Condensed Consolidated Statements of Operations (USD $) In Thousands, except Share data	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Collaboration revenues:
License and milestone revenue	$ 1,143	$ 1,143	$ 3,429	$ 3,429
Cost sharing reimbursements, net		2,240		7,337
Total collaboration revenues	1,143	3,383	3,429	10,766
Grant revenues	521		732
Total revenues	1,664	3,383	4,161	10,766
Operating expenses:
Research and development	10,751	11,023	30,605	30,906
General and administrative	3,131	2,591	8,749	8,393
Total operating expenses	13,882	13,614	39,354	39,299
Loss from operations	(12,218)	(10,231)	(35,193)	(28,533)
Interest expense, net	(516)	(31)	(1,444)	(111)
Net loss	$ (12,734)	$ (10,262)	$ (36,637)	$ (28,644)
Net loss per common share:
Basic and diluted net loss per common share (in dollars per share)	$ (0.30)	$ (0.25)	$ (0.87)	$ (0.71)
Weighted-average common shares outstanding:
Basic weighted average number of common shares outstanding (in shares)	42,211,858	40,382,862	42,129,882	40,062,453
Diluted weighted average number of common shares outstanding (in shares)	42,211,858	40,382,862	42,129,882	40,062,453

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