The FDA approved Regeneron Pharmaceuticals’ Pasatru (garetosmab-grts) for adults with Fibrodysplasia Ossificans Progressiva (FOP). FOP is an ultra-rare genetic disorder that causes muscles and tendons to progressively turn into bone. This condition leads to severe mobility loss.
Pasatru is a monoclonal antibody that blocks the Activin A protein. This protein drives abnormal bone formation in FOP patients. The Phase 3 OPTIMA trial demonstrated that Pasatru reduced new abnormal bone growth lesions by 90% or more compared to a placebo. Researchers measured this reduction over a 56-week period.
Pasatru is the second approved therapy for FOP. It is the first treatment to show lesion reduction in a placebo-controlled trial. The drug competes with Ipsen’s Sohonos, which was approved in 2023. Regeneron plans an immediate launch for the estimated 900 people diagnosed with FOP worldwide.