Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 126,467	$ 48,555
Restricted cash	237	37
Prepaid clinical expenses	223	1,528
Prepaid expenses and other current assets	618	137
Total current assets	127,545	50,257
Property and equipment, net	1,732	279
Other assets	70	0
Total assets	129,347	50,536
Current liabilities:
Accounts payable	2,506	730
Accrued expenses	1,224	926
Accrued payroll and related expenses	1,090	424
Total current liabilities	4,820	2,080
Shareholders’ equity:
Common Stock, $0.0001 par value; 100,000,000 shares authorized, 18,244,009 and 15,225,980 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively	2	2
Additional paid-in capital	646,408	528,353
Accumulated deficit	(528,526)	(486,614)
Total shareholders’ equity	124,527	48,456
Total liabilities and shareholders' equity	129,347	50,536
Series C-1 Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	3,906	3,917
Series F Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	$ 2,737	$ 2,798