STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Ordinary Shares Private placement	Ordinary Shares Maximum	[2]	Ordinary Shares	Additional paid-in capital Private placement	Additional paid-in capital	Accumulated deficit	Private placement		Total
Balance, beginning at Dec. 31, 2015				$ 34		$ 91,814	$ (63,301)			$ 28,547
Balance, beginning (in shares) at Dec. 31, 2015				13,585,810
Increase (decrease) in Stockholders' Equity
Stock-based compensation						833				833
Issuance of Ordinary Shares, net of issuance costs	$ 17				$ 10,783			$ 10,800
Issuance of Ordinary Shares, net of issuance costs (in shares)	6,554,016
Net loss							(25,869)			(25,869)
Balance, ending at Dec. 31, 2016				$ 51		103,430	(89,170)			14,311
Balance, ending (in shares) at Dec. 31, 2016				20,139,826
Increase (decrease) in Stockholders' Equity
Stock-based compensation						940				940
Issuance of Ordinary Shares, net of issuance costs	$ 14				$ 21,543			$ 21,557	[1]
Issuance of Ordinary Shares, net of issuance costs (in shares)	5,031,550
Exercise of options into Ordinary Shares		$ 1				165				165
Exercise of options into Ordinary Shares (in shares)				49,577
Exercise of warrants into Ordinary Shares				$ 4		4,862				4,866
Exercise of warrants into Ordinary Shares (in shares)				1,351,766
Reclassification of liability related to warrants exercised						5,177				5,177
Net loss							(23,205)			(23,205)
Balance, ending at Dec. 31, 2017				$ 69		$ 136,117	$ (112,375)			$ 23,811
Balance, ending (in shares) at Dec. 31, 2017				26,572,719

[1] Gross proceeds of $30,000 net of $6,994 that were classified as warrants and $1,449 issuance costs that were allocated to the shares. $441 of issuance costs were allocated to the warrants and recorded in the financial expense (income), net.

[2] Represents an amount lower than $1.