Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		103 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014
Operating expenses:
Research and development	$ 3,051	$ 2,591	$ 6,293	$ 3,804	$ 32,086
General and administrative	1,688	2,481	3,517	4,119	26,644
Total operating expenses	4,739	5,072	9,810	7,923	58,730
Operating loss	(4,739)	(5,072)	(9,810)	(7,923)	(58,730)
Other income (expense):
Other income					383
Interest income	1	6	2	9	73
Interest expense	(35)	(33)	(68)	(62)	(1,336)
Modification of warrants		(765)		(765)	(765)
Derivatives gain (loss)	1,127	(8,422)	1,127	(18,871)	(30,283)
Other income (expense), net	1,093	(9,214)	1,061	(19,689)	(31,928)
Net loss	$ (3,646)	$ (14,286)	$ (8,749)	$ (27,612)	$ (90,658)
Net loss per share, basic (in dollars per share)	$ (0.04)	$ (0.20)	$ (0.11)	$ (0.40)	$ (2.15)
Net loss per share, diluted (in dollars per share)	$ (0.04)	$ (0.20)	$ (0.11)	$ (0.40)	$ (2.15)
Weighted average number of common shares outstanding, basic (in shares)	87,285,418	72,389,679	78,245,818	69,234,059	42,598,059
Weighted average number of common shares outstanding, diluted (in shares)	87,285,418	72,389,769	78,245,818	69,234,059	42,598,059