Consolidated Balance Sheets - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 5,132,000	$ 5,711,000
Prepaid expenses and other current assets	253,000	602,000
Total current assets	5,385,000	6,313,000
Property and equipment, net	816,000	1,072,000
In process research and development	4,661,000	10,461,000
Acquired patents, net	276,000	307,000
Total assets	11,138,000	18,153,000
Current liabilities
Accounts payable and accrued expenses	1,968,000	2,735,000
Accrued compensation	1,050,000	895,000
Notes payable (Note 8)		803,000
Total current liabilities	1,968,000	3,538,000
Derivative liabilities	292,000	2,443,000
Deferred tax liability	1,147,000	2,449,000
Total liabilities	3,407,000	8,430,000
Series B redeemable convertible preferred stock
$0.01 par value, 9,357,935 shares authorized at December 31, 2016 and 2015, respectively, no shares and 7,527,853 shares issued and outstanding at December 31, 2016 and 2015, respectively (liquidation preference of $0 and $13,383,000 at December 31, 2016 and 2015, respectively)
Stockholders' equity
Common stock, $0.01 par value; 67,000,000 shares authorized at December 31, 2017 and 2016; 9,498,928 and 1,648,751 shares issued and outstanding at December 31, 2017 and 2016, respectively	95,000	16,000
Additional paid-in capital	401,842,000	391,067,000
Accumulated deficit	(394,206,000)	(381,360,000)
Total stockholders' equity (deficit)	7,731,000	9,723,000
Total liabilities, Series B redeemable convertible preferred stock and stockholders' equity	$ 11,138,000	$ 18,153,000