Cancer Drugs Letrozole and Irinotecan May Reverse Alzheimer’s Effects, UCSF Study Finds

In a groundbreaking development, researchers at the University of California San Francisco (UCSF) have uncovered a potential game-changer in the fight against Alzheimer’s disease. Two FDA-approved cancer drugs, letrozole (used for breast cancer) and irinotecan (used for colon and lung cancer), have shown promise in not just slowing but potentially reversing the devastating effects of this form of dementia.

The study, published in the journal Cell, delved into how Alzheimer’s alters gene expression in brain cells—essentially, how it flips the switches of certain genes on or off. By analyzing millions of electronic medical records of adults over 65, the team pinpointed these two medications as having a correlation with reduced Alzheimer’s likelihood among patients already taking them. When tested in mice, the combination of these drugs reversed harmful gene changes, reduced tau protein clumps—a hallmark of the disease—and even improved learning and memory.

‘A complex beast to tackle,’ as co-senior author Marina Sirota put it, Alzheimer’s has long baffled scientists with its intricate impact on the brain. Yet, through cutting-edge computational tools, this team has opened a door to a potential therapy using drugs already on the market. Co-senior author Yadong Huang emphasized the challenge of targeting a disease driven by multiple genetic and protein alterations, making this multi-pronged approach all the more exciting.

However, the researchers are candid about the study’s limitations. The data originated from cancer cells rather than brain cells, and animal models, while insightful, don’t fully mirror human biology. A curious gender difference also emerged—male mice responded better to the treatment than females, possibly due to letrozole’s role as a hormone modulator. Still, with over seven million Americans living with Alzheimer’s—a number projected to nearly double by 2050—the urgency for innovative solutions is undeniable.

Looking ahead, the team is gearing up for clinical trials to test this drug combination in human patients. If successful, this could mark a turning point for millions grappling with a disease that currently has only two FDA-approved disease-modifying treatments, both limited to early-stage cases and carrying risks of serious side effects. Here’s hoping this unexpected crossover from cancer care to brain health brings the breakthrough we’ve all been waiting for.