Stock-Based Compensation

6 Months Ended

Jun. 30, 2011

Stock-Based Compensation

9. Stock-Based Compensation

The Company recognized stock-based compensation expense on all employee and non-employee awards as follows:

	For the three months				For the six months
	ended June 30,				ended June 30,
(in thousands)	2011		2010		2011		2010
Research and development, including costs of research contracts	$	166	$	206	$	276	$	414
General and administrative		446		1,035		1,038		1,760
Stock-based employee compensation expense	$	612	$	1,241	$	1,314	$	2,174

The Company granted 548 thousand and 516 thousand stock options during the three and six months ended June 30, 2011 that had a weighted-average grant date fair value of $3.99 and $4.33 per share, respectively.  During the three and six months ended June 30, 2010, the Company granted 62 thousand and 152 thousand stock options that had a weighted-average grant date fair value of $3.68 and $3.63 per share, respectively.

At June 30, 2011, total unrecognized compensation costs related to unvested stock options outstanding amounted to $6.8 million. The cost is expected to be recognized over a weighted-average period of 1.82 years.

For the six months ended June 30, 2011 and 2010, the fair value of stock options was estimated on the date of grant using a Black-Scholes option valuation models with the following assumptions:

	For the six months ended June 30,
	2011			2010
Risk-free interest rate		1.83 - 2.61	%		1.93 - 2.75	%
Expected life in years		5.77 - 6			5
Expected volatility		84.4 - 87.4	%		89.0 - 90.0	%
Expected dividend yield		0			0

Stock option activity under the Company’s stock option plan for the six months ended June 30, 2011 is as follows:

(in thousands, except share and per share data)	Number of Shares		Weighted- Average Exercise Price		Weighted- Average Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding, December 31, 2010		4,566,935	$	3.39
Granted		1,063,900		5.99
Exercised		430,283		1.97
Cancelled		410,000		4.80
Outstanding, June 30, 2011		4,790,552	$	3.97		7.32	$	10,548
Options exercisable, June 30, 2011		2,627,902	$	3.16		5.57	$	7,830
Options available for future grant		1,413,168

A summary of the status of unvested restricted stock for the six months ended June 30, 2011 is as follows:

	Number of Shares		Weighted-Average Grant Date Fair Value
Non-vested, December 31, 2010		348,753	$	3.32
Granted		25,000		5.21
Vested		108,334		4.36
Cancelled		16,667		2.85
Non-vested, June 30, 2011		248,752	$	3.09

At June 30, 2011, total unrecognized compensation costs related to unvested restricted stock outstanding amounted to $533 thousand. The cost is expected to be recognized over a weighted-average period of 1.27 years.