# Flat dose intravenous immunoglobulin primary infection prophylaxis in multiple myeloma patients on BCMA and GPRC5D bispecific antibody therapy: the Vanderbilt experience

## TL;DR

This study examines the use of flat-dose IVIG to prevent infections in multiple myeloma patients receiving bispecific antibody therapy.

## Contribution

The study introduces flat-dose IVIG as a feasible alternative to weight-based IVIG for infection prophylaxis in this patient group.

## Key findings

- 73% of patients experienced at least one infection, and 43% had two or more.
- 27% of infections were classified as grade three or higher in severity.
- Flat-dose IVIG was found to be feasible for primary infection prophylaxis.

## Abstract

Bispecific antibodies (BsAbs) can cause profound hypogammaglobulinemia. Conventional infection prophylaxis has utilized weight-based IVIG dosing. However, the use of flat IVIG dosing can significantly reduce IVIG utilization. We evaluated hypogammaglobulinemia and infection risk in relapsed/refractory multiple myeloma (RRMM) patients treated with BsAbs who received flat-dose IVIG for primary infection prophylaxis. Among thirty patients, 73% had ≥1 and 43% had ≥2 infectious episodes. By severity, 27% of infections were CTCAE v5 grade three or higher and there were 2 sepsis-related deaths. Overall, flat-dose IVIG demonstrates feasibility for primary infection prophylaxis in RRMM patients receiving BsAbs.