Harvard Medical School's

 New research could revolutionise the treatment of headaches caused by anti-CGRP therapy.

In 2018, the launch of anti-calcitonin-related peptide therapy (CGRP) for migraine was the most significant therapeutic advancement in the last 30 years. This treatment is very effective, reducing monthly headache days by more than half for many of those with the most severe migraines.

About 50% of migraine sufferers do not respond well to anti-CGRP treatment. It was not possible to predict whether 50% of migraine patients would respond or not before taking the anti-CGRP therapy.

First, A Non-Invasive.

patient-friendly test has been prospectively proven in a clinical study. In a study published in Cephalalgia, the test was shown to be able to accurately predict anti-CGRP response prior to treatment initiation with greater than 80% accuracy.

The study showed that non-ictal cephalic allodynia, a type of pain sensitivity felt during a specified period of time, was a statistically significant indicator of response to anti-CGRP therapy. This was present in 84% of the 19 nonresponders but absent in 79% of the 24 respondents, giving an accuracy rate of 86% (p 0.0001).

Anti-CGRP medications

 Neutralize the CGRP peptide or block CGRP receptors within the dura. The dura is a membrane that covers the brain and spinal cord. Blocking CGRP in the meninges can prevent dilation of blood vessels and activation of pain fibres, which mediate migraine headaches.

The anti-CGRP drugs

 However, are too large to pass through the blood-brain barriers and can only be used by patients whose migraine is triggered outside of the brain. The study, published in Cephalalgia, used a proprietary quantitative sensory testing algorithm (QST) to determine whether or not cephalic pain was present during the "non-ictal" phase (more than 12 hours after the migraine attack but more than 12 hours before the next migraine attack).

The study confirmed that the manifestation of non-ictal extracephalic allodynia (peripherally governed) was less effective in identifying non-responders and that the non-ictal cephalic adolescent allodynia (non-ictal cephalic) was consistently predictive for response, both among chronic migraine (CM) patients as well as the high-frequency episodic headache (HFEM) group.

Rami Burstein

 PhD, Professor of Anaesthesia at Harvard Medical School and President-Elect for the International Headache Society, in collaboration with CGRP Diagnostics, developed the concept of predicting response to anti-CGRP treatment through testing for the presence or absence of non-ictal cranial allodynia.

The Harvard authors are Drs. Ashina and Burstein, and their colleagues wrote: "Key differences in disease pathology between responders and nonresponders have been identified." They also said that the "simplified paradigm of Quantitative Sensitivity Testing (QST), which is non-invasive and patient-friendly, may be a way to prospectively distinguish between responders and nonresponders to prophylactic treatments of chronic episodic migraines and drugs that reduce CGRP signals.

It could be a great benefit for patients, payers, and clinicians. According to David Greeley, MD, FAAN, who is the director of Northwest Neurological in Spokane, Washington, this could transform migraine treatment.

"CGRP antagonists are a great advance in migraine treatment. But to be able to predict with accuracy which patients would respond to these powerful drugs could change the game." "The teams at Harvard Diagnostics and CGRP Diagnostics seem to have achieved this with a non-invasive, quick, and affordable test," Greeley stated.

The payers seem to be in agreement, as the largest managed care organisations have revealed that they are aligned that this precision medicine "fits our desire to tailor the right drug to the patient" and "it would be a "no-brainer' to prefer a test that comes with a product."

It is better to find out which patients respond to treatment than to waste time, money, and suffering for up to six months before they fail," said Thomas Lundquist, MD, former chief medical officer and senior vice president of a large regional health plan as well as a multi-state

 Blues Plan.

Manufacturers who align their products with the test can also benefit from this significant advancement in knowledge.

Mark Hasleton, PhD, CEO of CGRP Diagnostics, said that the ability to largely avoid treatment failures allows earlier use of anti-CGRP therapy for migraine treatment protocols in tested responders. It also offers excellent formulary positioning and increases brand loyalty. We now have a tool that accurately predicts response before treatment is initiated. This allows clinicians to prescribe treatment early with confidence and reduces the need for previous treatment failures. The tool also allows non-responders to make a rapid transition to alternative treatment strategies. This prevents a lot of frustration and suffering for everyone.