Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 58,896	$ 148,643
Marketable securities (note 6)	640,706	489,439
Accounts receivable	833	874
Prepaid expenses and other current assets	6,769	6,006
Total current assets	707,204	644,962
Marketable securities, long-term (note 6)	185,836	292,792
Operating lease right-of-use asset, net (note 7)	8,884	9,193
Property, plant and equipment, net	9,393	9,653
Deferred tax assets	400	802
Prepaid expenses, long-term	7,306	7,396
Total assets	919,023	964,798
Current liabilities:
Accounts payable and accrued expenses (note 8)	20,900	25,974
Operating lease liability (note 7)	1,323	1,299
Total current liabilities	22,223	27,273
Operating lease liability, long-term (note 7)	9,102	9,604
Total liabilities	31,325	36,877
Shareholders’ equity:
Common shares, without par value; unlimited shares authorized; issued and outstanding: 75,549,681 (December 31, 2023 - 75,370,977) (note 9)	1,438,961	1,436,374
Additional paid-in capital	163,577	156,764
Accumulated deficit	(713,071)	(665,140)
Accumulated other comprehensive loss	(1,769)	(77)
Total shareholders' equity	887,698	927,921		$ 721,497
Total liabilities and shareholders’ equity	$ 919,023	$ 964,798
Commitments and contingencies (note 10)