CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
REVENUE:
Product Development and Licensing Agreements	$ 30	$ 35
Contracts and Grants	50	54
Product Royalties	2,334	2,344
Total Revenue	2,414	2,433
OPERATING EXPENSE:
Research and Development	14,090	10,769
Royalty	2,334	2,344
General and Administrative	3,138	2,317
Amortization of Acquired Intangible Assets	253	291
Total Operating Expense	19,815	15,721
Operating Loss	(17,401)	(13,288)
Investment and Other Income, Net	379	205
Interest Expense	(310)	(433)
Net Loss	(17,332)	(13,516)
Basic and Diluted Net Loss Per Common Share (Note 3) (in dollars per share)	$ (0.23)	$ (0.27)
Shares Used in Calculating Basic and Diluted Net Loss per Share (Note 3) (in shares)	74,027	50,145
COMPREHENSIVE INCOME:
Net Loss	(17,332)	(13,516)
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustments	(2)	2
Unrealized (Loss) Gain on Marketable Securities	(54)	108
Comprehensive Loss	$ (17,388)	$ (13,406)