Abstract
INTRODUCTION: B-cell maturation antigen-targeting bispecific antibodies such as teclistamab have been associated with increased risk of infections as compared with conventional treatment regimens. This study explored the efficacy of intravenous immunoglobulin (IVIG) prophylaxis in reducing infection-related hospitalizations (IRHs) in MM patients who underwent treatment with teclistamab. METHODS: This was a retrospective study of MM treated with teclistamab at Taussig Cancer Center from December 16, 2022, to March 31, 2024. The primary endpoint was incidence rate of IRHs per patient-day on-IVIG vs. off-IVIG. RESULTS: Among the 44 patients included in the study, there were 19 infectious episodes that required inpatient hospitalization, occurring among 17 patients. Five infections occurred during 4,378 days during the "on-IVIG" period, compared to 14 infections occurring during 4,619 days for the "off-IVIG" period for an infectious incidence rate ratio between the two groups of 2.65 (p value = 0.027). CONCLUSION: Patients treated with bispecific antibodies such as teclistamab are highly susceptible to infections due to impaired humoral immunity and hypogammaglobulinemia. Our findings demonstrate a reduction in infection incidence in patients while receiving IVIG. These results support the use of IVIG as an effective prophylactic strategy to reduce infectious risk in this vulnerable patient population.