v3.26.1
Intangible assets - Additional Information (Details)
$ in Thousands
1 Months Ended 12 Months Ended 89 Months Ended
Jun. 30, 2024
EUR (€)
Aug. 02, 2022
USD ($)
Feb. 05, 2014
EUR (€)
Jul. 31, 2023
EUR (€)
Jun. 30, 2023
EUR (€)
Oct. 31, 2022
EUR (€)
Aug. 31, 2022
USD ($)
Jan. 31, 2022
EUR (€)
Oct. 31, 2020
EUR (€)
Jun. 30, 2020
EUR (€)
Jun. 30, 2020
USD ($)
Apr. 30, 2020
EUR (€)
Jun. 30, 2019
EUR (€)
Apr. 30, 2016
EUR (€)
Dec. 31, 2025
EUR (€)
Dec. 31, 2024
EUR (€)
Dec. 31, 2023
EUR (€)
Dec. 31, 2022
EUR (€)
Dec. 31, 2018
EUR (€)
Dec. 31, 2018
USD ($)
Dec. 31, 2015
EUR (€)
Dec. 31, 2025
EUR (€)
Dec. 31, 2018
USD ($)
Jul. 31, 2017
EUR (€)
Disclosure of detailed information about intangible assets [line items]                                                
Intangible assets other than goodwill                             € 0 € 0 € 416,000 € 1,553,000       € 0    
Purchase of intangible assets                             0 0 2,000,000              
Additions considerations                             0 0 2,000,000              
Impairment of intangible assets                             0 0 0              
Financial liabilities                             22,571,000 30,995,000 € 39,893,000 42,251,000       22,571,000    
Monalizumab rights under the 2014 monalizumab (NKG2A) Novo Nordisk agreement                                                
Disclosure of detailed information about intangible assets [line items]                                                
Intangible assets other than goodwill     € 7,000,000                                          
Purchase of intangible assets                                     € 13,050,000 $ 15,000 € 6,325,000      
2014 Novo Nordisk A/S monalizumab agreement                                                
Disclosure of detailed information about intangible assets [line items]                                                
Intangible assets other than goodwill     7,000,000.0                       0 0           0    
Purchase of intangible assets     € 2,000,000.0                     € 6,500,000                    
Financial liabilities                                     € 13,100,000       $ 15,000  
IPH5201 (Anti-CD39) rights acquired from Orega Biotech                                                
Disclosure of detailed information about intangible assets [line items]                                                
Intangible assets other than goodwill                               € 1,800,000                
Additions considerations       € 2,000,000.0   € 600,000   € 400,000   € 200,000   € 2,500,000 € 7,000,000.0                      
Licensing agreement, maximum milestone payment                             47,000,000                  
IPH5201 agreement, with AstraZeneca                                                
Disclosure of detailed information about intangible assets [line items]                                                
Milestone payment received | $   $ 5,000         $ 5,000       $ 5,000                          
PH5401 (anti-C5aR) rights acquired from Novo Nordisk A/S                                                
Disclosure of detailed information about intangible assets [line items]                                                
Intangible assets other than goodwill                                               € 40,000,000
Payments for milestone                 € 1,000,000.0                              
Impairment of intangible assets                                   € 41,000,000       0    
Financial liabilities                             € 0             € 0    
IPH6101 agreement, with Sanofi                                                
Disclosure of detailed information about intangible assets [line items]                                                
Milestone payment received € 4,000,000       € 2,000,000.0                                      
Milestone payments, percentage                             15.00%                  
Milestone payments, maximum amount                             € 40,000,000