IM interferon beta-1a delays definite multiple sclerosis 5 years after a first demyelinating event.

Background: The Controlled High Risk Subjects Avonex Multiple Sclerosis Prevention Study (CHAMPS) showed that IM interferon beta-1a (IFNbeta-1a) significantly slows the rate of development of clinically definite multiple sclerosis (CDMS) over 2 years in high-risk patients who experience a first clinical demyelinating event. This report highlights the primary results of a 5-year, open-label extension of CHAMPS (the Controlled High Risk Avonex Multiple Sclerosis Prevention Study in Ongoing Neurologic Surveillance [CHAMPIONS Study]).

Objective: To determine if the benefits of IFNbeta-1a observed in CHAMPS are sustained for up to 5 years.