Share-based payments - Summary of Employee Related Share Based Compensation Expense (Detail) - EUR (€) € in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Disclosure Of Detailed Information About Share Based Compensation Expense [Line Items] | ||||
| Share-based compensation expenses | € (5,068) | € (4,141) | € (10,977) | € (8,471) |
| Research and development expenses [Member] | ||||
| Disclosure Of Detailed Information About Share Based Compensation Expense [Line Items] | ||||
| Share-based compensation expenses | (3,050) | (2,066) | (6,191) | (4,220) |
| General and administrative expenses [Member] | ||||
| Disclosure Of Detailed Information About Share Based Compensation Expense [Line Items] | ||||
| Share-based compensation expenses | € (2,018) | € (2,075) | € (4,786) | € (4,251) |