Efficacy and safety of erenumab in Japanese migraine patients with prior preventive treatment failure or concomitant preventive treatment: subgroup analyses of a phase 3, randomized trial

BACKGROUND: These subgroup analyses of a Phase 3, randomized, double-blind, placebo-controlled study evaluated the efficacy and safety of erenumab 70 mg in Japanese migraine patients with/without prior preventive treatment failure(s) (“failed-yes” and “failed-no” subgroups) and with/without concomitant preventive treatment (“concomitant preventive-yes” and “concomitant preventive-no” subgroups). METHODS: Overall, 261 patients were randomized; 130 and 131 patients to erenumab 70 mg and placebo, respectively. Subgroup analyses evaluated the change from baseline to Months 4–6 in mean monthly migraine days (MMD) (primary endpoint), achievement of a ≥50% reduction in mean MMD, and change from baseline in mean monthly acute migraine-specific medication (MSM) treatment days. Treatment-emergent adverse events were also evaluated. RESULTS: Of the 261 patients randomized, 117 (44.8%) and 92 (35.3%) patients were in the failed-yes and concomitant preventive-yes subgroups, respectively. Erenumab 70 mg demonstrated consistent efficacy across all subgroups, with greater reductions from baseline in mean MMD versus placebo at Months 4–6 (treatment difference versus placebo [95% CI], failed-yes: − 1.9 [− 3.3, − 0.4]; failed-no: − 1.4 [− 2.6, − 0.3]; concomitant preventive-yes: − 1.7 [− 3.3, 0.0]; concomitant preventive-no: − 1.6 [− 2.6, − 0.5]). Similar results were seen for achievement of ≥50% reduction in mean MMD and change from baseline in mean monthly acute MSM treatment days. The safety profile of erenumab 70 mg was similar across subgroups, and similar to placebo in each subgroup. CONCLUSION: Erenumab was associated with clinically relevant improvements in all efficacy endpoints and was well tolerated across all subgroups of Japanese migraine patients with/without prior preventive treatment failure(s) and with/without concomitant preventive treatment. TRIAL REGISTRATION: Clinicaltrials.gov. NCT03812224. Registered January 23, 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s10194-021-01313-8.