As of 2016, migraine is the second leading cause of disability around the world. This is the first study to exhibit that CGRP-directed therapy could have preventive efficacy in patients with episodic migraine in whom multiple previous preventive treatments have not been successful. With 50% or more reduction in the mean number of monthly migraine days, the number of patients in erenumab group increased compared to placebo.

Oral preventive treatments are not suitable for a significant number of patients with migraine. Erenumab has been reported to have sufficient efficacy in terms of preventive treatment of migraine. In this study, efficacy and tolerability of erenumab in patients with episodic migraine who have failed to respond to two-to-four migraine treatments have been assessed.

A 12-week double-blind, placebo-controlled randomized study, was carried out at 59 sites in 16 countries by the name of LIBERTY. The patients of age 18-65 years, having episodic migraine history and who were treated unsuccessfully with two to four preventive treatments were included in the study. For 12 weeks, patients were given Erenumab 140 mg subcutaneously in two doses or placebo every four weeks.

The proportion of patients having 50% or more reduction in the mean number of MMD (Monthly migraine days) during week 9-12 was considered the primary endpoint. Assessment of efficacy was done by including all patients who completed the minimum one post-baseline monthly migraine measurement after starting their assigned treatment. All the patients who received a minimum one dose of study drug were assessed for safety.

A total of 246 participants were included in the trial, which was randomly assigned to erenumab group (n=121) and placebo group (n=125). Out of them, 39% had unsuccessfully tried two preventive drugs, 38% had tried three preventive drugs, and 23% had tried four preventive drugs. As observed at week 12, 30% of the patients in the erenumab group had a 50% or more reduction from baseline in the mean number of MMDs when compared to placebo. Both erenumab and placebo groups were found to have similar tolerability and safety profiles. In both groups, 6% of the participants were reported to have treatment-related injection site pain as an adverse event.

Erenumab has proved to be an effective migraine treatment strategy in patients who have not responded to the other two to four previous preventive treatment strategies. Therefore, erenumab can be a ray of hope for patients who cannot tolerate or respond to other treatments.