Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 82,930	$ 45,009
Marketable securities	177,593	131,988
Accounts receivable	2,919	1,822
Prepaid expenses and other current assets	3,313	2,964
Total current assets	266,755	181,783
Operating lease right-of-use asset, net (note 6)	3,086	3,326
Property, plant and equipment, net	4,326	3,554
Deferred tax assets (note 11)	544	523
Total assets	274,711	189,186
Current liabilities:
Accounts payable and accrued expenses (note 7)	11,198	10,874
Deferred revenue (note 10)	3,025	3,642
Operating lease liability (note 6)	759	265
Total current liabilities	14,982	14,781
Operating lease liability, long-term (note 6)	2,746	3,050
Total liabilities	17,728	17,831
Shareholders’ equity:
Preferred shares, without par value; unlimited shares authorized; issued and outstanding: 1,016,000 (December 31, 2020 - 1,016,000) (note 9)	7,732	7,732
Common shares, without par value; unlimited shares authorized; issued and outstanding: 41,117,568 (December 31, 2020 - 35,012,125) (note 9)	499,351	397,748
Additional paid-in capital	67,255	45,357
Accumulated deficit	(316,365)	(278,492)
Accumulated other comprehensive loss	(990)	(990)
Shareholders' equity	256,983	171,355
Total liabilities and shareholders’ equity	274,711	189,186
Commitments and contingencies (note 12)