Sustained response of reduction in migraine headache days (MHD) in patients with episodic migraine treated with galcanezumab (GMB) was evaluated.

Galcanezumab is a humanized igG4 monoclonal antibody that binds to calcitonin gene-related peptide (CGRP) and prevents its biological activity without blocking the CGRP receptor. Galcanezumab is approved for the preventive treatment of migraine in adults.

This was a post-hoc analysis of 2 double-blind, 6-month GMB studies in patients randomized (1:1:2) to monthly subcutaneous GMB 120 mg (after 240 mg initial loading dose) or 240 mg or placebo. The proportions of patients with a ≥50%, ≥75%, or 100% reduction from baseline in monthly MHD on an average month from Months 1 to 3 and Months 4 to 6 were evaluated. A generalized linear mixed model with effects for baseline MHD, treatment, month, and treatment-by-month interaction was used to estimate the mean monthly response rate.

A total of 1739 patients (GMB,n=864 and placebo n=875) were evaluated. In the GMB groups, the mean rates on an average month from Months 1 to 3 of ≥50% (53% to 56%), ≥75% (29% to 32%), and 100% (9% to 12%) responses were greater (p<0.001) than placebo rates of ≥50% (30% to 34%), ≥75% (13% to 15%), and 100% (5%) response. The mean response rates on an average month in the GMB groups were sustained in Months 4 to 6 and greater (p<0.001) than placebo. The average reduction of 5 MHD/month in the GMB groups was greater than the reduction of 3 MHD/month with placebo (p<0.001).

More GMB-treated patients achieved ≥50% response; this was sustained during Months 4 to 6. The odds of achieving ≥50% response was double for GMB, despite the high placebo response; the number of MHD/month with GMB was nearly half that of placebo.