Mirum Pharmaceuticals, Inc.: management transactions · United States · SEC (Form 4)

About Mirum Pharmaceuticals, Inc.

Mirum Pharmaceuticals, Inc. is a U.S.-based biopharmaceutical company listed on the Nasdaq under the ticker MIRM and headquartered in Foster City, California, United States. The company operates in the rare-disease segment, with a strong strategic focus on rare cholestatic liver disorders affecting both pediatric and adult patients. Founded in 2018, Mirum has built its identity around developing and commercializing therapies for underserved rare conditions, combining marketed products with a clinical pipeline aimed at expanding its long-term opportunity set. Mirum’s business model is anchored by three approved medicines. LIVMARLI (maralixibat) is the flagship asset and an IBAT inhibitor used for cholestatic pruritus in rare liver diseases, including Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC). CHOLBAM (cholic acid) addresses bile-acid synthesis disorders and other rare metabolic conditions. CTEXLI (chenodiol) is approved for cerebrotendinous xanthomatosis (CTX), a severe orphan disease. Together, these products give Mirum a diversified commercial base within a highly specialized therapeutic niche, while keeping the company focused on rare liver disease and adjacent orphan indications. From a competitive standpoint, Mirum is differentiated by its deep specialization. Rather than competing broadly across hepatology or rare disease, it concentrates on a small number of high-unmet-need conditions where physician expertise is centralized and clinical differentiation matters. Its competitive set includes other rare-disease biotechs and, potentially, larger pharmaceutical groups that may enter the space through licensing or acquisition. Mirum’s advantage lies in its targeted commercial infrastructure, its established relationships with rare-disease centers, and its ability to extend existing scientific platforms into adjacent indications. Recent developments underscore the company’s momentum. In 2025, the FDA approved a tablet formulation of LIVMARLI, which improves product convenience and may support broader patient uptake. Mirum also reported continued growth in LIVMARLI sales and advanced several development programs, including volixibat, its clinical-stage asset for cholestatic diseases. More recently, the company completed the acquisition of Bluejay Therapeutics, adding worldwide rights to brelovitug, a late-stage monoclonal antibody in chronic hepatitis delta, thereby widening Mirum’s pipeline beyond pediatric cholestasis into another severe rare liver disease with significant unmet need. For international equity investors, Mirum is a Nasdaq-listed U.S. rare-disease platform with meaningful commercial traction, but one that remains highly dependent on regulatory execution, clinical success, and continued product adoption.