Mirum's liver infection drug lowers virus levels in late-stage study. By Thomson Reuters Sep 28, 2026 | 8:49 AM By Sneha S K Sept 28 (Reuters) - Mirum Pharmaceuticals on Monday said its experimental hepatitis drug reduced levels of the virus in patients, meeting the main goal of a late-stage study. Here are some key details: - Mirum was testing brelovitug, an experimental monoclonal antibody that binds to the hepatitis B surface antigen, a protein found on the surface of the virus - The company was testing the treatment for chronic hepatitis delta virus, a liver infection that affects people already infected with hepatitis B - The disease, which the company estimates affects about 230,000 people in the US and Europe, can cause severe symptoms that can lead to liver damage and, in some cases, death - At 24 weeks, 56% of patients given 300 milligrams of brelovitug and 45% of those given 900 milligrams showed reduced hepatitis D virus levels and normal liver enzyme levels, compared with 0% in the delayed-treatment group, the company said - The company expects the drug to generate peak sales of at least $1 billion - The only FDA-approved treatment for the condition is Gilead's Hepcludex - "Brelovitug has a better benefit/risk profile," said RBC Capital Markets analyst Lisa Walter, adding that the latest results position it as the best-in-class treatment option - The drug was well tolerated across dose groups, with a safety profile consistent with previously reported data, Mirum said - Full results from the study will be presented at an upcoming medical congress, with the company expecting to submit a marketing application for the drug to the US FDA in the first half of 2027. (Reporting by Sneha S K in Bengaluru; Editing by Jonathan Ananda and Diti Pujara)

The US Food and Drug Administration has approved Atebrioz (zilurgisertib) for adult and paediatric patients aged 12 and older with fibrodysplasia ossificans progressiva, a rare genetic disease affecting approximately 300 people in the United States. Mirum Pharmaceuticals and Incyte announced the approval, which makes Atebrioz the latest treatment option for the progressive condition that causes bone to form in muscles, tendons, and other soft tissues. The once-daily oral tablet works by inhibiting ALK2, targeting the disease-driving pathway. Clinical trial data showed that at 24 weeks, mean total new heterotopic ossification volume decreased by 3.2 cm³ in patients receiving the drug compared with an increase of 24.6 cm³ in placebo-treated patients. Atebrioz is expected to be commercially available in October through Mirum Access Plus, with eligible patients paying as little as $0 per month.

U.S. FDA approves Mirum Pharmaceuticals' zilurgisertib as a treatment for FOP. Posted on September 25, 2026 Atebrioz(TM) is the third treatment approved for people living with FOP in the United States. Today, September 25, is an incredible day for the FOP community! IFOPA want to start by thanking FOP community members from around the world who participated in the zilurgisertib trial. Mirum Pharmaceuticals and Incyte have announced the U.S. Food & Drug Administration's (FDA) approval of zilurgisertib tablets for the treatment of fibrodysplasia ossificans progressiva (FOP) in the United States. Zilurgisertib is the first FOP drug approved after completing only a Phase 2 clinical trial. * The brand name of the drug is Atebrioz(TM) * Once-daily oral ALK2 inhibitor approved to reduce the volume of total new heterotopic ossification in patients aged 12 years and older with FOP. * Mirum will soon release websites to help people with FOP and their local healthcare providers learn more about Atebrioz. * Atebrioz is expected to be available in the United States in October through Mirum Access Plus (MAP), with eligible patients paying as little as $0 per month. * Atebrioz is only available for treatment of FOP for individuals in the United States. * The European Medicines Agency (EMA) in the European Union is also reviewing zilurgisertib. Letter from Mirum's CEO. Thank you. Zilurgisertib (now known as Atebrioz) was tested in the PROGRESS Phase 2 clinical trial. IFOPA is deeply grateful to the 63 people with FOP who participated. IFOPA is also grateful to the Principal Investigators, Study Coordinators, and all of the staff at the trial sites who took such good care of its families. IFOPA want to thank Novartis, Incyte, and Mirum for their commitment and dedication to the FOP community. Publications & Presentations. The links below include press releases, a poster, and a plain language summary of the PROGRESS trial results. IFOPA expect a publication in a peer-reviewed journal. Presentations from the 2026 7th FOP Drug Development Forum Incyte shared this poster and plain-language summary of their results, which show an 81% reduction in the proportion of patients with new lesions at Week 24 (compared to placebo), at ENDO 2026, the leading global meeting on endocrinology research and clinical care hosted by the Endocrine Society. Where is Atebrioz approved? It is important to note that the FDA's approval of Atebrioz is only for people aged 12 and older with FOP living in the United States. On August 5, 2026, Mirum announced during an Investor Call that the EMA in the European Union accepted zilurgisertib for review. IFOPA await the EMA's decision. In what other countries is Mirum seeking approval of zilurgisertib? Zilurgisertib previously received Fast Track designation and Orphan Drug Designation from the FDA, as well as Orphan Designation by the European Medicines Agency in the European Union. IFOPA communicate regularly with Mirum about developments with zilurgisertib and will share announcements with the FOP community when they are publicly available. Is zilurgisertib in a trial for children younger than 12? The PROGRESS Phase 2 trial includes an active Cohort 2 for children ages 6 to < 12 years of age that is fully enrolled. Cohort 3 for children ages 2 to < 12 years is recruiting. You can learn more at ifopa.org/progress If you would like to receive updates on clinical trials and drug reviews, please sign up for IFOPA's Clinical Trial Alerts at ifopa.org/clinical-trial-alerts About zilurgisertib. People with FOP harbor mutations in the ALK2 protein (also known as ACVR1) that drives excessive bone morphogenetic protein (BMP) signaling, which regulates cartilage and bone development. Zilurgisertib (INCB000928) is an oral investigational drug designed to target and block this disease-causing mutant FOP protein hyperactivity. In preclinical studies, zilurgisertib demonstrated potency for the target kinase, selectivity, safety and strong suppression of heterotopic ossification (HO) in animal models.