PM359 trial begins, the first prime editor to enter the clinic

Prime Medicine/PM359 (CGD)

Prime Medicine initiated a Phase 1/2 clinical trial of PM359, marking the first time a prime editor—a gene-editing approach that rewrites DNA without cutting both strands—was given to humans. The trial targets the p47phox variant of chronic granulomatous disease, an inherited immune deficiency; patients' own blood stem cells are edited outside the body and reinfused.

• Prime editor differs from CRISPR by making single-strand breaks and inserting corrections, potentially more precise and reversible.
• CGD is a rare inherited immune disorder marked by increased susceptibility to bacterial, mycobacterial and fungal infections.
• FDA cleared the IND application in April 2024; initial Phase 1/2 data expected in 2025.
• The trial is global; patients range from adults to children, with enrollment of ~12 participants planned.