Background: Zavegepant is the first small molecule calcitonin gene-related peptide receptor antagonist for intranasal administration for the acute treatment of migraine. The objective of this study was to evaluate the safety and tolerability of zavegepant in the acute treatment of migraine under repeated, as-needed dosing for up to one year.

Methods: This phase 2/3, one-year open-label safety study of zavegepant 10 mg nasal spray for the acute treatment of migraine enrolled adults aged ≥18 years with a history of two to eight moderate to severe monthly migraine attacks. Participants used one dose of zavegepant as needed to self-treat migraine attacks of any severity, up to eight times per month, for 52 weeks.

Results: Participants were enrolled between 29 June and 4 December 2020. Of the 608 participants entering long-term treatment, 603 were treated with study drug. Participants administered a mean (SD) of 3.1 (1.55) zavegepant doses per month. There were no deaths. Of the seven serious adverse events reported, none was considered related to treatment. Altogether, 6.8% (41/603) of treated participants had an adverse event leading to study drug discontinuation. The most frequent adverse event leading to discontinuation was dysgeusia (1.5% [9/603]). The most common treatment-emergent adverse events (≥5% of participants) were dysgeusia (39.1% [236/603]); nasal discomfort (10.3% [62/603]); COVID-19 (7.5% [45/603]); nausea (6.1% [37/603]); nasal congestion and throat irritation (5.5% [33/603] each); and back pain (5.3% [32/603]). Aminotransferases >3x the upper limit of normal occurred in 2.6% [16/603] of participants; none had concurrent elevations in bilirubin >2x upper limit of normal.

Conclusions: One year of zavegepant 10 mg nasal spray up to eight times per month was safe and well tolerated.Trial registration: Clinicaltrials.gov: NCT04408794.