Intranasal Third-Generation CGRP Effective for Acute Migraine

Erik Greb

April 19, 2021

Intranasal zavegepant, a third-generation calcitonin gene-related peptide (CGRP) receptor agonist, is effective and well tolerated in the treatment of acute migraine, new research shows.

In a randomized dose-ranging, placebo-controlled, phase 2/3 trial, investigators found both the 10-mg and 20-mg doses of the drug were associated with pain freedom in more than 20% of patients and alleviated the most bothersome symptom defined as photophobia (light sensitivity), phonophobia (fear of loud sounds), or nausea, in more than 40% of patients.

Most adverse events associated with zavegepant were mild or moderate. The drug is not associated with liver toxicity.

"The intranasal formulation demonstrated some separation on pain relief as early as 15 minutes, though in terms of the statistical hierarchy, those differences were not significant," said study investigator Richard B. Lipton, MD, professor and vice chair of neurology at Albert Einstein College of Medicine in New York City, who presented the findings.

"Sustained pain freedom was observed from 2 to 48 hours post-dose," Lipton added. A phase 3 clinical trial has been initiated to compare the efficacy of the 10-mg dose with that of placebo for the acute treatment of migraine.

The study was presented at the virtual American Academy of Neurology (AAN) 2021 Annual Meeting.

Three Doses

Zavegepant is the only intranasal CGRP receptor antagonist undergoing late-stage development for the acute treatment of migraine. A previous single ascending dose study suggested the drug provided systemic exposure and had potentially therapeutic effects.

The study included participants age 18 years or older who had a diagnosis of migraine for at least 1 year, had two to eight migraine attacks of moderate or severe intensity and fewer than 15 monthly headache days over the previous 3 months.

The investigators randomly assigned participants in this phase 2/3 trial to placebo or a 5-mg, 10-mg, or 20-mg dose of intranasal zavegepant. Participants treated a single attack of moderate to severe pain with their assigned treatment.

The study's two primary endpoints were freedom from pain and freedom from the most bothersome symptom at 2 hours after dosing.

The investigators randomly assigned 1673 participants to treatment. Of this group, 1588 treated an attack with study medication. The researchers also included 1581 participants in the modified intention-to-treat population. Of this group, 387 received the 5-mg dose, 391 received the 10-mg dose, 402 received the 20-mg dose, and 401 received placebo.

Pain Freedom

The population's median age was approximately 41 years, 86% of participants were female, and 14% were taking preventive migraine medication.

Participants' mean number of moderate or severe attacks per month was 4.9 overall. The most common most bothersome symptom was photophobia.

The researchers observed a difference in outcome between the active and placebo arms as early as 15 minutes post-dose, but this difference was not statistically significant.

At 2 hours, the rate of pain freedom was 15.5% in the placebo group, 22.5% in the 10-mg group (P = .0113), and 23.1% in the 20-mg group (P = .0055). The result for the 5-mg group (19.6%) was not significantly different from that of the placebo group.

The rate of freedom from the most bothersome symptom was 33.7% in the placebo group, 41.9% in the 10-mg group (P = .0155), and 42.5% in the 20-mg group (P = .0094). For this endpoint as well, the result of the 5-mg group (39%) was not significantly different from that among controls.

The most common adverse events were dysgeusia (impaired sense of taste) and nasal discomfort. The rate of dysgeusia ranged from 13.5% to 16.1% in the zavegepant groups, compared with 3.5% among controls. The rate of nasal discomfort ranged from 1.3% to 5.2% in the zavegepant groups, compared with 0.2% among controls. The investigators concluded that intranasal zavegepant had a favorable safety profile.

"Exciting Potential Addition"

Commenting on the findings for Medscape Medical News, Alan M. Rapoport, MD, clinical professor of neurology at the David Geffen School of Medicine, University of California, Los Angeles, said: "Zavegepant is an exciting potential addition to rimegepant for the acute care of migraine."

Many patients like the orally dissolving tablet formulation of rimegepant (Nurtec), but some have nausea and do not absorb oral preparations well, said Rapoport, who is past president of the International Headache Society. "So, it makes sense to have a gepant, which is not a vasoconstrictor and has few adverse events, developed as a nasal spray." Nasal preparations often work more quickly than oral preparations, he added.

Other intranasal treatments available for migraine include dihydroergotamine (Migranal), zolmitriptan (Zomig), sumatriptan (Imitrex), and ketorolac (Sprix). It is not possible to compare zavegepant with these medications, or with other CGRP receptor antagonists, because they have not been studied in head-to-head trials, said Rapoport, who was not involved in the study but has previously consulted for Biohaven Pharmaceuticals, the drug's manufacturer.

"I would predict a nasal spray would work somewhat faster and better in some patients with nausea or poor absorption, so I would be happy to have it approved and available.

The current study uses endpoints typically prescribed by the US Food and Drug Administration and includes a large sample size, said Rapoport.

"During the informed consent [stage], the patients in this trial would be told that there is a 3-in-4 chance that they would be getting an active drug vs placebo, and that often increases the placebo response," he added. "In this trial, a placebo response of 15.5% is slightly high, but not atypical," he added.

This study raises the question of whether other acute-care migraine medications should be studied as nasal preparations. "I think the answer is yes," said Rapoport. "Fast-acting, effective nasal preparations that are easy to use and cause few adverse events is what we need."

Biohaven Pharmaceuticals sponsored the study. Lipton has been a consultant for Biohaven, has conducted studies funded by the company, and has stock in the company. Rapoport has consulted and spoken for Biohaven, but did not participate in the current study.

American Academy of Neurology (AAN) 2021 Annual Meeting: Abstract S5.003. Presented April 17, 2021.

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