Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 15,402	$ 21,837
Accounts receivable, interest and other receivables	8	0
Prepaid expenses and other current assets	1,826	1,964
Total current assets	17,236	23,801
Property and equipment, net	24	22
Total assets	17,260	23,823
Current liabilities:
Accounts payable	1,226	486
Accrued expenses and other current liabilities	3,255	2,477
Warrant derivative liability	235	809
Total liabilities	4,716	3,772
Commitments and contingencies
Redeemable preferred stock: $0.01 par value; 10,000,000 shares authorized Series 1 redeemable convertible preferred stock, $0.01 par value, 1,517,500 shares authorized at March 31, 2023 and December 31, 2022, 425,000 shares issued and outstanding at March 31, 2023 and December 31, 2022	22,564	18,036
Stockholders’ equity:
Common stock, $0.01 par value; 160,000,000 shares authorized at March 31, 2023 and December 31, 2022, 9,114,044 shares issued and 9,046,298 shares outstanding at March 31, 2023; 8,682,447 shares issued and 8,614,701 shares outstanding at December 31, 2022	91	87
Treasury stock: 67,746 shares held at March 31, 2023 and December 31, 2022	(5,056)	(5,056)
Additional paid-in capital	578,790	582,763
Accumulated other comprehensive loss	(354)	(354)
Accumulated deficit	(583,491)	(575,425)
Total stockholders’ (deficit) equity	(10,020)	2,015
Total liabilities, redeemable preferred stock and stockholders’ (deficit) equity	$ 17,260	$ 23,823