There is growing excitement among headache specialists about initial research into a new class of antimigraine drugs.
Called CGRP monoclonal antibodies, these drugs appear to substantially 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."
According to Dr Kapoor, these drugs have significant potential to change the landscape for migraine treatment.
"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," said DR Kapoor. "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 antimigraine 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 2 studies on each of the 4 drugs currently in development reveal huge reductions in the incidence of migraine, 1 drug, from Alder BioPharmaceuticals, has demonstrated reductions from 50% to almost 100%.
So why aren't these drugs being rushed to market? Not so fast, DR Kapoor warns.
"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 5 years away from public distribution. The next step is Phase 3 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," said DR Kapoor.
Source: News Release
University of Kentucky
June 19, 2015