By Matthew S. Robbins, MD, FAAN, FAHS
Neurology Residency Program Director; Associate Professor of Neurology, Weill Cornell Medical College, New York-Presbyterian Hospital
Dr. Robbins reports no financial relationships relevant to this field of study.
SYNOPSIS: Atogepant, an oral calcitonin gene-related peptide (CGRP) antagonist, was shown to be effective and safe for migraine prevention. This adds an additional CGRP antagonist to the growing arsenal of such medications, both oral and parenteral, for both prevention and treatment of migraine.
SOURCE: Goadsby PJ, Dodick DW, Ailani J, et al. Safety, tolerability, and efficacy of orally administered atogepant for the prevention of episodic migraine in adults: A double-blind, randomised phase 2b/3 trial. Lancet Neurol 2020;19:727-737.
In this study, Goadsby and colleagues conducted a multicenter, randomized controlled trial (RCT) of atogepant, a novel small molecule antagonist to the calcitonin gene-related peptide (CGRP) receptor, for the preventive treatment of migraine. The study included patients ages 18 to 75 years with preexisting migraine with or without aura for at least one year and a frequency of four to 14 migraine days per month.
The trial enrollment featured 825 subjects who ultimately received at least one dose of study medication. Participants were randomized to twice daily placebo or the study medication of varying doses at once or twice daily over a 12-week treatment period after a four-week run-in period. All groups receiving the study medication reached the primary endpoint vs. placebo (-2.9 days), ranging from a reduction of -3.6 to -4.2 monthly migraine days, with slightly higher efficacy in twice-daily dosing. Atogepant was safe; adverse events were infrequent and most commonly manifested as nausea (3% to 9%), with lower rates for constipation and fatigue and no serious adverse events deemed related to the study drug.
COMMENTARY
CGRP is an inflammatory neuropeptide that is fundamentally involved in migraine pathophysiology. Gepants, small molecule CGRP receptor antagonists, represent an important treatment advance for migraine, but their development initially was limited by hepatotoxicity, leading to the successful development of monoclonal antibodies that target CGRP or its receptor as preventive treatments. Two gepants, rimegepant and ubrogepant, recently were approved by the Food and Drug Administration and are available for acute migraine treatment. Although rimegepant also is under investigation as a preventive treatment, atogepant is the first gepant to demonstrate both efficacy and safety for migraine prevention in a large-scale RCT. Its safety profile in the trial was encouraging, with neither hepatotoxicity nor cardiovascular events apparent.
Gepants provide distinct advantages over existing preventive treatments. Their tolerability seems excellent, although long-term cardiovascular safety questions remain. They may be a true blend of acute and preventive treatments, since the same medication class has demonstrated efficacy in both paradigms. They also do not seem to cause medication overuse headache, a common complicating factor in patients with frequent or chronic migraine. Compared to CGRP monoclonal antibodies, which have half-lives of approximately one month, their short half-life (10 hours) enables rapid dose changes and medication cessation in certain circumstances, such as side effects or a planned or unplanned pregnancy. Many patients do not like the injections required of CGRP monoclonal antibodies; atogepant may provide a more tolerable alternative.
There were study limitations. Real-world patients may not be well represented, since most patients were not on preventive therapy previously; such a population would be unlikely to receive atogepant as first-line therapy in clinical practice. The therapeutic gain for atogepant (-0.7 to -1.4 monthly migraine day reduction) is comparable to CGRP monoclonal antibodies and other oral preventive treatments but is not superior to such therapies. Further studies of atogepant, including RCTs of patients with episodic and chronic migraine, are ongoing.
