Efficacy of Erenumab for Migraine Prevention in Japanese Patients with Episodic and Chronic Migraine: Results of a Post-Hoc Pooled Analysis.

Abstract

Erenumab, a fully human monoclonal antibody against the calcitonin gene-related peptide receptor, is approved in Japan for the prevention of adult migraine. This post-hoc analysis evaluated the efficacy of erenumab in Japanese patients with low-frequency episodic migraine (LFEM) versus those with high-frequency episodic migraine (HFEM) and chronic migraine (CM). A pooled analysis of data from the 24-week double-blind treatment phases (DBTPs) of phase 2 and 3 studies evaluated the efficacy of once-monthly erenumab 70mg in Japanese patients. Patients were categorized into subgroups by monthly migraine days (MMD): LFEM and HFEM/CM. The main efficacy outcomes were change from baseline in MMD, acute migraine-specific medication treatment days (MSMD), and six-item Headache Impact Test (HIT-6™) scores. Patients with migraine (n=532) were included in the analysis (LFEM, n=215; HFEM, n=215; CM, n=102). Overall, mean age was 44years, 86.5% were female, and 63.3-88.2% had used or were taking migraine preventive treatment at baseline. Throughout the DBTP, the placebo-adjusted mean change from baseline in MMD, MSMD, and HIT-6 scores with erenumab was similar across LFEM and HFEM/CM subgroups. The proportion of patients achieving at least 50% or 75% reduction from baseline in MMD and MSMD was similar across migraine frequency groups. Reduction in MMD moderately correlated with improvement in HIT-6 scores in the LFEM and HFEM/CM groups. Furthermore, the proportion of patients converting from HFEM/CM to LFEM during the DBTP was higher in the erenumab group than in the placebo. In Japanese patients with different migraine frequencies, erenumab treatment resulted in significant improvements in MMD, MSMD, and headache impact. This pooled analysis of data from phase 2 and 3 studies increases confidence that erenumab is efficacious in patients with high MMD, which is associated with increased disability.