CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
REVENUE:
Product Development and Licensing Agreements	$ 40	$ 28	$ 117	$ 103
Contracts and Grants	940	79	1,040	228
Product Royalties		3,006	2,334	7,224
Total Revenue	980	3,113	3,491	7,555
OPERATING EXPENSE:
Research and Development	20,417	11,769	49,597	33,650
Royalty		3,006	2,334	7,224
General and Administrative	3,578	2,835	10,128	7,372
Amortization of Acquired Intangible Assets	254	254	760	836
Total Operating Expense	24,249	17,864	62,819	49,082
Operating Loss	(23,269)	(14,751)	(59,328)	(41,527)
Investment and Other Income, Net	142	105	682	436
Interest Expense	(13)	(381)	(842)	(1,225)
Net Loss	(23,140)	(15,027)	(59,488)	(42,316)
Basic and Diluted Net Loss Per Common Share (Note 3) (in dollars per share)	$ (0.29)	$ (0.25)	$ (0.76)	$ (0.75)
Shares Used in Calculating Basic and Diluted Net Loss per Share (Note 3) (in shares)	81,015	59,467	78,676	56,090
COMPREHENSIVE LOSS:
Net Loss	(23,140)	(15,027)	(59,488)	(42,316)
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustments		1	(3)	2
Unrealized Gain (Loss) on Marketable Securities	138	52	(56)	121
Comprehensive Loss	$ (23,002)	$ (14,974)	$ (59,547)	$ (42,193)