Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (70,097)	$ (42,718)
Items not involving cash:
Depreciation and amortization of property and equipment	1,539	1,001
Amortization of intangible assets	1,971	1,302
Impairment on acquired IPR&D	0	768
Stock-based compensation expense	4,257	13,866
Amortization and impairment of operating lease right-of-use assets	1,572	760
Deferred income tax expense	191	(51)
Non-cash consideration from licensing agreement	(218)	0
Change in fair value of contingent consideration	68	285
Unrealized foreign exchange (gain) loss	(2,866)	275
Changes in non-cash operating working capital:
Accounts receivable	(12,640)	(2,351)
Prepaid expenses and other current assets	(9,284)	(6,195)
Accounts payable and accrued liabilities	(1,766)	2,796
Operating lease liabilities	(170)	(528)
Deferred revenue	0	(3,530)
Income taxes payable	0	(299)
Net cash used in operating activities	(87,443)	(34,619)
Cash flows from financing activities:
Proceeds from public offering, net of issuance costs (note 8a)	300,910	189,035
Issuance of common shares on exercise of stock options (note 8e)	1,795	1,247
Issuance of common shares through employee stock purchase plan	419	233
Deferred financing fees	(80)	0
Finance lease payments	(7)	(11)
Net cash provided by financing activities	303,037	190,504
Cash flows from investing activities:
Net (purchases) redemptions of short-term and long-term investments	(121,822)	86,786
Acquisition of property and equipment	(2,185)	(1,407)
Acquisition of intangible assets	(419)	0
Net cash (used in) provided by investing activities	(124,426)	85,379
Effect of exchange rate changes on cash and cash equivalents	(50)	51
Net change in cash and cash equivalents	91,118	241,315
Cash and cash equivalents, beginning of period	128,451	42,205
Cash and cash equivalents, end of period	219,569	283,520
Supplemental disclosure of non-cash investing and financing items:
Leased assets obtained in exchange for operating lease liabilities	1,817	8,012
Acquisition of property and equipment in accounts payable and accrued liabilities	$ 706	$ 1,592