Comparison of Treatment Patterns in Patients with Migraine Initiating Calcitonin Gene-Related Peptide Monoclonal Antibodies: A Retrospective Real-World US Study

Background: Calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs) are indicated for migraine prevention in the United States. Limited data comparing real-world treatment patterns for CGRP mAbs are available. Objective: To compare the treatment patterns among patients with migraine initiating galcanezumab, fremanezumab, and erenumab. Methods: This retrospective study included adult patients with one or more claims for a self-injectable CGRP mAb (galcanezumab, fremanezumab, or erenumab), with continuous enrollment in medical and pharmacy benefits for 12 months pre-index and 6 and 12 months post-index using MerativeTM MarketScan (R) Commercial and Medicare databases from May 2017 through March 2021. Propensity-score matching was used to address confounding by observed covariates. Outcomes analyzed included proportion of days covered (PDC), medication-possession ratio (MPR), persistence (<= 60-day gap), treatment discontinuation, and switch to a non-index drug. Descriptive X2 and t-test analyses were conducted. Results: At the 12-month follow-up, matched galcanezumab and fremanezumab cohorts each comprised 2674 patients and the galcanezumab and erenumab cohorts 3503 each. The mean (SD) PDC and MPR were both 0.6 (0.3) across all cohorts. Based on PDC 20.80 and MPR 20.80, a greater proportion of galcanezumab vs fremanezumab (46.2% vs 43.7%, p=0.053; 46.8% vs 44.3%, p=0.053) and galcanezumab vs erenumab (46.2% vs 44%, p=0.156; 46.7% vs 44.5%, p=0.262), respectively, initiators were adherent. Compared to galcanezumab, fremanezumab (248.0 days vs 236.5 days, p=0.001), and erenumab (247.8 days vs 241.7 days, p=0.061) initiators had lower mean persistence. Galcanezumab initiators were less likely to discontinue treatment than fremanezumab (47.8% vs 51.7%, p=0.005) and erenumab (47.7% vs 50.2%, p=0.040) initiators. Across cohorts, most switchers initiated onabotulinum toxin A as subsequent treatment. Similar results were observed for 6-month follow-up cohorts. Conclusion: Patients with migraine who initiated treatment with galcanezumab showed higher persistence and lower treatment discontinuation rates than those initiating either fremanezumab or erenumab.