BOSTON—Erenumab reduces the number of migraine days per month in patients with episodic migraine, according to a study presented at the 69th Annual Meeting of the American Academy of Neurology. The treatment also reduces the use of acute migraine medication and improves function.
Erenumab is a fully human monoclonal antibody developed to block the pathway of calcitonin gene-related peptide (CGRP). The treatment showed promise in a phase II study in patients with episodic migraine and in a phase II study of patients with chronic migraine, according to Peter Goadsby, MD, PhD, Professor of Neurology at the University of California, San Francisco School of Medicine.
A Test of Two Doses
Dr. Goadsby and colleagues conducted a phase III study of 955 participants to examine whether erenumab would be an effective preventive treatment for episodic migraine. Eligible patients had between four and 14 migraine days per month and were allowed to take one concomitant migraine medication. Patients who previously had failed two preventive medications were excluded. After screening, patients underwent a four-week baseline period during which they kept electronic migraine diaries. The investigators then randomized patients in groups of equal size to placebo, 70 mg of subcutaneous erenumab, or 140 mg of subcutaneous erenumab. The treatment period lasted for six months.
As has been the case in many studies of migraine during the past 25 years, the typical patient in this study was a 41-year-old Caucasian woman, said Dr. Goadsby. Slightly more than half of participants had no previous exposure to a preventive therapy. The mean number of migraine days in all treatment groups was eight, and the mean number of headache days was nine. The treatment groups were well balanced.
Treatment Reduced Medication Use
During the last three months of treatment, the mean number of monthly migraine days decreased by 3.2 for patients receiving 70 mg of erenumab and by 3.7 for patients receiving 140 mg of erenumab, compared with 1.8 for patients receiving placebo. The difference between the active and control arms was statistically significant. The rate of participants who had a 50% reduction in migraine attacks was 26.6% for controls, 43% for patients receiving the 70-mg dose, and 50% for patients receiving the 140-mg dose.
The use of acute medicines decreased by 1.1 days for patients receiving 70 mg of erenumab and by 1.6 days for patients receiving 140 mg, compared with a decrease of 0.2 days for patients receiving placebo. Using the Migraine Physical Function Impact Diary, participants in the 70-mg group reported that the impact of migraine on everyday activities decreased by 5.5 points. Participants in the 140-mg group reported a 5.9-point reduction in this end point. Participants in the placebo group reported a 3.3-point reduction. Physical impairment decreased by 4.2 points for the 70-mg group and by 4.8 points for the 140-mg group versus 2.4 points for the placebo group.
Erenumab was well tolerated, and none of the serious adverse events appeared to be related to treatment. The most common adverse event was injection-site reactions. About 6% of the entire cohort developed antibodies to erenumab, including 8% in the 70-mg group and 3.2% in the 140-mg group. One patient receiving 70 mg had a neutralizing antibody, and no patients in the 140-mg group had neutralizing antibodies.
The study results are exciting, said Dr. Goadsby. In the future, treatments that target the CGRP pathway could be provided to migraineurs who do not respond to or cannot tolerate the current therapies, he added.
The trial was sponsored by Amgen, and Dr. Goadsby previously has consulted for the company.