Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 23,024	$ 19,493
Prepaid expenses and other current assets	531	163
Total current assets	23,555	19,656
Property, equipment and leasehold improvements, net	68	85
Restricted cash - non current	150	110
Operating lease right-of-use assets	919	928
Prepaid clinical trial expenses	1,122	1,122
Other assets		9
Total assets	25,814	21,910
Current liabilities:
Accounts payable	610	481
Operating lease liabilities	375	327
Accrued expenses	813	1,164
Total current liabilities	1,798	1,972
Other liabilities	77	59
Operating lease liabilities - non current	629	693
Total liabilities	2,504	2,724
Commitments and contingencies (Note 5)
Stockholders' equity:
Common stock, $0.00001 par value, authorized 50,000,000 shares; 34,264,806 shares issued and outstanding, including 6,302 shares of unvested restricted stock, at June 30, 2021; authorized 50,000,000 shares; 23,631,886 shares issued and outstanding, including 6,302 shares of unvested restricted stock, at December 31, 2020	3	3
Additional paid-in capital	256,073	247,417
Accumulated deficit	(232,766)	(228,234)
Total stockholders' equity	23,310	19,186
Total liabilities and stockholders' equity	$ 25,814	$ 21,910