Mirum receives FDA approval for Atebrioz, third therapy for ultra-rare bone disease FOP

Mirum Pharmaceuticals announced that the U.S. Food and Drug Administration approved its ALK2 inhibitor, zilurgisertib, to be marketed as Atebrioz, for the treatment of fibrodysplasia ossificans progressiva (FOP).

FOP, sometimes called “stone man syndrome,” is an ultra-rare genetic disorder that causes bone to form in muscles, tendons and ligaments, leading to pain, stiffness and loss of mobility. The condition affects roughly one in a million people worldwide and previously had no approved therapies.

Atebrioz becomes the third FDA-cleared option for FOP, joining Regeneron’s Pasatru and Ipsen’s Sohonos, each introduced in the past year. The new drug offers patients and clinicians an additional choice to slow disease progression.

Mirum’s chief executive highlighted the severity of the disease and the importance of having a treatment that can interrupt the abnormal bone-forming process, noting that even minor injuries can trigger new bone growth.