The US Food and Drug Administration (FDA) has approved Garetosmab-grts (Pasatru), an activin signaling inhibitor indicated to reduce the formation of new heterotopic ossification (HO) lesions and clinician-assessed flare-ups in adults with fibrodysplasia ossificans progressiva (FOP). Garetosmab-grts specifically binds to and inhibits activin A signaling, blocking activation of FOP-mutant ACVR1 and reducing the formation and progression of new heterotopic bone lesions. Clinical Evidence Supporting Approval The efficacy of garetosmab-grts was evaluated in a clinical trial involving 63 adults with FOP.

Patients received garetosmab-grts 10 mg/kg, 3 mg/kg, or placebo every 4 weeks for 56 weeks. Key findings at Week 56 included: 90% reduction in new HO lesions with 10 mg/kg vs placebo 94% reduction with 3 mg/kg vs placebo Clinician-assessed flare-ups: 9 with 10 mg/kg, 53 with 3 mg/kg, and 66…