Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues:
Revenues from collaborative agreements	$ 12,494	$ 1,792
Operating expenses:
Research and development, including stock-based compensation of $989 and $1,104, respectively	37,002	20,865
Increase in fair value of Symphony Icon, Inc. purchase liability	965	1,753
General and administrative, including stock-based compensation of $846 and $849, respectively	8,398	5,701
Total operating expenses	46,365	28,319
Loss from operations	(33,871)	(26,527)
Interest expense	(1,649)	(1,702)
Interest and other income, net	637	153
Net loss	$ (34,883)	$ (28,076)
Net loss per common share, basic and diluted	$ (0.34)	$ (0.27)
Shares used in computing consolidated net loss per common share, basic and diluted	103,682	103,516
Unrealized gain on investments	$ 516	$ 86
Comprehensive loss	$ (34,367)	$ (27,990)