Rituximab is a monoclonal antibody that binds to the CD20 antigen expressed on the surface of B lymphocytes. This interaction activates mechanisms that lead to depletion of CD20-positive B cells. As a result, rituximab can reduce malignant B-cell populations and suppress abnormal B-cell activity in selected autoimmune diseases.
Rituximab may be used:
Rituximab has an extensive clinical evidence base. It has been studied in B-cell lymphomas, rheumatoid arthritis, and ANCA-associated vasculitis. For example, GPA/MPA Study 1 included 197 patients with granulomatosis with polyangiitis or microscopic polyangiitis and evaluated rituximab versus cyclophosphamide for remission induction.
A controlled study in pemphigus evaluated rituximab combined with short-term prednisone versus prednisone monotherapy. The study enrolled 90 patients and contributed to the evidence supporting rituximab use in pemphigus.
Rituximab also has a long history of clinical use; the FDA first approved it for certain B-cell non-Hodgkin lymphomas in 1997.
Rituximab is used to treat selected diseases involving CD20-positive B cells.
Approved treatment areas include certain forms of:
Its mechanism involves selective binding to CD20 on B lymphocytes and subsequent depletion of the CD20-positive B-cell population.
Rituximab is administered only by intravenous infusion. The dose, infusion schedule, and treatment duration depend on the disease, treatment regimen, body weight or body surface area, and other clinical factors. It must be administered by a healthcare professional in a setting equipped to manage severe infusion-related reactions. Intravenous bolus administration is not recommended.
