Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating expenses
Research and development	$ 18,191	$ 17,100
General and administrative	5,915	5,181
Total operating expenses	24,106	22,281
Loss from operations	(24,106)	(22,281)
Interest income	105	49
Other income (expense), net	(230)	226
Net loss	$ (24,231)	$ (22,006)
Net loss per share - basic and diluted	$ (0.82)	$ (0.79)
Weighted-average common shares used to compute basic and diluted net loss per share	29,422	27,810