Cytomegalovirus Infection After Chimeric Antigen Receptor T‐Cell Therapy or Bispecific Antibody Treatment for Hematologic Malignancies

ABSTRACT Background Limited data exists on the incidence of CMV infections after chimeric antigen receptor (CAR) T‐cell or bispecific antibody (BsAb) therapy for hematologic malignancies. Methods We reviewed medical records of patients with hematologic malignancies treated with CAR T‐cells or BsAbs between July 2018 and October 2024 in a tertiary hospital in Seoul, South Korea. CMV infections were detected using CMV DNA qPCR assays performed within 180 days after CAR T‐cell infusion or the last BsAb treatment. Secondary outcomes were the occurrence of clinically significant CMV infections (CS‐CMVi) and end‐organ diseases. Results Of 179 patients, 76 (42%) received CAR T‐cell therapy, and 103 (58%) received BsAb therapy. The incidence of CMV infection was 62% in BsAb recipients, and 43% in CAR T‐cell recipients. Two (6.1% of total CMV infections) CAR T‐cell recipients had CS‐CMVi, and 1 (3.0%) developed possible CMV pneumonia. In the BsAb group, 10 (16% of total CMV infections) patients received antiviral therapy, and 4 (6.3%) had end‐organ diseases. Receiving three or more previous systemic chemotherapy regimens in the CAR T‐cell group was associated with increased CMV infection risks (HR 4.7, 95% CI 1.88–11.8, p < 0.001), and older age in the BsAb group had a trend toward having more CMV infection (HR 1.02, 95% CI 1.00–1.05, p = 0.06). Conclusion Approximately 43% and 62% of patients receiving CAR T‐cell and BsAb therapy had CMV infection, with 1%–4% developing CMV diseases. Effective strategies for preventing CMV infections in these patients are warranted.