Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (3,755)	$ (7,517)
Items not involving cash:
Depreciation	150	165
Amortization of discount on term loan	72
Stock-based compensation	663	478
Unrealized foreign exchange (gain) loss	267	(326)
Gain on termination of collaboration agreement (note 9b)	(4,398)
Changes in operating assets and liabilities:
Accounts receivable	3	11
Prepaid expenses, and other current assets	(435)	404
Prepaid expenses, long term	230	139
Accounts payable and accrued expenses	(1,016)	186
Net cash used in operating activities	(8,219)	(6,460)
Investing activities:
Purchases of property, plant and equipment	(181)	(137)
Purchase of marketable securities	(8,148)
Proceeds from marketable securities	13,306	9,384
Net cash provided by investing activities	4,977	9,247
Financing activities:
Issuance of common shares pursuant to exercise of stock options	119	174
Net cash provided by financing activities	119	174
Effect of exchange rate changes on cash and cash equivalents	(163)	104
Increase (decrease) in cash and cash equivalents	(3,286)	3,065
Cash and cash equivalents, beginning of period	20,486	17,095
Cash and cash equivalents, end of period	17,200	20,160
Supplemental disclosures:
Interest paid	71
Interest received	141	55
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	176	$ 19
Issuance of preferred shares in exchange for common shares (note 9a)	21,825
Teva Pharmaceuticals International GmbH and Teva Canada Limited [Member]
Supplemental disclosures of non-cash transactions:
Termination of Teva agreement through cancellation of common shares (note 9b)	$ 4,470