Financial Information by Quarter (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information [Abstract]

Schedule of quarterly financial information

Financial Information By Quarter (Unaudited)

	Three Months Ended
2013	March 31			June 30			September 30			December 31
	(in thousands, except for per share data)
Revenues	$	1,328		$	965		$	2,292		$	934
Selling, general and administrative	3,031			3,166			3,266			3,782
Research and development	3,645			3,131			4,261			2,819
Patent preparation fees	458			301			329			333
Restructuring charges	—			—			—			513
Operating loss	(5,807		)	(5,633		)	(5,564		)	(6,513		)
Net loss	(4,876		)	(3,061		)	(4,902		)	(4,338		)
Earnings (loss) per share: basic and diluted	$	(0.09	)	$	(0.06	)	$	(0.09	)	$	(0.08	)

	Three Months Ended
2012	March 31			June 30			September 30			December 31
	(in thousands, except for per share data)
Revenues	$	1,466		$	2,701		$	2,290		$	2,514
Selling, general and administrative	2,214			3,475			3,139			2,583
Research and development	4,465			5,183			4,170			4,396
Patent preparation fees	336			376			377			794
Operating loss	(5,549		)	(6,332		)	(5,396		)	(5,259		)
Net loss	(4,616		)	(3,767		)	(3,059		)	(2,618		)
Earnings (loss) per share: basic and diluted	$	(0.09	)	$	(0.07	)	$	(0.06	)	$	(0.04	)