Abstract
BACKGROUND: Frailty syndrome in older adults is a growing public health concern associated with increased vulnerability and adverse outcomes. Umbilical cord-derived mesenchymal stem cell (UC-MSC) therapy shows promise in improving physical function and quality of life. This study evaluated the safety and efficacy of intravenous UC-MSC infusion in older frail adults. METHODS: A phase 2 randomised controlled trial at Vinmec Times City International General Hospital (2021-2024) enrolled 147 frail adults aged 60-85 (Modified Fried Criteria ≥3). Participants were randomly assigned to receive two intravenous UC-MSC infusions (1.5 × 10(6) cells/kg, three months apart) plus oral supplements, or supplements alone, with nine months of follow-up. Safety was assessed by adverse events (AEs) and serious adverse events (SAEs). Efficacy outcomes included Short Physical Performance Battery (SPPB), handgrip strength, physical activity (CHAMPS), fatigue (MFI), knee function (WOMAC), and quality of life (SF-36). FINDINGS: No UC-MSC therapy-related SAEs occurred. Twelve mild AEs (headache, dizziness, chest discomfort) resolved spontaneously. At nine months, the UC-MSC group showed higher SPPB scores than controls (least-squares mean difference 1.1 points, 95% CI: 0.6-1.6). INTERPRETATION: In this study, UC-MSC infusion was associated with no safety concerns and was associated with higher SPPB scores than in the control group. These findings provide the necessary rationale and foundation for larger, double-blind, multicentre phase 3 trials. FUNDING: Vingroup Joint Stock Company, grant ISC.21.11.