CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
REVENUE:
Product Development and Licensing Agreements	$ 35	$ 30
Contracts and Grants	381	50
Product Royalties		2,334
Total Revenue	416	2,414
OPERATING EXPENSE:
Research and Development	27,070	14,090
Royalty		2,334
General and Administrative	4,582	3,138
Amortization of Acquired Intangible Assets	253	253
Total Operating Expense	31,905	19,815
Operating Loss	(31,489)	(17,401)
Investment and Other Income, Net	1,586	379
Interest Expense		(310)
Net Loss	(29,903)	(17,332)
Basic and Diluted Net Loss Per Common Share (Note 3) (in dollars per share)	$ (0.33)	$ (0.23)
Shares Used in Calculating Basic and Diluted Net Loss per Share (Note 3) (in shares)	89,270	74,027
COMPREHENSIVE LOSS:
Net Loss	(29,903)	(17,332)
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustments	1	(2)
Unrealized (Loss) Gain on Marketable Securities	1	(54)
Comprehensive Loss	$ (29,901)	$ (17,388)