Natalizumab (BG00002, Tysabri) Study in Japanese Participants With Relapsing-Remitting Multiple Sclerosis (RRMS)

This multicenter study has 2 parts and is designed to provide data in Japanese participants, as required for registration of natalizumab (BG00002) in Japan. Part A will consist of an open-label cohort of 12 participants who will receive 300 mg natalizumab intravenously (IV) every 4 weeks over a 6-month treatment period. Part B will consist of a double-blind, placebo-controlled cohort of approximately 90 participants randomized in a ratio of 1:1 to receive IV infusions of placebo or 300 mg BG00002 every 4 weeks over a 6-month period.