FDA Approves Mirum's Atebrioz, Offering Third Treatment Option for Ultra-Rare Bone Disease
The U.S. Food and Drug Administration (FDA) has granted approval to Mirum Pharmaceuticals for Atebrioz (zilurgisertib), an ALK2 inhibitor designed to treat fibrodysplasia ossificans progressiva (FOP). This approval marks the third treatment option available for the ultra-rare bone-forming disease, often referred to as 'stone man syndrome,' which causes soft tissue to turn into bone, leading to pain, stiffness, and immobility. Atebrioz is a once-daily pill that inhibits the activin receptor-like kinase 2 (ALK2) protein, a key factor in abnormal bone growth in FOP. The approval was based on data from the Phase 2 PROGRESS study, which demonstrated an 81% reduction in new lesion volume and a 99% reduction in total volume compared to placebo at 24 weeks. Mirum acquired full ownership of Atebrioz in April, having previously been licensed by Incyte for clinical development. The drug is approved for patients aged 12 years and older.