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
Research and development revenue	$ 5,447	$ 7,106	$ 18,852	$ 13,431
Costs and expenses:
Research and development	12,836	12,318	24,229	24,762
General and administrative	3,552	3,526	7,095	6,855
Total costs and expenses	16,388	15,844	31,324	31,617
Loss from operations	(10,941)	(8,738)	(12,472)	(18,186)
Interest income	112	217	167	527
Interest expense	(6)	(133)	(12)	(255)
Other income (expense)	31	(123)	47	(615)
Loss before taxes	(10,804)	(8,777)	(12,270)	(18,529)
Income tax benefit		550		550
Net loss	$ (10,804)	$ (8,227)	$ (12,270)	$ (17,979)
Basic and diluted net loss per share:
Net loss per share (in dollars per shares)	$ (0.20)	$ (0.18)	$ (0.24)	$ (0.40)
Weighted average basic and diluted common shares outstanding (in shares)	53,255	44,517	51,961	44,461