On the scientific front, the past two years have been dismal when it comes to breakthroughs in migraine treatment. It isn’t due to the lack of trying. We have learned much more about migraine and other headache disorders than we ever did before, however, like with all areas of human physiology, the more we know the more complex it seems to be. We know that the underlying problem is a faulty circuit in the brain’s headache alarm system. Most of the time this is inherited and can’t be fixed, however, the disease can usually be treated.
A few years ago several researchers took a new approach of turning off migraine by blocking a powerful chemical call CGRP (for calcitonin gene related peptide), which the brain uses to create headache pain. This very irritating chemical is released from the ends of nerves both inside and outside the skull when told to do so by the brain’s headache alarm system. Antagonists (chemicals that block other chemicals’ actions) were produced to blocked CGRP. Years ago studies were set up with animals, then human volunteers before they tried them on real headache sufferers. They worked quite well in stopping a migraine in its tracks. These medications also seemed safer than Triptans (Imitrex® type medications) because they didn’t constrict blood vessels.
We thought that these medications would be on the market by last year. However, when patients took these CGRP Antagonists on a daily basis, to see if they would prevent migraines, they started to notice that a small group of patients had minor liver enzyme elevations. This could mean that the liver, where the antagonists were processed, was getting irritated.
Drug companies are terrified of even giving the appearance of injuring a patient with their medications. The airways are full of lawyers advertising to go after the “makers of bad drugs.” If a suit is filed, the company can lose hundreds of millions of dollars. So, because of those fears, the CGRP Antagonist, although very promising and probably safer than things we use now, were forever dropped.
But this doesn’t mean the end of the story.
As they say, there is more than one way to skin a cat. Really smart researchers knew of another way of stopping the CGRP from being released from the nerve endings without using these antagonist chemicals. In this new way, the body’s own antibodies could be developed to stop the release of the irritating chemicals. It seems to work. These are biologic agents, rather than strictly chemical, and are not in need of being broken down by the liver.
The anti-CGRP antibodies (also called monoclonal antibodies because they are very precise, involving one gene strain) have a very promising future in treating migraines. They could be used as abortives and possibly even a long-term preventative program with little side effects. It is hard to know how these antibodies could be delivered by injection and possibly orally. Right now monoclonal antibodies are already finding great success in the treatment of cancer and autoimmune diseases.
If this process involves a natural, human antibody, could the body be coaxed into producing its own through a vaccine? It borderlines on science fiction, but is at least theoretically possible. But can you imagine getting one vaccine, or a short series of injections, and from then on being headache free or almost headache free?
But even if the vaccine is never realized, the use of monoclonal anti-CGRP antibodies is a real possibility for effective treatment and you will be hearing much more about it in the future.
I’m looking forward to bringing more up-to-date research information after I return from the International Headache Congress in two weeks.