CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Collaboration revenues:
Product revenue	$ 19,305	$ 5,690	$ 22,027	$ 10,502
Research and development revenue	25,595	5,260	31,436	11,233
Total collaboration revenue	44,900	10,950	53,463	21,735
Operating expenses:
Research and development	33,983	26,089	56,733	52,781
General and administrative	13,329	11,219	21,219	22,936
Total operating expenses	47,312	37,308	77,952	75,717
Operating loss	(2,412)	(26,358)	(24,489)	(53,982)
Other income:
Interest income	122	140	234	340
Other income	68	62	156	124
Total other income	190	202	390	464
Net loss	$ (2,222)	$ (26,156)	$ (24,099)	$ (53,518)
Basic and diluted net loss per share (in dollars per share)	$ (0.04)	$ (0.51)	$ (0.41)	$ (1.04)
Weighted average shares used in computing basic and diluted net loss per share (in shares)	61,680	51,466	58,106	51,411
Comprehensive loss:
Net loss	$ (2,222)	$ (26,156)	$ (24,099)	$ (53,518)
Net unrealized holding gains on available-for-sale marketable securities	18	37	36	21
Comprehensive loss	$ (2,204)	$ (26,119)	$ (24,063)	$ (53,497)