A paper published today in the journal Cell Reports Medicine offers new hope for an Alzheimer’s drug that doesn’t just slow cognitive decline but stops it. The study, by researchers at the University of Colorado Anschutz, found that Leukine or GM-CSF, a drug long-approved to treat other conditions, was able to stop brain cells from dying in Alzheimer’s patients when measured in a blood test. Brain cell death is a hallmark of Alzheimer’s disease.
“The main thing that we found…is that the people who were treated with Leukine or GM-CSF actually lost the ability to kill their nerve cells…to such an extent that it reduced nerve cell death to what would be the equivalent of a normal person about five years old,” Potter said.
The study also found that a simple blood test can measure brain cell death and damage, a phenomenon that begins in early childhood and becomes more acute as we age.
The findings add to previous research at CU Anschutz which found that Alzheimer’s patients given Leukine showed improvement in other blood biomarkers of the disease, including brain amyloid and neurodegeneration. Patients also improved in one test of memory and cognition, though showed no change in other tests.
Huntington Potter, director of the University of Colorado Alzheimer’s and Cognition Center and senior author of the study said the drug appears to attack the disease itself, something other Alzheimer’s drugs currently on the market don’t do.
“All other Alzheimer's drugs that have been published and certainly the ones that have been approved only slow the course of the disease. They do not improve it.”
Potter said those drugs also come with adverse side-effects, while Leukine seems to be well-tolerated.
“Leukine or GM-CSF has been FDA approved for decades and has been used to treat some 500,000 people with very little in the way of side effects,” Potter said. “ It's one of the safest drugs that has been studied.”
Still, Potter cautions, more research is needed before Leukine can be used as a drug for Alzheimer’s disease.
“No one should go out and try to take Leukine or prescribe it for Alzheimer's disease until the studies are finished and the FDA has given its approval,” Potter said. “That would be potentially dangerous.”
The study released today was a randomized, placebo-controlled, double-blind study of more than 300 people. Half of the patients were given Leukine and the other half a placebo for three weeks. Researchers followed up with patients after 45 days and again at 90 days. Potter said patients in the next study will take the drug for 24 weeks, which will give researchers more understanding about whether Leukine slows memory loss in people with Alzheimer’s or can actually improve it.
Another question is whether Leukine can help people with memory loss due to normal aging. Potter said it’s reasonable to assume the drug could halt brain cell death in those people and improve cognition but that further study is needed.
Potter said memory loss, including Alzheimer's disease, occurs in about one-third of people over the age of 80 and about 10-percent of people over the age of 65.
The CU Anschutz study also sheds new light on what happens to brain cells as we age. The research found a simple blood test can measure brain cell death and damage, which begins early in life and increases exponentially from age 2 to 85. The findings show women lose brain cells faster than men and the loss is particularly acute in people with Alzheimer’s. Researchers also found that brain inflammation starts around age 40 and increases more quickly in women than men.
