Real-world experience with calcitonin gene-related peptide-targeted antibodies for migraine prevention: a retrospective observational cohort study at two Japanese headache centers

Background Although randomized controlled trials (RCTs) have shown that calcitonin gene-related peptide (CGRP)-targeted monoclonal antibodies (CGRP mAbs) are an efficacious and safe therapeutic modality for migraine prevention, their clinical benefits have not been well validated in Japanese patients in the real-world setting. The present study aimed to evaluate the real-world efficacy and safety of galcanezumab, fremanezumab, and erenumab in Japanese patients with migraine.Methods This observational retrospective cohort study was conducted at two headache centers in Japan. Patients with migraine who had experienced treatment failure with at least one traditional oral migraine preventive agent were treated with a CGRP mAb de novo. The primary efficacy endpoints were the changes from baseline in monthly migraine days (MMDs) and Headache Impact Test-6 (HIT-6) score after 3 dosing intervals (V3). We explored whether demographic and clinical characteristics predicted therapeutic outcomes at V3.Results Sixty-eight patients who completed three doses of a CGRP mAb (85.3% female [58/68], mean age: 46.2 +/- 13.1 years) were included in the analysis. There were 19 patients with chronic migraine. The baseline MMDs were 13.4 +/- 6.0. After 3 doses, the MMDs significantly decreased to 7.4 +/- 5.5 (p < 0.0001), and the 50% response rate was 50.0%. HIT-6 score was significantly reduced from 66.7 +/- 5.4 to 56.2 +/- 8.7 after 3 doses (P = 0.0001). There was a positive correlation between the changes in MMDs and HIT-6 score from baseline after 2 doses (p = 0.0189). Those who achieved a >= 50% therapeutic response after the first and second doses were significantly more likely to do so at V3 (crude odds ratio: 3.474 [95% CI: 1.037 to 10.4], p = 0.0467). The most frequent adverse event was constipation (7.4%). None of the adverse events were serious, and there was no need for treatment discontinuation.ConclusionsThis real-world study demonstrated that CGRP mAbs conferred Japanese patients with efficacious and safe migraine prevention, and an initial positive therapeutic response was predictive of subsequent favorable outcomes. Concomitant measurement of MMDs and HIT-6 score was useful in evaluating the efficacy of CGRP mAbs in migraine prevention.