Dataset from An Open-Label, Multicenter, Extension Study to Evaluate the Safety and Tolerability of Natalizumab Following Re-Initiation of Dosing in Multiple Sclerosis Subjects Who Have Completed Study C-1801, C-1802, or C-1803 and a Dosing Suspension Safety Evaluation

The primary objectives of this study are to further evaluate the safety of natalizumab (Tysabri®) monotherapy by evaluating the risk of hypersensitivity and immunogenicity following re-exposure to natalizumab, and to confirm the safety of switching to natalizumab from interferon beta (IFN-β), glatiramer acetate (GA), or other multiple sclerosis (MS) therapies.