To evaluate changes in canonical migraine symptom-free days in patients with chronic migraine (CM) after treatment with eptinezumab.

Migraine diagnosis (ICHD-3) is based on ≥2 of the following characteristics: unilateral location, pulsating quality, moderate or severe pain intensity, or avoidance of physical activity. During migraine, patients must experience ≥1 of: nausea and/or vomiting, or photophobia and phonophobia. Eptinezumab, a selective and potent anti-CGRP monoclonal antibody, demonstrated significant reductions in mean monthly migraine days in a phase 3 clinical trial of CM (NCT02974153).

Adults with CM (ICHD-3β) were randomized to eptinezumab 100mg, 300mg, or placebo, administered intravenously every 12 weeks for 2 infusions. Migraine symptoms were assessed using daily eDiary entries and evaluated in 4-week intervals. Baseline was the daily average over the 28-day screening period. Results are for baseline and Week 4 (Month 1).

Baseline mean days free from moderate or severe pain were 10.4 (300mg), 10.3 (100mg), and 10.4 (placebo), increasing to 19.1, 18.1, and 15.8 days, respectively, by Month 1. Baseline mean nausea-free days were 14.6 (300mg), 14.6 (100mg), and 14.9 (placebo), increasing to 21.7, 21.4, and 19.5 days, respectively, by Month 1. Baseline mean vomiting-free days were 24.7 (300mg), 25.1 (100mg), and 24.6 (placebo), increasing to 26.8, 26.9, and 26.2 days, respectively, by Month 1. Baseline mean days free from photophobia and phonophobia were 14.0 (300mg), 13.4 (100mg), and 13.2 (placebo), increasing to 21.3, 20.0, and 17.8 days, respectively, by Month 1. Baseline mean days free from avoidance of physical activity were 12.2 (300mg), 12.4 (100mg), and 12.1 (placebo), increasing to 20.0, 19.0, and 16.6 days, respectively, by Month 1.

Within the first month in CM, eptinezumab increased the frequency of canonical migraine symptom-free days, with patients gaining ~1 week back compared with placebo.