Consolidated Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:
Collaborative research	$ 238	$ 214	$ 733	$ 565
Subscription and license fees	0	158	79	306
Total revenues	238	372	812	871
Operating expenses:
Research and development, including stock-based compensation of $1,027, $923, $3,379 and $2,875, respectively	25,400	19,192	69,419	61,584
Increase in fair value of Symphony Icon, Inc. purchase liability	1,338	5,844	3,079	10,087
General and administrative, including stock-based compensation of $723, $669, $2,349 and $2,030, respectively	4,716	4,396	13,709	13,123
Total operating expenses	31,454	29,432	86,207	84,794
Loss from operations	(31,216)	(29,060)	(85,395)	(83,923)
Interest income	39	44	136	158
Interest expense	(492)	(527)	(1,494)	(1,594)
Other income, net	11	4	41	21
Consolidated net loss	(31,658)	(29,539)	(86,712)	(85,338)
Consolidated net loss per common share, basic and diluted	$ (0.06)	$ (0.06)	$ (0.17)	$ (0.18)
Shares used in computing consolidated net loss per common share, basic and diluted	513,419	490,049	512,980	483,693
Unrealized gain on investments	7	41	15	0
Comprehensive loss	$ (31,651)	$ (29,498)	$ (86,697)	$ (85,338)