Mirum is committed to transforming the treatment of rare diseases by putting the needs of patients first. We are an established leader in the development and commercialization of life changing medicines for rare and orphan diseases where the unmet medical need is high. Our desire to fill a therapeutic void for people with rare diseases drives our passion for science and continued clinical evaluation of investigational therapies.
LIVMARLI
Our first commercial product, LIVMARLI (maralixibat) is an orally administered, ileal bile acid transporter (IBAT) inhibitor approved by the U.S. Food and Drug Administration for two pediatric cholestatic liver diseases. It is approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS) in the U.S. three months of age and older and in Europe for patients two months of age and older. It is also approved in the U.S. for the treatment of cholestatic pruritus in patients with progressive familial intrahepatic cholestasis (PFIC) 12 months of age and older and in Europe for the treatment of PFIC in patients three months of age and older.
ALGS is a rare genetic disorder of severe cholestasis where bile ducts abnormally narrow and malform, leading to bile accumulation in the liver and ultimately progressive liver disease. In patients with ALGS, multiple organ systems may be affected by the mutation, including the liver, heart, kidneys and central nervous system. The high levels of bile acid buildup in patients with ALGS is an underlying cause of cholestatic pruritus (itch), which affects 88% of people with the syndrome and is considered the most burdensome symptom. In children with cholestasis due to ALGS, it is estimated that six in ten children progress to transplant or death by adulthood. We believe the prevalent patient population for ALGS in the United States and Europe is approximately 4,000 - 5,500 pediatric patients. ALGS is estimated to impact one out of every 30,000 births globally.
Cholestatic pruritus also occurs in patients with PFIC, a rare genetic disorder caused by defects in genes that produce proteins needed to form bile and transport it out of the liver. In children, PFIC represents 10% to 15% of indications for liver transplant, either due to intractable pruritus or end-stage liver disease. The prevalent patient population for PFIC is approximately 1,000.
CHOLBAM
The FDA approved CHOLBAM (cholic acid) capsules in March 2015, as the first FDA-approved treatment for pediatric and adult patients with bile acid synthesis disorders due to single enzyme defects and for adjunctive treatment of patients with peroxisomal disorders, including PBD-ZSD and SLOS. Bile acid synthesis disorders (BASD) due to single enzyme defects are a rare group of inherited genetic disorders caused by defects in the enzymes that make bile acids. These defects interfere with normal production of bile acids. As a result, bile cannot flow from the liver to the small intestine, a condition called cholestasis that presents as prolonged jaundice in newborns. The effectiveness of CHOLBAM has been demonstrated in clinical trials for bile acid synthesis disorders and the adjunctive treatment of peroxisomal disorders.
CHENODAL
CHENODAL (chenodiol) is a naturally occurring bile acid that is approved for the treatment of people with radiolucent stones in the gallbladder. While indicated for radiolucent stones in the gallbladder, CHENODAL has received medical necessity recognition by the FDA for the treatment of cerebrotendinous xanthomatosis (CTX), and is the standard of care for CTX, although it is not currently labeled or promoted for this indication. CTX is a rare, progressive and underdiagnosed bile acid synthesis disorder affecting many parts of the body. We estimate there are 1,000 - 2,000 prevalent CTX patients in the United States, however only 10% are currently diagnosed. We submitted an NDA for the treatment of CTX to the FDA in the first half of 2024.
Patient Assistance
The Mirum Access Plus (MAP) program helps patients and families navigate the treatment journey for all three of our medicines – LIVMARLI, CHOLBAM, and CHENODAL. Through this program, MAP experts support patients by explaining the process of getting medication, working with dedicated healthcare teams to figure out insurance coverage and eligibility for financial support programs, and providing education and resources to help patients start and stay on therapy. Mirum is committed to finding access solutions to support appropriate patients in need of our products. CHOLBAM, CHENODAL and LIVMARLI all have reimbursable pathways with most payers.
In addition, Mirum has an expanded access program open across multiple countries for eligible patients with ALGS and PFIC.
Development Pipeline
Our late-stage pipeline includes three investigational treatments for debilitating liver diseases. LIVMARLI is currently being evaluated in the Phase 3 EXPAND study in additional settings of cholestatic pruritus. Volixibat, an IBAT inhibitor, is being evaluated in two potentially registrational studies including the Phase 2b VISTAS study for primary sclerosing cholangitis and Phase 2b VANTAGE study for primary biliary cholangitis. Lastly, chenodiol, has been evaluated in a Phase 3 clinical study, RESTORE, to treat patients with CTX, with positive topline results reported in 2023. Mirum has submitted a new drug application with the FDA for the approval of chenodiol to treat CTX in the U.S.