Stock Compensation (Tables)

6 Months Ended

Jun. 30, 2012

Stock Compensation [Abstract]

Summary of the Company's stock option activity

A summary of the Company’s stock option activity with respect to the six months ended June 30, 2012 follows:

Stock Options	Underlying Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at December 31, 2011		2,417,659		$	11.18
Granted		206,408			6.95
Exercised		(111	)		5.52
Canceled or expired		(499,118	)		10.16
Outstanding at June 30, 2012		2,124,838		$	11.01		6.68	$	13,578
Vested at June 30, 2012 and expected to vest		2,050,432		$	11.12		6.47	$	12,584
Exercisable at June 30, 2012		994,370		$	14.31		3.81	$	78

Fair values of stock options granted

The fair values of stock options granted during the periods presented were measured on the date of grant using the Black-Scholes option-pricing model, with the following assumptions:

	Three and Six Months Ended June 30,
	2012			2011
Risk-free interest rate		0.8%-1.1	%		1.9%-2.4	%
Expected dividend yield		0	%		0	%
Expected lives		5.3 years			5.4-5.5 years
Expected volatility		79.7%-82.5	%		80.9%-81.6	%

Restricted Stock

The following table sets forth restricted stock unit activity for the period shown:

	Six Months Ended June 30, 2012
	Shares			Weighted Average Grant Date Fair Value per Share
Restricted Stock Units, beginning of period		—		$	—
Granted		32,377			5.40
Vested		—			—
Forfeited or canceled		(486	)		5.40
Restricted Stock Units, end of period		31,891			5.40

Summary of the stock-based compensation expense recognized in the statements of operations

A summary of the stock-based compensation expense, including options, restricted stock units, and restricted stock, recognized in the statements of operations is as follows:

	Three Months Ended				Six Months Ended
	June 30, 2012		June 30, 2011		June 30, 2012		June 30, 2011
	(in thousands)				(in thousands)
Research and development	$	259	$	359	$	512	$	732
General and administrative		181		357		636		1,130
Total	$	440	$	716	$	1,148	$	1,862