An enzyme-antibody complex of clinical interest is Valanafusp alpha, which consists of the enzyme alpha-l-iduronidase conjugated to an IgG antibody, and was developed for the treatment of MPS I. In 2018 Pardridge et al. evaluated the pharmacokinetics of Valanafusp alpha in 18 patients, five adults and 13 children, with MPS I [111]. The gene discussed is IDUA; the disease is Scheie syndrome.