Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net loss	$ (22,639)	$ (16,993)
Items not involving cash:
Depreciation and amortization	502	698
Stock-based compensation	1,643	1,642
Unrealized foreign exchange gain	(1,585)	(2,011)
Changes in operating assets and liabilities:
Accounts receivable	77	(272)
Prepaid expenses, and other current assets	243	636
Prepaid expenses, long term	190	615
Accounts payable and accrued expenses	(319)	945
Deferred revenue		(157)
Net cash used in operating activities	(21,888)	(14,897)
Investing activities:
Purchases of property, plant and equipment	(252)	(251)
Purchase of marketable securities	(22,281)	(15,365)
Proceeds from marketable securities	41,024
Net cash provided by (used in) investing activities	18,491	(15,616)
Financing activities:
Issuance of common shares pursuant to exercise of stock options	177	84
Issuance of common shares, net of issuance costs (note 7a)		23,832
Net cash provided by financing activities	177	23,916
Effect of exchange rate changes on cash and cash equivalents	813	2,081
Decrease in cash and cash equivalents	(2,407)	(4,516)
Cash and cash equivalents, beginning of period	17,095	58,651
Cash and cash equivalents, end of period	14,688	54,135
Supplemental disclosures:
Interest received	544	261
Supplemental disclosures of non-cash transactions:
Fair value of options exercised on a cashless basis	$ 25	$ 168