Consolidated statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net loss	$ (69,442)	$ (31,585)	$ (50,183)
Non-cash items and reclassifications:
Stock-based compensation (Note 8(g))	7,683	4,698	3,839
Acquired in-process research & development (Note 3)	47,716
Depreciation and amortization	340	289	360
Unrealized foreign exchange loss and others	263	452	349
Changes in operating assets and liabilities:
Receivable, prepayments and deposits	290	1,041	(905)
Accounts payable and other liabilities	(2,244)	(6,472)	1,822
Cash used in operating activities	(15,394)	(31,577)	(44,718)
Investing activities
Acquisition of Neoleukin Therapeutics, Inc., net of cash acquired	191
Purchase of investments			(5,995)
Proceeds from maturity of investments		56,000	70,500
Purchase of property and equipment	(879)	(49)	(494)
Cash (used in) provided by investing activities	(688)	55,951	64,011
Financing activities
Public offering of common stock (Note 8(e))	86,216
Public offering costs (Note 8(e))	(5,525)
Proceeds from exercise of stock options	1,555	602	438
Payment on finance lease obligations	(9)	(32)	(15)
Cash provided by financing activities	82,237	570	423
Effect of exchange rate changes on cash and cash equivalents	10	(48)	15
Net change in cash and cash equivalents during the year	66,165	24,896	19,731
Cash and cash equivalents, beginning of year	76,928	52,032	32,301
Cash and cash equivalents, end of year	143,093	76,928	52,032
Supplemental disclosure of cash flow information:
Interest paid	1	4	4
Interest received	1,544	$ 1,684	1,342
Non-cash investing and financing activities:
Receivables, prepayments and deposits acquired through the issuance of common stock	560
Property, equipment and intangibles acquired through the issuance of common stock	1,693
Accounts payable, finance lease and other liabilities assumed through the issuance of common stock	$ (1,673)
Accrued purchase of property & equipment			(77)
Accrued offering costs			$ (30)