Bortezomib, Bendamustine, and Rituximab in Patients With Relapsed or Refractory Follicular Lymphoma: The Phase II VERTICAL Study

Abstract

Purpose The aims of this multicenter study were to evaluate the response rate, progression-free survival, and toxicity of the combination of bortezomib, bendamustine, and rituximab in patients with follicular lymphoma whose disease was relapsed or refractory to prior treatment. Patients and Methods Patients received five 35-day cycles of bortezomib, bendamustine, and rituximab: bortezomib administered intravenously (IV) at a dose of 1.6 mg/m2 on days 1, 8, 15, and 22, cycles one to five; bendamustine 50, 70, or 90 mg/m2 IV over a 60-minute infusion on days 1 and 2, cycles one to five; and rituximab 375 mg/m2 on days 1, 8, 15, and 22 of cycle one and day 1 of subsequent cycles. Patients were assessed using the International Workshop Response Criteria, with the primary end point of 60% complete response rate. Results Seventy-three patients were enrolled. During the dose-escalation phase, the maximum-tolerated dose for bendamustine was not reached; the 90 mg/m2 dose level was expanded for the efficacy assessment, and a total of 63 patients received bendamustine 90 mg/m2. In these 63 patients, the overall response rate was 88% (including 53% complete response). Median duration of response was 11.7 months (95% CI, 9.2 to 13.3). Median progression-free survival was 14.9 months (95% CI, 11.1 to 23.7). Toxicities were manageable; myelosuppression was the main toxicity (25% and 14% of patients experienced grade 3 to 4 neutropenia and grade 3 to 4 thrombocytopenia, respectively). Transient grade 3 to 4 neuropathy occurred in 11% of patients. Conclusion The combination of bortezomib, bendamustine, and rituximab is highly active in patients with follicular lymphoma who have received previous treatment.