Income Taxes - Schedule of Income Tax Expense Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Corporation tax at UK statutory rate	$ (38,382)	$ (27,656)
Permanent differences	27	1
UK R&D tax credit	14,375	10,720
Change in valuation allowance	25,410	20,971
State income taxes	57	23
Deferred tax asset true-up	676	187
Return to provision	(1,214)	(2,259)
Share-based compensation	774	33
Change in UK tax rate	0	(1,258)
Other	(129)	18
Total provision for income taxes	$ 1,594	$ 780