Headaches related to migraine affects about 14% of people, or more than a billion individuals worldwide. This chronic neurologic disorder involves periodic attacks of head pain coupled with symptoms that may include nausea as well as sensitivity to light and sound. 75% of migraine sufferers experience at least one migraine attack per month, and more than 50% are severely impaired during their attacks.
Existing drug protocols for treatment include triptan drugs (examples include sumitriptan, eletriptan, and rizatriptan), which were introduced in the 1990s. Triptans stop acute migraines by stimulating serotonin receptors, which in turn reduces inflammation and constricts blood vessels.
Triptans are not effective for everyone as they they can produce intolerable side effects, and since they constrict vessels, they should not be taken by individuals with cardiovascular disease or having major CVD risk factors.
There is however a new class of drugs called, gepants, which includes the new formulated rimegepant. Gepants work by targeting the receptors for a small protein, called CGRP, long implicated in migraine. During migraine attacks, CGRP is released resulting in pain. Gepants relieve the pain and other symptoms of migraine by blocking the CGRP pathway.
In a large Phase 3 Clinical trial led by researchers at Albert Einstein College of Medicine and Montefiore Health System and involving more than 1,000 men and women with migraine at 49 centers in the U.S., results showed a very promising indicators.
The trial patients were instructed to take a tablet of rimegepant, or a matching placebo tablet, during a migraine attack, once moderate or severe pain developed. Prior to taking the tablet and for 48 hours afterwards, patients answered questions in an electronic diary concerning their pain and their most troubling symptoms such as intolerance to light, intolerance to loud sounds, or nausea.
Results showed that two hours after taking their tablets, 19.8% of patients in the rimegepant group were free from pain compared with 12.0% in the placebo group, a major statistically significant difference. Freedom from their most bothersome symptoms occurred in 37.8% of patients in the rimegepant group. Side effects were minimal, with nausea and urinary tract infections the only adverse effects reported in more than 1% of patients in each group and no adverse CVD effects observed.
Professor Richard B. Lipton MD, the study's first author and vice chair of the Saul R. Korey Department of Neurology at Einstein and director of the Montefiore Headache Center, commented in a phone interview with Thailand Medical News,” "For the first time in nearly three decades, people with migraine not helped by existing medications may have a new option to find relief during attacks. These results confirm that rimegepant's mechanism of action, blocking the CGRP pathway ,effectively relieves pain and associated symptoms that occur during acute migraine attacks. As someone who has studied CGRP blockers for more than a decade, I am thrilled to see their benefits confirmed in a large-scale clinical trial."
Rimegepant is awaiting U.S. Food and Drug Administration approval and may offer advantages over currently available migraine medications.