Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2012

Stock-Based Compensation

Schedule of stock option activity

	Shares		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (In Years)
Options Outstanding at December 31, 2011	4,459,034		$	6.08	6.9
Granted	31,000		$	3.99
Exercised	—		—
Canceled	(185,137	)	$	8.50
Options Outstanding at June 30, 2012	4,304,897		$	5.96	6.7
Options Vested and Expected to Vest at June 30, 2012	4,271,786		$	5.99	6.7
Options Exercisable at June 30, 2012	2,923,338		$	7.04	5.8

Schedule of restricted stock activity

	Shares		Weighted Average Grant Date Fair Value (per share)
Outstanding and unvested at December 31, 2011	6,000		$	3.24
Granted	12,000		4.50
Vested	(6,000	)	3.24
Canceled	—		—
Outstanding and unvested at June 30, 2012	12,000		$	4.50

Schedule of stock-based compensation expense

	Three months ended June 30,				Six months ended June 30,
	2012		2011		2012		2011
	(In thousands)
Research and development	$	284	$	344	$	679	$	705
General and administrative	164		209		409		428
Total stock-based compensation expense	$	448	$	553	$	1,088	$	1,133

Schedule of assumptions used for the fair values of employee stock options granted

	Three months ended June 30,				Six months ended June 30,
	2012		2011		2012		2011
Expected stock price volatility	71	%	68	%	70 - 71	%	68	%
Expected option term	6.0 years		6.0 years		6.0 years		6.0 years
Risk-free interest rate	0.9 – 1.3	%	2.5	%	0.9 – 1.4	%	2.5 – 2.9	%
Expected dividend yield	None		None		None		None