New cancer drug candidate may treat Alzheimer's disease

New York: Opening a new window of opportunity for treating dementia, researchers have found that a drug compound created to treat cancer can restore memory in mice with Alzheimer's like disease.

Alzheimer's is the most common form of dementia that causes problems with memory, thinking and behaviour.

The drug flushes away the abundant inflammatory cells produced in reaction to beta-amyloid plaques that are the hallmark of Alzheimer's disease, the findings showed.

The study, published in the journal Brain, showed that these cells, called microglia, contribute to the neuronal and memory deficits seen in this neurodegenerative disease. 

"Our work is telling us that these cells may contribute to the disease process, and targeting them with such specific drugs is a promising new approach,” said one of the researchers Kim Green, assistant professor at the University of California, Irvine, US.

In healthy tissue, microglia act as the first and main form of immune defence in the central nervous system. 

But in a diseased state, such as Alzheimer's, microglia appear to turn against the healthy tissue they were originally assigned to protect, causing inflammation in the brain. 

The beta-amyloid plaques in brain areas related to Alzheimer's disease are rich with these rogue microglia, Green added.

In their experiments, the researchers treated mice with Alzheimer's like disease with a small-molecule inhibitor compound called pexidartinib, or PLX3397, which is currently being used in several phase two oncology studies.

The researchers noted a lack of neuron death and improved memory and cognition in the pexidartinib-treated mice, along with renewed growth of dendritic spines that enable brain neurons to communicate.

Green said that although the compound swept away microglia, the beta-amyloid remained, raising new questions about the part these plaques play in Alzheimer's neurodegenerative process.