Use of rituximab, the new FDA-approved antibody.

Rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA) is the first monoclonal antibody approved by the US Food and Drug Administration for the treatment of cancer. It is a genetically engineered chimeric (murine-human) monoclonal antibody (mAb) directed against the CD20 antigen found on the surface of normal and malignant B cells. Multicenter studies have demonstrated its efficacy against relapsed low-grade and follicular non-Hodgkin's lymphoma (NHL). The mAb demonstrated tolerable side effects, primarily limited to fevers and chills associated with the first infusion. The currently recommended dosage is 375 mg/m2/infusion, given weekly for 4 weeks. Because of its human component, rituximab has low immunogenicity and should not significantly hinder future retreatment. Future studies will evaluate the antitumor activity of rituximab combined with various other chemotherapeutic or biologic agents in the treatment of B-cell lymphoma and other CD20-positive lymphoid neoplasms.