Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 15,362	$ 25,846
Prepaid expenses and other current assets	432	554
Total current assets	15,794	26,400
Property and equipment, net	0	0
Intangible assets, net	1	8
Total assets	15,795	26,408
Current liabilities:
Accounts payable	910	448
Accrued expenses	2,802	845
Accrued dividends payable	68	67
Total current liabilities	3,780	1,360
Total liabilities	3,780	1,360
Commitments and contingencies (Note 9)
Stockholders' equity:
Undesignated stock, $0.01 par value; 20,000,000 shares authorized at December 31, 2016 and 2015, 14,001,000 shares designated at December 31, 2016 and 2015	0	0
Common stock, $0.001 par value; 50,000,000 shares authorized at December 31, 2016 and 2015, 32,912,942 and 28,825,033 issued and outstanding at December 31, 2016 and 2015, respectively	33	28
Additional paid-in capital	166,721	157,504
Retained deficit	(163,701)	(140,049)
Total stockholders' equity	10,292	18,040
Total liabilities, redeemable convertible preferred stock and stockholders' equity	15,795	26,408
Series B-1 12% redeemable convertible preferred stock
Current liabilities:
Convertible preferred stock, value		1,748
Series B-2 12% redeemable convertible preferred stock
Current liabilities:
Convertible preferred stock, value		3,537
Series C super dividend convertible preferred stock
Current liabilities:
Convertible preferred stock, value	1,723	1,723
Series A 12% convertible preferred stock
Stockholders' equity:
Convertible preferred stock, value	557	$ 557
Series B-1 12% convertible preferred stock
Stockholders' equity:
Convertible preferred stock, value	1,761
Series B-2 12% convertible preferred stock
Stockholders' equity:
Convertible preferred stock, value	3,697
Series B-3 8% convertible preferred stock
Stockholders' equity:
Convertible preferred stock, value	$ 1,224