REAL‐LIFE USE OF BENDAMUSTINE FOR B‐CELL NON‐HODGKIN LYMPHOMA IN A COMMUNITY HOSPITAL IN JAPAN—RETREATMENT WITH BENDAMUSTINE IS SAFE AND FEASIBLE

Abstract

Introduction: Bendamustine is an alkylating agent with antimetabolite properties that has little cross resistance to other alkylating agents and purine analogues. It has shown to be effective in treatment of relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) and indolent B-cell non-Hodgkin lymphomas (NHL). Combination of bendamustine with rituximab is currently actively incorporated not only in R/R settings but also in first line treatment of these diseases. Once patients relapse after bendamustine (B)-containing therapy, data is limited on whether retreatment with bendamustine is feasible. In this study, we assessed the utility of B-containing regimen in a community hospital in Japan, especially focusing on the feasibility of retreatment with bendamustine. Methods: Patients with B-NHL treated with B-containing therapy were identified from our pharmacy database. Relevant clinical information was retrospectively collected from the patients' medical record. Results: We identified 39 patients with B-NHL treated with B-containing therapy. The median age of the patients was 70 years old (range 39–88). The male to female ratio of the patients was 25:14. Twenty-nine patients were initially diagnosed as indolent B-NHL (follicular lymphoma (FL): 23, mantle cell lymphoma (MCL): 4, small lymphocytic lymphoma (SLL): 1, splenic marginal zone lymphoma (SMZL): 1), and the remaining 10 had diffuse large B-cell lymphoma (DLBCL). The median number of treatment prior to bendamustine use was 1 (range 1–17). Patients were treated with a median of 3 (range 1–66) cycles of B-containing regimen, and the overall response rate (ORR) was 59.0% (CR: 10, PR: 13, SD: 6, PD: 10). The median overall survival and progression-free survival was 60 (0.5-68.8+) months and 10 (0.3–68.6+) months, respectively. Among these patients, 10 were retreated with B-containing therapy at subsequent relapses. The median time from initial treatment was 14.8 (range 9.1–38.0) months. Seven patients had FL, 2 had DLBCL and 1 had MCL. The ORR of second bendamustine treatment was 100% (CR: 3, PR: 7). Among the 8 patients who subsequently relapsed or had progression of disease, 4 patients were further treated with B-containing regimen, and the median number of bendamustine treatment beyond first progression among all 10 patients was 5 (range 1–13) cycles. There was no apparent increase of infection after retreatment with bendamustine. Conclusions: Treatment of R/R B-NHL with B-containing therapy in a single institute yielded similar results to previous reports. Retreatment with B-containing regimen showed high response rate with few complications, making multiple retreatment possible in some patients. Bendamustine retreatment should be considered a treatment option in patients relapsed beyond first treatment with bendamustine. Keywords: B-cell lymphoma; bendamustine.