Safety profile of Tysabri: international risk management plan.

Therapeutic monoclonal antibodies are potent new tools for a molecular targeted approach to modify the course of multiple sclerosis (MS). Natalizumab is a monoclonal antibody targeted against alpha-4 integrin that has proved to be very effective in the treatment of MS. It is well tolerated, although severe side effects have been reported that have conditioned its use as a second-line drug for the treatment of MS. The clinical benefit of natalizumab should be weighed carefully against the potential risk of serious adverse events. Therefore, risk management plans have already been developed in order to prevent or minimise risks relating to natalizumab. Data so far obtained from these observational programs confirm the already demonstrated risk-benefit profile of natalizumab in clinical trials.