Balance Sheets - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 4,842,000	$ 6,532,000
Prepaid expenses and other	1,947,000	1,718,000
Total current assets	6,789,000	8,250,000
Fixed assets, net	4,157,000	4,748,000
Right-of-use asset	915,000	1,003,000
Total assets	11,861,000	14,001,000
Current liabilities
Accounts payable and accrued expenses	2,267,000	4,025,000
Lease liability-current portion	272,000	259,000
Total current liabilities	2,539,000	4,284,000
Lease liability-long-term	1,071,000	1,210,000
Warrant derivative liability	1,908,000	2,064,000
Total liabilities	5,518,000	7,558,000
Commitments and contingencies (Note 7)
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 as of 2020 and 2019; shares issued and outstanding - 173,342,000 as of June 30, 2020 and 158,645,000 as of December 31, 2019	17,000	16,000
Additional paid-in capital	198,869,000	191,060,000
Accumulated deficit	(192,543,000)	(184,633,000)
Total stockholders' equity	6,343,000	6,443,000
Total liabilities and stockholders' equity	$ 11,861,000	$ 14,001,000