Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 85,035	$ 126,467
Restricted cash	200	237
Prepaid clinical expenses	105	223
Prepaid expenses and other current assets	1,396	618
Total current assets	86,736	127,545
Property and equipment, net	2,566	1,732
Other assets	219	70
Total assets	89,521	129,347
Current liabilities:
Accounts payable	1,998	2,506
Accrued expenses	3,917	1,224
Accrued payroll and related expenses	1,321	1,090
Total current liabilities	7,236	4,820
Shareholders’ equity:
Common Stock, $0.0001 par value; 100,000,000 shares authorized, 18,254,009 and 18,244,009 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	2	2
Additional paid-in capital	657,464	646,408
Accumulated deficit	(581,824)	(528,526)
Total shareholders’ equity	82,285	124,527
Total liabilities and shareholders’ equity	89,521	129,347
Series C-1 Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	3,906	3,906
Series F Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	$ 2,737	$ 2,737