Increased Campylobacter Infections in Multiple Myeloma Patients on BCMA/GPRC5D Bispecific Antibodies

Overview

In a cohort of 85 relapsed/refractory multiple myeloma patients treated with bispecific antibodies targeting BCMA and GPRC5D, 9 patients developed Campylobacter spp. infections, including bloodstream and gastrointestinal episodes. This finding highlights a significant infection risk linked to therapy-induced hypogammaglobulinemia and immunosuppression.

Background

Relapsed/refractory multiple myeloma remains challenging to treat, with bispecific antibodies (BiAbs) targeting BCMA and GPRC5D emerging as promising therapies. These antigens are overexpressed on malignant plasma cells but also present on normal plasma cells, leading to hypogammaglobulinemia and increased infection susceptibility. Campylobacter spp. infections are recognized complications in immunocompromised hosts, yet their incidence in this patient population has not been systematically quantified. Understanding infection risks is critical to optimizing patient management and preventive strategies.

Data Highlights

Key Findings

• Bispecific antibodies targeting BCMA and GPRC5D effectively treat refractory multiple myeloma but cause hypogammaglobulinemia by depleting normal plasma cells.
• Among 85 treated patients, 9 developed Campylobacter spp. infections, indicating a notable incidence in this immunocompromised cohort.
• Infections included 5 bloodstream and 5 gastrointestinal episodes, underscoring systemic and localized vulnerability.
• Hypogammaglobulinemia and baseline immunosuppression contribute significantly to infection risk.
• Standardized microbiological methods confirmed Campylobacter species and antimicrobial susceptibility profiles.
• There is an urgent need for targeted infection surveillance and preventive strategies in patients receiving these therapies.

Clinical Implications

Clinicians should be vigilant for Campylobacter infections in multiple myeloma patients treated with BCMA/GPRC5D bispecific antibodies, especially given the therapy-induced hypogammaglobulinemia. Regular monitoring of immunoglobulin levels and early microbiological testing for gastrointestinal and bloodstream infections are recommended. Consideration of prophylactic measures and intravenous immunoglobulin therapy may help mitigate infection risk.

Conclusion

Bispecific antibody therapies targeting BCMA and GPRC5D in refractory multiple myeloma patients are associated with a significant incidence of Campylobacter infections, reflecting the immunosuppressive impact of treatment. These findings emphasize the need for enhanced infection surveillance and preventive interventions in this vulnerable population.

References

1. Clinical Report 2025 -- Increased Incidence of Campylobacter spp. Infections Linked to Bispecific Antibodies Targeting BCMA and GPRC5D