Research in context
Evidence before this study
We searched PubMed with the terms “episodic migraine”, “CGRP OR calcitonin gene-related peptide”, and “antibody OR antibodies” to identify articles published in English between Jan 1, 2010, and June 18, 2018. We identified 38 articles. Published work suggests that CGRP is involved in the pathophysiology of migraine. Biologics targeting CGRP (eg, erenumab, galcanezumab, fremanezumab, eptinezumab) showed efficacy compared with placebo in phase 2 and 3 trials of episodic migraine. However, efficacy and safety data have not yet been published for patients with episodic migraine in whom multiple previous preventive treatments were unsuccessful. Oral preventive therapies for episodic migraine are associated with low adherence because of poor efficacy or tolerability, or both. Thus, management of patients who have unsuccessfully tried multiple treatments becomes a challenge for physicians. Erenumab is a fully human monoclonal antibody that inhibits the canonical CGRP receptor. It has been approved in the USA by the Food and Drug Administration and in Australia for the preventive treatment of migraine in adults. In phase 2 and 3 studies in chronic and episodic migraine, erenumab was associated with significant reductions in monthly migraine days and use of acute migraine medications compared with placebo. The effects on monthly migraine days were sustained for up to 15 months in an open-label extension study in episodic migraine (4–14 headache days per month).
Added value of this study
In this 12-week, randomised, double-blind, placebo-controlled trial in patients with episodic migraine in whom multiple previous preventive treatments were unsuccessful, the proportion of patients with a 50% or greater reduction in the mean monthly number of migraine days from baseline was significantly higher in the erenumab 140 mg group than in the placebo group. In line with previously reported evidence, the tolerability and safety profiles of erenumab were similar to those of placebo, and no patients developed binding or neutralising antibodies during the double-blind treatment phase. These results suggest that erenumab is a potential treatment for difficult-to-treat episodic migraine in patients who have previously unsuccessfully tried multiple preventive medications.
Implications of all the available evidence
Erenumab 140 mg is a well tolerated and potentially effective preventive treatment for patients with episodic migraine, even in those in whom multiple other migraine preventives had either low efficacy or low tolerability.