Benefits of high-dose, high-frequency interferon beta-1a in relapsing-remitting multiple sclerosis are sustained to 16 months: Final comparative results of the EVIDENCE trial

The EVIDENCE trial demonstrated that interferon (IFN) beta-1a, 44 mcg subcutaneously (sc) three times weekly (tiw) (Rebif®), was significantly more effective than IFN beta-1a, 30 mcg intramuscularly (im) once weekly (qw) (Avonex®), in reducing relapses and magnetic resonance imaging (MRI) activity in patients with relapsing-remitting multiple sclerosis at both 24 and 48 weeks of therapy. We now present final comparative data on these patients, showing that the superior efficacy of IFN beta-1a, 44 mcg sc tiw, for relapse measures and MRI activity, compared with IFN beta-1a, 30 mcg im qw, was sustained for at least 16 months. The development of antibodies to IFN was associated with reduced efficacy on MRI measures and fewer IFN-related adverse events, but did not have an impact on relapse outcomes.