David G. Maloney, MD, PhD

Recent trials have demonstrated improvements in progression-free and overall survival with the inclusion of the chimeric anti-CD20 monoclonal antibody rituximab (Rituxan) in chemotherapy regimens for treatment-naive and relapsed patients with advanced-stage follicular non-Hodgkin's lymphoma (NHL). As rituximab therapy has significant single-agent activity in follicular NHL, is generally well tolerated, and has no dose-limiting or significant hematologic toxicity, a number of approaches evaluating maintenance therapy with extended dosing of rituximab are being tested. Trials have demonstrated prolonged progression-free survival in patients treated with maintenance rituximab using a variety of schedules following treatment with single-agent rituximab, induction or salvage chemotherapy, or salvage therapy with rituximab and chemotherapy combinations. Small increases in neutropenia and infections have been reported with extended rituximab use. Ongoing trials are evaluating the optimal use of rituximab (maintenance vs retreatment) and the benefit of rituximab maintenance following treatment of therapy-naive patients treated with rituximab-containing chemoimmunotherapy induction regimens. This article discusses the risks and benefits of maintenance rituximab for follicular NHL.

The first attempt at using monoclonal antibodies in lymphoma therapy, reported in 1980, was unsuccessful. Since that time, several immunotherapeutic approaches to treating non-Hodgkin’s lymphoma have been developed,

Rituximab (IDEC-C2B8 [Rituxan]) is a chimeric anti-CD20 monoclonal antibody (MoAb) that was recently approved by the FDA for the treatment of patients with low-grade or follicular B-cell non-Hodgkin’s lymphoma. Its potential efficacy in other B-cell malignancies is currently being explored. This article reviews the mechanisms of action of rituximab, as well as preclinical data and results of the clinical trials that led to its approval. Also discussed are the mechanics of administering rituximab on the recommended weekly ´ 4 outpatient schedule. Finally, the article describes ongoing and planned trials of rituximab in other dosage schedules, in other B-cell neoplasms, and in conjunction with chemotherapy. As the first MoAb to gain FDA approval for the treatment of a malignancy, rituximab signals the beginning of a promising new era in cancer therapy. [ONCOLOGY 12(12):1763-1770, 1998]

Significant advances have been made in the application of monoclonal antibody-based therapies to the treatment of patients with lymphoma. The most promising areas appear to be the use of unconjugated monoclonal