Intravenous administration of umbilical cord lining stem cells in left ventricular assist device recipient: Rationale and design of the uSTOP LVAD BLEED pilot study.

Background: Left ventricular assist device (LVAD) implantation provides a robust survival advantage, however despite improvements in mortality, the adverse event burden of durable mechanical circulatory support remains high. Bleeding complications are one such significant complication. The uSTOP LVAD BLEED (Utilization of umbilical cord lining Stem cells TO Prevent LVAD associated angiodysplastic BLEEDing) pilot study is designed to evaluate the safety and tolerability of escalating doses of umbilical cord lining stem cells (ULSCs) in LVAD recipients to ameliorate the dysregulation of angiogenic factors seen in this population. Design: This Phase Ia single-ascending dose pilot study will evaluate the IV administration of ULSCs in stable out-patients supported with an LVAD. In a 3 + 3 design, a maximum of 18 patients will receive an IV infusion of ULSCs. Main outcome measures: The primary endpoints are safety and tolerability, secondary exploratory endpoints will include biomarker evaluation of angiogenic dysregulation. Summary: This represents a novel cell type and route of administration in this population, while collecting initial data regarding the magnitude and duration of effects of cell therapy, and assessing the possibility of decreasing bleeding by a strategy of vascular stabilization. Clinical trial registration: ClinicalTrials.gov Identifier: NCT04811261. https://clinicaltrials.gov/ct2/show/NCT04811261.