Gene Therapy Clinical Study in Adult PKU

Part 1 of this study will evaluate the safety and efficacy of HMI-102 gene therapy in adult subjects with PKU due to PAH deficiency. Subjects will receive a single dose of HMI-102 administered intravenously. Up to 3 dose levels of HMI-102 may be investigated in this study. At a given dose level, a minimum of 2 subjects will be enrolled and dosed. Dosing of the first two subjects will be staggered. Following evaluation of data from the first 2 subjects in a cohort, a decision can be made to either escalate to the next dose level or expand the cohort at the selected dose level. Additional doses may be added by HMI to investigate intermediate or higher doses. In Part 2 dose expansion, evaluation of up to 2 dose levels is planned. Subjects will be randomized to receive HMI-102 or a concurrent delayed treatment control arm. Subjects in the delayed treatment control will be eligible to receive HMI-102 after 28 weeks.