CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 20,000	$ 24,736
Restricted cash	103	103
Prepaid expenses and other current assets	413	620
Total current assets	20,516	25,459
Restricted cash, non-current	300	300
Right of use assets, net	697	863
Property and equipment, net	46	67
Other non-current assets	186	186
Total assets	21,745	26,875
Current liabilities:
Accounts payable	2,193	1,192
Accrued research and development	1,857	1,397
Accrued expenses	751	1,711
Current portion of operating lease liabilities	765	752
Total current liabilities	5,566	5,052
Long term operating lease liabilities	8	203
Common stock warrant liability	1	1
Total liabilities	5,575	5,256
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value per share; 200,000,000 shares authorized and 9,545,451 and 9,491,111 shares issued and outstanding at December 31, 2021 and December 31, 2020, respectively	95	95
Preferred stock, $0.01 par value per share; 5,000,000 shares authorized, zero shares issued and outstanding at December 31, 2021 and December 31, 2020	0	0
Additional paid-in capital	253,963	253,771
Accumulated deficit	(237,888)	(232,247)
Total stockholders' equity	16,170	21,619
Total liabilities and stockholders' equity	$ 21,745	$ 26,875