Overview Open-Label Safety Extension Study of Avonex Status: Completed Trial end date: 2003-07-01 Target enrollment: Participant gender: Summary To collect data on serious adverse events which occur during extended treatment with Avonex in subjects at high risk for developing multiple sclerosis (MS) and in subjects with secondary progressive MS. Phase: Phase 4 Details Lead Sponsor: BiogenTreatments: Interferon beta-1aInterferon-betaInterferons