Erenumab treatment for migraine prevention in Japanese patients: Efficacy and safety results from a Phase 3, randomized, double‐blind, placebo‐controlled study

OBJECTIVES: Erenumab is a human anti‐calcitonin gene‐related peptide receptor monoclonal antibody approved for migraine prevention. Global studies have demonstrated its efficacy in chronic and episodic migraine (EM). Here we report the outcomes from a Phase 3 study of erenumab in Japanese patients with chronic migraine (CM) or EM. METHODS: Japanese patients with EM (<15 headache days/month, including ≥4 migraine days/month) or CM (≥15 headache days/month, including ≥8 migraine days/month) were randomized 1:1 to placebo or erenumab 70 mg once monthly for a 24‐week double‐blind treatment phase (DBTP). The primary endpoint of change from baseline in mean monthly migraine days (MMD) over months 4, 5, and 6 of the DBTP was compared between erenumab and placebo groups. Secondary efficacy and safety endpoints were also assessed. RESULTS: A total of 261 patients were randomized to placebo (n = 131) or erenumab 70 mg (n = 130); all patients were included in the efficacy and safety analyses. The mean (standard deviation) MMD at baseline was 11.84 (5.70) for the placebo group and 12.40 (5.99) for erenumab 70 mg. The mean (standard error) change in MMD was –1.98 (0.38) for the placebo group (n = 131) and –3.60 (0.38) for erenumab 70 mg (n = 130). The difference in MMD reduction between groups was −1.67 (95% CI: –2.56, –0.78, p < 0.001) for EM and –1.57 (95% CI: –3.39, 0.24, p = 0.089) for CM. Adverse events (AEs) were consistent with earlier studies. The most frequent AEs (placebo, erenumab) were nasopharyngitis (28.2% and 26.9%, respectively), back pain (4.6% and 5.4%), and constipation (0.8% and 4.6%). CONCLUSION: Treatment with erenumab 70 mg once monthly demonstrated favorable efficacy and safety findings in Japanese patients with EM or CM.