Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net loss	$ (37,873)	$ (7,659)
Items not involving cash:
Depreciation	427	271
Amortization of discount on term loan		216
Deferred income tax recovery	(21)	(52)
Stock-based compensation	4,669	2,487
Unrealized foreign exchange loss	11	23
Unrealized loss (gain) on marketable securities	92	(532)
Loss on repayment of term loan (note 8)		988
Changes in operating assets and liabilities:
Accounts receivable	(608)	(1,009)
Prepaid expenses and other current assets	(349)	225
Accounts payable and accrued expenses	484	(1,054)
Deferred revenue	(617)	(17,760)
Net cash used in operating activities	(33,785)	(23,856)
Investing activities:
Purchases of property, plant and equipment	(1,313)	(1,016)
Purchases of marketable securities	(122,279)	(146,773)
Proceeds from marketable securities	76,680	105,798
Net cash used in investing activities	(46,912)	(41,991)
Financing activities:
Repayment of term loan and repayment fees (note 8)		(16,743)
Proceeds from issuance of common shares and pre-funded warrants, net of issuance costs (note 9a)	118,615	102,456
Issuance of common shares pursuant to exercise of stock options	217	37
Net cash provided by financing activities	118,832	85,750
Effect of exchange rate changes on cash and cash equivalents	(214)	(459)
Increase in cash and cash equivalents	37,921	19,444
Cash and cash equivalents, beginning of period	45,009	24,755
Cash and cash equivalents, end of period	82,930	44,199
Supplemental disclosures:
Interest paid		339
Interest received	1,537	2,191
Cash paid for operating lease	412	311
Supplemental disclosures of non-cash transactions:
Fair value of stock options exercised on a cashless basis	1,324	$ 876
Increase in operating lease liability and accounts receivable related to lease incentives claimed in the period	$ 493