Consolidated Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Collaborative research	$ 284	$ 152
Subscription and license fees	76	148
Total revenues	360	300
Operating expenses:
Research and development, including stock-based compensation of $1,330 and $1,037, respectively	20,327	23,037
Increase in fair value of Symphony Icon, Inc. purchase liability	1,264	2,081
General and administrative, including stock-based compensation of $779 and $681, respectively	4,324	4,565
Total operating expenses	25,915	29,683
Loss from operations	(25,555)	(29,383)
Interest income	53	56
Interest expense	(506)	(537)
Other income (expense), net	34	(4)
Consolidated net loss	(25,974)	(29,868)
Consolidated net loss per common share, basic and diluted	$ (0.05)	$ (0.06)
Shares used in computing consolidated net loss per common share, basic and diluted	512,428	480,324
Unrealized gain (loss) on investments	19	(78)
Comprehensive loss	$ (25,955)	$ (29,946)