eng Science and Education Publishing American Journal of Medical and Biological Research 2328-4099 2024-12-13 12 2 73 80 10.12691/ajmbr-12-2-6 AJMBR20241226 article Haylaa Parqi 1 Dahbah Alkaabi 1 Saadah Tanoon 1 Kholod Naseri 1 Azizah Aljwen 1 Meshal Alotaibi 1 Laila Alsulobi Lalsoipi@moh.gov.sa 1 Nursing, Ministry of Health, Riyadh, Saudi Arabia B-cell-maturation-antigen (BCMA)-directed therapies are highly active for multiple myeloma, but infections are emerging as a major challenge. In this retrospective, single-center analysis we evaluated infectious complications after BCMA-targeted chimeric-antigen-receptor T-cell therapy (CAR-T), bispecific-antibodies (BsAb) and antibody-drug-conjugates (ADC). The primary endpoint was severe (grade ¡Ý3) infection incidence. Amongst 256 patients, 92 received CAR-T, 55 BsAb and 109 ADC. The incidence of severe infections was higher with BsAb (40%) than CAR-T (26%) or ADC (8%), including grade 5 infections (7% vs 0% vs 0%, respectively). Comparing T-cell redirecting therapies, the incidence rate of severe infections was significantly lower with CAR-T compared to BsAb at 1-year (incidence-rate-ratio [IRR]?=?0.43, 95%CI 0.25?0.76, P?=?0.004). During periods of treatment-emergent hypogammaglobulinemia, BsAb recipients had higher infection rates (IRR:2.27, 1.31?3.98, P?=?0.004) and time to severe infection (HR 2.04, 1.05¨C3.96, P?=?0.036) than their CAR-T counterparts. During periods of non-neutropenia, CAR-T recipients had a lower risk (HR 0.44, 95%CI 0.21?0.93, P?=?0.032) and incidence rate (IRR:0.32, 95% 0.17¨C0.59, P?<?0.001) of severe infections than BsAb. In conclusion, we observed an overall higher and more persistent risk of severe infections with BsAb. Our results also suggest a higher infection risk during periods of hypogammaglobulinemia with BsAb, and with neutropenia in CAR-T recipients. https://pubs.sciepub.com/ajmbr/12/2/6/ajmbr-12-2-6.pdf BCMA therapies ADC