Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash Flows From Operating Activities:
Net loss and comprehensive loss for the period	$ (72,850)	$ (47,726)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	9,500	5,240
Depreciation expense	1,039	734
Non-cash lease expense	1,091	748
Foreign exchange gain	(136)	(13)
Amortization of premiums on marketable securities	34	54
Deferred tax	(2,609)	(626)
Changes in operating assets and liabilities:
Prepaid expenses	3,072	4,622
Research and development tax credits receivable	(31)	(627)
Other receivables	(358)	556
Other non-current assets	89
Accounts payable	2,698	1,155
Accrued expenses and other current liabilities	3,334	4,509
Operating lease liability, current portion	460	(272)
Income taxes	(1,322)	44
Operating lease liability, net of current portion	(1,123)	(238)
Deferred revenue	(1,087)	(445)
Net cash used in operating activities	(58,199)	(32,285)
Cash Flows From Investing Activities:
Purchases of property and equipment	(2,056)	(1,201)
Proceeds from maturities of marketable securities	5,150	3,750
Purchase of marketable securities	(4,000)	(3,438)
Net cash used in investing activities	(906)	(889)
Cash Flows From Financing Activities:
Proceeds from exercise of stock options	233	632
Proceeds from issuance of common stock under the 2020 Employee Share Purchase Plan	213
Net cash provided by financing activities	446	632
Effect of exchange rate fluctuations on cash held	66	(1)
Net Decrease In Cash And Cash Equivalents And Restricted Cash	(58,593)	(32,543)
Cash and cash equivalents and restricted cash at beginning of period	334,427	326,396
Cash and cash equivalents and restricted cash at end of period	275,834	293,853
Reconciliation Of Cash And Cash Equivalents And Restricted Cash
Cash and cash equivalents	275,834	293,635
Restricted cash		218
Total cash and cash equivalents and restricted cash	275,834	293,853
Supplemental Disclosure Of Cash Flow Information:
Property and equipment purchases incurred but not yet paid	222	38
Right-of-use asset obtained in exchange for new operating lease liability	$ 56	$ 705