The combination of bendamustine, bortezomib, and rituximab for patients with relapsed/refractory indolent and mantle cell non-Hodgkin lymphoma

Given the significant activity and tolerability of bendamustine, rituximab, and bortezomib in patients with relapsed indolent and mantle cell non-Hodgkin lymphoma, and laboratory studies suggesting synergistic activity, we conducted a multicenter phase 2 study of the bendamustine/bortezomib/rituximab combination. Patients with relapsed or refractory indolent and mantle cell lymphoma with adequate organ function were treated with bendamustine 90 mg/m² days 1 and 4; rituximab 375 mg/m² day 1, and bortezomib 1.3 mg/m ² days 1, 4, 8, 11. Six 28-day cycles were planned. Thirty patients (7 with mantle cell lymphoma) were enrolled and treated. Eight patients experienced serious adverse events, including one event of grade 5 sepsis. Common nonhematologic adverse events were generally grade 1 or grade 2 and included nausea (50%), neuropathy (47%), fatigue (47%), constipation (40%), and fever (40%). Of 29 patients evaluable for efficacy, 24 (83%) achieved an objective response (including 15 with complete response). With median follow-up of 24 months, 2-year progression-free survival is 47% (95% confidence interval, 25%-69%). On the basis of these promising results, the US cooperative groups have initiated randomized trials to evaluate this regimen in follicular and mantle cell lymphoma. This trial was registered at www.clinicaltrials.gov as #NCT00547534.