CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (23,205)	$ (25,869)
Adjustments required to reconcile net loss to net cash used in operating activities:
Stock-based compensation	940	833
Depreciation	794	620
Impairment of property and equipment	388	0
Re-evaluation of fair value of warrants to purchase Ordinary Shares	2,448	(2,491)
Issuance costs related to warrants to purchase Ordinary Shares	441	784
Decrease (increase) in other accounts receivable and prepaid expenses	(340)	136
Decrease in deferred revenues	(1,065)	(1,065)
Increase (decrease) in trade payables	(1,545)	1,010
Increase (decrease) in other accounts payable and accrued expenses	(1,098)	192
Net cash used in operating activities	(22,242)	(25,850)
Cash flows from investing activities:
Proceeds from maturity of investments in restricted cash		308
Purchase of property and equipment	(1,710)	(2,384)
Release (investment) in long-term deposits	49	(61)
Net cash used in investing activities	(1,661)	(2,137)
Cash flows from financing activities:
Proceeds from issuance of Ordinary Shares and warrants, net of issuance costs	28,110	19,585
Repayment of loan		(234)
Proceeds from exercise of warrants into Ordinary Shares	4,866
Proceeds from exercise of options into Ordinary Shares	165
Net cash provided by financing activities	33,141	19,351
Net increase (decrease) in cash and cash equivalents	9,238	(8,636)
Cash and cash equivalents at the beginning of the year	23,215	31,851
Cash and cash equivalents at the end of the year	32,453	23,215
Supplemental disclosure of non-cash investing and financing activities:
Purchase of property and equipment	231	201
Exercise of warrants into Ordinary Shares	5,177
Cash paid during the year:
Cash paid for taxes and interest	$ 212	$ 449