MPS I (encompassing Hurler, Hurler/Scheie, Scheie syndromes) is the most common MPS disease. It is caused by genetic deficiencies in the lysosomal enzyme α-L-iduronidase (IDUA). Current IDUA-based ERTs for MPS I patients effectively treat most somatic symptoms, but do not correct significant debilitating manifestations of this disease, especially those affecting the central nervous system (CNS).  We are developing an improved enzyme replacement therapeutic for MPS I that integrates safety and cost advantages of plant-based bioproduction with innovations that enhance ERT delivery and disease correction.