A high affinity IRMAb against the human insulin receptor (HIR) was genetically fused to the lysosomal enzyme, iduronidase (IDUA), and this HIRMAb-IDUA fusion protein, designated valanafusp alpha, was tested in a year-long clinical trial in pediatric patients with mucopolysaccaridosis Type I (MPSI), also called Hurler syndrome [2]. Here, IDUA is linked to Hurler syndrome.