Perinatal Arterial Stroke Treated With Stromal Cells Intranasally: 2-Year Safety and Neurodevelopment

Abstract

BACKGROUND: The PASSIoN study (Perinatal Arterial Stroke Treated With Stromal Cells Intranasally) demonstrated the feasibility and short-term safety of single-dose allogeneic mesenchymal stromal cells (MSCs) administered intranasally to neonates with perinatal arterial ischemic stroke between February 2020 and April 2021. In this study, we assessed long-term safety and neurodevelopmental outcomes and explored outcome differences with a non–MSC-treated cohort. METHODS: In this post hoc analysis, we evaluated the safety of MSC administration by assessing brain tissue loss, adverse events, and neurodevelopmental outcomes of PASSIoN participants (N=10). The tissue loss ratio was calculated using semiautomatic segmentation based on neonatal and 3-month magnetic resonance imaging. At the age of 2 years, we assessed the occurrence of cerebral palsy, motor and cognitive delays (Z score