Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating expenses:
General and administrative	$ 18,401	$ 11,039
Research and development	54,801	60,207
Total Operating Expense	73,202	71,246
Loss from operations	(73,202)	(71,246)
Other (expenses) income:
Interest income	350	282
Other (expenses) income	(13)	(8)
Total Other Income	337	274
Net loss	(72,865)	(70,972)
Net loss applicable to common stock	$ (72,865)	$ (70,972)
Net loss per common share—basic and diluted	$ (1.97)	$ (2.19)
Weighted-average common shares outstanding—basic and diluted	36,931,167	32,478,408