Pharmacists Help Reduce Infection Risk During Bispecific Antibody Treatment for Multiple Myeloma

Infection Risk Extends Beyond Initial Dosing

Bispecific antibodies have expanded treatment options for relapsed or refractory multiple myeloma by redirecting T cells toward targets expressed on malignant plasma cells. Their activity also creates sustained immune dysfunction that can leave patients vulnerable to serious bacterial, viral, and opportunistic infections.¹

B-cell maturation antigen (BCMA)-directed agents can suppress normal plasma cells and reduce functional immunoglobulin production. Prior treatment, active disease, corticosteroid exposure, and treatment-related cytopenias add to this risk. Infections can occur well after step-up dosing, making longitudinal prevention as important as initial monitoring for cytokine release syndrome.^1,2

Current prescribing information for teclistamab-cqyv (Tecvayli; Janssen Biotech) and elranatamab-bcmm (Elrexfio; Pfizer) warns that severe, life-threatening, or fatal infections can occur. Both labels direct clinicians to monitor patients before and during treatment, administer prophylactic antimicrobial therapy according to applicable guidelines, and withhold treatment based on infection severity.^3,4

Establishing a Baseline Prevention Plan

Pharmacists can help establish an individualized prevention plan before the first dose. Baseline assessment should address infection history, previous antimicrobial exposure, vaccination status, immunoglobulin levels, and complete blood cell counts. Screening for hepatitis B virus is also important because T-cell–redirecting therapy can contribute to viral reactivation in susceptible patients. Additional testing should reflect the patient’s history and institutional protocol.^1,2

Expert recommendations support herpes simplex virus and varicella-zoster virus prophylaxis during bispecific antibody treatment. Pneumocystis jirovecii pneumonia prophylaxis is also recommended because severe cases have occurred in patients receiving these therapies.^1,2

Routine antibacterial prophylaxis is not necessary for every patient. It can be considered during prolonged neutropenia or for patients with recurrent bacterial infections. Antifungal prophylaxis is generally reserved for patients with prolonged severe neutropenia, a previous fungal infection, or another substantial risk factor.^1,2

These decisions require medication reconciliation and continued reassessment. Renal function can affect the selection and dosing of antiviral or antimicrobial agents, whereas cytopenias may make certain options less appropriate. Pharmacists can identify interactions, recommend alternatives, and confirm that prophylaxis continues for the intended duration.

Monitoring Immunoglobulins and Considering Replacement

Hypogammaglobulinemia is a central concern with BCMA-directed bispecific antibodies. Immunoglobulin G (IgG) levels should be measured at baseline and monitored during treatment, but results should be interpreted alongside the patient’s infection history.¹

Expert guidance supports immunoglobulin replacement for patients with IgG levels below 400 mg/dL and for selected patients who experience recurrent or severe infections despite antimicrobial management. Real-world evidence strengthens the rationale for timely intervention. In a retrospective analysis of patients receiving anti-BCMA bispecific antibodies, intravenous immunoglobulin use was associated with a 90% reduction in the rate of grade 3 or higher infections during periods of supplementation.^1,5

The study did not establish the optimal threshold, dose, or treatment duration for every patient. Its findings show why pharmacists should monitor trends rather than wait for repeated hospitalizations. Documentation should include IgG levels, infection frequency, antimicrobial courses, treatment interruptions, and the patient’s response to immunoglobulin replacement.

Vaccination Requires Deliberate Timing

Patients should receive recommended inactivated vaccines, including influenza, COVID-19, pneumococcal, and recombinant zoster vaccines, preferably before bispecific antibody treatment begins. Immune responses may be weaker after therapy starts, but reduced immunogenicity does not eliminate the potential benefit of vaccination.^1,2

Live vaccines should be avoided during treatment and until immune recovery is established. Pharmacists can review vaccination records, distinguish live vaccines from nonlive products, and coordinate administration with the broader treatment schedule. Vaccination should complement prophylaxis and monitoring rather than replace them.¹

Pharmacists Connect Prevention With Rapid Response

Patient education is essential because fever may reflect infection, cytokine release syndrome, or both, particularly during initial dosing. Patients should know which symptoms require immediate contact and should not attempt to manage a persistent fever with antipyretics alone. New respiratory symptoms, confusion, urinary complaints, or localized pain also warrant prompt evaluation.

At each treatment encounter, pharmacists can review blood counts, IgG levels, prophylactic medications, vaccination needs, and recent infections. This repeated surveillance helps the care team identify changing risks before an infection becomes severe or disrupts treatment.

Bispecific antibodies have made deep responses possible for patients with heavily treated multiple myeloma. Protecting those responses requires infection prevention to remain embedded in care from the first dose through long-term follow-up.

REFERENCES

1. Raje N, Anderson K, Einsele H, et al. Monitoring, prophylaxis, and treatment of infections in patients with MM receiving bispecific antibody therapy: consensus recommendations from an expert panel. Blood Cancer J. 2023;13(1):116. Published 2023 Aug 1. doi:10.1038/s41408-023-00879-7

2. Mohan M, Chakraborty R, Bal S, et al. Recommendations on prevention of infections during chimeric antigen receptor T-cell and bispecific antibody therapy in multiple myeloma. Br J Haematol. 2023;203(5):736-746. doi:10.1111/bjh.18909

3. Tecvayli (teclistamab-cqyv) [prescribing information]. Janssen Biotech, Inc; 2026. Accessed September 23, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/761291s018lbl.pdf

4. Elrexfio (elranatamab-bcmm) [prescribing information]. Pfizer Inc; 2025. Accessed September 23, 2026. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/761345s007lbl.pdf

5. Lancman G, Parsa K, Kotlarz K, et al. IVIg Use Associated with Ten-Fold Reduction of Serious Infections in Multiple Myeloma Patients Treated with Anti-BCMA Bispecific Antibodies. Blood Cancer Discov. 2023;4(6):440-451. doi:10.1158/2643-3230.BCD-23-0049