The FDA cleared Regeneron’s Pasatru (garetosmab) for fibrodysplasia ossificans progressiva (FOP), setting up a commercial race against Ipsen’s Sohonos. The approval follows Phase 3 results reported last September showing a 90% or greater reduction in new abnormal bone formations compared with placebo over one year. Regeneron said Pasatru is priced at an average annual per-patient list price of about $1.4 million, with dosing dependent on weight. The approval also brings the antibody into a category where flare-up safety considerations have been a recurring theme in this ultra-rare space. The competitive impact is immediate: payers, specialty centers, and patient groups will compare efficacy signals and flare-up profiles as treatment access expands in the U.S.