0.001 par value; 5,000,000 shares authorized, none issued or outstanding at June 30, 2023 and December 31, 2022
Common stock-$0.001 par value; 200,000,000 shares authorized at June 30, 2023 and December 31, 2022; 13,712,139 and 7,744,692 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively	14	8
Additional paid-in capital	573,371	563,362
Accumulated deficit	(563,603)	(547,772)
Accumulated other comprehensive income		1
Total stockholders' equity	9,782	15,599
Total liabilities and stockholders' equity	$ 38,859	$ 48,680