CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
REVENUE:
Product Development and Licensing Agreements	$ 453	$ 342
Contracts and Grants	850	144
Total Revenue	1,303	486
OPERATING EXPENSE:
Research and Development	27,447	25,125
General and Administrative	9,307	6,089
Amortization of Acquired Intangible Assets	253	253
Total Operating Expense	37,007	31,467
Operating Loss	(35,704)	(30,981)
Investment and Other Income, Net	1,031	807
Net Loss	$ (34,673)	$ (30,174)
Basic and Diluted Net Loss Per Common Share (in dollars per share)	$ (0.35)	$ (0.33)
Shares Used in Calculating Basic and Diluted Net Loss per Share (in shares)	98,689	92,437
COMPREHENSIVE LOSS:
Net Loss	$ (34,673)	$ (30,174)
Other Comprehensive Income:
Foreign Currency Translation Adjustments		15
Unrealized Gain on Marketable Securities	380	11
Comprehensive Loss	$ (34,293)	$ (30,148)