The FDA approved Mirum and Incyte’s Atebrioz (zilurgisertib) for fibrodysplasia ossificans progressiva (FOP) in patients aged 12 and older. In a 24-week trial, treated patients’ bone-lesion volume fell by a mean of 3.2 cm³, versus a 24.6 cm³ increase with placebo.
Incyte developed Atebrioz and licensed it to Mirum for global commercialization. The oral ALK2 inhibitor targets a pathway involved in FOP; the recommended dose is 100 mg once daily. FOP is a rare genetic disorder in which ACVR1 variants cause abnormal bone formation in soft tissues. Trial effects persisted through a 48-week open-label extension. Common side effects during the 24-week controlled period included headache, upper respiratory tract infections, joint pain, nosebleeds and nausea; these were generally mild to moderate, and no participant needed to stop treatment or reduce the dose.
US availability is expected to begin in October through Mirum Access Plus, which offers insurance and financial assistance as well as educational resources; eligible patients may pay as little as $0 per month. Enrollment has concluded for children aged 6 to under 12 and is underway for those aged 2 to under 6. The European Medicines Agency is evaluating Atebrioz’s marketing application. The FDA also awarded Incyte a rare paediatric disease priority review voucher for a future drug application.
