Erenumab (Amgen/Novartis), a fully human monoclonal antibody, has demonstrated a statistically significant reduction in monthly migraine days compared with placebo in patients with chronic migraine in a phase 2 study. Erenumab targets and blocks the calcitonin gene-related peptide (CGRP) receptor, which is thought to be pivotal in the genesis of migraine.
The global 12-week, randomized, double-blind, placebo-controlled trial evaluated the safety and efficacy of erenumab in chronic migraine prevention. A total of 667 patients (mean age: 42 years; 79% female) were randomly assigned to receive once-monthly subcutaneous (SC) erenumab 70 mg (n = 191), SC erenumab 140 mg (n = 190), or SC placebo (n = 286). The study’s primary endpoint was the change in monthly migraine days from baseline to the last four weeks of the 12-week treatment phase in patients with chronic migraine (i.e., the number of migraine days between weeks 9 and 12). Secondary study endpoints included a reduction of at least 50% from baseline in monthly migraine days; the change from baseline in monthly acute migraine-specific medication days; and the change from baseline in cumulative monthly headache hours.
The patients had a mean baseline of 18.0 migraine days per month and a mean baseline of 21.1 headache days per month. Patients assigned to both erenumab groups experienced a statistically significant 6.6-day reduction from baseline in mean monthly migraine days compared with 4.2 days in the placebo group (P < 0.001). All endpoint assessments compared the last four weeks of the 12-week treatment phase with baseline values.
A reduction of 50% or more in the number of monthly migraine days was observed in 40% and 41% of individuals in the erenumab 70-mg and 140-mg groups, respectively, at week 12, representing a significantly higher likelihood of a response, compared with 24% of those receiving placebo (both doses: P < 0.001). Monthly acute migraine-specific medication days were reduced by 3.5 days and 4.1 days in the 70-mg and 140-mg groups, respectively, representing significant improvements from baseline, compared with a 1.6-day reduction in those receiving placebo (both doses: P < 0.001 vs. baseline).
All treatment groups showed numeric improvements in cumulative monthly headache hours. The reductions versus baseline for erenumab 70 mg and erenumab 140 mg were 64.8 hours and 74.5 hours, respectively, compared with 55.2 hours versus baseline for placebo.
In an analysis of exploratory endpoints, both doses of erenumab were associated with significant improvements in health-related quality of life, headache impact, disability, and level of pain interference compared with placebo.
The most common adverse events associated with erenumab 70 mg, erenumab 140 mg, and placebo included injection-site pain (3.7%, 3.7%, and 1.1%, respectively); upper respiratory tract infection (2.6%, 3.2%, and 1.4%); and nausea (2.1%, 3.2%, and 2.5%).
The data will be presented at the 5th European Headache and Migraine Trust International Congress in Glasgow, Scotland.
Source: Amgen; September 15, 2016.