Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Clinical treatment programs	$ 133	$ 197	$ 150
Total Revenues	133	197	150
Costs and Expenses:
Production costs	1,598	1,251	1,234
Research and development	8,038	8,988	8,360
General and administrative	7,147	9,057	7,723
Total Costs and Expenses	16,783	19,296	17,317
Operating loss	(16,650)	(19,099)	(17,167)
Interest and other income	364	665	791
Impairment loss on investments	(315)	(145)	(800)
Interest expense	(3)	(11)	(16)
Gain from sale of income tax operating losses	$ 1,374	1,126	686
Redeemable warrants valuation adjustment		14	281
Net loss	$ (15,230)	(17,450)	(16,225)
Other Comprehensive Income (Loss)
Unrealized loss on securities	(252)	(191)	(871)
Reclassification adjustments for impairment losses on investments included in net loss	315	145	800
Net comprehensive loss	$ (15,167)	$ (17,496)	$ (16,296)
Basic and diluted loss per share (in dollars per share)	$ (0.06)	$ (0.09)	$ (0.1)
Weighted average shares outstanding basic and diluted (in share)	236,151,781	188,291,976	167,325,584