CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
License and milestone fees	$ 1,321	$ 31,080	$ 12,861	$ 49,810
Non-cash royalty revenue related to the sale of future royalties	7,242	6,439	14,432	14,052
Research and development support	388	902	771	2,380
Clinical materials revenue	336	599	1,038	1,277
Total revenues	9,287	39,020	29,102	67,519
Operating Expenses:
Research and development	38,701	35,319	83,532	68,207
General and administrative	8,652	8,836	18,647	16,955
Restructuring charge	686		2,417	386
Total operating expenses	48,039	44,155	104,596	85,548
Loss from operations	(38,752)	(5,135)	(75,494)	(18,029)
Investment income, net	814	143	1,476	258
Non-cash interest expense on liability related to the sale of future royalties and convertible senior notes	(2,611)	(3,501)	(5,657)	(7,076)
Interest expense on convertible senior notes	(23)	(1,125)	(47)	(2,250)
Other (expense) income, net	(1,052)	751	(515)	885
Net loss	$ (41,624)	$ (8,867)	$ (80,237)	$ (26,212)
Basic and diluted net loss per common share (in dollar per share)	$ (0.31)	$ (0.10)	$ (0.61)	$ (0.30)
Basic and diluted weighted average common shares outstanding (in shares)	134,384	87,174	132,512	87,167
Total comprehensive loss	$ (41,624)	$ (8,867)	$ (80,237)	$ (26,212)