BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 6,062	$ 39,058
Restricted cash	0	13,938
Receivables	1	4
Prepaid expenses and other current assets	2,198	799
Total current assets	8,261	53,799
Property and equipment, net	2	8,460
Right-of-use assets	0	2,136
Deposits	0	42
Other non-current assets	0	500
Total assets	8,263	64,937
Current liabilities:
Accounts payable	616	1,389
Current portion of long-term debt	0	16,765
Accrued expenses	1,340	5,454
Lease liabilities, current	0	558
Total current liabilities	1,956	24,166
Lease liabilities, non-current	0	2,188
Other non-current liabilities	0	28
Total liabilities	1,956	26,382
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock $0.001 par value; 34,666,667 shares authorized, 16,012,522 shares issued and outstanding at December 31, 2023 and 28,000,000 shares authorized,16,027,384 shares issued and outstanding at December 31, 2022	16	16
Additional paid-in capital	922,058	919,166
Accumulated deficit	(915,767)	(880,627)
Total stockholders' equity	6,307	38,555
Total liabilities and stockholders' equity	$ 8,263	$ 64,937