Clinical Outcome of Patients Receiving Rituximab in Combination with Bendamustine in Indolent B-cell Lymphomas: A Single-center Institutional Study

Introduction: Indolent non-Hodgkin's lymphomas (NHLs) are a diverse category of malignancies characterized by a chronic relapsing-remitting disease course. In the modern era, patients usually receive a combination of bendamustine plus rituximab as the initial therapy, otherwise known as an R-Benda regimen. While clinical trials have demonstrated R-Benda to be superior to other regimens, our study aims to provide insight into real-world outcomes of R-Benda therapy.Materials and methods: We conducted a retrospective study for January 2015-July 2022 among patients receiving R-Benda for indolent NHLs at the Aga Khan University Hospital, Karachi, Pakistan. All patients underwent pre- and post-treatment assessment through positron emission tomography scan and computed tomography (CT) imaging. The response to treatment was assessed, and the overall survival (OS) and progression-free survival (PFS) were assessed using a Kaplan-Meier survival analysis.Results: We enrolled 118 patients, out of which the majority were elderly males (64%). The 2-year follow-up rate was 76.3% (n = 90), and the median follow-up time was 29 months. The most common histopathology encountered was follicular lymphoma (52%) presenting with stage IV disease (56%). Approximately 73% experienced a complete metabolic response to the treatment. Of these, 31.4% subsequently experienced a relapse. In addition, 17.7% of patients underwent a partial response, while 7% had refractory disease. The mean OS was 140 months (95% CI: 120-160), while the lower quartile value was 50 months. On the other hand, the median PFS was 80 months (95% CI: 43-N/A).Conclusion: Our study demonstrated that patients on R-Benda had good clinical outcomes, with the vast majority living beyond 50 months. Moreover, 76.1% had no disease progression for the first 2 years. It adds to the existing body of literature that demonstrates that in real-world experience, the outcomes of R-Benda treatment are better than those reported by earlier randomized-control trials.