Selected Quarterly Financial Data

12 Months Ended

Dec. 31, 2011

Selected Quarterly Financial Data [Abstract]

Selected Quarterly Financial Data

13. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)

The following table presents the unaudited quarterly results of operations of the Company for the years ended December 31, 2011 and 2010, respectively. The unaudited information is prepared on the same basis as the audited consolidated financial statements. The Company's operating results for any quarter are not necessarily indicative of results for any future quarters or for a full year.

	Quarters Ended
	March 31,			June 30,			September 30,			December 31,
2011:
Collaboration revenue	$	14,709		$	15,799		$	14,940		$	14,941
Operating expenses	$	(23,774	)	$	(26,175	)	$	(26,430	)	$	(26,940	)
Loss from operations	$	(9,065	)	$	(10,376	)	$	(11,490	)	$	(11,999	)
Net loss	$	(8,452	)	$	(9,474	)	$	(10,044	)	$	(10,871	)
Basic and diluted net loss per common share	$	(0.24	)	$	(0.27	)	$	(0.29	)	$	(0.31	)
Weighted-average common shares used in the calculation of basic and diluted net loss per common share		34,663			34,888			34,909			35,375
2010:
Collaboration revenue	$	15,734		$	15,792		$	14,350		$	16,632
Operating expenses	$	(33,421	)	$	(23,229	)	$	(21,087	)	$	(17,496	)
Loss from operations	$	(17,687	)	$	(7,437	)	$	(6,737	)	$	(864	)
Net loss	$	(17,465	)	$	(7,240	)	$	(5,443	)	$	(3,889	)
Basic and diluted net loss per common share	$	(0.51	)	$	(0.21	)	$	(0.16	)	$	(0.11	)
Weighted-average common shares used in the calculation of basic and diluted net loss per common share		33,953			34,053			34,570			34,573