CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (17,286)	$ (23,437)
Adjustments required to reconcile net loss to net cash used in operating activities:
Stock-based compensation	720	599
Depreciation	588	481
Accrued severance pay, net	4	6
Increase in fair value of warrants to purchase Ordinary Shares	1,360	1,507
Increase (decrease) in other accounts receivable and prepaid expenses	(539)	107
Allocation of issuance costs related to warrants to purchase Ordinary Shares	441	784
Decrease in deferred revenue	(957)	(745)
Decrease (increase) in trade payables	(1,497)	1,258
Decrease (increase) in other accounts payable and accrued expenses	(792)	654
Net cash used in operating activities	(17,958)	(18,786)
Cash flows from investing activities:
Proceeds from maturity of investment in restricted cash		308
Purchase of property and equipment	(992)	(1,158)
Decrease (increase) in other assets	57	(62)
Net cash used in investing activities	(935)	(912)
Cash flows from financing activities:
Repayment of loan		(234)
Proceeds from warrants exercised by shareholders	4,866
Proceeds from options exercise by employees	119
Proceeds from issuance of Ordinary Shares and warrants, net of issuance cost	28,110	19,585
Net cash provided by (used in) financing activities	33,095	19,351
Increase (decrease) in cash and cash equivalents	14,202	(347)
Cash and cash equivalents at the beginning of the period	23,215	31,851
Cash and cash equivalents at the end of the period	37,417	31,504
Supplemental disclosure of non-cash investing and financing activities:
Purchase of property and equipment	642	286
Exercise of warrants into Ordinary Shares	5,177
Cash paid during the period:
Cash paid for interest		3
Cash paid for taxes	$ 237	$ 341