Maximizing therapeutic benefit of rituximab: maintenance therapy versus re-treatment at progression in patients with indolent non-Hodgkin's lymphoma--a randomized phase II trial of the Minnie Pearl Cancer Research Network.

PURPOSE: To compare the benefit of maintenance rituximab therapy versus rituximab re-treatment at progression in patients with previously treated indolent non-Hodgkin's lymphoma.

PATIENTS AND METHODS: Between June 1998 and August 2002, 114 patients who had received previous chemotherapy for indolent non-Hodgkin's lymphoma were treated with a standard 4-week course of rituximab. Patients with objective response or stable disease were randomly assigned to receive either maintenance rituximab therapy (standard 4-week courses administered at 6-month intervals) or rituximab re-treatment at the time of lymphoma progression. The duration of rituximab benefit was measured from the date of first rituximab treatment until the date other treatment was required.

RESULTS: Ninety (79%) of 114 patients had objective response or stable disease after initial rituximab treatment, and were randomly assigned to treatment. Progression-free survival was prolonged in the maintenance group (31.3 v 7.4 months; P = .007). Final overall and complete response rates were higher in the maintenance group. Duration of rituximab benefit was similar in the maintenance and re-treatment groups (31.3 v 27.4 months, respectively). More maintenance patients remain in continuous remission, and more are currently in complete remission. Both treatment approaches were well tolerated.

CONCLUSION: In patients who have objective response or stable disease with single-agent rituximab therapy, duration of rituximab benefit is substantially prolonged with either scheduled maintenance treatment or rituximab re-treatment at the time of progression. At present, the magnitude of benefit with either approach appears similar. However, additional follow-up of this trial is required, and completion of phase III randomized trials is necessary to definitively answer this question.