Researchers are continually looking for therapies or cures for Alzheimer’s disease. According to a recent study from UC San Francisco and Gladstone Institutes, a combination of two repurposed cancer drugs may be able to reverse the brain changes brought on by Alzheimer’s, potentially delaying or even reversing the symptoms of the condition.
Alzheimer’s, which affects millions of people worldwide, continues to be one of medicine’s most difficult problems. For decades, researchers have sought a medicine that does more than manage symptoms. They are attempting to find a complete cure.
Current Alzheimer’s medications work primarily to manage symptoms and slow disease progression. One technique scientists are now using to identify medicines for Alzheimer’s is drug repurposing, which involves investigating presently approved drugs used for other disorders [1].
A recent discovery that combines two cancer medications may give people new hope. Researchers from Gladstone Institutes and UC San Francisco used extensive databases containing pre-existing medicinal information rather than attempting to develop a new medication from scratch. Their objective was to identify licensed medications that could undo the genetic alterations that Alzheimer’s patients experience.
The researchers discovered two cancer drugs that could help reverse brain alterations induced by Alzheimer’s, potentially minimizing or even reversing the disease’s symptoms.
The journal Cell published the new study [2].
Finding the Right Drugs
Researchers first used previous research to evaluate how Alzheimer’s disease altered the gene expression in brain cells.
They discovered how Alzheimer’s affected neurons and glial cells differently by analyzing each one individually. Alzheimer’s disease causes significant damage to neurons, which are involved in information processing. In contrast, when a disease occurs, glial cells—which typically shield neurons—become detrimental.
The team examined the Connectivity Map, a database containing gene responses from thousands of medications, to identify drugs that could reverse the genetic effects of Alzheimer’s. They selected ten FDA-approved choices from a list of 1,300 medications. They then discovered which medications were associated with a lower incidence of Alzheimer’s disease in real-world situations by looking through the medical records of 1.4 million older individuals.
Focusing on Two Cancer Drugs: Letrozole and Irinotecan
The researchers selected irinotecan and letrozole, two cancer medications, for additional testing from the top contenders. Usually, doctors recommend irinotecan for lung or colon cancer and letrozole for breast cancer. However, this study indicated that irinotecan may target issues with glial cells, whereas letrozole may restore detrimental genetic changes in neurons.
To test their hypothesis, scientists employed genetically modified mice that developed Alzheimer’s quickly. These mice had human genes that replicate the memory loss and brain damage that are hallmarks of severe Alzheimer’s disease. Researchers administered drugs to them individually or in combination.
The outcomes were astounding. In addition to reducing brain degeneration and preventing the accumulation of harmful tau and beta-amyloid proteins (the hallmarks of Alzheimer’s disease), the combination therapy markedly enhanced the mice’s memory. These outcomes demonstrated the benefit of treating both cell types simultaneously, as single medications were unable to match these results.
Researchers believe that clinical trials should soon start.
Alzheimer’s Research: Shifting Strategies
For many years, studies on Alzheimer’s disease focused mainly on neuronal damage, highlighting protein clusters called tau tangles and amyloid plaques. However, clinical studies for most of the novel Alzheimer’s medications have failed. Why is that? Scientists now believe this is because Alzheimer’s is more than simply one disease. It is a complex disorder that involves several different types of cells, proteins, and genes.
According to Yadong Huang, MD, PhD, a co-author and senior researcher at Gladstone, Alzheimer’s disease is probably caused by a variety of changes in different genes and proteins. Drug development is highly challenging because typically one medicine is created for each gene or protein [3].
Recently, researchers have focused on glial cells, the previously overlooked cells in the brain. When these cells are not functioning correctly, they exacerbate inflammation and further harm neurons. A novel approach to better treating Alzheimer’s is to target these glial cells in addition to neurons.
Faster Progress via Drug Repurposing
Repurposing existing drugs offers significant benefits, especially considering the high failure rate of new Alzheimer’s therapies. Since the safety of these medications is already established, researchers can quickly advance them into clinical studies. Furthermore, developing repurposed drugs is generally less costly, which accelerates their availability on pharmacy shelves.
