Adaptimmune Annual report [Section 13 and 15(d), not S-K Item 405]

Annual report [Section 13 and 15(d), not S-K Item 405]

Borrowings - Narrative (Details)

Borrowings - Narrative (Details) - USD ($)			12 Months Ended
Borrowings - Narrative (Details) - USD ($)	Aug. 13, 2024	May 14, 2024	Dec. 31, 2024	Mar. 24, 2024
Borrowings
Proceeds from issuance of debt			$ 49,500,000
Outstanding borrowings			50,000,000
Term loan
Borrowings
Pre-pay amount				$ 25,000,000
Loan and Security Agreement
Borrowings
End of term charge (in percent)				5.85%
Pre-pay amount				$ 25,000,000
Loan and Security Agreement \| Term loan
Borrowings
Amount of term loan facility		$ 125,000,000
PIK interest rate (in percent)		2.00%
End of term charge (in percent)		5.85%
Outstanding borrowings			50,520,000
Amount of unamortized discount			468,000
Accreted value of the End of Term Charge			$ 185,000
Imputed interest rate			13.70%
Loan and Security Agreement \| Term loan \| Level 2
Borrowings
Fair value of term loan			$ 51,622,000
Loan and Security Agreement \| Term loan \| Tranche 1 Advance
Borrowings
Amount of term loan facility		$ 25,000,000
Amount drew down		25,000,000
Proceeds from issuance of debt		24,500,000
Initial amount recognized		24,750,000
Loan and Security Agreement \| Term loan \| Tranche 2 Advance
Borrowings
Amount of term loan facility		25,000,000
Amount drew down	$ 25,000,000
Proceeds from issuance of debt	25,000,000
Initial amount recognized	$ 24,750,000
Loan and Security Agreement \| Term loan \| Tranche 3 Advance
Borrowings
Amount of term loan facility		5,000,000
Loan and Security Agreement \| Term loan \| Tranche 4 Advance
Borrowings
Amount of term loan facility		30,000,000
Loan and Security Agreement \| Term loan \| Tranche 5 Advance
Borrowings
Amount of term loan facility		$ 40,000,000
Loan and Security Agreement \| Term loan \| Minimum
Borrowings
Variable interest rate (in percent)		1.15%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember
Loan and Security Agreement \| Term loan \| Maximum
Borrowings
Variable interest rate (in percent)		9.65%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		us-gaap:PrimeRateMember