P187 | SINGLE-CENTER REAL-LIFE EXPERIENCE IN MULTIPLE MYELOMA PATIENTS TREATED WITH CAR-T THERAPY (IDE-CEL)

Idecabtagene vicleucel is the first chimeric antigen receptor (CAR)-T approved in Italy for the treatment of relapsed and refractory three-class exposed multiple myeloma. This therapy is showing encouraging results in heavily pretreated patients, changing the therapeutic setting for advanced disease. We report our center's experience with a retrospective analysis of the first eight patients treated with ide-cel from January 1 to April 1 2025, evaluating toxicity and response to treatment. The median age was 62 years, five patients (62%) had prior received four lines of therapy, one patient (12%) three lines and two patients (25%) five lines. Manufacturing success rate was 100% (none required second lymphapheresis or received an out-of-specification product). At the time of relapse, five patients (62%) had extramedullary disease and six (75%) had bone progression disease. A PET scan was done for all patients at the time of disease progression: in 7 out of 8 patients (87%) it showed FDG uptake at bone or extranodal sites. 50% of patients were treated with bridge therapy after lymphocytoapheresis for rapid progressive disease. Baseline, median Hematotox score was 2. Cytokine Release Syndrome (CRS) occurred in all patients post-infusion between the first and second day; in 100% of cases it was grade 1. The anti-IL6 antibody tocilizumab 8 mg/kg iv was administered to all patients, from a minimum of one dose to a maximum of three. Two cases were refractory to tocilizumab: one patient was treated with dexamethasone 20 mg iv every 6 hours, while in another patient refractory to dexamethasone, treatment with solumedrol 1 g iv every 12 hours and continuous infusion of anakinra was necessary for persistent fever. None manifested immune effector cell-associated neurotoxicity syndrome (ICANS). During hospitalization, grade 3-4 neutropenia occurred in all patients who have been treated with GCSF. Severe thrombocytopenia (G4) in only 37% of cases and grade 2-3 hypofibrinogenemia in 50% of cases and these patients received support with plasma infusions. Only five patients have undergone PET scan one month after treatment to date: three are in complete remission, two have disease progression. We report first cases of multiple myeloma treated with ide-cel, showing early toxicities of the therapy and setting the stage for larger studies.