CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
REVENUE:
Product Development and Licensing Agreements	$ 334	$ 200	$ 676	$ 235
Contracts and Grants	1,844	392	1,988	773
Total Revenue	2,178	592	2,664	1,008
OPERATING EXPENSE:
Research and Development	26,490	24,100	51,615	51,169
General and Administrative	8,184	4,787	14,273	9,369
Amortization of Acquired Intangible Assets	254	254	507	507
Total Operating Expense	34,928	29,141	66,395	61,045
Operating Loss	(32,750)	(28,549)	(63,731)	(60,037)
Investment and Other Income, Net	391	275	1,198	1,860
Net Loss	$ (32,359)	$ (28,274)	$ (62,533)	$ (58,177)
Basic and Diluted Net Loss Per Common Share (in dollars per share)	$ (0.33)	$ (0.32)	$ 0.65	$ (0.65)
Shares Used in Calculating Basic and Diluted Net Loss per Share (in shares)	98,482	89,361	95,477	89,316
COMPREHENSIVE LOSS:
Net Loss	$ (32,359)	$ (28,274)	$ (62,533)	$ (58,177)
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustments		(2)	15	(1)
Unrealized (Loss) Gain on Marketable Securities	(180)	80	(169)	81
Comprehensive Loss	$ (32,539)	$ (28,196)	$ (62,687)	$ (58,097)