A drug with a 30-year track record as an effective tool for fighting cancer may significantly improve memory and thinking in patients with mild-to moderate Alzheimer's disease, new research suggests.
Sargramostim (brand name: Leukine) has long been used after cancer treatment to coax a patient's bone marrow to make more disease-fighting white blood cells. It uses a protein called GM-CSF that has been linked to a significantly lower risk of Alzheimer's among patients with rheumatoid arthritis (RA). RA patients typically have higher-than-normal levels of GM-CSF in their blood.
Working with 40 Alzheimer's patients, researchers have now concluded that a three-week regimen of sargramostim can actually reverse telltale brain damage associated with the disease, and markedly improve memory and thinking ability.
"This discovery of the safety and [effectiveness] of GM-CSF in Alzheimer's disease has the potential to be a breakthrough, which will be proved when a larger, longer trial is done to show that the benefits we saw are stronger and long-lasting," said study lead author Huntington Potter. He's the director of the University of Colorado Alzheimer's and Cognition Center in Aurora.
The new findings come on the heels of another potential Alzheimer's breakthrough, in the form of an experimental drug called donanemab.
As reported March 13 in the New England Journal of Medicine, a monthly shot of donanemab for about 18 months effectively eliminated the buildup of amyloid-beta plaques in the brains roughly 70% of Alzheimer's patients studied.
For the new study, 20 patients were treated with sargramostim five days a week for three weeks. Twenty other patients received placebo shots. The trial was double-blind, meaning neither the investigators nor participants knew which treatment they were getting.
At the end of the trial, those in the sargramostim group scored nearly 2 points higher on a standard 30-point test of thinking skills.
Their production of disease-fighting immune cells also shot up. And preexisting nervous system damage -- including levels of amyloid plaque and Alzheimer's-related tangles in the brain -- all reversed, in what researchers described as a "partial normalization" process.
The study showed the benefits induced by GM-CSF were found to last as much as 45 days after treatment ended, Potter noted. The drug was also found to be safe and well-tolerated.
Researchers have approval from the U.S. Food and Drug Administration and funding from the U.S. National Institutes of Health and the Alzheimer's Association to carry out a longer, larger trial of GM-CSF to verify their findings.
Heather Snyder, vice president of medical and scientific relations for the Alzheimer's Association, called the research into the use of anti-inflammatory drugs in dementia treatment "intriguing."
"The Alzheimer's Association is actively investing in clinical trials to explore their potential use for dementia treatment," she said.
At the same time, Snyder cautioned that this line of research is still "very preliminary" and work must continue in larger, more diverse populations.
"Alzheimer's is complex, and successful treatment will most likely address the disease in multiple ways with medication and behavior interventions, like combination therapies similar to heart disease and cancer," she said. "We must accelerate the pursuit of a wide variety of Alzheimer's treatments with the idea that they will likely be used in combination to be most effective."
Snyder said the association is funding and collaborating with scientists around the world to make this happen.
Potter's team reported its findings on March 25 in the online edition of the journal Alzheimer's & Dementia: Translational Research & Clinical Interventions.