BY FAY ELLIS
The US Food and Drug Administration (FDA) on Thursday approved erenumab (Aimovig), the first in a new class of calcitonin-gene related peptide (CGRP) antagonists, for the prevention of migraine.
Erenumab, which is given by monthly injection, is one of four monoclonal antibodies that have been tested in large clinical trials that target or block CGRP, which is produced by trigeminal nerve endings and elevated during migraine attacks. Other CGRP antagonists — eptinezumab, fremanezamb, and galcanezumab — bind to the peptide itself, while erenumab binds to the receptor.
The FDA based its approval of erenumab on three randomized, controlled trials. In the largest trial of 955 patients, reported in November in the New England Journal of Medicine, erenumab administered subcutaneously at a monthly dose of 70 mg or 140 mg significantly reduced migraine frequency, the effects of migraines on daily activities, and the use of acute migraine-specific medication over a period of six months.
Among the findings, 43.3 percent of patients in the 70-mg erenumab group and 50 percent of patients in the 140-mg erenumab group had a 50 percent or greater reduction in the mean number of migraine days per month compared with 26.6 percent in the placebo group (p<0.001 for each dose vs. placebo). And the number of days of use of acute migraine-specific medication was reduced by 1.1 days in the 70-mg erenumab group and by 1.6 days in the 140-mg erenumab group, as compared with 0.2 days in the placebo group (p<0.001 for each dose vs. placebo).
In a subgroup analysis of that group, presented in April at the AAN Annual Meeting, erenumab was found effective at 70 mg and 140 mg for patients with and without a history of aura. Responder rates (showing greater than 50 percent reductions in monthly migraine days) for people without aura history were 39 percent for erenumab at 70 mg compared with 23 percent for the placebo group (p=0.003) and 49 percent for the 140 mg group (p<0.001). For those with a history of aura, responder rates were 47 percent for those taking 70 mg compared with 30 percent for placebo (p=0.001), and 51 percent for the 140 mg group (p<0.001).
Jennifer Bickel, MD, FAAN, associate professor of pediatrics at Children's Mercy Hospital of the University of Missouri in Kansas City, highlighted the emergence of CGRPs as one of the most promising developments in 2017.
"These antibodies offer the ability to target the migraine pathway in ways that we have never done before," Dr. Bickel told Neurology Today. "In addition to demonstrating efficacy, these antibodies appear well tolerated without the sedation and mood changes that can limit the use of conventional migraine medications."
Still, while the class of drugs is promising, the long-term safety profile is largely unknown. In the current trials, the most common side effects reported were injection site reactions and constipation.
The FDA granted the approval of erenumab to Amgen, Inc.
LINK UP FOR RELATED INFORMATION:
AAN Annual Meeting Abstract P4.094: McAllister P, Gomez JP, Newman L, et al. Efficacy of erenumab for the treatment of patients with episodic migraine with aura.
Dodick DW, Ashina M, Brandes JL, et al. ARISE: A phase 3 randomized trial of erenumab for episodic migraine. Cephalgia 2018: 38(6): 1026-1037.
Goadsby PJ, Reuter U, Hallstrom Y, et al. A controlled trial of erenumab for episodic migraine. N Engl J Med 217: 377(22):2123-2132.