CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
REVENUE:
Product Development and Licensing Agreements	$ 47	$ 40	$ 77	$ 75
Contracts and Grants	50	96	100	149
Product Royalties		1,873	2,334	4,218
Total Revenue	97	2,009	2,511	4,442
OPERATING EXPENSE:
Research and Development	15,090	11,114	29,180	21,881
Royalty		1,873	2,334	4,218
General and Administrative	3,411	2,219	6,549	4,536
Amortization of Acquired Intangible Assets	254	291	507	583
Total Operating Expense	18,755	15,497	38,570	31,218
Operating Loss	(18,658)	(13,488)	(36,059)	(26,776)
Investment and Other Income, Net	161	126	540	331
Interest Expense	(519)	(411)	(829)	(844)
Net Loss	(19,016)	(13,773)	(36,348)	(27,289)
Basic and Diluted Net Loss Per Common Share (Note 3) (in dollars per share)	$ (0.24)	$ (0.23)	$ (0.47)	$ (0.50)
Shares Used in Calculating Basic and Diluted Net Loss per Share (Note 3) (in shares)	80,899	58,733	77,482	54,439
COMPREHENSIVE LOSS:
Net Loss	(19,016)	(13,773)	(36,348)	(27,289)
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustments	(1)	(1)	(3)	1
Unrealized (Loss) Gain on Marketable Securities	(140)	(39)	(194)	69
Comprehensive Loss	$ (19,157)	$ (13,813)	$ (36,545)	$ (27,219)