The Gladstone and UCSF team quickly identified viable candidates by combining cell investigations, human clinical data, and sophisticated computer techniques. The interim head of the UCSF Bakar Computational Health Sciences Institute, Marina Sirota, PhD, highlighted this distinctive strategy.
According to her, their computational tools made it possible to address the complexity head-on. They are thrilled to have discovered a potential combination therapy based on currently approved FDA drugs, thanks to the computational technique.
A New Hope for Alzheimer’s Treatment
The successful animal trials of letrozole-irinotecan combo therapy are a significant step forward. Alzheimer’s patients may soon have new hope thanks to these medications, which are currently used to treat cancer.
Huang and Sirota are hopeful about the future. Their creative combination approach may lead to individualized Alzheimer’s medicines based on patient genetic data. This precise approach may ultimately break past long-standing hurdles in Alzheimer’s research.
Limitations and the Next Step
Although the results are encouraging, this is not enough. That’s because, as is evident, the drugs have only been tested directly on mice thus far, and they also have side effects. Reexamining the drugs is necessary if they are to be used for a different illness than the one for which they were first approved.
Clinical studies for Alzheimer’s patients should be among the next steps. The researchers believe that this method, which considers the changes in gene expression in each case, may lead to more personalized and effective treatments.
Alzheimer’s Research Association is a non-profit organization dedicated to helping caregivers of Alzheimer’s disease and dementia. We provide the latest information and news about the illness and helpful tips to help caregivers cope with their daily caregiving challenges. We realize the most important thing that a caregiver needs is financial assistance. Therefore, we provide grants to caregivers to ease their financial burden. Caregivers can apply for grants here: Alzheimer’s Grant Application.
You can also help caregivers in their endeavor by donating as much as possible: Donation To Alzheimer’s Research Associations.
References
- Cummings, J.L., Zhou, Y., Van Stone, A., Cammann, D., Tonegawa-Kuji, R., Fonseca, J. and Cheng, F., 2025. Drug repurposing for Alzheimer’s disease and other neurodegenerative disorders. Nature Communications, 16(1), p.1755.
- Li, Y., Serras, C.P., Blumenfeld, J., Xie, M., Hao, Y., Deng, E., Chun, Y.Y., Holtzman, J., An, A., Yoon, S.Y. and Tang, X., 2025. Cell-type-directed network-correcting combination therapy for Alzheimer’s disease. Cell.
- Shavit, J. Two FDA-approved cancer drugs significantly reverse Alzheimer’s disease. Brighter Side of News. https://www.thebrighterside.news/post/two-fda-approved-cancer-drugs-significantly-reverse-alzheimers-disease/. Published Online: 22nd July, 2025. Accessed: 18th August, 2025.
- Pelc, C. Might a combination of 2 cancer drugs help treat Alzheimer’s disease? Medical News Today. https://www.medicalnewstoday.com/articles/might-a-combination-of-2-cancer-drugs-help-treat-alzheimers-disease. Published Online: 3rd August, 2025. Accessed: 18th August, 2025.
- Nield, D. Scientists Find 2 Existing Drugs Can Reverse Alzheimer’s Brain Damage in Mice. Science Alert. https://www.sciencealert.com/scientists-find-2-existing-drugs-can-reverse-alzheimers-brain-damage-in-mice. Published Online: 25th July, 2025. Accessed: 18th August, 2025.
- Gadye, L. Do These Two Cancer Drugs Have What It Takes to Beat Alzheimer’s? University of California San Francisco (UCSF). https://www.ucsf.edu/news/2025/07/430386/do-these-two-cancer-drugs-have-what-it-takes-beat-alzheimers. Published Online: 21st July, 2025. Accessed: 18th August, 2025.
- Bendix, A. Could cancer drugs be the future of Alzheimer’s treatment? NBC News. https://www.nbcnews.com/health/health-news/cancer-drugs-future-alzheimers-treatment-rcna219581. Published Online: 21st July, 2025. Accessed: 18th August, 2025.
