The FDA cleared Regeneron’s activin A-targeting antibody garetosmab, branded Pasatru, for fibrodysplasia ossificans progressiva (FOP). The approval follows Phase 3 results showing reductions in new abnormal bone formations of 90% or more versus placebo over 56 weeks, and high-dose Pasatru also reduced clinician-assessed flare-ups. Pasatru becomes the second FDA-cleared therapy for FOP, after Ipsen’s Sohonos (palovarotene). Regeneron’s decision to advance the program was preceded by a study pause tied to deaths of trial participants; the company said it determined the treatment was not the cause. Pricing and commercial positioning were also outlined, with Regeneron indicating an annual list price around $1.4 million per patient based on enrolled clinical-studies enrollees. With regulators now granting a second mechanism-based option in the ultra-rare disease, competitive dynamics could intensify—especially as Regeneron prepares for launch in the roughly 220 adult U.S. patients treated under the indication.