Overview Tysabri Observational Program Status: Active, not recruiting Trial end date: 2029-01-03 Target enrollment: Participant gender: Summary The primary objective of this study is to assess the long-term safety and impact on disease activity and progression of natalizumab in participants with relapsing remitting multiple sclerosis (RRMS) in a clinical practice setting. Details Lead Sponsor: BiogenTreatments: Natalizumab