OBJECTIVES: To analyse effectiveness and safety of isatuximab in patients with Multiple Myeloma(MM).

METHODS: Retrospective observational study was conducted. We included patients treated with isatuximab in combination with carfilzomib-dexamethasone or pomalidomide-dexamethasone from June/2022-March/2023. Variables collected: sex, age, type of MM, staging according to the International Staging System(R-ISS), high-risk cytogenetic alterations(HRCA), disease follow-up time, receipt of autologous Hematopoietic Cell Transplantation(AHCT), drug in combination with isatuximab, duration and number of cycles, previous chemotherapy regimens, overall response rate(ORR) and progression-free survival(PFS) calculated by Kaplan-Meier method, and adverse events(AEs) reported.

RESULTS: Seven patients were analyzed(71.4% women); median age of 62 years(Interquartile range (IQR):55-70). The type of MM was: 57.1% IgG-kappa, 14.3% IgG-lambda, 14.3% IgA-kappa and 14.3% light-chain-lambda. 42.9% had R-ISS:3 and 28.6% R-ISS:2(28.5% no data recorded). 57.1% presented HRCAs(1q gain:57.1%, IgH-FGFR3-t(4;14) rearrangement:42.9% and p53 (17p13):14.3%). At the start of treatment, patients had been diagnosed for a median of 22 months(IQR:14-33) and 14.3% had received AHCT.

85.7% had isatuximab in combination with carfilzomib-dexamethasone and 14.3% pomalidomide-dexamethasone. The mean number of isatuximab cycles received was 4.3(±2), for a mean of 3.7(±2.5) months. Patients had a mean of 2.8(±1,19) previous chemotherapy lines(100% on lines including bortezomib and lenalidomide).

Regarding effectiveness, 2 patients progressed, not reaching the median PFS; at 3 months 64.3% had not progressed. ORR was partial in 28.6% of patients.

85.7% had some AE during treatment: 28.6% infusional reactions, 28.6% nausea-vomiting, and 28.6% upper respiratory tract infections. All these AEs were mild.

42.8% patients ongoing treatment, 28.6% because of progression and 28.7% to start AHCT.

CONCLUSIONS: Median PFS was not reached in our study, which prevents us from comparing the results with the pivotal trial due to the immature data. Further studies with a larger sample size and longer follow-up period are needed to confirm these real-life results.

It shows a good safety and tolerability profile in our patients.