Monoclonal antibodies, such as natalizumab, are produced in cell culture systems. They can be designed to bind to receptors on the body’s normal cells. By recognizing and attaching to these receptors, monoclonal antibodies can interfere with (or alter) normal or abnormal cellular responses. In this way, monoclonal antibodies may be useful in the treatment of certain diseases.
Safety and efficacy in patients with chronic progressive multiple sclerosis have not been established.
Several other products are already available for the treatment of MS, including Betaseron, Avonex, Rebif, Copaxone, and Novantrone. One of the clinical studies with natalizumab was performed in patients already being treated with Avonex. The addition of natalizumab resulted in a further reduction in the occurrence of relapses, beyond the benefit that those patients had already received from Avonex.
The approval is granted on the condition that the manufacturer must continue testing to demonstrate that the drug indeed provides therapeutic benefit to the patient. If it does not, the FDA can withdraw the product from the market more easily than usual.
Common side effects include:
A complete list of side effects may be found in the product labeling.