Long-term safety and tolerability of eptinezumab in patients with chronic migraine: a 2-year, open-label, phase 3 trial

BACKGROUND: Eptinezumab, an anti-calcitonin gene-related peptide monoclonal antibody recently approved in the United States for preventive treatment of migraine in adults, was found to be well tolerated in double-blind, placebo-controlled studies in patients with episodic and chronic migraine. The objective of the PREVAIL study was to evaluate the long-term safety, immunogenicity, and impact on patient-reported outcomes of repeat doses of eptinezumab in patients with chronic migraine. METHODS: PREVAIL was an open-label, phase 3 trial comprising a 48-week treatment phase followed by a second 48-week treatment phase. Adults with chronic migraine received eptinezumab 300 mg by 30-min intravenous administration every 12 weeks for up to 8 doses. Patients were followed for 20 weeks after the final infusion (end-of-study visit at week 104). RESULTS: Overall, 128 adults (mean age, 41.5 years) with chronic migraine were included. During the 2 years, the most frequently reported treatment-emergent adverse events were nasopharyngitis (14.1%), upper respiratory tract infection (7.8%), sinusitis (7.8%), influenza (6.3%), bronchitis (5.5%), and migraine (5.5%). The rate of study-drug discontinuation due to adverse events was 6.3%, which included 3 patients with infusion-related hypersensitivity. The incidence of anti-eptinezumab antibodies peaked at week 24 and declined despite continued dosing, to nondetectable levels at week 104. Improvements in patient-reported outcomes were observed at first assessment (week 4) and generally sustained through week 104. CONCLUSION: In adults with chronic migraine, eptinezumab 300 mg demonstrated a favorable safety profile, limited long-term immunogenicity, early and sustained reductions in migraine-related burden, and improvements in health-related quality of life over 2 years. TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT02985398). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-021-02123-w.