Immunotherapy for Migraine Shows Promising Results

Number of headaches per month reduced in phase 3 trial

Fremanezumab (Teva Pharmaceuticals), an immunotherapy that counteracts a molecule released during migraine, reduced the number of days that chronic migraine sufferers experienced headaches in phase 3 trial results published by the New England Journal of Medicine.

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; although a number of interventions exist, many only work for a certain time before they fail to prevent or relieve pain.

"This therapeutic approach offers new hope for people whose migraines cannot be treated with existing medicine," says Stephen D. Silberstein, MD, principal investigator of the HALO CM trial, Professor of Neurology, and Director of the Jefferson Headache Center at the Vicki & Jack Farber Institute for Neuroscience at Thomas Jefferson University Hospital in Philadelphia. "Our worldwide effort to evaluate this novel therapeutic approach has shown positive results and was safe in patients."

Fremanezumab, a monocolonal antibody, 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 1,130 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% reduction in migraine, others with 75% reduction," says Dr. Silberstein. 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% 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% of patients on the monthly regimen, and 40.8% on the quarterly regimen, had at least a 50% reduction in the number of moderate headaches per month, compared to 18.1% 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.

Source: Thomas Jefferson University; November 30, 2017.