Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Revenues	$ 0	$ 0
Operating expenses:
Research and development	7,875	6,042
Selling, general and administrative	2,835	3,578
Depreciation and amortization	32	30
Total operating expenses	10,742	9,650
Loss from operations	(10,742)	(9,650)
Interest income	39	30
Interest expense	(519)	0
Other income, net	15	4
Net loss	$ (11,207)	$ (9,616)
Net loss per share - basic and diluted	$ (0.06)	$ (0.06)
Weighted average shares outstanding - basic and diluted	178,115,217	159,458,772
Comprehensive Income/(Loss):
Net loss	$ (11,207)	$ (9,616)
Other comprehensive income	22	23
Comprehensive net loss	$ (11,185)	$ (9,593)