LEXINGTON, Ky. (June 22, 2015) — There is growing excitement among headache specialists about initial research into a new class of anti-migraine drugs.
Called CGRP monoclonal antibodies, these drugs appear to significantly reduce the frequency of migraine in human clinical trials.
"We know that levels of CGRP are elevated during migraine attacks and decrease with resolution of the attacks," said Sid Kapoor, MD, Fellow of the American Headache Society and Director of the Headache Program at the University of Kentucky's Kentucky Neuroscience Institute (KNI). "This new class of drugs aims to reduce CGRP levels either by inactivating CGRP or disabling the receptor that binds to it, effectively disrupting the chain of events that causes migraine pain."
These drugs have significant potential to change the landscape for migraine treatment, Kapoor said. [youtube]
"Currently, my only course of action is to patiently and methodically work through a morass of drugs for blood pressure, depression, or epilepsy, and if those don't work, it's on to more complex and expensive therapy options like Botox," Kapoor said. "It's a frustrating process for both the doctor and the patient."
"If these CGRP drugs can deliver as promised, they will represent the first new class of anti-migraine drugs in more than 20 years -- and those only treated migraines after they occurred, and rarely prevented them."
What's particularly exciting to headache specialists is the profound effect the drugs appear to have on migraine incidence. Initial results from Phase II studies on each of the four drugs currently in development reveal huge reductions in the incidence of migraine — one drug, from Alder BioPharmaceuticals, has demonstrated reductions from 50 percent to almost 100 percent.
So why aren't these drugs being rushed to market? Not so fast, Kapoor said.
"We don't yet fully know how blocking CGRP affects other organ functions long term. Previous attempts at modifying this pathway were too dangerous for patients and studies had to be discontinued. It is exciting that we are succeeding with a fresh approach."
CGRP monoclonal antibody drugs are at least five years away from public distribution. The next step is Phase III trials, which aim to establish efficacy and long-term safety compared to a placebo.
"Pain studies are notorious for a high placebo response and hence this step will be critical," Kapoor said.
According to the American Headache Society, more than 36 million Americans suffer from migraine attacks, and about four million of those people experience more than 15 migraine days a month. Migraine can be extremely disabling and costly, accounting for more than $20 billion in direct and indirect expenses each year in the United States.
The Best Places Organization ranks U.S. cities by migraine prevalence according to several factors, including the number of migraine-related drug prescriptions per capita, lifestyle and environmental factors, and the consumption of migraine-triggering foods. The Cincinnati Metropolitan Area, which includes large parts of Northern Kentucky, ranks first, and both Louisville and Lexington are in the top 30.
"Our hope is that KNI will be a Phase III test site," Kapoor said. "We have notable expertise in migraine treatment, and we are located at the epicenter of migraine incidence."