New drug shows promise stopping Alzheimer's before memory loss begins

A compound called NU-9 has done something researchers have been chasing for years: it stopped early Alzheimer's damage in mice before any symptoms appeared. The drug targets a newly identified toxic cluster of proteins that seems to trigger the brain inflammation that eventually kills neurons.

The work comes from Northwestern University, where chemist Richard Silverman and neuroscientist William Klein identified a particularly dangerous subtype of amyloid beta oligomers—toxic protein clumps that accumulate in Alzheimer's brains. They named it ACU193+ after the antibody used to detect it. What makes this discovery matter: ACU193+ appears early, inside stressed neurons, then moves to nearby astrocytes (the brain's support cells). Once there, it seems to kick off an inflammatory chain reaction that spreads through the brain long before memory loss begins.

In their new study, published in Alzheimer's & Dementia, the team gave NU-9 to pre-symptomatic mice for 60 days. The results were striking. The drug sharply reduced ACU193+ levels and dramatically cut the inflammatory response that usually begins years before someone notices cognitive decline. The mice also showed decreased levels of another harmful protein linked to neurodegeneration.

The prevention angle

What makes this different from other Alzheimer's research is the timing. Most current treatments try to slow disease once symptoms have already appeared—when significant brain damage is already done. NU-9 works earlier, targeting the molecular dominos before they fall.

Silverman and his colleagues compare the strategy to how we already prevent heart disease and cancer. "Most people monitor their cholesterol," Silverman noted. "High cholesterol doesn't mean you'll have a heart attack soon, but you take drugs to prevent it. NU-9 could work the same way. If someone has a biomarker signaling Alzheimer's disease, they could start taking it before symptoms appear."

This matters because biomarker tests—blood tests that detect early signs of Alzheimer's pathology—already exist and are becoming more accessible. People with these markers could theoretically take NU-9 as a preventive measure, similar to taking statins for cholesterol.

NU-9 itself isn't new. Silverman spent 15 years developing it as a small-molecule compound to stop toxic protein buildup in neurodegenerative diseases. In 2021, it showed benefits in animal models of ALS. The FDA cleared it for human clinical trials in ALS patients in 2024. The drug is now being commercialized by Akava Therapeutics under the name AKV9.

The team is expanding their work, testing NU-9 in additional Alzheimer's models designed to better match how the disease develops in aging humans. They're also tracking treated animals over longer periods to see whether cognitive decline actually slows or stops compared to untreated mice.

The path from mouse studies to human treatment is long. But this research identifies a specific toxic protein subtype and shows a drug that targets it can prevent early damage—a combination that gives researchers a clearer target for the next phase of trials.