STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Contract revenue	$ 4,642	$ 834
Costs and expenses:
Cost of contract revenue	3,786	343
Research and development	5,077	5,071
General and administrative	3,246	2,850
Total costs and expenses	12,109	8,264
Loss from operations	(7,467)	(7,430)
Other income (expense):
Interest income	33	46
Interest expense	(3)	(2)
Change in fair value of warrant liability	101	(67)
Net loss	(7,336)	(7,453)
Basic and diluted net loss per share	$ (0.06)	$ (0.07)
Basic and diluted weighted average number of common shares outstanding	120,558	111,188
Comprehensive loss:
Net loss	(7,336)	(7,453)
Unrealized gains on short-term investments available-for-sale	144	127
Comprehensive loss	$ (7,192)	$ (7,326)