Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Selected Quarterly Financial Data (Unaudited) [Abstract]

Schedule of Quarterly Financial Information

The following table contains unaudited statement of operations information for each quarter of 2012 and 2011.  The operating results for any quarter are not necessarily indicative of results for any future period.

2012 Quarters Ended:
(in thousands, except per share data)	Mar. 31			June 30			Sept. 30			Dec. 31			Total Year
Grant Revenues	$	–		$	–		$	–		$	195		$	195
Expenses:
Research and development		4,533			5,206			5,743			6,088			21,570
Selling, General and administrative		2,047			3,610			4,255			6,532			16,444
Total expenses		6,580			8,816			9,998			12,620			38,014
Operating loss		(6,580	)		(8,816	)		(9,998	)		(12,425	)		(37,819	)
Change in fair value of common stock warrant liability		(3,434	)		1,680			(3,309	)		5,618			555
Other expense, net		(2	)		(2	)		(39	)		(8	)		(51	)
Net loss	$	(10,016	)	$	(7,138	)	$	(13,346	)	$	(6,815	)	$	( 37,315	)
Net loss per common share -  basic and diluted	$	(0.37	)	$	(0.16	)	$	(0.31	)	$	(0.16	)	$	(0.95	)
Weighted average number of common shares outstanding		27,162			43,369			43,444			43,521			39,396

2011 Quarters Ended:
(in thousands, except per share data)	Mar. 31			June 30			Sept. 30			Dec. 31			Total Year
Grant Revenues	$	381		$	201		$	–		$	–		$	582
Expenses:
Research and development		4,620			4,615			3,981			4,014			17,230
General and administrative		1,820			1,966			2,189			1,889			7,864
Total expenses		6,440			6,581			6,170			5,903			25,094
Operating loss		(6,059	)		(6,380	)		(6,170	)		(5,903	)		(24,512	)
Change in fair value of common stock warrant liability		2,228			(1,693	)		1,422			1,603			3,560
Other expense, net		(6	)		(3	)		(3	)		(1	)		(13	)
Net loss	$	(3,837	)	$	(8,076	)	$	(4,751	)	$	(4,301	)	$	(20,965	)
Net loss per common share -  basic and diluted	$	(0.21	)	$	(0.34	)	$	(0.20	)	$	(0.18	)	$	(0.93	)
Weighted average number of common shares outstanding		18,114			24,027			24,106			24,309			22,660