A team of researchers has posted potentially paradigm shifting research in the field of Alzheimer’s disease (AD) therapy, showing for the first time that advanced pathology can be pharmacologically reversed in preclinical models. The researchers were based at Case Western Reserve University in the United States, working alongside collaborators at University Hospitals (Cleveland) and the Louis Stokes Cleveland VA Medical Center, with findings published in Cell Reports Medicine.
Restoring brain energy balance with P7C3-A20
The study focused on NAD+ (nicotinamide adenine dinucleotide), a vital coenzyme found in all living cells that plays a central role in cellular metabolism, energy production, and DNA repair. NAD+ is essential for the function of mitochondria (the cell’s energy factories) and is involved in redox reactions, transferring electrons during metabolic processes. Its levels naturally decline with age and in certain disease states.
Researchers tested a small molecule called P7C3-A20, a synthetic small molecule and a member of the P7C3 class of neuroprotective compounds, thought to work by enhancing NAD+ synthesis without overshooting physiological levels, which could pose safety risks.
In two established mouse models of severe AD pathology, including animals already exhibiting late-stage cognitive decline, P7C3-A20 treatment restored NAD+ balance in the brain, reversed hallmark neurodegenerative changes such as tau hyperphosphorylation, oxidative stress, neuroinflammation and blood–brain barrier disruption, and fully restored cognitive performance in behavioral tests to levels comparable with healthy controls.
Molecular and translational insights
Beyond the behavioral rescue, cross-species proteomic and transcriptomic analyses revealed a set of proteins and pathways that are abnormally regulated in both mouse models and human AD brains can be normalized by NAD+ restoration.
Human brain tissue from individuals with AD showed a clear association between disrupted NAD+ metabolism and disease severity, while individuals with AD pathology but preserved cognition maintained better NAD+ balance. This supports the idea that NAD+ homeostasis may be a core determinant of neural resilience.
Research context
There is significant research momentum behind NAD+ and its potential role in AD. Recent research has shown that NAD+ and its metabolites are crucial for neuronal health, supporting mitochondrial function, reducing oxidative stress, and maintaining cellular energy balance, processes that are disrupted in AD.
Reduced NAD+ levels have been observed in AD brains, and supplementation in preclinical models appears to offer protective effects against neurodegeneration. Supplementing NAD+ or its precursors (such as nicotinamide riboside, NMN, or niacin) may help prevent cognitive decline and improve synaptic plasticity.
Several ongoing clinical trials are investigating NAD+ or NAD+ precursors in AD: A study at Florida Atlantic University is measuring brain NAD levels in AD patients. Brigham and Women’s Hospital is testing a sirtuin-NAD activator (MIB-626) in AD, assessing changes in brain NAD and related metabolites. And a trial at Massachusetts General Hospita will assess NAD augmentation in people with Down syndrome, who are at high risk for AD.
Historically, Alzheimer’s has been considered a progressive, irreversible neurodegenerative disease, with most drug efforts targeting amyloid-beta or tau aggregates. This study challenges that notion by demonstrating that even in advanced disease states, cellular energy imbalance contributes directly to pathology. Correcting energy metabolism may unlock intrinsic recovery mechanisms, offering a path toward true disease reversal rather than mere slowing of progression. The authors emphasize that clinical translation will require rigorous preclinical safety and dosing studies, identification of biomarkers to monitor NAD+ pathway engagement in humans, and Phase 1 clinical trials to evaluate safety and early efficacy in patients.