Condensed Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenues:
Collaboration agreements	$ 608	$ 6,210	$ 2,095	$ 12,409
Research grants	906	315	1,619	764
Total revenues	1,514	6,525	3,714	13,173
Operating expenses:
Research and development	8,119	7,147	16,381	14,512
General and administrative	3,676	3,257	7,215	6,543
Total operating expenses	11,795	10,404	23,596	21,055
Loss from operations	(10,281)	(3,879)	(19,882)	(8)
Interest and other income, net	22	19	45	44
Net loss	$ (10,259)	$ (3,860)	$ (19,837)	$ (7,838)
Basic and diluted net loss per share	$ (0.20)	$ (0.09)	$ (0.41)	$ (0.17)
Shares used in computing basic and diluted net loss per share	51,500	45,157	48,514	45,096