First-Ever Personalized CRISPR Therapy Helps Infant With CPS1 Deficiency Thrive

Researchers at Children’s Hospital of Philadelphia and the University of Pennsylvania developed a bespoke base-editing CRISPR therapy delivered to the liver to fix a CPS1 gene variant in a newborn with a rare metabolic disorder. After a first infusion in early 2025 and subsequent doses, the child has tolerated treatment with no adverse effects, has been able to halt medications and gradually reintroduce protein, and is thriving per a New England Journal of Medicine report; the approach is experimental and not FDA-approved, but signals a path toward patient-specific gene therapies that could be scalable to individual needs.