Abstract 128: A Translational Strategy Targeting Type I BMP Receptors to Prevent Heterotopic Ossification

PURPOSE: Trauma-induced heterotopic ossification (tHO) is the aberrant growth of ectopic bone in soft tissue, which develops in patients following severe musculoskeletal trauma. Much of HO literature focuses on a related pathology known as fibrodysplasia ossificans progressiva (FOP), which is caused by a hyperactivating mutation in the type I bone morphogenetic protein receptor (T1-BMPR) ACVR1 (ACVR1 R206H). Consequently, emphasis has been placed on developing inhibitors with improved specificity for ACVR1. However, patients who develop tHO do not harbor known ACVR1 mutations, and it is unclear whether emphasis on ACVR1-specific inhibition is beneficial for the treatment of tHO. Here investigate whether any single T1-BMPR is required for tHO, or whether these receptors perform overlapping roles during tHO development. We further evaluate the efficacy of the BMP ligand trap, Alk3Fc, as a broad-spectrum inhibitor of T1-BMP receptors in the treatment and prevention tHO.