Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 135,055	$ 48,555
Restricted cash	237	37
Prepaid clinical expenses	360	1,528
Prepaid expenses and other current assets	484	137
Total current assets	136,136	50,257
Property and equipment, net	1,751	279
Other assets	57	0
Total assets	137,944	50,536
Current liabilities:
Accounts payable	2,567	730
Accrued expenses	1,145	926
Accrued payroll and related expenses	629	424
Total current liabilities	4,341	2,080
Shareholders’ equity:
Common Stock, $0.0001 par value; 100,000,000 shares authorized, 18,241,509 and 15,225,980 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	2	2
Additional paid-in capital	643,651	528,353
Accumulated deficit	(516,693)	(486,614)
Total shareholders’ equity	133,603	48,456
Total liabilities and shareholders' equity	137,944	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