Real-World Impact of Maralixibat Treatment on Concomitant Medication Use in USA-Based Patients with Alagille Syndrome and Cholestatic Pruritus: A Retrospective Analysis

INTRODUCTION: Alagille syndrome (ALGS) is a rare cholestatic liver disease characterized by severe pruritus, with many patients also experiencing impaired growth, failure to thrive, and fat-soluble vitamin deficiencies. Patients often require multiple antipruritic medications to control pruritus and may also receive nutritional or vitamin supplements to address nutritional deficiencies and improve growth, leading to substantial polypharmacy burden. Maralixibat, a minimally absorbed ileal bile acid transporter inhibitor, is approved for the treatment of cholestatic pruritus in patients with ALGS ≥ 3 months of age in the USA and ≥ 2 months of age in the European Union (EU). This study evaluated real-world concomitant medication usage during long-term maralixibat treatment using pharmacy data from Mirum Access Plus, a single-source specialty pharmacy and education program for patients receiving maralixibat. METHODS: A retrospective analysis was conducted using pharmacy data from the Mirum Access Plus program to evaluate concomitant medication trends for at least 2 years of potential use. Data were extracted on April 30, 2024, and included all patients in the USA who initiated maralixibat by April 1, 2022, and had not discontinued therapy. RESULTS: This analysis included 178 patients with ALGS who received maralixibat. The median age at maralixibat initiation was 6 years. At the start of maralixibat treatment, patients were taking a median of two antipruritic medications and one nutritional or vitamin supplement. During maralixibat treatment, 43% of patients discontinued ≥ 1 concomitant medication, 21% discontinued ≥ 2 medications, and 8% discontinued ≥ 3 medications. CONCLUSIONS: These real-world results indicate treatment with maralixibat may reduce polypharmacy burden in patients with ALGS and their caregivers by enabling discontinuation of antipruritic medications and nutritional or vitamin supplements.