CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (20,425)	$ (26,706)
Adjustments required to reconcile net loss to net cash used in operating activities:
Stock-based compensation	813	477
Depreciation and impairment of property and equipment	446	386
Accrued severance pay, net	6	8
Re-evaluation of fair value of warrants to purchase Ordinary Shares	7,093	15,496
Decrease (increase) in other accounts receivable and prepaid expenses	169	(52)
Issuance costs related to warrants to purchase Ordinary Shares		441
Decrease in deferred revenue		(635)
Increase (decrease) in trade payables	355	(742)
Increase (decrease) in other accounts payable and accrued expenses	1,322	(608)
Net cash used in operating activities	(10,221)	(11,935)
Cash flows from investing activities:
Purchase of property and equipment	(1,219)	(887)
Decrease (increase) in long-term deposit	(3)	56
Net cash used in investing activities	(1,222)	(831)
Cash flows from financing activities:
Proceeds from warrants exercised		4,866
Proceeds from options exercised	119	119
Proceeds from issuance of Ordinary Shares and warrants, net of issuance costs		28,110
Net cash provided by financing activities	119	33,095
Net increase (decrease) in cash and cash equivalents	(11,324)	20,329
Cash and cash equivalents at the beginning of the period	32,453	23,215
Cash and cash equivalents at the end of the period	21,129	43,544
Supplemental disclosure of non-cash investing and financing activities:
Purchase of property and equipment	54	33
Exercise of warrants into Ordinary Shares		5,177
Cash paid during the period:
Cash paid for taxes	$ 35	$ 220