Migraines are debilitating and often compromise the normal functioning of people's lives. Onset can be sudden, symptoms may vary, and the pain sometimes last for days, leading to a reduced quality of life.
A host of new drugs that appear to prevent migraine headaches are in the final stages of testing and approval in the United States.
"What's really exciting about this is that until this development, we have not had a migraine-specific preventive at all," said Dr Peter Goadsby, a professor of neurology at the University of California, San Francisco.
Blocking a migraine-related protein
These are the first drugs to prevent migraine made specifically for migraine patients, said Goadsby. He led a research trial, with findings scheduled for presentation at an American Headache Society meeting, in Boston.
The new injectable drugs work by blocking a migraine-related protein called the calcitonin gene-related peptide (CGRP) or the receptor it acts on.
"CGRP is a small molecule that's released from pain nerves in the head, and is a key part of the process of migraine," said Goadsby.
According to the WHO, headache disorders, characterised by recurrent headache, are among the most common disorders of the nervous system, and globally, it has been estimated that prevalence among adults is about 50%.
Migraine is a disabling disease affecting more than 36 million men, women and children in the United States. Besides headache, symptoms can include nausea, sensitivity to light and/or smells, mood changes, difficulty concentrating and visual disturbances.
Chronic migraine means headaches occur 15 or more days a month; episodic migraine occurs less frequently.
Improved quality of life
His research – funded by drug maker Amgen – involved the new drug erenumab. In the phase three trial assessing the drug's effectiveness, nearly 1 000 patients with episodic migraine were randomly assigned to one of two doses of erenumab or placebo for six months.
Half the patients receiving monthly injections of the higher dose of erenumab experienced a 50% reduction in the number of migraines they suffered, Goadsby said. As a result, their quality of life improved, too.
Goadsby said the drug was well-tolerated. The only side effect was irritation at the site of the injection, which he said, quickly went away.
In separate phase two trials testing erenumab's safety for chronic migraine sufferers, the drug was also tied to fewer attacks.
Goadsby hopes erenumab will be approved by the US Food and Drug Administration and made available by mid-2018.
While erenumab works by blocking the receptor CGRP acts on, other drugs work by blocking CGRP itself. They include fremanezumab by Teva; eptinezumab from Alder Biopharmaceuticals, and galcanezumab from Eli Lilly and Co.
According to a Health24 article non-drug migraine treatment is often the better option. The first step in non-drug treatment is to diagnose where the pain is actually coming from, and in migraine, there are two anatomical structures where the pain most often starts, i.e. the muscles of the jaw and neck, and the arteries of the scalp (not from inside the brain).
For these three medications, researchers reported results of phase two trials that tested the drugs' safety.
In each case, patients reported more headache-free days. And side effects, such as changes in blood pressure or potential liver damage, were found not to be a problem, researchers said.
In addition, the drugs started working the first week of treatment. In some cases, patients were also able to cut back their other medications, researchers found.
These drugs will need to go through larger phase three trials to evaluate their effectiveness before they can be considered for FDA approval.
Goadsby said the overall outlook is promising for migraine sufferers.
"There is light on the horizon, which is entirely new and specifically designed for them," he said. "So for the person who is completely frustrated... it's really going to change."
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