# Feasibility of Salvage Therapy With High-Dose Bendamustine and Rituximab Based on a Series of Two Cases From a Planned Phase II Trial for Relapsed/Refractory Diffuse Large B-cell Lymphoma

## TL;DR

This study shows that high-dose bendamustine and rituximab can effectively mobilize stem cells in two patients with relapsed or refractory lymphoma.

## Contribution

The study demonstrates the feasibility of BR120 salvage therapy for stem cell mobilization in R/R DLBCL patients.

## Key findings

- Both enrolled patients achieved successful stem cell mobilization and collection.
- BR120 salvage therapy showed a 100% mobilization-adjusted response rate.
- Grade 3-4 adverse events like lymphopenia were observed in both patients.

## Abstract

Background: High-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (HDC/AHSCT) is an important option to improve the prognosis of relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL). Combination therapy of bendamustine and rituximab (BR120: 120 mg/m2/day bendamustine for two consecutive days, with 375 mg/m2 rituximab) has shown good efficacy against R/R DLBCL. However, its myelosuppressive effects may impair subsequent hematopoietic stem cell (HSC) mobilization and collection.

Methods: This study involved patients treated at two institutions: the Department of Hematology, Iwate Prefectural Central Hospital (Iwate, Japan), and the Department of Hematology and Oncology, Japanese Red Cross Society Himeji Hospital (Hyogo, Japan). To evaluate the feasibility of HSC mobilization and the efficacy and safety of BR120 combined with G-CSF and plerixafor, we conducted a multicenter, open-label, phase II clinical study of BR120 salvage therapy in patients with R/R DLBCL indicated for HDC/AHSCT. Patients underwent HSC collection and continued BR120 therapy for up to four cycles. The expected number of patients enrolled in the 11 participating institutions is 20.

Results: Only two patients were enrolled in the study. However, both also achieved a target harvest of 2×106 cells/kg of CD34+ cells within 2 days of apheresis. The mobilization-adjusted response rate was 100%. Grade 3-4 adverse events included lymphopenia in both patients.

Conclusion: We could achieve successful mobilization and stem cell collection with BR120 salvage therapy in two cases.