A phase 2 study of rituximab, bendamustine, bortezomib and dexamethasone for first line treatment of older patients with mantle cell lymphoma

We present results of a prospective, multicenter, phase II study evaluating rituximab, bendamustine, bortezomib and dexamethasone as first-line treatment for mantle cell lymphoma patients of 65 years or older. A total of 74 patients were enrolled (median age, 73 years). Patients received a maximum of 6 treatment cycles at 28 day intervals. The primary objective was to achieve an 18 month progression-free-survival of ≥ to 65%. Secondary objectives were to evaluate toxicity and the mantle cell lymphoma prognostic index, Ki67 expression, [18F]fluorodeoxyglucose-positron emission tomography and molecular minimal residual disease, in peripheral blood or bone marrow, for prognostic impact. With a median follow-up of 52 months, the 24 month progression free survival rate was 70%, hence the primary objective was reached. After 6 cycles, 91% (54/59) of responding patients were analyzed for peripheral blood residual disease and 87% of these (47/54) were negative. Four year overall survival rates, for blood molecular residual disease negative patients at treatment end, were 86.6% and 28.6%, respectively (P