Three-Year Interim Results from a Post-Marketing Surveillance Study of Patients with Migraine Treated with Fremanezumab in South Korea

There is limited real-world evidence on the safety and effectiveness of fremanezumab in South Korea. We aimed to evaluate the safety and effectiveness of fremanezumab as a preventive migraine treatment in adults with migraine in real-life clinical practice in South Korea. A 6-year, non-interventional, prospective, post-marketing surveillance study conducted in up to 60 clinics and hospitals in South Korea from July 2021 to 2027. Eligible participants are aged ≥ 18 years, have a formal migraine diagnosis, and are receiving fremanezumab for the first time. The primary endpoint is the proportion of new adverse events, including serious adverse events, from first administration of fremanezumab to the 12-week observation period or discontinuation. Secondary endpoints include the mean change from baseline to week 12 in average monthly migraine days (MMD), proportion of participants achieving a ≥ 50% reduction in MMD, and the Patient Global Impression of Change (PGIC) scale at week 12. We present an interim analysis of data collected up to the third year of this study. As part of the overall study, this 3-year interim analysis included data from 14 sites, with 1230 participants for safety and 1096 for effectiveness analyses (mean age: 46.1 years, standard deviation: 13.7; episodic/chronic migraine: 45.2%/54.8%; mean disease duration: 6.9 years [standard deviation 8.2]). Adverse events were reported by 17.6% of participants; the most common were injection-site reactions (5.7%); serious adverse events were infrequent (1.0%). After 12 weeks of treatment, mean change from baseline in MMD was − 7.8 ± 8.1 days (episodic migraine: − 3.4 ± 4.5 days, chronic migraine: − 11.4 ± 8.7 days), all p < 0.0001; 56.5% of participants (episodic migraine: 55.0%, chronic migraine: 57.7%) achieved a ≥ 50% reduction in MMD. Most participants (87.0%) rated treatment as effective on the PGIC scale. Fremanezumab was well tolerated and effective for migraine prevention in Korean adults in a real-world setting. These results support the use of fremanezumab in routine clinical practice across South Korea. This real-world study in South Korea assessed the safety and effectiveness of fremanezumab for preventing migraine in adults (aged ≥ 18 years). The main outcome was the proportion of new side effects reported during the first 12 weeks of treatment. Other study outcomes included the average change in the number of migraine days per month, the proportion of participants whose migraine days were reduced by at least half, and the patients’ overall perception of improvement in their migraine over the first 12 weeks of treatment. This interim analysis was based on data collected over a 3-year period from 14 of up to 60 sites participating in an ongoing multicenter study evaluating the safety and effectiveness of fremanezumab in adults with either episodic or chronic migraine across South Korea. Approximately 18% of participants experienced side effects, mostly mild reactions at the injection site, and serious side effects were rare (1%). On average, participants experienced nearly 8 fewer migraine days each month after receiving fremanezumab treatment compared with before receiving treatment, with those who had chronic migraine showing the greatest improvement. More than half (~ 57%) of the participants had their monthly migraine days reduced by at least half. Most participants (87%) felt their condition improved with treatment. Overall, fremanezumab was well tolerated and was effective in preventing migraine in Korean adults when used in everyday clinical practice. This study provides important real-world evidence supporting the use of fremanezumab in South Korea and helps healthcare professionals understand its benefits and risks in routine care.