Safety and Efficacy of Bendamustine with or without Rituximab in the Treatment of Heavily Pretreated Patients with Haematological Malignancies: A Multicenter Retrospective Study

Bendamustine is an purine analog alkylating agent with marked efficacy in haematological malignancies either when given as monotherapy or in combination with rituximab. The efficacy and safety of this drug was investigated in heavily pretreated patients (pts) with hematological malignancies. A total of 44 patients (median age 63 years ranging from 22–87) from 6 Italian centers treated with bendamustine alone or in combination with rituximab were analyzed in this retrospective study. The diagnoses were multiple myeloma (n=2), chronic lymphocytic leukemia or small lymphocytic lymphoma (n=19), diffuse large B cell lymphoma (n=7), follicular lymphoma (n=8), mantle cell lymphoma (n=4), marginal zone lymphoma (n=2), Hodgkin’s disease (n=1) and peripheral T cell lymphoma (n=1). All pts received bendamustine 60–90 mg/m² at day 1+2, alone or in combination with rituximab 375 mg/m² (n=35) at day 1 of each cycle given every 21 or 28 days. The pts were heavily pretreated with a median of 3 previous treatments (range 1–8); 37 pts had previously received rituximab and 9 pts had undergone autologous transplantation. Prior to receiving bendamustine, 14 pts had relapsed disease, 7 had refractory disease and 23 were progressing during therapy. The median number of bendamustine cycles was 3 (range 1–8); 11 pts were still on treatment at the time of this analysis. Patients who completed therapy with at least 1 cycle of chemotherapy were evaluated for response and toxicity; pts in continuous therapy were evaluated for toxicity only. Of 33 pts evaluable for response 7 pts achieved a CR (21%) and 14 a PR (42%) resulting in an ORR of 64%. The remaining 12 pts were non-responders. No differences in the results were observed between groups with different bendamustine doses or scheduling. The best results were obtained in 10 evaluable pts with indolent lymphoma (4 CR, 6 PR) and in 9 pts with chronic lymphocytic leukemia (1 CR, 6 PR). Two evaluable pts with mantle cell lymphoma obtained a response (1 CR, 1 PR). By contrast, only 1 pt with diffuse large B cell lymphoma of 6 patients evaluable for response obtained a CR: the other 5 were non-responders. No pt with myeloma, Hodgkin’s disease or T cell lymphoma achieved a response. After a median follow-up of 4 months, 80% of pts were alive. During 150 treatment cycles, 2 pts experienced grade 4 thrombocytopenia and 1 experienced grade 4 neutropenia; non-hematological toxicity was mild. In conclusion, this retrospective analysis shows that treatment with bendamustine, alone or in combination with rituximab, is a safe and effective regimen in heavily pretreated pts. The best results were obtained in indolent lymphoma: the data in mantle cell lymphoma were also encouraging. No lack of efficacy can be inferred in pts with diffuse large B cell lymphoma, due to the refractory nature of their disease and the advanced age of this particular group (median age 76 years ranging from 67–87).