v3.26.1
Share-based payments - Disclosure of Number and Weighted Average Remaining Contractual Life of Share Options Outstanding (Details)
 12 Months Ended
May 24, 2024
€ / shares
May 23, 2024
shares
€ / shares
Jul. 20, 2023
shares
€ / shares
Jun. 22, 2022
shares
€ / shares
Jun. 21, 2021
shares
€ / shares
Apr. 20, 2021
shares
€ / shares
Mar. 11, 2020
shares
€ / shares
Oct. 24, 2019
shares
€ / shares
Mar. 29, 2019
shares
€ / shares
Mar. 06, 2018
shares
€ / shares
Jan. 07, 2017
shares
€ / shares
Nov. 03, 2016
shares
€ / shares
Feb. 02, 2016
shares
€ / shares
Dec. 31, 2025
shares
Dec. 31, 2024
shares
Dec. 31, 2023
shares
OSA                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                           1,249,005 1,224,780  
Number of share options outstanding in share-based payment arrangement (in shares)                           4,632,953 3,512,302 2,336,175
Number of options as of including options exercised during the period (in shares)                           97,530 0  
OSA 2016-1 P                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                         6,400      
Exercise price (euro per share) | € / shares                         € 0      
Exercise price (in euros per share) | € / shares                         € 13.05      
Number of share options outstanding in share-based payment arrangement (in shares)                           400    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           6,000    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2016-2                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                       4,000   0 0  
Exercise price (euro per share) | € / shares                       € 0        
Exercise price (in euros per share) | € / shares                       € 14.26        
Number of share options outstanding in share-based payment arrangement (in shares)                           4,000 4,000 4,000
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0 0  
Number of options lapsed or cancelled (in shares)                           0    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2017 O                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                     3,500          
Exercise price (euro per share) | € / shares                     € 0          
Exercise price (in euros per share) | € / shares                     € 14.97          
Number of share options outstanding in share-based payment arrangement (in shares)                           500    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           3,000    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2018                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                   62,000       0 0  
Exercise price (euro per share) | € / shares                   € 0            
Exercise price (in euros per share) | € / shares                   € 12.87            
Number of share options outstanding in share-based payment arrangement (in shares)                           50,000 50,000 52,000
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0 0  
Number of options lapsed or cancelled (in shares)                           12,000    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2019-1                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                 37,500         0 0  
Exercise price (euro per share) | € / shares                 € 0              
Exercise price (in euros per share) | € / shares                 € 11.08              
Number of share options outstanding in share-based payment arrangement (in shares)                           24,750 24,750 25,750
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0 0  
Number of options lapsed or cancelled (in shares)                           12,750    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA LLY 2019                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)               500,000           0 0  
Exercise price (euro per share) | € / shares               € 0                
Exercise price (in euros per share) | € / shares               € 6.41                
Number of share options outstanding in share-based payment arrangement (in shares)                           500,000 500,000 500,000
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0 0  
Number of options lapsed or cancelled (in shares)                           0    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2020                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)             407,972             0 0  
Exercise price (euro per share) | € / shares             € 0                  
Exercise price (in euros per share) | € / shares             € 6.25                  
Number of share options outstanding in share-based payment arrangement (in shares)                           306,807 368,707 377,775
Number of options, exercised (in shares)                           53,900    
Number of options as of including options exercised during the period (in shares)                           53,900 0  
Number of options lapsed or cancelled (in shares)                           47,265    
Number of awards lapsed or cancelled during the period (in shares)                           8,000    
OSA 2021-04                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)                           0 0  
Exercise price (in euros per share) | € / shares           € 13.74                    
Number of share options outstanding in share-based payment arrangement (in shares)                           379,132 384,132 396,200
Number of options as of including options exercised during the period (in shares)                           0 0  
OSA 2021-04 P                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)           428,000                    
Exercise price (euro per share) | € / shares           € 0                    
Exercise price (in euros per share) | € / shares           € 13.74                    
Number of share options outstanding in share-based payment arrangement (in shares)                           340,600    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           87,400    
Number of awards lapsed or cancelled during the period (in shares)                           5,000    
