Over the past 50 years there hasn't been a single preventative drug developed that specifically targets migraines. But new research in its early stages shows hope that a preventative drug may be within reach for the 36 million Americans that suffer from these chronic headaches.
Studies presented Tuesday at the American Academy of Neurology's annual meeting unveiled two new drugs that work by blocking a protein that ultimately stops the migraine from starting. This could also mean big business in the pharmaceutical industry, which sees dollar signs behind any significantly successful treatment for the disease.
Joining The Takeaway to discuss the new drugs is a co-author of the research, Dr. David Dodick. He's also a professor of neurology at the Mayo Clinic and chairman of the American Migraine Foundation. Anne-Elise Tobin, an analyst with Decision Resources, a healthcare information company, also joins the conversation.
"We've known for about 20 years that there's a protein known as calcitonin gene-related peptide, or CGRP for short, that appears to be very important in generating and maintaining a migraine attack," says Dr. Dodick. "These drugs may work by preventing CGRP from exerting or doing what it does to generate an attack of migraine outside and even inside the brain."
Dr. Dodick says that the the CGRP protein binds to receptors in nerves and throughout the brain, which generate migraine attacks. These new drugs, the doctor says, bind to the protein in order to prevent it from attaching to a receptor, and thus preventing a migraine.
Individuals that participated in Dr. Dodick's studies received biweekly injections of either the drug or a placebo for 12 weeks. Those that got the drug saw a 66 percent decrease in the frequency of migraines they experienced over the course of a month. However, participants that received a placebo had a 50 percent decrease in the number of migraines they experienced.
"It's something that we've struggled with in the migraine research space for quite sometime," says Dr. Dodick. "It's a problem with pain in general, but with migraines in particular—placebo response rates are very high. There's probably a number of reasons for that. In this particular study, we believe that not only was there a lot of anticipation and heightened expectation in getting a very new and novel drug that people thought was going to be effective, but as the invasiveness of the treatment goes up, so too does the placebo response."
Dr. Dodick says that injecting a placebo under the skin or intravenously has a much more powerful effect than taking a pill orally, which causes a larger number of people to "experience" positive results.
Could something like this actually come to market? While some say that an intravenous injection may lack mass market appeal, Dr. Dodick says an injection every three months is less invasive than taking oral medication once or twice a day. Tobin, who is involved in the pharmaceutical market, says there is a substantial and immediate need for better migraine prevention drugs, and that patients are already receiving injections of Botox that are specifically designed to curb their migraines.
"These were issues that were considered when [Botox maker] Allergan was first getting regulatory approval for Botox for the prevention of chronic migraines," she says. "Before Botox was on the market for migraines, all of the other medications were oral pills that you would take at home. Now that Botox is approved for migraines, the uptake of Botox seems to be fairly good in the market."
The Botox treatment is injected into facial and neck muscles once every three months by a trained physicians and is designed to dull the symptoms of migraines. Botox therapy for migraines commands a small percentage of the market because it is more expensive than other treatments, but Tobin says the uptake so far has been good, drawing in about $200 to $300 million.
"They're failing, the oral therapies, and [people are] looking for relief and going to Botox," she says. "In some cases patients are responding well to that therapy. Allergan's Botox has shown a path that there is an opportunity for physician-administered drugs in the migraine prevention space."
Dr. Dodick says that while the initial trials targeting CGRP showed some success, there is still a ways to go.
"What's left to do is to take these preliminary results and move into large, pivotal phase three studies," he says. "Hopefully, if the efficacy, safety, and tolerability are confirmed in larger phase three studies, that may lead to regulatory approval by the FDA. There's still work to be done to confirm these preliminary findings."