Stock-Based Compensation

3 Months Ended

Mar. 31, 2013

Stock-Based Compensation [Abstract]

STOCK-BASED COMPENSATION

2.       STOCK-BASED COMPENSATION

Total stock-based compensation expense was allocated to research and development, manufacturing and production and general and administrative expense as follows (in thousands):

	Three Months Ended March 31,
	2013		2012
Research and development	$	312	$	287
Manufacturing and production		68		49
General and administrative		758		584
Total stock-based compensation expense	$	1,138	$	920

During the three months ended March 31, 2013 and 2012, the Company granted stock-based awards with a total estimated value of $3.1 million and $3.6 million, respectively. At March 31, 2013, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $4.3 million, which is expected to be recognized over a weighted-average period of 1.5 years. Stock-based awards granted during the three months ended March 31, 2013 and 2012, were equal to 1.8% and 1.9%, respectively, of outstanding shares of common stock at the end of the applicable period.