Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
REVENUES	$ 302	$ 0
OPERATING EXPENSES
Research and development	6,443	4,308
General and administrative	8,455	4,942
Depreciation and amortization	694	491
TOTAL OPERATING EXPENSES	15,592	9,741
OPERATING LOSS	(15,290)	(9,741)
OTHER INCOME (EXPENSE)
Interest and investment income	22	27
Other income	(1)	0
TOTAL OTHER INCOME (EXPENSE)	21	27
LOSS BEFORE INCOME TAXES	(15,269)	(9,714)
Provision for (benefit from) income taxes	22	(1)
NET LOSS	(15,247)	(9,715)
Foreign currency translation adjustment, net of tax	(51)	0
COMPREHENSIVE LOSS	$ (15,298)	$ (9,715)
NET LOSS PER SHARE - BASIC AND DILUTED (in dollars per share)	$ (1.57)	$ (1.36)
Weighted average shares outstanding — basic and dilute (shares)	9,691,115	7,160,567