Stock-Based Compensation

9 Months Ended

Sep. 30, 2011

Stock-Based Compensation [Abstract]

Stock-Based Compensation

8 –   Stock-Based Compensation

We maintain equity compensation plans under which grants of incentive stock options, nonqualified stock options, stock appreciation rights, stock awards, stock units and other stock-based awards may be granted to employees, non-employee directors and key advisors.  We have also granted certain awards outside of such equity compensation plans.  Since our inception on August 8, 2002, we have recognized equity compensation expense over the requisite service period using the Black-Scholes-Merton formula to estimate the fair value of stock options.  The following table summarizes the total stock-based compensation expense included in our unaudited condensed consolidated statements of operations (in thousands):

	Three-Months Ended September 30,				Nine-Months Ended September 30,				Period from August 8, 2002 (Inception) to
	2011		2010		2011		2010		September 30, 2011
Research and Development	$	197	$	246	$	656	$	704	$	4,111
General and administrative		333		268		1,027		749		7,207
Total stock-based compensation expense	$	530	$	514	$	1,683	$	1,453	$	11,318

During the nine-months ended September 30, 2011, stock options to purchase 2,853,000 shares of common stock were awarded to employees and nonemployee directors at a combined grant date fair value of approximately $1,386,000.  There have been no significant changes to the assumptions used to calculate fair value from those which were disclosed in our Annual Report on Form 10-K for the year ended December 31, 2010. As of September 30, 2011, there were approximately 18,172,000 shares of common stock issuable upon exercise of outstanding stock options and approximately 8,422,000 shares of common stock available for issuance of future equity compensation awards in connection with our equity compensation plans.  As of September 30, 2011, there was approximately $2,596,000 of total unrecognized compensation cost related to non-vested stock options, which will be amortized over the weighted average remaining service period.