Condensed Balance Sheets - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 22,890,000	$ 33,892,000
Prepaid expenses and other	1,754,000	1,740,000
Total current assets	24,644,000	35,632,000
Fixed assets, net	2,046,000	2,564,000
Right-of-use asset, net	525,000	629,000
Total assets	27,215,000	38,825,000
Current liabilities
Accounts payable and accrued expenses	4,757,000	4,811,000
Lease liability-current portion	325,000	311,000
Total current liabilities	5,082,000	5,122,000
Lease liability-long-term	448,000	614,000
Warrant derivative liability	1,588,000	5,805,000
Total liabilities	7,118,000	11,541,000
Commitments and contingencies (Note 5)
Stockholders' equity
Preferred Stock, par value $0.0001; 10,000,000 shares authorized; none issued
Common Stock, par value $0.0001; 300,000,000 shares authorized; shares issued and outstanding - 226,286,867 as of June 30, 2022 and 227,325,381 as of December 31, 2021	23,000	23,000
Additional paid-in capital	245,382,000	244,863,000
Accumulated deficit	(225,308,000)	(217,602,000)
Total stockholders' equity	20,097,000	27,284,000
Total liabilities and stockholders' equity	$ 27,215,000	$ 38,825,000