Time to treatment response in patients with follicular lymphoma treated with bortezomib is longer compared with other...

To determine the antitumor activity of the novel proteasome inhibitor bortezomib in patients with indolent non-Hodgkin's lymphoma.

Patients with follicular lymphoma (FL), marginal zone lymphoma, mantle cell lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, and Waldenstrom's macroglobulinemia were eligible for study. Bortezomib was given at a dose of 1.5 mg/m(2) as an i.v. push on days 1, 4, 8, and 11 of a 21-day cycle. Eligibility included the following: (a) no more than three prior therapies, (b) at least 1 month since prior chemotherapy, (c) measurable disease, and (d) an absolute neutrophil count of >1,000/microL and a platelet count >50,000/microL for the first dose of any cycle.

Seventy-seven patients were registered, of which 69 were assessable for response based on the completion of two cycles of therapy. Subtypes included FL (59.5%), mantle cell lymphoma (52%), small lymphocytic lymphoma/chronic lymphocytic leukemia (16.2%), marginal zone lymphoma (21.6%), and one Waldenstrom's macroglobulinemia. The median number of prior therapies was three. The most common grade 3 toxicity was lymphopenia (35%) and thrombocytopenia (31%). Twenty-five patients experienced grade

These data suggest that bortezomib has significant single agent activity in patients with FL, and that longer durations of treatment may improve overall response.