License Agreements (Details) £ in Thousands, $ in Thousands		1 Months Ended			12 Months Ended
License Agreements (Details) £ in Thousands, $ in Thousands	Nov. 08, 2024 GBP (£)	Mar. 31, 2018 GBP (£)	Mar. 31, 2016 GBP (£) shares	Sep. 30, 2014 shares	Dec. 31, 2025 USD ($)	Dec. 31, 2025 GBP (£)	Dec. 31, 2024 USD ($)	Dec. 31, 2020 GBP (£)
Schedule Of License Agreements
Issuance of ordinary shares, net of issuance costs (shares) \| shares			313,971
UCLB milestone						£ 180		£ 350
License milestone payment \| $					$ 8,089		$ 12,744
Product Sales \| Minimum
Schedule Of License Agreements
Conditional payment						1,000
Product Sales \| Maximum
Schedule Of License Agreements
Conditional payment						18,500
UCLB
Schedule Of License Agreements
Issuance of ordinary shares, net of issuance costs (shares) \| shares				1,497,643
Payment of upfront fees		£ 1,500	£ 300
Payments for accrued license fees \| $					$ 100
UCLB \| Intellectual Property
Schedule Of License Agreements
License milestone payment	£ 10,000					6,000
UCLB \| Regulatory Approval
Schedule Of License Agreements
Conditional payment						37,500
UCLB \| Product Sales
Schedule Of License Agreements
Conditional payment						18,000
UCLB \| Net Sales Levels
Schedule Of License Agreements
Conditional payment						£ 51,000
UCLB \| Regulatory Milestone
Schedule Of License Agreements
Conditional payment	£ 10,000
Miltenyi Biotech B.V. & Co. KG ("Miltenyi")
Schedule Of License Agreements
Upfront license payment \| $							$ 400