A Real‐World Study of <scp>CGRP</scp> Monoclonal Antibodies for Migraine: Long‐Term Effectiveness and Treatment Adherence

BACKGROUND: Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are effective for migraine prophylaxis; however, real-world evidence beyond 1 year remains limited. METHODS: This single-center, retrospective observational cohort study in Japan included 307 migraine patients who received CGRP mAbs (erenumab, galcanezumab, or fremanezumab) for ≥ 3 months between April 2022 and February 2025 for an effectiveness analysis. Outcomes included monthly migraine days (MMDs), ≥ 50% responder rates, adverse events (AEs), and treatment persistence. Patients were categorized as nonresponders or responders: early (≥ 50% MMD reduction by Month 3), late (Months 4-5), and ultralate (after Month 6). RESULTS: Significant MMD reductions were observed across 24 months. The ≥ 50% response rates were 45.9%, 57.0%, 63.6%, and 71.0% at 3, 6, 12, and 24 months, respectively. AEs occurred in 12.6% and were mild. Early responders had the lowest baseline MMDs and Migraine Disability Assessment (MIDAS) scores; nonresponders had the highest baseline MMDs and MIDAS scores and the highest rates of comorbid medication overuse headache (MOH) and psychiatric disorders. Compared with early responders, late and ultralate responders had higher baseline MMDs, higher MIDAS scores, higher rates of MOH, and more prior preventive failures. Additionally, ultralate responders presented the highest rates of photophobia and pulsatile headache and the fewest psychiatric comorbidities. Effectiveness appeared similar among the three CGRP mAbs. Treatment continuation rates were 68.3%, 58.0%, and 50.6% at 12, 18, and 24 months, respectively. CONCLUSION: CGRP mAbs were associated with a long-term reduction in migraine frequency and favorable tolerability.