Regeneron's Pasatru receives FDA approval for ultra-rare bone-growth disease FOP

Regeneron Pharmaceuticals has secured FDA approval for Pasatru, a therapy aimed at treating fibrodysplasia ossificans progressiva (FOP), an ultra‑rare condition in which bone forms in soft tissues.

In a pivotal trial the drug dramatically cut the risk of new bone formation, effectively halting disease progression, according to primary investigator Richard Keen of the Royal National Orthopaedic Hospital.

Patients with FOP typically become wheelchair‑bound by their mid‑20s and have limited life expectancy; the new treatment offers hope of preserving mobility and potentially extending survival.