Statements Of Operations (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Operating revenues:
Milestones and license fees from collaborations	$ 20,699	$ 20,704	$ 59,621	$ 39,793
Grant revenue	44	198	116	627
Net operating revenues	20,743	20,902	59,737	40,420
Operating expenses:
Research and development (including stock-based compensation of $1,257 and $748 for the three months ended June 30, 2011 and 2010, respectively and $2,494 and $1,515 for the six months ended June 30, 2011 and 2010, respectively)	20,185	14,122	43,702	24,729
General and administrative (including stock-based compensation of $943 and $493 for the three months ended June 30, 2011 and 2010, respectively and $1,869 and $963 for the six months ended June 30, 2011 and 2010, respectively)	3,129	1,814	6,304	3,636
Total operating expenses	23,314	15,936	50,006	28,365
(Loss) income from operations	(2,571)	4,966	9,731	12,055
Other income (expense):
Interest income	343	366	659	740
Interest expense	(29)	(38)	(60)	(80)
Total other income (expense)	314	328	599	660
(Loss) income before income taxes	(2,257)	5,294	10,330	12,715
Income tax expense		(1,512)		(2,138)
Net (loss) income	$ (2,257)	$ 3,782	$ 10,330	$ 10,577
Basic net (loss) income per share	$ (0.07)	$ 0.13	$ 0.35	$ 0.37
Diluted net (loss) income per share	$ (0.07)	$ 0.13	$ 0.33	$ 0.35
Weighted average common shares outstanding - basic	30,725,227	28,509,619	29,865,420	28,411,083
Weighted average common shares outstanding - diluted	30,725,227	30,152,309	31,207,325	30,082,275