Impact of Age and Sex on the Efficacy of Fremanezumab in Patients with Difficult-to-treat Migraine: Results of the Randomized, Placebo-controlled, Phase 3b FOCUS Study

Background: Migraine prevalence is age and sex dependent, predominating in women in early and middle adulthood; however, migraine also represents a substantial burden for men and adults of all ages. Thus, understanding this burden and the efficacy of migraine preventive medications in both sexes and across age groups is critical. The randomized, placebo-controlled, double-blind, phase 3b FOCUS study demonstrated the safety and efficacy of fremanezumab, a fully humanized monoclonal antibody (IgG2∆a) that selectively targets calcitonin gene-related peptide as a migraine preventive treatment for individuals with migraine and prior inadequate response to 2 to 4 migraine preventive medication classes. Here, we assessed the efficacy of fremanezumab in participants from FOCUS subgrouped by age (18-45 years and > 45 years) and sex.

Methods: In the FOCUS study, eligible participants were randomized (1:1:1) to 12 weeks of double-blind treatment with quarterly fremanezumab, monthly fremanezumab, or matched monthly placebo. In this post hoc analysis, we evaluated changes from baseline in monthly migraine days (primary endpoint of FOCUS) and other secondary and exploratory efficacy outcomes in prespecified age (18-45 and > 45 years) and sex subgroups.

Results: The modified intention-to-treat population (received ≥ 1 dose of study drug and had ≥ 10 days of postbaseline efficacy assessments for the primary endpoint) totaled 837 participants (18-45 years, n = 373; > 45 years, n = 464; male, n = 138; female, n = 699). Consistent reductions in monthly average number of migraine days during 12 weeks were observed, regardless of age (18-45 years: quarterly fremanezumab, - 4.1 days; monthly fremanezumab, - 4.7 days; placebo, - 0.9 days; P < 0.001; > 45 years: quarterly fremanezumab, - 3.6 days; monthly fremanezumab, - 3.7 days; placebo, - 0.3 days; P < 0.001) and sex (male: quarterly fremanezumab, - 4.1 days; monthly fremanezumab, - 4.6 days; placebo, - 0.3 days; P < 0.001; female: quarterly fremanezumab, - 3.6 days; monthly fremanezumab, - 3.9 days; placebo, - 0.6 days; P < 0.001). Fremanezumab also reduced monthly headache days of at least moderate severity, monthly days of acute medication use, and improved Migraine Disability Assessment scores across subgroups.

Conclusions: These results demonstrate the efficacy of fremanezumab in patients with difficult-to-treat migraine for reducing migraine and headache days, acute medication use, and disability, regardless of age or sex.

Trial Registration: ClinicalTrials.gov Identifier NCT03308968 (FOCUS), registered October 13, 2017.