Rosiglitazone therapy is associated with major clinical improvements in a patient with fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic condition characterized by progressive heterotopic ossification, increasing disability, and cumulative immobility. Thiazolidinediones, introduced in 1999 for the treatment of diabetes, enhance bone marrow adipogenesis at the expense of new bone formation, and this might be exploited for the treatment of FOP. A 48-year-old woman with severe FOP characterized by continuous flares that she was partially controlling only with high prednisone doses was given rosiglitazone (initially 4 mg and then 8 mg daily) for 14 months. No new flare-ups were observed during rosiglitazone therapy as compared to the five episodes observed during the previous year while on 20 to 25 mg prednisone daily. The steroid dose could be lowered progressively to 5 mg/day, the skin became softer, and the articular mobility improved impressively. This case report seems to suggest that rosiglitazone therapy, possibly in association with small doses of prednisone, is associated with important clinical improvements in patients with FOP. (c) 2010 American Society for Bone and Mineral Research.