First-line treatment with Bendamustine plus Rituximab for patients with indolent non-Hodgkin’s lymphoma or Mantle cell lymphoma: Real-world experience.

Abstract

e19540 Background: Bendamustine plus rituximab (B+R) was established as a preferred first line therapy for patients with previously untreated indolent non-Hodgkin’s lymphoma based on the BRIGHT and STIL trials. However, only few reports on efficacy and safety data of this combination in the real-world setting are available to-date. Methods: We conducted a retrospective review of patients who received therapy with standard doses of B+R in our cancer center from June 2013 to January 2021. Patients with indolent non-Hodgkin’s lymphoma (iNHL) and mantle cell lymphoma (MCL) who received more than one cycle of B+R were evaluated. Results: Amongst a total of 201 patients 56% were males and 44% females. Median age at B+R initiation was 72 years (range 34-94). Follicular lymphoma (FL) (50.3%), marginal zone lymphoma (MZL) (19.4%), and lymphoplasmacytic lymphoma (LPL) (14.5%) were the most common iNHL. Stage 3 and 4 diseases represented 19.9% and 68.6% of patients. Extranodal disease was found in 35.8%. The proportion of patients with high risk disease was 48.5% for FL (FLIPI ≥3), 86.6% for LPL (WMISS score ≥2), and 80.5% for MCL (MIPI score ≥6.2). Prior history of secondary malignancy had 23.4% of patients; 11.4% patients had ECOG 3. Most common indications for B+R initiation were bulky symptomatic lymphadenopathy (69.1%), cytopenia (36.8%) and constitutional symptoms (36.8%). Fifty-eight percent of patients had more than one indication for therapy. Median number of B+R cycles delivered was 6 (range: 1-6), median dose of bendamustine was 90 mg/m2 (range 45-90). Full doses of treatment were given in 66.7% of patients, reduced in 33.3% with mean dose 78.3 mg/m2. A total of 50.8% completed 6 cycles with no delays, in 49.2% treatment was delayed (mean delay time 1.8 weeks). Overall response was 94.5%, with 77.6% complete and 16.9% partial remission. Median duration of follow-up was 35 months (range: 4-91). At the end of follow-up, event free survival (EFS) was 77.1% and overall survival (OS) was 79.6%. Six percent of patients relapsed, 8% developed secondary hematological malignancies, including 14 cases of aggressive B-cell lymphoma and 2 cases of MDS. 16.9% of patients required support with G-CSF. Grade 3-4 neutropenia was recorded in 22.4%, febrile neutropenia in 7.5%, grade 3-4 anemia in 7.9%, and grade 3-4 thrombocytopenia in 3.9% of patients. Rituximab-associated infusion reactions, skin rash, thrombophlebitis, and infection were the most common non-hematological adverse events. A total of 80.6% of patients proceeded to rituximab maintenance. Conclusions: B+R chemoimmunotherapy is feasible to administer in non-clinical trial setting. Despite more dose reduction as compared to STIL trial, B+R retained its efficacy with comparable EFS and OS. No new adverse events or increase in secondary malignancies were found.