Nature Medicine, Published online: 21 October 2025; doi:10.1038/s41591-025-04011-z
In a phase 1 dose-escalation study including 11 patients with heart failure who were followed for 12 months, delivery of a cardiotropic adeno-associated viral vector designed to deliver constitutively active protein phosphatase 1 inhibitor 1 to the heart was well tolerated and showed preliminary evidence of efficacy.