Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 7,410	$ 21,837
Prepaid expenses and other current assets	1,302	1,964
Total current assets	8,712	23,801
Property and equipment, net	21	22
Total assets	8,733	23,823
Current liabilities:
Accounts payable	472	486
Accrued expenses and other current liabilities	2,487	2,477
Warrant derivative liability	523	809
Total liabilities	3,482	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 June 30, 2023 and December 31, 2022; 452,000 shares issued and outstanding at June 30, 2023 and December 31, 2022	27,091	18,036
Stockholders’ (deficit) equity:
Common stock, $0.01 par value; 160,000,000 shares authorized at June 30, 2023 and December 31, 2022; 9,564,044 shares issued and 9,496,298 shares outstanding at June 30, 2023; 8,682,447 shares issued and 8,614,701 shares outstanding at December 31, 2022	96	87
Treasury stock: 67,746 shares held at June 30, 2023 and December 31, 2022	(5,056)	(5,056)
Additional paid-in capital	574,317	582,763
Accumulated other comprehensive loss	(354)	(354)
Accumulated deficit	(590,843)	(575,425)
Total stockholders’ (deficit) equity	(21,840)	2,015
Total liabilities, redeemable preferred stock and stockholders’ (deficit) equity	$ 8,733	$ 23,823