Migraine and the New Anti-CGRP Treatments
What to know about fremanezumab (AJOVY™), the second anti-CGRP treatment for migraine
In September 2018, fremanezumab (AJOVY™), was approved by the FDA for the treatment and prevention of migraine. The news came four months after the FDA approved the first monoclonal antibody, erenumab (Aimovig™), the first treatment specifically designed to prevent migraine. Clinical trials found both treatments to be effective at reducing headache frequency and also found them to be well tolerated.
During a recent Facebook Live, Dr. David Dodick, Chair of the American Migraine Foundation and Professor of Neurology at the Mayo Clinic Arizona, discussed the latest CGRP advancements with the migraine community.
About Anti CGRP Treatments
CGRP stands for calcitonin gene-related peptide, and is a protein that transmits pain signals along the trigeminal nerve into the brain stem and, ultimately, up through the brain itself. Researchers and doctors believe that CGRP is “important in generating and maintaining the headache associated with migraine,” said Dr. Dodick. Erenumab works by targeting CGRP’s receptor, while fremanezumab targets the CGRP molecule itself.
Anti-CGRP treatments consist of monoclonal antibodies, which are not drugs, but instead are antibody proteins engineered to target and neutralize other proteins or their receptors. These monoclonal antibodies do get into the brain to any significant degree, and are not metabolized by the liver. That means organ toxicity and interactions with other drugs should be minimal, and thus far, the side effect profile overall appears very favorable.
The new treatments were tested on a wide variety of migraine patients, meaning that they could help those living with either episodic or chronic migraine, and those who have tried other migraine treatments and have a high level of disability. Patients using topiramate (Topamax), onabotulinumtoxinA (Botox) and taking acute medication more than 10 days a month also responded well to the treatment.
Erenumab vs. Fremanezumab
“The most important difference, from a biological standpoint, is that fremanezumab targets the protein, and erenumab targets the receptor,” says Dr. Dodick. Whether there are implications of this difference with regard to efficacy and safety are not yet known at this time.
Apart from the differences in how each monoclonal antibody targets the CGRP, there are several other factors to consider when picking a treatment. “Practically speaking, they are both delivered as a single subcutaneous injection, although fremanezumab can be delivered as three injections once every three months,” says Dr. Dodick.
Erenumab comes as a prefilled autoinjector, whereas fremanezumab comes as a prefilled syringe. And, after you take the medications out of the fridge, erenumab has to be injected in seven days whereas fremanezumab has to be injected within 24 hours.
The most common side effects in clinical trials for both treatments were reactions around the injection site reactions, like redness, swelling and itching. The FDA’s label for fremanezumab cautions users about hypersensitivity reactions, like a rash, itching or hives. The hypersensitivity reactions identified with fremanezumab weren’t reported with erenumab, whereas constipation, which was a side effect with erenumab, doesn’t seem to be reported to a significant degree with fremanezumab.
Researchers still don’t know about the comparative effectiveness of the drugs, or if patients who don’t respond to one would respond to the other. “If history tells us anything, it’s that different drugs within the same class can have a different effect in an individual patient,” said Dr. Dodick. He remains “cautiously optimistic” that patients who failed to respond to one monoclonal antibody may respond to another.
In the week following Dr. Dodick’s Facebook Live with the migraine community on fremanezumab (AJOVY™) and the latest CGRP advancements, Eli Lilly and Company announced that the FDA approved galcanezumab (Emgality™) for preventive migraine treatment in adults. The new treatment is the third anti-CGRP treatment on the market. For more information on erenumab, fremanezumab and galcanezumab, visit our resource library.
Click here to read and watch the Q&A portion of Dr. Dodick’s Facebook Live. For more information on the latest anti-CGRP treatment for migraine, consult your health care provider and visit our resource library.