v3.26.1
Shareholders' equity - Movements in BSPCE and BSA share warrants (Details)
12 Months Ended
Dec. 15, 2023
EquityInstruments
€ / shares
May 25, 2023
EquityInstruments
€ / shares
Apr. 16, 2021
EquityInstruments
€ / shares
Mar. 09, 2020
EquityInstruments
€ / shares
Jun. 28, 2019
EquityInstruments
€ / shares
May 29, 2017
EquityInstruments
€ / shares
Dec. 31, 2025
EquityInstruments
€ / shares
shares
Dec. 31, 2025
EUR (€)
EquityInstruments
€ / shares
shares
Dec. 31, 2025
EquityInstruments
€ / shares
shares
Dec. 31, 2024
EquityInstruments
€ / shares
shares
Dec. 31, 2024
EUR (€)
EquityInstruments
€ / shares
shares
Dec. 31, 2024
EquityInstruments
€ / shares
shares
Dec. 31, 2023
EquityInstruments
€ / shares
shares
Dec. 31, 2023
EUR (€)
EquityInstruments
€ / shares
shares
Dec. 31, 2023
EquityInstruments
€ / shares
shares
Shareholders' equity                              
Outstanding, Beginning balance                   1,410,814     790,600    
Issued                         1,060,000    
Exercised                         (363,000)    
Forfeited / Lapsed                         (76,786)    
Outstanding, Ending balance               0         1,410,814    
BSPCE and BSA Share Warrants                              
Shareholders' equity                              
Outstanding, Beginning balance             776,333     776,333     806,800    
Issued                         30,000    
Forfeited / Lapsed                         (60,467)    
Outstanding, Ending balance             776,333     776,333     776,333    
Number of exercisable shares             746,333 746,333 746,333 746,333 746,333 746,333 732,000 732,000 732,000
Number of shares callable by warrants | shares             776,333 776,333 776,333 776,333 776,333 776,333 776,333 776,333 776,333
Expense from share-based payment transactions | €               € 30,000     € 236,000     € 827,000  
BSPCE plans                              
Shareholders' equity                              
Outstanding, Beginning balance             430,000     430,000     488,800    
Forfeited / Lapsed                         (58,800)    
Outstanding, Ending balance             430,000     430,000     430,000    
Number of exercisable shares             430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000
Number of shares callable by warrants | shares             430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000
BSPCE - Plan 2013                              
Shareholders' equity                              
Exercise price (in euros) | € / shares                   € 0.59 € 0.59 € 0.59 € 0.59 € 0.59 € 0.59
Outstanding, Beginning balance                         8,800    
Forfeited / Lapsed                         (8,800)    
Number of bonus shares lapsed                         8,800    
BSPCE - Plan 2021                              
Shareholders' equity                              
Exercise price (in euros) | € / shares     € 11.74       € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74
Outstanding, Beginning balance             430,000     430,000     480,000    
Issued     600,000                        
Forfeited / Lapsed                         (50,000)    
Outstanding, Ending balance             430,000     430,000     430,000    
Number of exercisable shares             430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000 430,000
BSPCE - Plan 2021 | Based on Market Condition                              
Shareholders' equity                              
Forfeited / Lapsed                         (30,000)    
BSPCE - Plan 2021 | Based on Non-Market Condition                              
Shareholders' equity                              
Forfeited / Lapsed                         (20,000)    
BSA Plans                              
Shareholders' equity                              
Outstanding, Beginning balance             346,333     346,333     318,000    
Issued                         30,000    
Forfeited / Lapsed                         (1,667)    
Outstanding, Ending balance             346,333     346,333     346,333    
Number of exercisable shares             316,333 316,333 316,333 316,333 316,333 316,333 302,000 302,000 302,000
Number of shares callable by warrants | shares             346,333 346,333 346,333            
BSA - Plan 2017                              
Shareholders' equity                              
Exercise price (in euros) | € / shares           € 6.675 € 6.67 € 6.67 € 6.67 € 6.67 € 6.67 € 6.67 € 6.67 € 6.67 € 6.67
Outstanding, Beginning balance             130,000     130,000     130,000    
Issued           195,000                  
Outstanding, Ending balance             130,000     130,000     130,000    
Number of exercisable shares             130,000 130,000 130,000 130,000 130,000 130,000 130,000 130,000 130,000
BSA - Plan 2018                              
Shareholders' equity                              
Exercise price (in euros) | € / shares             € 6.07 € 6.07 € 6.07 € 6.07 € 6.07 € 6.07 € 6.07 € 6.07 € 6.07
Outstanding, Beginning balance             116,000     116,000     116,000    
Outstanding, Ending balance             116,000     116,000     116,000    
Number of exercisable shares             116,000 116,000 116,000 116,000 116,000 116,000 116,000 116,000 116,000
BSA - 2019 plan                              
Shareholders' equity                              
Exercise price (in euros) | € / shares         € 2.2   € 2.2 € 2.2 € 2.2 € 2.2 € 2.2 € 2.2 € 2.2 € 2.2 € 2.2
Outstanding, Beginning balance             10,000     10,000     10,000    
Issued         10,000                    
Outstanding, Ending balance             10,000     10,000     10,000    
Number of exercisable shares             10,000 10,000 10,000 10,000 10,000 10,000 10,000 10,000 10,000
BSA 2019 bis                              
Shareholders' equity                              
Exercise price (in euros) | € / shares       € 3.68     € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68
Outstanding, Beginning balance             10,000     10,000     10,000    
Issued       10,000                      
Outstanding, Ending balance             10,000     10,000     10,000    
Number of exercisable shares             10,000 10,000 10,000 10,000 10,000 10,000 10,000 10,000 10,000
BSA 2019 ter                              
Shareholders' equity                              
Exercise price (in euros) | € / shares       € 3.68     € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68 € 3.68
Outstanding, Beginning balance             36,000     36,000     36,000    
Issued       36,000                      
Outstanding, Ending balance             36,000     36,000     36,000    
Number of exercisable shares             36,000 36,000 36,000 36,000 36,000 36,000 36,000 36,000 36,000
BSA 2021                              
Shareholders' equity                              
Exercise price (in euros) | € / shares     € 11.74       € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74 € 11.74
Outstanding, Beginning balance             14,333     14,333     16,000    
Issued     50,000                        
Forfeited / Lapsed                         (1,667)    
Outstanding, Ending balance             14,333     14,333     14,333    
Number of exercisable shares             14,333 14,333 14,333 14,333 14,333 14,333      
BSA 2021 | Based on Non-Market Condition                              
Shareholders' equity                              
Forfeited / Lapsed                         (1,667)    
BSA 2023-1                              
Shareholders' equity                              
Exercise price (in euros) | € / shares   € 2.51         € 2.51 € 2.51 € 2.51 € 2.51 € 2.51 € 2.51 € 2.51 2.51 € 2.51
Outstanding, Beginning balance             10,000   10,000 10,000   10,000      
Issued   10,000                     10,000    
Outstanding, Ending balance             10,000     10,000   10,000 10,000   10,000
BSA 2023-2                              
Shareholders' equity                              
Exercise price (in euros) | € / shares € 3.91           € 3.91 € 3.91 € 3.91 € 3.91 € 3.91 € 3.91 € 3.91 € 3.91 € 3.91
Outstanding, Beginning balance             20,000     20,000          
Issued 20,000                       20,000    
Outstanding, Ending balance             20,000     20,000     20,000