Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (211,843,000)	$ (180,552,000)	$ (145,437,000)
Items not involving cash:
Depreciation and amortization of property and equipment	3,739,000	3,355,000	2,312,000
Amortization of intangible assets	2,793,000	4,160,000	3,113,000
Impairment of acquired IPR&D	0	0	768,000
Stock-based compensation (note 10e)	10,756,000	29,116,000	48,996,000
Amortization and impairment of operating lease right-of-use assets	3,051,000	2,764,000	1,906,000
Deferred income tax expense (recovery)	(953,000)	266,000	(726,000)
Non-cash consideration from licensing agreement	0	(218,000)	0
Change in fair value of contingent consideration liability (note 17)	213,000	307,000	271,000
Change in fair value of investments in equity instruments	(167,000)	0	0
Unrealized foreign exchange (gain) loss	(433,000)	(453,000)	504,000
Changes in non-cash operating working capital:
Accounts receivable	(266,000)	(13,107,000)	(1,828,000)
Prepaid expenses and other current assets	(15,792,000)	(3,519,000)	(8,680,000)
Accounts payable and accrued liabilities	16,477,000	7,618,000	21,572,000
Operating lease liabilities	(26,000)	(1,140,000)	(795,000)
Deferred revenue	0	0	(3,530,000)
Income taxes payable	0	0	(299,000)
Net cash used in operating activities	(192,451,000)	(151,403,000)	(81,853,000)
Cash flows from financing activities:
Proceeds from public offerings, net of issuance costs (note 10a)	0	300,910,000	188,231,000
Issuance of common shares on exercise of stock options (note 10e)	6,428,000	7,111,000	5,498,000
Issuance of common shares through employee stock purchase plan (note 10f)	2,070,000	1,111,000	598,000
Deferred financing fees	(470,000)	(113,000)	(650,000)
Finance lease payments	(17,000)	(41,000)	(16,000)
Net cash provided by financing activities	8,011,000	308,978,000	193,661,000
Cash flows from investing activities:
Net redemptions (purchases) of short-term investments	157,881,000	13,325,000	(11,714,000)
Purchases of long-term investments	0	(50,500,000)	0
Acquisition of property and equipment	(12,404,000)	(4,310,000)	(6,322,000)
Acquisition of intangible assets	(881,000)	(1,955,000)	(7,556,000)
Net cash provided by (used in) investing activities	144,596,000	(43,440,000)	(25,592,000)
Effect of exchange rate changes on cash and cash equivalents	(325,000)	(550,000)	30,000
Net change in cash and cash equivalents	(40,169,000)	113,585,000	86,246,000
Cash and cash equivalents, beginning of year	242,036,000	128,451,000	42,205,000
Cash and cash equivalents, end of year	201,867,000	242,036,000	128,451,000
Supplemental disclosure of non-cash investing and finance items:
Leased assets obtained in exchange for operating lease liabilities	24,609,000	2,407,000	7,026,000
Acquisition of property and equipment in accounts payable and accrued liabilities	$ 1,933,000	$ 130,000	$ 607,000