OSA 2021-06                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)         60,000                 0 0  
Exercise price (euro per share) | € / shares         € 0                      
Exercise price (in euros per share) | € / shares         € 12.99                      
Number of share options outstanding in share-based payment arrangement (in shares)                           60,000 120,000 120,000
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0 0  
Number of options lapsed or cancelled (in shares)                           0    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2021-06 P                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)         60,000                      
Exercise price (euro per share) | € / shares         € 0                      
Exercise price (in euros per share) | € / shares         € 12.99                      
Number of share options outstanding in share-based payment arrangement (in shares)                           60,000    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           0    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2022-06 O                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)         410,500                      
Exercise price (euro per share) | € / shares         € 0                      
Exercise price (in euros per share) | € / shares         € 4.16                      
Number of share options outstanding in share-based payment arrangement (in shares)                           362,266    
Number of options, exercised (in shares)                           17,734    
Number of options as of including options exercised during the period (in shares)                           17,734    
Number of options lapsed or cancelled (in shares)                           30,500    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2022-06 P                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)       170,400                        
Exercise price (euro per share) | € / shares       € 0                        
Exercise price (in euros per share) | € / shares       4.16                        
Number of share options outstanding in share-based payment arrangement (in shares)                           123,190    
Number of options, exercised (in shares)                           510    
Number of options as of including options exercised during the period (in shares)                           510    
Number of options lapsed or cancelled (in shares)                           46,700    
Number of awards lapsed or cancelled during the period (in shares)                           9,380    
OSA 2023-01 O                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)     338,860                          
Exercise price (euro per share) | € / shares     € 0                          
Exercise price (in euros per share) | € / shares     € 5.00                          
Number of share options outstanding in share-based payment arrangement (in shares)                           318,860    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           20,000    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2024-01 Ordinary                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)   1,224,780                            
Exercise price (euro per share) | € / shares   € 0                            
Exercise price (in euros per share) | € / shares   € 5.81                            
Number of share options outstanding in share-based payment arrangement (in shares)                           1,194,144    
Number of options, exercised (in shares)                           25,286    
Number of options as of including options exercised during the period (in shares)                           25,286    
Number of options lapsed or cancelled (in shares)                           5,350    
Number of awards lapsed or cancelled during the period (in shares)                           2,110    
OSA 2025-01                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)         8,000                 8,000    
Exercise price (euro per share) | € / shares         € 0                      
Exercise price (in euros per share) | € / shares € 3.36     3.36 € 3.36                      
Number of share options outstanding in share-based payment arrangement (in shares)                           8,000 0  
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           0    
Number of awards lapsed or cancelled during the period (in shares)                           0    
OSA 2025-02                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)         1,241,005                 1,241,005    
Exercise price (euro per share) | € / shares         € 0                      
Exercise price (in euros per share) | € / shares € 2.97     € 2.97 € 2.97                      
Number of share options outstanding in share-based payment arrangement (in shares)                           1,240,904 0  
Number of options, exercised (in shares)                           100    
Number of options as of including options exercised during the period (in shares)                           100    
Number of options lapsed or cancelled (in shares)                           1    
Number of awards lapsed or cancelled during the period (in shares)                           1    
OSA 2021-04 O                                
Disclosure of number and weighted average remaining contractual life of outstanding share options [table]                                
Number of options granted (in shares)           143,200                    
Exercise price (euro per share) | € / shares           € 0                    
Exercise price (in euros per share) | € / shares           € 13.74                    
Number of share options outstanding in share-based payment arrangement (in shares)                           38,532    
Number of options, exercised (in shares)                           0    
Number of options as of including options exercised during the period (in shares)                           0    
Number of options lapsed or cancelled (in shares)                           104,668    
Number of awards lapsed or cancelled during the period (in shares)                           0