EGT-301

**EGT-301** is an investigational **gene therapy** developed by ESTEVE in collaboration with Universitat Autònoma de Barcelona (UAB) for the treatment of **Hunter syndrome** (mucopolysaccharidosis II, MPS II), a rare lysosomal storage disorder caused by deficiency of the iduronate-2-sulfatase (I2S) enzyme. It consists of an **adeno-associated viral vector serotype 9 (AAV9)** encoding the human **I2S transgene**, designed to restore functional I2S enzyme activity systemically, including in the central nervous system, to address glycosaminoglycan accumulation leading to progressive neurological and somatic manifestations. EGT-301 has received **orphan drug designation** from both the FDA and EMA.[1][2][3]