Phase II Study: Mesenchymal Stem Cell Therapy for Mild Alzheimer’s Shows Anti Inflammatory Effects and Slows Brain Atrophy

In July 2026, a new study on Alzheimer’s disease treatment garnered attention at the Alzheimer’s Association International Conference (AAIC 2026) in London, UK.

The research team presented the latest exploratory analyses of laromestrocel (brand name LomecelB), a mesenchymal stem cell therapy for mild Alzheimer’s disease (AD). The data suggest that the therapy may slow disease related brain atrophy by reducing neuroinflammation and improving the brain’s microenvironment.

This update builds on the therapy’s previously positive clinical performance. In March 2025, results from the randomized, double blind, placebo controlled Phase IIa trial of laromestrocel in mild AD were published in the prestigious journal Nature Medicine, marking the first time a mesenchymal stem cell therapy had demonstrated disease modifying potential in humans for AD.[1]

For years, Alzheimer’s treatment has primarily revolved around beta amyloid and tau proteins. In recent years, novel anti amyloid antibody drugs have achieved breakthroughs, offering patients new options to delay disease progression.

However, AD is not driven by a single factor. A growing body of research indicates that persistent neuroinflammation, blood brain barrier dysfunction, and deterioration of the brain’s microenvironment also contribute to neuronal damage and cognitive decline. Thus, in addition to clearing abnormal proteins, protecting neurons and improving the brain environment have become major research priorities in AD.

Laromestrocel is a cell based therapeutic strategy developed under this paradigm. Unlike conventional drugs that target a single pathological pathway, mesenchymal stem cells possess multiple biological actions—including immunomodulation, anti inflammation, angiogenesis, and tissue repair—that may collectively improve the diseased brain environment.

In the CLEAR MIND Phase IIa trial, researchers enrolled 49 patients with mild AD and compared the safety and potential efficacy of laromestrocel across different doses and administration regimens.

The results showed that the therapy was generally well tolerated, with no infusion related reactions, severe hypersensitivity, or ARIA (amyloid related imaging abnormalities) observed during the study period.

More notably, brain imaging findings revealed that patients receiving laromestrocel showed a trend toward slower brain atrophy compared to placebo. The treatment group experienced approximately 48% less reduction in whole brain volume, and hippocampal atrophy was also significantly slowed. Given that the hippocampus is one of the earliest and most prominently affected brain regions in Alzheimer’s, this finding suggests a potential neuroprotective effect.

a: Changes in brain volume measured by MRI at week 39 in the placebo group and treatment Group 4 (yellow indicates increase; blue indicates decrease).

b: Whole brain volume changes in the placebo group and the three treatment groups.

In new data presented at AAIC 2026, the research team further used free water MRI to track inflammatory changes in the brain. The results showed that in the placebo group, free water levels in multiple AD related brain regions continued to rise as the disease progressed, indicating worsening neuroinflammation. In contrast, patients receiving laromestrocel showed a declining trend in free water levels, with more pronounced effects in key areas such as the hippocampus and temporal lobe.

Blood based biomarker analyses also provided mechanistic support. The study found that in some treatment group patients, levels of neurogranin—a marker of neuronal injury—declined, while levels of the anti inflammatory cytokine IL 13 increased, suggesting that laromestrocel may exert its effects by modulating inflammatory responses and reducing neuronal damage.

Of course, these findings are still from a Phase IIa clinical study. Given the relatively limited sample size, some endpoints will require confirmation in larger Phase III trials. However, based on the current data, laromestrocel offers a novel therapeutic pathway for Alzheimer’s disease that differs from traditional anti protein strategies. Looking ahead, if larger studies further validate its efficacy and safety, mesenchymal stem cell therapy may become a meaningful component of disease modifying treatment for Alzheimer’s, bringing new hope to patients.

[1]Brian G. Rash, Kevin N. Ramdas, Nataliya Agafonova, et al. Allogeneic mesenchymal stem cell therapy with laromestrocel in mild Alzheimer’s disease: a randomized controlled phase 2a trial. Nature Medicine. 31, pages1257–1266 (2025) https://www.nature.com/articles/s41591-025-03559-0