v3.26.1
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Schedule of Deferred Tax Assets and Liabilities
The tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities were as follows (amounts in thousands):
December 31,
20252024
Deferred tax assets:
Tax loss carryforwards$144,366 $96,444 
Capitalized research and development8,239 13,606 
Research and development credits13,557 11,063 
Other4,321 3,068 
Total deferred tax assets170,483 124,181 
Valuation allowance(143,002)(94,894)
Deferred tax assets, net of allowance
27,481 29,287 
Deferred tax liabilities:
Other
(2,703)(2,701)
Net deferred tax assets
$24,778 $26,586 
Schedule of Income before Income Tax, Domestic and Foreign
Components of the Company’s pre-tax loss are as follows (amounts in thousands):
Years Ended December 31,
20252024
(Loss) Income before tax:
UK$(217,984)$(248,649)
Non-UK22,271 15,736 
Total $(195,713)$(232,913)
Schedule of Components of Income Tax Provision
The income tax expense (benefit) consists of the following (amounts in thousands):
December 31,
20252024
Federal - U.S.
Current(40)(513)
Deferred2,491 2,599 
State - U.S.
Current(659)702 
Deferred18 56 
Foreign
Current9 — 
Deferred— — 
Income tax expense (benefit)
$1,819 $2,844 
Schedule of Effective Income Tax Rate Reconciliation
A reconciliation of the United Kingdom (“UK”) income tax rate to the Company’s effective tax rate is as follows:

Years Ended December 31,
20252024
Statutory tax rate benefit25 %25 %
Non-deductible share-based compensation
(4)%(3)%
Other non-deductible expenses— %(4)%
Enhanced UK research and development expenses
8 %6 %
Losses surrendered for UK research tax incentive
(13)%(18)%
UK non-taxable research and development incentive
3 %3 %
U.S. research & development tax credits
1 %— %
Return to provision adjustments
1 %— %
Increase in valuation allowance
(22)%(10)%
Effective income tax rate(1)%(1)%
Schedule of Operating Loss Carryforwards and Research Tax Credits
The following table summarizes carryforwards of U.S. federal and UK net operating losses (NOL) and U.S. research tax credits (amounts in thousands):
December 31,
20252024
UK$557,930 $365,638 
U.S.
$35,197 $33,423 
Schedule of Gross Unrecognized Tax Benefits
A reconciliation of gross unrecognized tax benefits, as of December 31, 2025 and 2024 is as follows (amounts in thousands):
20252024
Gross unrecognized tax benefits at beginning of period
$2,614 $2,614 
Increase related to current year tax positions
— — 
Gross unrecognized tax benefits at end of period
$2,614 $2,614