v3.26.1
Intangible assets other than goodwill (Details)
 12 Months Ended
Sep. 30, 2025
EUR (€)
Dec. 31, 2025
EUR (€)
Dec. 31, 2024
EUR (€)
Dec. 31, 2024
USD ($)
Dec. 31, 2022
item
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   € 164,862,000      
Ending balance   848,000 € 164,862,000    
Number Of CAR T Product Candidates Acquired | item         2
Upfront Exclusivity Consideration Paid | $       $ 70,000,000  
Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment € (132,000,000) (132,000,000)      
Acquisition value          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   235,451,000 175,290,000    
Additions   156,000 65,391,000    
Sales and disposals     (5,476,000)    
Translation differences   (477,000) 246,000    
Ending balance   235,130,000 235,451,000    
Amortization and impairment          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   (70,589,000) (47,384,000)    
Amortization.   (26,331,000) (28,613,000)    
Impairment   (137,614,000)      
Sales and disposals     5,476,000    
Translation differences   252,000 (68,000)    
Ending balance   (234,282,000) (70,589,000)    
In process technology | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   (28,200,000)      
Software and databases          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   4,722,000      
Ending balance   848,000 4,722,000    
Software and databases | Acquisition value          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   25,817,000 27,014,000    
Additions   156,000 666,000    
Sales and disposals     (1,863,000)    
Ending balance   25,973,000 25,817,000    
Software and databases | Amortization and impairment          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   (21,095,000) (18,574,000)    
Amortization.   (2,249,000) (4,384,000)    
Impairment   (1,781,000)      
Sales and disposals     1,863,000    
Ending balance   (25,125,000) (21,095,000)    
Licenses, rights, technology and in process R&D          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   38,502,000      
Ending balance     38,502,000    
Licenses, rights, technology and in process R&D | Acquisition value          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   39,804,000 43,171,000    
Sales and disposals     (3,613,000)    
Translation differences   (477,000) 246,000    
Ending balance   39,327,000 39,804,000    
Licenses, rights, technology and in process R&D | Amortization and impairment          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   (1,302,000) (4,354,000)    
Amortization.   (355,000) (493,000)    
Impairment   (37,922,000)      
Sales and disposals     3,613,000    
Translation differences   252,000 (68,000)    
Ending balance   (39,327,000) (1,302,000)    
Exclusive rights          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   114,456,000      
Ending balance     114,456,000    
Exclusive rights | Acquisition value          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   154,445,000 89,720,000    
Additions     64,725,000    
Ending balance   154,445,000 154,445,000    
Exclusive rights | Amortization and impairment          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   (39,989,000) (17,791,000)    
Amortization.   (22,189,000) (22,198,000)    
Impairment   (92,267,000)      
Ending balance   (154,445,000) (39,989,000)    
CAR-T Product Candidates [member]          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   28,200,000      
Ending balance     28,200,000    
Exclusive Rights With Lonza [member]          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   60,300,000 71,900,000    
Ending balance     60,300,000    
Exclusive Rights With Lonza [member] | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   (51,600,000)      
Exclusive Rights Paid To Adaptimmune [member] | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   (40,700,000)      
Exclusive Rights Paid To Pregene [member] | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   (7,500,000)      
Contract costs          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   7,182,000      
Ending balance     7,182,000    
Contract costs | Acquisition value          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   15,384,000 15,384,000    
Ending balance   15,384,000 15,384,000    
Contract costs | Amortization and impairment          
Disclosure of detailed information about intangible assets [line items]          
Beginning balance   (8,202,000) (6,664,000)    
Amortization.   (1,538,000) (1,538,000)    
Impairment   (5,644,000)      
Ending balance   (15,384,000) € (8,202,000)    
Other intangible assets [member] | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   (2,200,000)      
Other intangible Related To Acquisition Of Cell Point And AboundBio [member] | Cell Therapy Business Associated Assets [member]          
Disclosure of detailed information about intangible assets [line items]          
Impairment   € (1,300,000)