Predictors of response to galcanezumab in patients with chronic migraine: a real-world prospective observational study

Background Despite high efficacy and tolerability, not all patients with chronic migraine benefit from anti-CGRP monoclonal antibodies. We aimed to identify the clinical predictors of the response to galcanezumab treatment in patients with chronic migraine from real-world data. Methods We prospectively recruited patients with CM who underwent galcanezumab injections between December 2019 and February 2022. Treatment response was determined after three months of follow-up and was defined as ≥ 50% reduction in monthly headache days. The migraine characteristics, comorbidities, and other treatment responses were compared between the responder and non-responder groups. Results Of 238 patients with CM, 153 (64.3%) showed treatment response. The responder group was younger, had lower frequency of baseline headache days, and had more accompanying symptoms such as nausea, vomiting, and photophobia. Better triptan response and less depression were also observed in the responder group. Multivariable regression analysis revealed that the everyday headache (OR = 0.351, 95% CI = 0.133–0.874, p = 0.017), depression (OR = 0.439, 95% CI = 0.216–0.896, p = 0.024) and absence of accompanying symptoms (OR = 0.314, 95% CI = 0.118–0.834, p = 0.020) were significantly associated with response to galcanezumab treatment. Conclusions Our real-world data showed the efficacy of galcanezumab in patients with CM, regardless of medication overuse. Everyday headache, presence of depression, and absence of accompanying symptoms of migraine were significant predictors of a poor response.