A new treatment shows promise for preventing migraines in patients afflicted with frequent attacks, and it appears to work without the extreme side effects associated with other prophylactic medications.
According to data from a phase 3 trial, set to be presented at the American Academy of Neurology annual meeting, monthly injections of the drug erenumab may halve the number of migraines experienced by patients with episodic migraine, defined as up to 14 headaches a month.
Erenumab is a human monoclonal antibody designed to target a receptor for calcitonin gene-related peptide (CGRP), a protein involved in the transmission of pain signals and dilation of blood vessels that has been implicated to play a major role in migraines.
The current go-to medications for relieving a migraine after onset, drugs called triptans, have been prescribed for years without scientists fully understanding the mechanism by which they stop an attack. We now have evidence that triptans inhibit release of CGRP from overactive nerves in the trigeminal ganglion – a collection of nerve fibers that innervate the head, eye, and jaw.
Unfortunately, taking a pill after you have a migraine is only a band-aid treatment, and people who get episodic or chronic migraines (15 or more episodes a month) are typically recommended to try one of several preventative medications. These prophylactic agents must be taken every day and have mixed success. Furthermore, they may cause side effects as debilitating as the migraines themselves.
Erenumab, on the other hand, directly blocks migraine development by binding to the CGRP receptors on nerve cells, thus preventing CGRP from binding.
In a not-yet-published trial run by pharmaceutical company Novartis, 246 episodic migraine sufferers who had already tried two to four prophylactic medications to no avail were given injections of erenumab or a placebo once a month for three months. During the treatment period, 30 percent of the people who received erenumab experienced half the number of migraines that they had previously, compared with only 14 percent of placebo patients.
“That reduction in migraine headache frequency can greatly improve a person's quality of life," said study author Dr Uwe Reuter in a statement.
Patients taking erenumab reported mild side effects that were similar to those on the placebo.
According to Novartis' collaborator Amgen, other trials involving more than 3,000 patients have demonstrated the drug is safe and effective for up to five years. The FDA is set to announce their decision on whether or not to approve the drug, which would be marketed as a pre-loaded self-injector, on May 17, 2018.
"This is the first-ever mechanism specific migraine drug designed for prevention," said lead author Dr Peter Goadsby to Today. "This will change migraine treatment for those who don’t respond to conventional treatments.”