v3.25.2
Shareholders' equity (Details)
€ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended
Jun. 11, 2025
EUR (€)
Apr. 07, 2025
USD ($)
shares
Apr. 07, 2025
EUR (€)
€ / shares
shares
Mar. 27, 2025
EUR (€)
session
€ / shares
shares
Jun. 30, 2025
USD ($)
shares
Mar. 31, 2025
USD ($)
Jun. 30, 2024
USD ($)
Mar. 31, 2024
USD ($)
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2025
EUR (€)
€ / shares
shares
Apr. 06, 2025
EUR (€)
shares
Dec. 31, 2024
€ / shares
Dec. 31, 2024
USD ($)
shares
Dec. 31, 2023
USD ($)
Class of Stock [Line Items]                            
Common stock, value, issued     € 13,694,887.2   $ 15,393       $ 15,393 € 13,697,370 € 10,285,886.8   $ 11,651  
Common stock, shares oustanding (in shares)         136,973,697       136,973,697 136,973,697        
Common stock shares par value (in Euro per share) | € / shares     € 0.10             € 0.1   € 0.1    
Accumulated deficit € 102,284,799.3       $ 315,136       $ 315,136       286,375  
Allocation of accumulated net losses | $         0 $ 0 $ 0 $ 0            
Equity | $         (86,224) (2,873) (79,095) (111,654) $ (86,224)       $ (27,387) $ (140,187)
Number of consecutive trading session | session       5                    
Number of total trading session | session       30                    
Volume average price | € / shares       € 0.8989                    
Discount rate for exercise price       15.00%                    
Discounted volume average price | € / shares       € 0.7641                    
Issuance of ordinary shares | $         $ 30,982 0 0 0            
Common stock shares issued (in shares)     136,948,872   136,973,697       136,973,697 136,973,697 102,858,868   102,847,501  
Additional paid-in capital                            
Class of Stock [Line Items]                            
Allocation of accumulated net losses 35,154,861.25       $ 40,193   66,433              
Equity | $         (391,546) (317,313) (314,513) (379,426) $ (391,546)       $ (315,613) (377,468)
Issuance of ordinary shares | $         27,241 (1) (6)              
Accumulated deficit                            
Class of Stock [Line Items]                            
Allocation of accumulated net losses | $         (40,193)   (66,433)              
Equity € 67,129,938.05       $ 315,136 $ 313,454 $ 232,890 $ 266,207 $ 315,136       $ 286,375 $ 238,862
ABSA warrants                            
Class of Stock [Line Items]                            
Warrant shares to warrants, ratio       1.75                    
Class of warrant or right, exercise price of warrants or rights (in euro per share) | € / shares     € 1.1136 € 1.5939                    
Stock issued during period (in shares)   34,090,004 34,090,004                      
Shares issued (in dollars/euro per share) | € / shares     € 0.10                      
Issuance of ordinary shares   $ 42,000 € 38,000,000                      
Prefunded PFW-BS-PFW                            
Class of Stock [Line Items]                            
Class of warrant or right, unissued (in shares)     1 1                    
Class of warrant or right, exercise price of warrants or rights (in euro per share) | € / shares     € 1.1036                      
First prefunded warrants                            
Class of Stock [Line Items]                            
Class of warrant or right, number of securities called by each warrant or right (in shares)     1 1 1       1 1        
Class of warrant or right, exercise price of warrants or rights (in euro per share) | € / shares       € 0.01                    
BS Warrants                            
Class of Stock [Line Items]                            
Class of warrant or right, unissued (in shares)     1 1                    
Second prefunded warrants                            
Class of Stock [Line Items]                            
Warrant shares to warrants, ratio     1.75 1.75 1.75       1.75 1.75        
Class of warrant or right, number of securities called by each warrant or right (in shares)     1 1                    
ABSA                            
Class of Stock [Line Items]                            
Class of warrant or right, exercise price of warrants or rights (in euro per share) | € / shares       € 1.1136                    
Share issuance premium, percentage       23.89%                    
Stock issued during period (in shares)       34,090,004                    
Shares issued (in dollars/euro per share) | € / shares       € 0.10                    
Exercise price of issue premium (in euro per share) | € / shares       € 1.0136                    
Issuance of ordinary shares | €       € 3,409,000.4                    
PFW-BS-PFW                            
Class of Stock [Line Items]                            
Class of warrant or right, exercise price of warrants or rights (in euro per share) | € / shares     € 1.1136 € 1.1136                    
Stock issued during period (in shares)   71,005,656 71,005,656 71,005,656                    
Issuance of ordinary shares   $ 86,000 € 79,000,000                      
Maximum                            
Class of Stock [Line Items]                            
Deferred compensation arrangement with Individual, shares authorized for issuance       28,929,000                    
Maximum | First prefunded warrants                            
Class of Stock [Line Items]                            
Stock issued during period (in shares)   71,005,656 71,005,656           71,005,656          
Maximum | Second prefunded warrants                            
Class of Stock [Line Items]                            
Stock issued during period (in shares)   124,259,898 124,259,898           124,259,898