Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net loss	$ (34,497)	$ (30,704)
Items not involving cash:
Depreciation	586	649
Amortization of discount on term loan	284	11
Stock-based compensation	2,625	2,236
Unrealized foreign exchange (gain) loss	646	(1,474)
Gain on termination of collaboration agreement (note 12a)	(4,398)
Changes in operating assets and liabilities:
Accounts receivable	175	(232)
Prepaid expenses, and other current assets	(928)	613
Prepaid expenses, long term		178
Accounts payable and accrued expenses	783	(3)
Net cash used in operating activities	(34,724)	(28,726)
Investing activities:
Purchases of property, plant and equipment	(507)	(315)
Purchase of marketable securities	(77,002)	(28,007)
Proceeds from marketable securities	48,522	52,616
Net cash provided by (used in) investing activities	(28,987)	24,294
Financing activities:
Proceeds from issuance of refinanced term loan, net of issuance costs (note 9)	8,453	6,893
Issuance of common shares, net of issuance costs (note 10a)	102,850
Issuance of common shares pursuant to exercise of stock options	288	177
Net cash provided by financing activities	111,591	7,070
Effect of exchange rate changes on cash and cash equivalents	(612)	753
Increase in cash and cash equivalents	47,268	3,391
Cash and cash equivalents, beginning of year	20,486	17,095
Cash and cash equivalents, end of year	67,754	20,486
Supplemental disclosures:
Interest paid	561
Interest received	1,067	740
Supplemental disclosures of non-cash transactions:
Fair value of stock options and warrants exercised on a cashless basis	1,125	$ 25
Issuance of preferred shares in exchange for common shares (note 10d)	21,825
Conversion of preferred shares to common shares (note 10d)	14,093
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 12a)	$ 4,470