Prime Medicine Says US FDA Clears PM647 IND for Alpha-1 Antitrypsin Deficiency; Shares Rise After Hours

04:32 PM EDT, 09/24/2026 (MT Newswires) -- Prime Medicine (PRME) has received clearance from the US Food and Drug Administration for its investigational new drug application for PM647, allowing the gene-editing therapy to enter clinical testing in alpha-1 antitrypsin deficiency, the company said late Thursday. The company plans a phase 1/2 global, open-label study evaluating the safety, tolerability and preliminary efficacy of a one-time intravenous infusion of PM647 in adults with the disorder. The trial will initially enroll patients with lung-only manifestations of alpha-1 antitrypsin deficiency before expanding to adults with significant liver disease, the company said. PM647 is designed to correct the E342K mutation in the SERPINA1 gene, the most common cause of the condition, Prime Medicine said. Shares of Prime Medicine were up nearly 12% in after-hours activity.