Allogeneic human umbilical cord blood for acute ischemic stroke: Phase I clinical trial.

Objectives: Transplantation of human umbilical cord blood cells (hUCB) may enhance neuroprotection, and thus, the intravenous (IV) infusion of hUCB in patients with acute ischemic stroke (AIS) is being tested for its safety and efficacy.

Materials and methods: We conducted a 12-month, open-label, and single-center, phase I trial of hUCB treatment in AIS patients at the age of 45-80 years, with magnetic resonance imaging evidence of acute infarction in the internal carotid artery supplied territory and the National Institute of Health Stroke Scale (NIHSS) score between 6 and 18. Eligible participants received a single-dose IV infusion of hUCB followed by the two doses of mannitol infusion within 9 days after the onset of stroke symptoms. The primary endpoint was the incidence of adverse events (AEs) and the secondary endpoints were the changes in NIHSS, Barthel index (BI), and Berg Balance Scale (BBS) scores.

Results: Six patients (Male: Female = 3: 3) were enrolled with a mean age at 65.8 years. A total of 40 AEs occurred in six participants during this study, which included nine serious adverse events. Only transient erythema multiforme and hematuria were probably and possibly related to hUCB infusion, respectively. The mean NIHSS score was 11.5 at baseline and it significantly improved at 1, 3, 6, 9, and 12 months after treatment (mean change from baseline: -4.0, -5.3, -6.8, -7.0, and -7.3). The mean BI score was 22.5 at baseline and it significantly increased at 3 and 6 months after treatment (mean change from baseline: 26.7 and 42.5, respectively). The BBS score increased numerically but did not reach statistical significance. The changes in cytokine levels and spleen size were unremarkable.

Conclusion: The IV hUCB was safe and well tolerated in AIS patients, and the preliminary efficacy results demonstrated its therapeutic potential, supporting the conduct of a randomized, placebo controlled, phase II clinical trial in future.