Could efficacy at 1 week after galcanezumab administration for patients with migraine predict responders at 3 months? A real world study.

Background: In real-world studies, it is unclear whether galcanezumab has a significant effect in the first week after administration. Methods: We retrospectively assessed 55 high-frequency episodic migraine (HFEM) and chronic migraine patients who received three galcanezumab doses. Mean changes in the numbers of weekly migraine days (WMDs) during month 1 and migraine days per month (MMDs) after 1–3 months of treatment were obtained. Clinical factors related to a ≥ 50% response rate (RR) at month 3 were analyzed. The prediction of ≥ 50% responders at month 3 using different weekly RRs at week 1 (W1) was evaluated. The RR at W1 was calculated with the following formula: RR (%) = 100 − [(WMDs at W1/baseline WMD) × 100]. Results: The number of MMDs significantly improved from baseline to 1, 2 and 3 months. The ≥ 50% RR was 50.9% at 3 months. The number of WMDs decreased significantly from baseline to week 1 (− 1.6 ± 1.7 days), week 2 (− 1.2 ± 1.6 days), week 3 (− 1.0 ± 1.3 days), and week 4 (− 1.1 ± 1.6 days) during month 1. The RR at W1 was largest (44.6 ± 42.2%). The ≥ 30%, ≥ 50% and ≥ 75% RRs at W1 were significantly predictive of a ≥ 50% RR at 3 months. Logistic regression analysis predicting a ≥ 50% RR at month 3 showed that the RR at W1 was the sole contributing factor. Conclusion: In our study, galcanezumab showed a significant effect in the first week after administration, and the RR at W1 could predict the RR at 3 months. [ABSTRACT FROM AUTHOR]