A Study of the Safety and Efficacy of Prime Editing (PM647a) in Participants With Alpha-1 Antitrypsin Deficiency

The purpose of this study is to evaluate the safety, tolerability, biological activity, and initial efficacy of PM647a, an investigational Prime Editing therapy, in adults and adolescents with Alpha-1 Antitrypsin Deficiency (AATD). AATD is caused by a mutation (change) in a gene called SERPINA1 that prevents the cells in your liver from producing a functional protein (alpha-1 anti-trypsin; AAT) that helps protect your lung tissue. PM647a is designed to precisely correct the prevalent disease-causing mutation (SERPINA1 Pi\*Z (E342K)) with the goal of restoring functional AAT. This is the first study of PM647a in humans. Participants will receive a single intravenous (IV) infusion of PM647a and will be monitored closely to evaluate safety, how the body responds to treatment, changes in AAT protein levels, and whether treatment may improve signs and symptoms of AATD.