A New Alzheimer’s Drug Reversed Memory Decline in Mice Even After Symptoms Appeared: A new experimental Alzheimer’s compound called FLAV-27 improved memory and reduced disease-like damage in worms and mice.

For years, the great hope in Alzheimer’s research has been that if scientists could clear the brain of Alzheimer’s physical changes, memory might stop slipping away. The main targets were the disease’s familiar signs: amyloid plaques that build up between brain cells and tau tangles that form inside them.

A new experimental compound takes a less obvious route. In a study led by researchers at the University of Barcelona, the drug candidate, called FLAV-27, adjusts the gene-control system that tells neurons how to behave. In worms and mice, that shift reduced Alzheimer’s-like damage and improved memory-related behavior, even in animals already showing signs of decline.

The findings point beyond the usual focus on plaques and tangles, suggesting that Alzheimer’s may also involve gene-control changes that weaken brain cells before circuits fully break down.

A Different Target

The newest Alzheimer’s drugs, including lecanemab and donanemab, focus on amyloid beta, a protein that forms plaques in the brain. These antibody drugs can slow decline for some people when given early, but they do not bring back lost memory. They also target only one piece of a disease that involves inflammation, failing synapses, and broad changes in brain-cell biology.

FLAV-27 takes aim at the epigenome. That is the set of chemical marks that helps control gene activity without changing DNA itself. A useful way to imagine it is that DNA is the book of instructions, while the epigenome is the system of bookmarks, highlighters, and sticky notes that tells a cell which pages to read.

The compound blocks an enzyme called G9a. In Alzheimer’s, the researchers argue, G9a may help silence genes that neurons need for memory, communication, and repair.

“The compound FLAV-27 represents an innovative and promising approach to Alzheimer’s disease, with the potential to modify the disease process,” Aina Bellver, first author of the study, said in a statement. “It acts not only on its symptoms or a single pathological biomarker, but directly on its underlying molecular mechanisms.”

What Happened in the Lab

The researchers tested FLAV-27 in several systems, including brain cells in dishes, tiny worms, and mouse models of both early- and late-onset Alzheimer’s-like disease.

In lab-grown brain-cell cultures, FLAV-27 reduced clumps of amyloid beta, tau and phosphorylated tau—all proteins tied to Alzheimer’s pathology. It also helped restore neurites, the branch-like extensions neurons use to form connections.

In Caenorhabditis elegans, a transparent worm often used in aging research, the compound improved movement, reduced amyloid buildup, and boosted signs of cellular energy production. In one Alzheimer’s-like worm strain, treated animals lived longer on average.

The mouse findings were especially striking. In one model of age-related Alzheimer’s-like decline, mice given FLAV-27 performed better on tests of short-term memory, long-term memory, and spatial memory. Their neurons also showed more spines and more branching, which are physical signs that brain-cell connections had become stronger.

In another mouse model, designed to mimic inherited early-onset Alzheimer’s, FLAV-27 improved memory even when treatment began after disease signs had appeared.

More Than Plaques

FLAV-27 seemed to reach several parts of the disease process. In the brain, it reduced inflammation and strengthened signs of synapse health. It also eased forms of cellular stress, including damage linked to iron buildup, a process Alzheimer’s researchers are watching closely.

The team also identified possible blood signals for tracking the drug’s effects. Two stood out: H3K9me2, a chemical tag involved in gene silencing, and SMOC1, a protein tied to Alzheimer’s changes in the brain. In animals, both shifted after FLAV-27 treatment. In human Alzheimer’s samples, both appeared at higher levels.

“It has important implications for future clinical trials, as it will allow the selection of suitable patients with a simple blood test, monitoring of treatment and demonstration that the drug actually modifies its therapeutic target,” the authors said in the University of Barcelona release.

A Note of Caution

FLAV-27 is not an Alzheimer’s treatment yet. It has not been tested in people.

Many drugs that rescue memory in mice fail in human trials. Mouse models capture parts of Alzheimer’s, but they do not reproduce the full human disease, which can unfold over decades.

The compound must still go through more safety testing, toxicology studies in animals, formulation work, and regulatory review before researchers can request a human trial. The next stage will be led by Flavii Therapeutics, a University of Barcelona spin-off founded in 2025 to develop FLAV-27.

Still, the work opens an intriguing path. Alzheimer’s may not yield to a single cleanup crew for plaques or tangles. FLAV-27 suggests another possibility: loosening the molecular locks that keep aging neurons from repairing themselves.