v3.26.3
Revenue and other income - Disclosure of variance of deferred revenue (Details) - Deferred tax liabilities / Deferred revenue - EUR (€)
€ in Thousands
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Contract liabilities at beginning of period € 2,826 € 3,441
Recognition in P&L (2,699) (254)
Proceeds 0 0
Transfer from / (to) collaboration liabilities 0 4
Contract liabilities at end of period 127 3,191
Monalizumab    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Contract liabilities at beginning of period 0 215
Recognition in P&L 0 (56)
Proceeds 0 0
Transfer from / (to) collaboration liabilities 0 4
Contract liabilities at end of period 0 163
Sanofi (2022) option    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Contract liabilities at beginning of period 2,500 2,500
Recognition in P&L (2,500) 0
Proceeds 0 0
Transfer from / (to) collaboration liabilities 0 0
Contract liabilities at end of period 0 2,500
Sanofi (2022) services    
Disclosure of disaggregation of revenue from contracts with customers [line items]    
Contract liabilities at beginning of period 326 726
Recognition in P&L (199) (198)
Proceeds 0 0
Transfer from / (to) collaboration liabilities 0 0
Contract liabilities at end of period € 127 € 528