Natalizumab for Achieving Relapse-Free, T1 Gadolinium-Enhancing-Lesion-Free, and T2 Lesion-Free Status in Japanese Multiple Sclerosis Patients: A Phase 2 Trial Subanalysis

INTRODUCTION In a phase 2 trial of natalizumab in Japanese patients with relapsing-remitting multiple sclerosis (RRMS), treatment-related changes in relapses, brain lesions, and disability worsening were found to be comparable with those observed in the phase 3 studies of natalizumab in primarily non-Asian RRMS patients. METHODS This subanalysis of the placebo-controlled phase 2 trial of natalizumab in Japanese RRMS patients (n = 94) evaluated the effects of natalizumab versus placebo on the proportion of patients who achieved relapse-free, T1 gadolinium-enhancing (Gd+) lesion-free, and new/newly enlarged T2 lesion-free status, defined as "no evidence of inflammatory disease activity" (NEDA)-like status, after 24 weeks of treatment. RESULTS In this subanalysis, significantly more natalizumab-treated than placebo-treated patients achieved NEDA-like status (76.6% vs. 31.9%; P < 0.0001). In addition, the odds ratio (95% confidence interval) for patients on natalizumab to reach NEDA-like status was 6.98 (2.80-17.38) compared with placebo patients. CONCLUSION These results confirm previous findings indicating that natalizumab is efficacious in Japanese patients with RRMS. FUNDING Biogen. TRIAL REGISTRATION ClinicalTrials.gov identifier, NCT01440101.