Bendamustine, bortezomib and rituximab produces durable complete remissions in patients with previously untreated, low grade lymphoma.

This Phase II trial evaluated the efficacy of bendamustine, bortezomib and rituximab in patients with previously untreated low-grade lymphoma. Eligible patients had low grade lymphoma with no previous systemic disease treatment. Treatment for all patients was given in 28-day cycles for a maximum of 6 cycles. Patients received rituximab 375 mg/m2 intravenously (IV) on days 1, 8 and 15 of cycle 1 and day 1 of cycles 2-6; bendamustine 90 mg/m2 IV on days 1 and 2; and bortezomib 1·6 mg/m2 IV on days 1, 8 and 15. Patients were permitted to begin maintenance treatment with rituximab 6 months after completion of study treatment and after 6-month follow-up assessments had been conducted. Fifty-four eligible patients were enrolled. The most common grade 3/4 toxicities were leucopenia (28%), neutropenia (30%) and lymphopenia (17%). There were no treatment-related deaths and 1 unrelated death on study (embolic stroke). The overall response rate was 94% for all patients. The median follow-up was 54 months. Kaplan-Meier estimates of progression-free survival and overall survival at 36 months were 75% and 88%, respectively. The treatment regimen was well tolerated and produced high response rates. Further study of this regimen in patients with previously untreated lymphoma is warranted.