Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities:
Net loss	$ (7,517)	$ (3,263)
Items not involving cash:
Depreciation and amortization	165	282
Stock-based compensation	478	592
Unrealized foreign exchange gain	(326)	(2,260)
Changes in operating assets and liabilities:
Accounts receivable	11	(60)
Prepaid expenses, and other current assets	404	82
Prepaid expenses, long term	139
Accounts payable and accrued expenses	186	(160)
Deferred revenue		(157)
Net cash used in operating activities	(6,460)	(4,944)
Investing activities:
Purchases of property, plant and equipment	(137)	(83)
Proceeds from marketable securities	9,384
Net cash provided by (used in) investing activities	9,247	(83)
Financing activities:
Issuance of common shares pursuant to exercise of stock options	174	44
Net cash provided by financing activities	174	44
Effect of exchange rate changes on cash and cash equivalents	104	2,396
Increase (decrease) in cash and cash equivalents	3,065	(2,587)
Cash and cash equivalents, beginning of period	17,095	58,651
Cash and cash equivalents, end of period	20,160	56,064
Supplemental disclosures:
Interest received	55	$ 112
Supplemental disclosures of non-cash transactions:
Fair value of options exercised on a cashless basis	$ 19