Subcutaneous monoclonal antibodies could change the stagnant scope of migraine treatment.
It's strange to think the third-most prevalent illness in the world may not have a formidable treatment.
But that may be the case for migraines — which, according to the Migraine Research Foundation, afflict 12% of the global population. For as prominent as the painful headache condition is, it's never been treated by original therapy.
Juline Bryson, MD, FAHS, an attending migraine neurologist at the Department of Neurology at Wake Forest Baptist Medical Center, told MD Magazine that every class of drug used for migraines has been developed for another condition.
"We've been the redheaded step-children of medicine," Bryson said.
That may soon change. AMG 334 (erenumab) — along with 3 other investigative inhibitors galcanezumab, fremanezumab, and eptinezumab — has picked up steam as a potential migraine prevention drug after earning European Medicines Agency (EMA) Marketing Authorization Application (MAA) approval and US Food and Drug Administration (FDA) Biologics License Approval (BLA) this past summer.
The monoclonal antibody is scheduled for a Prescription Drug User Fee Act (PDUFA) target action date of May 17, 2018. It could become the second domestically approved drug for chronic migraines, Bryson said, following onabotulinumtoxinA (BOTOX). All other methods are prominently designated for anti-seizure, antidepressant, and other condition preventions.
"We used to try certain things, and eventually prescribe BOTOX," Bryson said. "If that didn’t work, the patients was sort of out of luck."
The potential groundbreaking therapy comes in the form of injectable inhibitors — a treatment form which Bryson said will become the future of neurological care. The novel drug works as an antibody that blocks calcitonin gene-related peptide receptor (CGRPR), the inflammatory protein generally linked to migraine conditions, which ultimately results in inhibiting CGRP transmission.
In its EMA application, erenumab was backed by data from 4 Phase II and III trials displaying statistically significant long-term efficacy versus placebo in the reduction of patient monthly migraine days. It also significantly improved the impact of migraines on patient disability and quality of life versus placebo.
The ability to improve quality of life touches on what Bryson believes is a significant point.
"It’s really important, because people are really affected," Bryson said. "People lose jobs and their marriages over being in this pain. I want to stress again that migraines are a disorder."
Domestically, migraines inflict about 18% of women, about 6% to 9% of men — though it may be higher — Bryson said. She noted there's clear indication it is a genetic disorder: a child has a 50% chance of having migraines if one parent suffers from them, and a 75% chance if both parents suffer from them.
Researchers are considering other receptors to target for therapy as well, Bryson said. While the potential inhibitors are subcutaneous treatments, a tablet form of therapy is also being considered. More early-stage immune modulating therapies are reporting strong preliminary results, but Bryson said she'll have to see how they hold.
Before any more developments, there's sustained excitement among headache specialists to potentially have their own medicine class for migraines.
"I’m so happy there’s new hope on the horizon," Bryson said.