Income Taxes - Summary of Operating Loss Carryforwards and Research Tax Credits (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
UK
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards and research tax credits	$ 225,662	$ 82,156
US
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards and research tax credits	48,523	34,059
France
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards and research tax credits	25,474	19,710
Germany
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards and research tax credits	$ 0	$ 11,062