Core Insights - Garetosmab is the first and only treatment to show significant reduction in both the number and volume of abnormal bone lesions in adults with fibrodysplasia ossificans progressiva (FOP) [1][2][6] - The Phase 3 OPTIMA trial met its primary endpoint, demonstrating a 90% or greater reduction in new heterotopic ossification (HO) lesions at 56 weeks [1][3][4] - The Independent Data Monitoring Committee recommended transitioning placebo patients to garetosmab, with U.S. regulatory submission planned for year-end 2025 [1][6] Trial Details - The OPTIMA trial was a global, multi-center, randomized, double-blind, placebo-controlled study involving 63 adults with FOP [2][9] - Participants received either placebo, 3 mg/kg garetosmab, or 10 mg/kg garetosmab every four weeks for 56 weeks [2][9] - Key secondary endpoints included a significant reduction in clinician-assessed flare-ups, with an 89% reduction in the 10 mg/kg group compared to placebo [4][5] Efficacy Results - At 56 weeks, the total number of new HO lesions was reduced by 94% in the 3 mg/kg group and 90% in the 10 mg/kg group compared to placebo [4][5] - The mean total volume of new HO lesions showed a reduction of 99% in both garetosmab treatment arms compared to placebo [4][5] Safety Profile - There were no discontinuations in the garetosmab treatment arms, with one discontinuation in the placebo arm due to an ovarian cyst [5] - A dose-dependent increase in skin and soft tissue infections was observed, but no serious bleeding events were reported [5] - Serious treatment-emergent adverse events occurred in a small number of patients across all treatment groups, with no deaths reported [5] Future Plans - A Phase 3 trial of garetosmab in adolescents and children with FOP, named OPTIMA 2, is planned to begin next year [6][11] - Global regulatory submissions for garetosmab are slated for 2026 following the U.S. submission [6]
Regeneron Announces Positive Phase 3 Trial in Adults with Ultra-Rare Genetic Disorder Fibrodysplasia Ossificans Progressiva (FOP), Demonstrating that Garetosmab Prevents Greater than 99% of Abnormal Bone Formation