In a stunning scientific discovery, researchers have found that a pair of drugs can not only slow down Alzheimer’s disease but actually reverse it and restore memory in mice.
And the best part of all? Both are already FDA-approved — albeit for cancer.
Researchers first pinpointed how Alzheimer’s disease scrambles gene activity in individual brain cells.
Using the Connectivity Map database of 1,300 FDA‑approved drugs, the researchers looked for medications that reverse Alzheimer’s‑associated gene expression — landing on a shortlist of five, and zeroing in on two cancer drugs.
In what one researcher called a “mock clinical trial,” they then mined 1.4 million patients’ medical records, finding that those who had taken letrozole or irinotecan for cancer were significantly less likely to develop Alzheimer’s.
When given together in an aggressive Alzheimer’s mouse model, letrozole — used to treat certain types of breast cancer in postmenopausal women — and irinotecan — an anti-cancer medication used to treat colon cancer and small cell lung cancer — reversed disease‑related gene expression signatures, dissolved toxic tau protein clumps and prevented brain degeneration.
Most importantly, they restored memory and learning in mice that had already developed severe symptoms.
It’s an exciting development for an illness that’s notoriously tricky.
“Alzheimer’s disease comes with complex changes to the brain, which has made it tough to study and treat, but our computational tools opened up the possibility of tackling the complexity directly,” Marina Sirota, the interim director of the UCSF Bakar Computational Health Sciences Institute, said in a statement.
“We’re excited that our computational approach led us to a potential combination therapy for Alzheimer’s based on existing FDA-approved medications.”
“Alzheimer’s is likely the result of numerous alterations in many genes and proteins that, together, disrupt brain health,” said Yadong Huang, a professor of neurology and pathology at UCSF.
“This makes it very challenging for drug development — which traditionally produces one drug for a single gene or protein that drives disease.”
The findings were published in the journal Cell.
Both drugs are already FDA‑approved for other uses, which could dramatically speed up the path to human trials.
However, because they are cancer drugs, repurposing them may be complex and risky.
This finding adds to a growing number of potential Alzheimer’s treatments.
A compound found in rosemary and sage — carnosic acid — has been shown to reverse memory loss and reduce brain inflammation in mice with Alzheimer’s, bringing their cognitive function back to near-normal levels.
A study from Stanford Medicine found that seniors who received the shingles vaccine were 20% less likely to develop dementia over seven years.
And researchers at Penn State and Stanford University discovered that a certain cancer drug could restore memory and brain function in early stage Alzheimer’s models.
