Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statements of Operations
Collaboration Revenue	$ 41,678us-gaap_SalesRevenueServicesNet
Costs and expenses:
Research and development	24,557us-gaap_ResearchAndDevelopmentExpense	14,377us-gaap_ResearchAndDevelopmentExpense
General and administrative	9,584us-gaap_GeneralAndAdministrativeExpense	6,349us-gaap_GeneralAndAdministrativeExpense
Total costs and expenses	34,141us-gaap_CostsAndExpenses	20,726us-gaap_CostsAndExpenses
Income (loss) from operations	7,537us-gaap_OperatingIncomeLoss	(20,726)us-gaap_OperatingIncomeLoss
Interest income	73	44
Income (loss) before income tax provision	7,610	(20,682)
Net income (loss)	$ 7,610us-gaap_NetIncomeLoss	$ (20,682)us-gaap_NetIncomeLoss
Net income (loss) per common share:
Basic(in dollars per share)	$ 0.22us-gaap_EarningsPerShareBasic	$ (0.64)us-gaap_EarningsPerShareBasic
Diluted( in dollars per share)	$ 0.22us-gaap_EarningsPerShareDiluted	$ (0.64)us-gaap_EarningsPerShareDiluted
Weighted average common shares outstanding:
Basic (in shares)	34,154	32,282
Diluted (in shares)	35,239	32,282

Total costs of sales and operating expenses for the period.

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