ASH: What is the role of rituximab maintenance in patients with low tumor burden follicular lymphoma?

By Peter Martin, MD

The optimal management of patients with newly diagnosed low tumor burden follicular lymphoma is uncertain. In the pre-rituximab era, multiple randomized phase 3 trials demonstrated the acceptability of a period of observation prior to initiation of chemotherapy. This period, which typically lasted for about three years, was considered beneficial because it allowed patients to enjoy a prolonged period of time before experiencing side effects associated with treatment. The development of rituximab led some clinicians to question the value of deferred therapy.

The ECOG 4402 trial (RESORT trial), presented at the American Society of Hematology (ASH) meeting, is a phase 3 trial in which patients with newly diagnosed low tumor burden follicular lymphoma were treated with single-agent rituximab and responders were randomized to either maintenance therapy with one dose of rituximab every three months or rituximab retreatment at the time of lymphoma progression. The goal was to determine which strategy was associated with a longer duration of benefit from rituximab.

At three years of follow-up, 95% of patients receiving maintenance rituximab and 86% of patients randomized to rituximab retreatment remained free of cytotoxic chemotherapy, a significant improvement over historical strategies with observation. Interestingly, despite receiving an average of almost four times as much rituximab (15.8 doses vs. 4.5 doses), patients randomized to maintenance rituximab did not experience a longer time to treatment failure or a better quality of life than those randomized to rituximab retreatment. The investigators concluded that maintenance rituximab should not be considered standard of care in patients with low tumor burden follicular lymphoma treated with single-agent rituximab at the time of diagnosis.

Lymphoma in the News: Lenalidomide Plus Rituximab Shows Promise as First-Line Therapy in Patients with Indolent Non-Hodgkin Lymphoma

By Peter Martin, MD

The results of a phase 2 study of lenalidomide plus rituximab in patients with previously untreated indolent lymphoma were presented at the American Society of Clinical Oncology annual meeting in June 2011. Investigators at MD Anderson Cancer Center treated 75 patients (41 with follicular lymphoma, 19 with marginal zone lymphoma, 15 with chronic lymphocytic leukemia) with the combination and found that 90% of patients responded, with 66% achieving a complete response. Treatment was generally well tolerated, with only 5 patients stopping due to toxicity.

These results are exciting due both to the promising response rate and the fact that cytotoxic chemotherapy was not a part of the treatment regimen: Lenalidomide is an immunomodulatory agent and rituximab is a biologic agent/monoclonal antibody.

Currently, the CALGB is conducting a similar phase 2 trial of lenalidomide plus rituximab in patients with previously untreated follicular lymphoma. The trial is being led by Dr. Rebecca Elstrom at Weill Cornell Medical Center and will provide important confirmatory evidence in a larger group of patients treated at multiple centers around the country. (Update: this study is closed to enrollment.)

Dr. Jia Ruan at Weill Cornell is leading a study of lenalidomide plus rituximab as front-line therapy for patients with previously untreated mantle cell lymphoma (click here for more information on this trial).

A phase 3 trial comparing lenalidomide plus rituximab to chemotherapy plus rituximab in patients with previously untreated follicular lymphoma is being considered in Europe.

Lugano Conference: Rituximab + Lenalidomide Prolonged Remission in Mantle Cell Lymphoma

Weill Cornell’s Dr. Rebecca Elstrom is attending the 11th International Conference on Malignant Lymphoma in Lugano, Switzerland and provides this update:

Researchers from MD Anderson Cancer Center reported results of a study of the combination of rituximab and lenalidomide in relapsed and refractory mantle cell lymphoma (MCL) at the 11th International Conference on Malignant Lymphoma on Thursday, June 16. The study included 52 patients treated on a combined phase 1/phase II study. The researchers found that more than half (57.8%) of patients responded to treatment, and most responses lasted for at least 18 months.  The combination was very well tolerated, with few bothersome side effects.  These results are striking for this group of patients, especially as many had not responded to previous therapy.

The combination of rituximab and lenalidomide is of interest because both drugs work, at least in part, by promoting the patient’s immune system to destroy lymphoma cells, and laboratory studies have suggested that each drug may make the other work better.  In addition to mantle cell lymphoma, this combination is being investigated in other B-cell lymphoma subtypes.

Weill Cornell Medical Center is conducting a study of the combination of rituximab and lenalidomide in follicular lymphoma. The study is sponsored by The Cancer and Leukemia Group B (CALGB) and is being led at Weill Cornell  by Dr. Elstrom. (Update: this study is closed to enrollment.)