The World Health Organization estimates that between 127 and 300 million people around the world experience chronic migraine, defined as 15 or more headaches per month for at least three months. The disease can be debilitating and although a number of interventions exist, many only work for a certain time before they fail to prevent or relieve pain.

A new study of fremanezumab, an immunotherapy that counteracts one of the molecules released during migraine, was found successful in reducing the number of days that chronic migraine sufferers experienced headaches. The results of the phase III clinical trial were published in the New England Journal of Medicine.

Fremanezumab, a monocolonal antibody developed by Teva Pharmaceuticals, is a biological agent that binds to and blocks the action of a migraine-associated protein called calcitonin gene-related peptide (CGRP). Mounting evidence of its importance in migraines has made CGRP a focal point of research and drug development. The peptide is released at high levels during migraine in response to inflammation, and triggers a cascade effect that stimulates more CGRP release. This results in increasing sensitivity of the brain to pain. By blocking this peptide, doctors hope to break the cycle of increasing inflammation and increased pain sensitivity that contributes to migraine headaches.

Researchers from 132 sites across nine countries enrolled 1130 patients and randomly assigned them to one of three groups: one that received quarterly treatments, a group that received one treatment per month, and one that received placebo injections. The trial lasted for 16 weeks, with a 12-week treatment window.

The results of the trial show that treatment with fremanezumab reduced the number of days patients experience headache by an average of 4.3 days with quarterly treatment and 4.6 days with monthly treatment. "We saw some patients with 100 percent reduction in migraine, others with 75 percent reduction," says the Principal Investigator. The level of response varied between patients.

The researchers also looked at how well the therapy worked relative to each patient's headache burden. They calculated the percent of patients who had more than a 50 percent reduction in the number of days they experienced either a severe or moderate headache per month. Using this measure, the researchers saw that 37.6 percent of patients on the monthly regimen, and 40.8 percent on the quarterly regimen had at least a 50 percent reduction in the number of moderate headaches per month, compared to 18.1 percent in the placebo group.

The therapy had a favorable safety profile with the most common adverse event reported as irritation at injection site, which was reported in the placebo group as well.

"If approved, this treatment would provide physicians with an important new tool to help prevent migraine, reduce a patient's migraine load, and potentially help patients return to normal" says the author.

http://www.nejm.org/doi/full/10.1056/NEJMoa1709038?query=featured_home