Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 22,356	$ 25,846
Prepaid expenses and other current assets	425	554
Total current assets	22,781	26,400
Intangible assets, net	7	8
Total assets	22,788	26,408
Current liabilities:
Accounts payable	1,311	448
Accrued expenses	1,939	845
Accrued dividends payable		67
Total current liabilities	3,250	1,360
Total liabilities	$ 3,250	$ 1,360
Commitments and contingencies (Note 8)
Stockholders' equity:
Undesignated stock, $0.01 par value; 20,000,000 shares authorized, 8,001,000 designated at March 31, 2016 and December 31, 2015	$ 0	$ 0
Series A 12% convertible preferred stock; 5,000,000 shares authorized, 1,377,500 issued and outstanding at March 31, 2016 and December 31, 2015, liquidation value $1,377,500 at March 31, 2016	557	557
Common stock, $0.001 par value; 50,000,000 shares authorized at March 31, 2016 and December 31, 2015, 28,979,179 and 28,825,033 issued and outstanding at March 31, 2016 and December 31, 2015, respectively	28	28
Additional paid-in capital	158,947	157,504
Retained deficit	(147,060)	(140,049)
Total stockholders' equity	12,472	18,040
Total liabilities, redeemable convertible preferred stock and stockholders' equity	22,788	26,408
Series B-1 12% redeemable convertible preferred stock
Current liabilities:
Convertible preferred stock, value	1,752	1,748
Series B-2 12% redeemable convertible preferred stock
Current liabilities:
Convertible preferred stock, value	3,591	3,537
Series C super dividend convertible preferred stock
Current liabilities:
Convertible preferred stock, value	$ 1,723	$ 1,723