Mesenchymal Stem Cells With Adjuvant Dexamethasone in Patients With Alzheimer's Disease: A Phase IIa Trial

This phase IIa trial assessed the safety and efficacy of mesenchymal stem cell (MSC) therapy for Alzheimer's disease (AD). An open-label extension (OLE) further explored the adjunctive role of dexamethasone.

MSCs (n=24) or a saline placebo (n=12) were administered intraventricularly three times at four-week intervals. In the OLE, MSCs and dexamethasone (15 mg, n=5) were administered to patients who received saline in phase IIa. Clinical parameters and cerebrospinal fluid (CSF) markers were evaluated.

MSC therapy exhibited no significant clinical benefits, but was associated with reductions in CSF AD biomarkers (amyloid-beta, phosphorylated-tau, and total-tau) compared to placebo. The MSC group experienced more adverse events (fever, headache, nausea, and vomiting), while co-administration of dexamethasone appeared to attenuate immune-related reactions and limit increases in CSF white blood cell and interleukin-6.

These findings suggest exploratory biological effects of MSCs on AD biomarkers, with dexamethasone potentially mitigating MSC-induced immune responses.

ClinicalTrials.gov Identifier: NCT02054208, NCT03172117, and NCT04954534.