SUMMARY: Natalizumab is a humanized IgG4 monoclonal antibody that is a selective adhesion molecule inhibitor, which prevents adhesion of leukocytes to endothelial cells. It is the first monoclonal antibody approved by the FDA for the treatment of relapsing-remitting MS. This article will review the mechanism of action and clinical role of this agent.

SUMMARY:Rituximab is a monoclonal antibody that was first approved by the FDA as an antineoplastic agent designed to treat B-cell malignancies. This article will review the mechanism of action and clinical role of this anti-B-cell agent.ABBREVIATIONS: FDA ϭ US Food and Drug Administration; FSE ϭ fast spin-echo