Cytomegalovirus Occurrence and Time-to-onset Analysis Under Bendamustine With Anti-CD20 Antibodies Using the JADER Database

Background/Aim: Patients with malignant lymphoma, in a latent state of weakened immune function, are at risk of chemotherapy -induced immunosuppression and cytomegalovirus (CMV) infection. Concomitant therapy with bendamustine and rituximab or obinutuzumab intensifies immunosuppression, potentially affecting CMV onset. This study aimed to assess CMV onset differences between bendamustine monotherapy and combination therapy with rituximab or obinutuzumab using the Japanese Adverse Drug Event Report database (JADER). Patients and Methods: A JADER analysis dataset (April 2004 to September 2022) defined CMV infection using 31 preferred term (PT) words from MedDRA 25.1J HLT "Cytomegalovirus infection (10011827)". Reporting odds ratios (ROR) calculated CMV infection signals for bendamustine monotherapy, rituximab, obinutuzumab, bendamustine+rituximab (BR), and bendamustine+obinutuzumab (GB). ROR confidence intervals exceeding 1 indicated a CMV signal. Days of CMV infection were calculated based on adverse event onset and administration start. Results: CMV signals were confirmed for monotherapy and combination therapies. CMV infection durations (median, interquartile range) were 41.0 days (23.569.5) for bendamustine monotherapy, 63.5 days (35.2-95.0) for BR, and 61.0 days (33.0-102.5) for GB, with cases exceeding 200 days. Conclusion: JADER analysis detected significant CMV signals for rituximab, obinutuzumab, and bendamustine. Caution may be warranted 7-9 months post-bendamustine administration, necessitating further investigation, including cell -mediated immunity suppression assessment.