CGRP Antibodies and Receptor Blockers
Dr. Amaal Starling discusses the recent anti-CGRP treatments and how they can help patients with migraine and cluster headache
Calcitonin gene-related peptide (CGRP) is a neuropeptide found all over the body, says Dr. Amaal Starling, an Assistant Professor of Neurology at the Mayo Clinic in Phoenix. This neuropeptide attaches to a receptor called a CGRP receptor. CGRP and its receptor are involved in numerous bodily processes—from gastrointestinal movement to the transmission of pain.
Over the past few decades, there has been increasing evidence that CGRP plays a role in both migraine and cluster headache. During a migraine attack, researchers have found increased levels of CGRP in patients’ blood and saliva. They discovered migraine medications like sumatriptan reduced levels of CGRP in patients living with migraine. They also found that patients with chronic migraine—meaning 15 or more migraine days per month, eight of which either meet criteria for migraine or are treated with migraine-specific medication—had chronically elevated levels of CGRP. In addition, recent research found that giving a patient with migraine an infusion of CGRP would lead to a migraine-like attack.
“All of these studies led to the hypothesis that CGRP and its receptor play a key role in migraine, as well as in cluster headache,” Dr. Starling says.
Groundbreaking New Treatments
Currently, there are several anti-CGRP treatments undergoing clinical trials. Some of these treatments involve monoclonal antibodies, which reduce the activity of CGRP, potentially leading to fewer migraine attacks. One of these anti-CGRP monoclonal antibodies, erenumab (Aimovig™), has been approved by the Federal Drug Administration (FDA) and is now available for patients. A second agent, fremanezumab (Ajovy™), was approved in September 2018. A week later, the FDA approved galcanezumab (Emgality™), making it the third anti-CGRP treatment currently on the market.
Results from the clinical trials involving anti-CGRP antibodies have shown that about 50 percent of patients will have at least a 50 percent reduction in migraine days.
“If you think about someone who has 20 migraine days per month, they have a 50 percent chance of having 10 or less migraine days,” Dr. Starling says. “We think that there are even these super-responders who have a 75 percent response rate, as well as super-super-responders who actually go into remission.”
The results from these clinical trials are very promising, Dr. Starling adds. “The adverse events have been very minimal and the efficacy has been very good. It’s all looking up.”
Dr. Starling says that although these medications are available, what really needs to be looked at is how to make them truly accessible for patients. Erenumab can cost about $7,000 per year without insurance coverage.
“Insurance coverage is very, very key for the majority of our patient population,” she says. “Because the medications just came out on the market, there are still a lot of unknowns about insurance coverage.”
Who is the Treatment Ideal for?
Dr. Starling says the FDA approval indicates that the anti-CGRP treatments are ideal for individuals with episodic migraine who have four to 14 headache days per month, and people with chronic migraine who have 15 or more headache days per month.
Clinical trials are also being conducted to see if anti-CGRP antibodies are effective for the treatment of cluster headache. “The initial studies have demonstrated that it’s likely effective for cluster headache patients,” Dr. Starling says.
The FDA’s approval of these medications has been incredibly meaningful for the migraine community.
“The migraine community is feeling like they’re relevant—that they’re being seen, heard and taken seriously,” Dr. Starling says. “There are many people who are working hard to develop more treatment options until we can address every patient who has migraine, and eventually find a cure.”
Advocating for Yourself
If you think either of the FDA-approved anti-CGRP treatments might be right for you, speak with your primary health care provider, neurologist or headache specialist. If your medical provider isn’t aware of the treatments, don’t be afraid to let him or her know about them, or ask for a referral to a local neurologist or headache specialist. This is just the first step in advocating for the care that you deserve. To find a headache specialist in your area, consult our Find a Doctor tool.
Dr. Starling believes that every person with migraine should be involved in advocacy, in order to bring awareness to the disease and break the stigma that surrounds it. She recommends that patients living with migraine get involved in advocacy organizations, such as our Move Against Migraine support community. You can also attend the annual Headache on the Hill event in which patients and providers go to Capitol Hill asking for more National Institutes of Health (NIH) research funding for migraine and other headache disorders. The next Headache on the Hill event is planned for February 11-12, 2019.
Within the coming weeks, the American Migraine Foundation will be compiling a guide to all three anti-CGRP treatments. For additional information on anti-CGRP migraine treatment options, consult our doctor-verified resource library.