Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 7,628	$ 3,600
Investments	24,754	42,333
Prepaid expenses and other current assets	1,143	2,219
Restricted cash	25	25
Total current assets	33,550	48,177
Operating lease, right-of-use asset	98	152
Other non-current assets	24	24
Property and equipment, net	98	128
Total assets	33,770	48,481
Current liabilities:
Accounts payable	1,741	1,210
Accrued expenses and other current liabilities	3,310	3,205
Operating lease liability, current portion	100	93
Total current liabilities	5,151	4,508
Operating lease liability, net of current portion		69
Total liabilities	5,151	4,577
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized and no shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively
Common stock, $0.001 par value; 300,000,000 shares authorized at June 30, 2022 and December 31, 2021, respectively; 90,823,597 and 90,573,597 shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively	91	91
Additional paid-in capital	290,499	289,282
Accumulated other comprehensive loss	(101)	(13)
Accumulated deficit	(261,870)	(245,456)
Total stockholders’ equity	28,619	43,904
Total liabilities and stockholders’ equity	$ 33,770	$ 48,481