CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue:
Research and development revenue under collaborative agreements	$ 35,214	$ 61,892
Licensing and royalty revenue	1,660	691
Total revenue	36,874	62,583
Expenses:
Research, development and patent expenses	80,964	64,447
General and administrative	10,562	7,466
Total operating expenses	91,526	71,913
Loss from operations	(54,652)	(9,330)
Other income (expense):
Investment income	1,457	845
Interest expense	(9,490)	(9,021)
Loss before income tax benefit	(62,685)	(17,506)
Income tax (expense) benefit	(232)	789
Net loss	$ (62,917)	$ (16,717)
Basic and diluted net loss per share (in dollars per share)	$ (0.52)	$ (0.14)
Shares used in computing basic and diluted net loss per share (in shares)	120,598	118,948