Alzheimer’s Breakthrough: Cancer Drugs Show Promise in Reversing Brain Changes
In a remarkable development, researchers have identified two cancer drugs that might reverse brain changes associated with Alzheimer’s disease. This discovery, based on gene expression analysis and extensive clinical data, opens a potential avenue for a new therapeutic strategy. The findings suggest that these drugs could slow down or even halt the progression of this devastating disease.
The Science Behind the Discovery
A team from UC San Francisco and the Gladstone Institutes spearheaded this groundbreaking research. They pinpointed oncology medications that appear to reverse the brain alterations characteristic of Alzheimer’s. The study analyzed how genes’ activity shifts in Alzheimer’s and cross-referenced these changes with over 1,300 approved medications.
Their findings revealed that two existing cancer drugs could be repurposed to combat Alzheimer’s, the most common type of dementia. This innovative approach targets both neurons and glial cells, which are impacted by the disease. The team also analyzed extensive medical records, demonstrating that patients taking these drugs for other conditions had a lower risk of developing Alzheimer’s.
When tested on a mouse model of Alzheimer’s, these drugs decreased brain degeneration and restored the animals’ memory function. This offers hope for human patients.
The Drugs in the Spotlight: Letrozole and Irinotecan
The study identified letrozole, used to treat breast cancer, and irinotecan, employed in the treatment of colon and lung cancers, as potential candidates. Letrozole was found to impact neurons, while irinotecan showed promise for glial cells.
“The complex nature of Alzheimer’s has made it difficult to study and treat, but advanced data analysis has allowed us to directly tackle this complexity,” said Marina Sirota, the lead researcher at UCSF, in a press release. “This data-driven approach has guided us toward a potential treatment combination based on already FDA-approved drugs.”
Alzheimer’s Disease: A Persistent Challenge
Alzheimer’s affects millions worldwide, gradually impairing memory and thinking. Despite decades of research, approved treatments are limited and do not halt disease progression.
Experts believe Alzheimer’s stems from various changes at the genetic and protein levels, affecting brain function. This complexity has hindered the development of effective drugs.
The Research Methodology
Researchers used public data from three studies on gene expression in the brains of deceased donors, with and without Alzheimer’s. This data helped create Alzheimer’s-specific genetic signatures in neurons and glial cells.
These signatures were compared with the Connectivity Map (CMAP) database, which contains the results of testing thousands of drugs on gene expression in human cells.
Out of 1,300 medications, 86 reversed Alzheimer’s genetic signature in one cell type, and 25 did so in multiple brain cell types. Only 10 of these were already approved for human use. Analyzing the anonymized records of 1.4 million patients aged 65 and older from the UC Health Data Warehouse, researchers found that some of these drugs seemed to reduce the risk of developing Alzheimer’s.
A team from the University of California, San Francisco (UCSF) and Gladstone Institutes discovered a combination of two cancer drugs that successfully treated a severe Alzheimer’s model. From left to right: Marina Sirota, Yaqiao Li, and Dr. Yadong Huang. Photo: Michael Short / Gladstone Institutes, July 21, 2025.
Promising Results in Animal Models
The team selected letrozole and irinotecan for testing in a mouse model with aggressive Alzheimer’s. The combined treatment reversed many signs of the disease, including genetic signatures, toxic protein aggregates, brain degeneration, and memory impairment.
In mice genetically modified to replicate Alzheimer’s disease, a protein called tau (marked in green) clumps together in the brain, as seen in the image above. Photo: Li et al., Cell, July 21, 2025
Two FDA-approved cancer drugs identified by UCSF researchers, letrozole and irinotecan, had reduced effects on tau protein accumulation in the brain when administered individually. Photo: Li et al., Cell, July 21, 2025
The combination of letrozole and irinotecan reduced the amount of these aggregates and also improved learning and memory. Photo: Li et al., Cell, July 21, 2025
Next Steps: Clinical Trials
The researchers aim to advance their findings to clinical trials soon. The aim is to validate these findings in human patients.
“If independent data sources, such as gene expression and medical records, have led us down the same path to the same drugs, and then they are shown to work in a genetic model of the disease, then we might be on the right track,” Sirota said.
Researchers are optimistic that this discovery can be translated into a real solution for millions with Alzheimer’s.
The study was published in the journal Cell.
Current Alzheimer’s Treatments and Their Limitations
The two drugs currently approved in the United States for Alzheimer’s treatment are Aducanumab (Aduhelm) and Lecanemab (Leqembi). Aducanumab, approved in 2021, targets beta-amyloid buildup in the brain, but its efficacy is debated. Lecanemab, approved in 2023, acts similarly, slowing disease progression but not curing it. It has side effects.
FAQ: Frequently Asked Questions
What is Alzheimer’s disease?
Alzheimer’s is a progressive brain disorder that gradually destroys memory and thinking skills.
What are the current treatments for Alzheimer’s?
Currently, there are a few FDA-approved drugs like Aducanumab and Lecanemab that can help slow down the progression of the disease, but there is no cure.
How do these cancer drugs work against Alzheimer’s?
The cancer drugs, letrozole and irinotecan, are believed to reverse brain changes associated with Alzheimer’s by targeting specific cells and processes involved in the disease.
What are the next steps in the research?
The researchers plan to move forward with clinical trials to test the drugs in human patients.
A Hopeful Outlook
The potential of these cancer drugs to treat Alzheimer’s is a significant breakthrough. While the research is still in its early stages, it provides hope for more effective treatments and improved outcomes for those affected by this devastating disease.
Did you know? Alzheimer’s disease affects an estimated 55 million people worldwide.
Pro tip: Stay informed about the latest advancements in Alzheimer’s research by following reputable medical journals and organizations.
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