CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue:
Licensing revenue	$ 100,000	$ 250,000	$ 100,000
Expenses:
Research and development	12,684,793	15,491,301	8,506,937
General and administrative	8,353,330	7,317,169	8,235,993
Depreciation and amortization	113,936	95,517	107,666
Total Expenses	21,152,059	22,903,987	16,850,596
Loss before other income	(21,052,059)	(22,653,987)	(16,750,596)
Other income:
Interest income	131,666	207,217	303,592
Other income, net	191,416	205,194	95,827
Gain on warrant liability	2,766,704	7,915,027	933,420
Gain on sale of affiliate's shares - RXi Pharmaceutical	0	0	15,826,217
Net (loss) income before provision for income taxes	(17,962,273)	(14,326,549)	408,460
Income tax expense	(1,600)	(97,996)	0
Net (loss) income	$ (17,963,873)	$ (14,424,545)	$ 408,460
Basic and diluted (loss) income per share (in dollars per share)	$ (0.78)	$ (0.8)	$ 0.03
Basic weighted average shares outstanding (in shares)	22,973,905	17,935,895	15,640,642
Diluted weighted average shares outstanding (in shares)	22,973,905	17,935,895	15,920,326