Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 48,555	$ 8,629
Restricted cash	37	37
Prepaid clinical expenses	1,528	0
Prepaid expenses and other current assets	137	43
Total current assets	50,257	8,709
Property and equipment, net	279	38
Total assets	50,536	8,747
Current liabilities:
Accounts payable	730	834
Accrued expenses	926	187
Accrued payroll and related expenses	424	73
Total current liabilities	2,080	1,094
Commitments and contingencies
Shareholders’ equity:
Common stock, $0.0001 par value; 100,000,000 and 12,000,000,000 shares authorized, 15,225,980 and 4,404,407 shares issued and outstanding at December 31, 2014 and 2013, respectively	2	4
Additional paid-in capital	528,353	462,684
Accumulated deficit	(486,614)	(465,301)
Total shareholders’ equity	48,456	7,653
Total liabilities and stockholders' equity	50,536	8,747
Series C-1 Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	3,917	7,016
Series F Convertible Preferred Stock [Member]
Shareholders’ equity:
Convertible preferred stock, value	$ 2,798	$ 3,250