Treatment Patterns for Calcitonin Gene-Related Peptide Monoclonal Antibodies Including Galcanezumab versus Conventional Preventive Treatments for Migraine: A Retrospective US Claims Study

Abstract

Background: Most conventional, oral, preventive treatments for migraine are non-specific and ~50% of patients discontinue them within six months. In 2018, the Food and Drug Administration approved three preventive migraine treatments: monoclonal antibodies (mAb) targeting the calcitonin gene-related peptide (CGRP) pathway implicated in migraine; galcanezumab and fremanezumab which target CGRP ligand; and erenumab which targets CGRP receptor. Real-world treatment patterns for CGRP mAb are limited. Purpose: To compare real-world treatment patterns for CGRP mAb, specifically galcanezumab versus standard-of-care (SOC) migraine preventive treatments. Patients and methods: This retrospective, observational study included 12-month baseline and 6-and 12-month follow-up analyses using IBM® MarketScan® databases. Patients identified were aged ≥18 years with ≥1 claim (first claim=index) for CGRP mAb (erenumab, fremanezumab, or galcanezumab) or SOC preventives (eg, antiepileptics, beta-blockers, antidepressants, or onabotulinumtoxinA) as index drugs between May/01/2018 and June/30/2019. Propensity score matching was used to address confounding by observed covariates. Outcomes analyzed included proportion of days covered (PDC), persistence (≤60-day gap), and first non-index drug switch. Descriptive, chi-square (categorical), and t-test (continuous) analyses were conducted. Results: The study included 3082 (CGRP mAb versus SOC) and 421 (galcanezumab versus SOC) matched patient pairs with 12-month follow-up. Mean age across cohorts ranged 43.2–44.4 years (females: 85.7–88.6%). Compared with SOC, the CGRP mAb cohort had higher mean persistence (212.5 vs 131.9 days), adherence (PDC: 55.1% vs 35.2%), and more patients were adherent with PDC ≥80% (32.7% vs 18.7%) (all p <0.001). During 12-month follow-up, fewer patients discontinued CGRP mAb versus SOC (58.8% vs 77.6%, p <0.001). Galcanezumab versus SOC comparisons yielded similar results. In the CGRP mAb cohort, most switchers (28.3%) used galcanezumab as subsequent treatment. Largely similar results were observed for 6-month follow-up cohorts. Conclusion: Patients on CGRP mAb and specifically galcanezumab showed higher adherence and persistence than patients on SOC migraine preventive treatments.