Prime Medicine, Inc.
-- Clearance highlights continued execution, modularity and momentum across Prime Medicine's liver franchise, building on recent regulatory clearances for PM577a --
-- Initial clinical data expected in 2027 --
CAMBRIDGE, Mass., Sept. 24, 2026 (GLOBE NEWSWIRE) -- Prime Medicine, Inc. (Nasdaq: PRME), a biotechnology company committed to delivering a new class of differentiated one-time curative genetic therapies, today announced that the U.S. Food and Drug Administration (FDA) has cleared the Company's Investigational New Drug (IND) application for PM647, an investigational in vivo Prime Editor for Alpha-1 Antitrypsin Deficiency (AATD). The clearance enables PM647 to proceed to clinical study initially in the United States, where approximately 100,000 people carry the PiZZ genotype that PM647 is designed to correct.
"FDA clearance of the PM647 IND is an important milestone for Prime Medicine, marking continued momentum across our liver franchise," said Allan Reine, M.D., Chief Executive Officer of Prime Medicine. "PM647 has the potential to change how AATD is treated, offering a Prime Editing-based approach that moves beyond protein replacement and targets the root cause of disease. By correcting the underlying mutation and restoring production of fully functional AAT, PM647 may simultaneously address both lung and liver manifestations of AATD and provide a differentiated, one-time treatment approach for patients. Beyond its therapeutic potential, PM647 demonstrates the repeatability and productivity of Prime Medicine's platform. Just months after regulatory clearances for PM577a, the advancement of PM647 into clinical development also reinforces how Prime Medicine's modular platform and universal liver LNP can support the rapid progression of multiple programs."
Phase 1/2 Clinical Trial
The Phase 1/2 clinical trial will be a global, single-arm, open-label, first-in-human study designed to evaluate the safety, tolerability and preliminary clinical efficacy of ascending doses of a one-time intravenous infusion of PM647 in adults with AATD. The study will initially enroll adult participants with lung-only manifestations of AATD. Upon demonstration of tolerability in lung-only participants, the study will expand to include a separate cohort enrolling adults with significant liver disease, with or without concurrent lung manifestations of AATD.
About PM647
PM647 is an investigational, one-time in vivo Prime Editor designed to correct the E342K (Pi*Z) mutation in the SERPINA1 gene, the most common cause of AATD. By correcting the mutation at its source, PM647 is designed to restore production of functional M-AAT and address both the liver and lung manifestations of the disease. In fully humanized mouse models, PM647 achieved high editing efficiency and restored corrected M-AAT protein into the healthy human range at clinically relevant doses with a single infusion. PM647 uses the same liver-directed lipid nanoparticle (LNP) as PM577a, Prime Medicine's investigational program for Wilson disease.