Objective: To evaluate the efficacy and safety of subcutaneous peginterferon beta-1a over 2 years in patients with relapsing-remitting multiple sclerosis in the ADVANCE study.
Methods: Patients were randomized to placebo or 125 µg peginterferon beta-1a every 2 or 4 weeks. For Year 2 (Y2), patients originally randomized to placebo were re-randomized to peginterferon beta-1a every 2 weeks or every 4 weeks.