AP103

AP103 is an experimental, topical, non-viral gene therapy being developed by Amryt Pharma (now a subsidiary of Chiesi) for the treatment of dystrophic epidermolysis bullosa (DEB), particularly recessive dystrophic epidermolysis bullosa, a severe inherited blistering skin disease caused by mutations in the COL7A1 gene encoding collagen VII.[1][2][5][9][13] The therapy uses a synthetic polymer delivery vector, highly branched poly β-amino ester (HPAE), to transfer a functional COL7A1 gene into skin cells, restoring production of collagen VII at the dermal–epidermal junction and thereby aiming to strengthen skin integrity and reduce blistering when applied topically.[1][2][5][9][13] AP103 has received orphan drug designation from the U.S. FDA and a positive orphan designation opinion in Europe for DEB, and is currently in preclinical development and regulatory designation stages as part of Amryt’s broader gene-therapy platform for genetic skin disorders.[2][5][10][12]