v3.25.3
Financial liabilities - Disclosure of reconciliation of liabilities arising from financing activities (Details) - EUR (€)
€ in Thousands
 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period € 109,218 € 74,466
Proceeds   47,444
Repayments (18,770) (9,357)
Interest paid (5,422) (5,364)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments   (3,204)
Non-cash changes: (gain)/loss on recognition or derecognition (1,557) (442)
Non-cash changes: interest expense and other 13,209 10,977
Non-cash changes: amortized cost remeasurement 11,318  
Non-cash changes: other fair value remeasurement 36,002 609
Non-cash changes: conversion into shares (69,979) (4,070)
Non-cash changes : subsidies   914
Non cash changes: additional leases   2,021
Non cash changes : Effect of the change in foreign currency exchange rates (33) (3)
Liabilities arising from financing activities at end of period 73,988 113,992
Kreos & Claret convertible notes (OCABSA)    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 23,370 21,643
Proceeds  
Repayments
Interest paid (1,688) (1,688)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 2,644 2,956
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares (16,058)
Non-cash changes : subsidies  
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period 8,269 22,912
Kreos & Claret bond loans    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 46,401
Proceeds   47,444
Repayments (14,551)
Interest paid (2,951) (2,267)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments   (3,204)
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 5,919 3,559
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares
Non-cash changes : subsidies  
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period 34,819 45,533
Heights convertible notes    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 21,574 29,605
Proceeds   0
Repayments (2,188) (6,563)
Interest paid (689) (1,378)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition (1,557) (442)
Non-cash changes: interest expense and other 778 1,333
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement 36,002 609
Non-cash changes: conversion into shares (53,921)
Non-cash changes : subsidies  
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period 0 23,164
PGE    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 2,488 3,678
Proceeds  
Repayments (1,250) (1,250)
Interest paid (43) (18)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 58 56
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares
Non-cash changes : subsidies  
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period 1,252 2,466
Conditional advances Bpifrance    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 0 6,771
Proceeds  
Repayments (1,142)
Interest paid
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 7
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares (4,070)
Non-cash changes : subsidies   914
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period 0 2,480
Lease liabilities    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 2,363 540
Proceeds  
Repayments (782) (402)
Interest paid (51) (14)
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 51 43
Non-cash changes: amortized cost remeasurement  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares
Non-cash changes : subsidies  
Non cash changes: additional leases   2,021
Non cash changes : Effect of the change in foreign currency exchange rates (33) (3)
Liabilities arising from financing activities at end of period 1,549 2,185
Royalty certificates    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities at beginning of period 13,023 12,229
Proceeds  
Repayments
Interest paid
Non-cash changes: classification of embedded derivatives as separate derivative financial instruments  
Non-cash changes: (gain)/loss on recognition or derecognition
Non-cash changes: interest expense and other 3,758 3,023
Non-cash changes: amortized cost remeasurement 11,318  
Non-cash changes: other fair value remeasurement
Non-cash changes: conversion into shares 0
Non-cash changes : subsidies  
Non cash changes: additional leases  
Non cash changes : Effect of the change in foreign currency exchange rates
Liabilities arising from financing activities at end of period € 28,099 € 15,253