CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Consolidated Statements Of Operations And Comprehensive Loss (Unaudited)
Revenue	$ 0	$ 0	$ 0	$ 0
Operating expenses:
Research and development	9,408	2,097	12,937	4,453
General and administrative	1,232	565	2,928	1,478
Total operating expenses	10,640	2,662	15,865	5,931
Loss from operations	(10,640)	(2,662)	(15,865)	(5,931)
Interest income	7	5	16	11
Net loss	(10,633)	(2,657)	(15,849)	(5,920)
Accretion of convertible preferred stock	(995)	(479)	(2,353)	(1,394)
Net loss attributable to common stockholders	$ (11,628)	$ (3,136)	$ (18,202)	$ (7,314)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (5.11)	$ (1.75)	$ (8.44)	$ (4.36)
Weighted average common shares outstanding, basic and diluted (in shares)	2,274,617	1,794,909	2,155,685	1,675,976
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net of tax of $0	$ 1	$ (3)	$ 7	$ (3)
Total other comprehensive income (loss)	1	(3)	7	(3)
Comprehensive loss	$ (10,632)	$ (2,660)	$ (15,842)	$ (5,923)