Researchers are calling it a landmark breakthrough in the efforts to find a cure for Alzheimer’s disease.

Scientists at Case Western Reserve University School in Cleveland say a cancer drug appears to quickly reverse the cognitive and memory deficits caused by the progressive brain disease.

For the study, published in the journal Science, researchers gave mice large doses of bexarotene, a drug used to treat a form of skin cancer called cutaneous T-cell lymphoma. (Bexarotene is also known by the brand name of Targretin.)

The findings were impressive: mice showed dramatic memory improvements within 72 hours — and more than half of amyloid plaque, which has long been associated with Alzheimer’s disease both in mice and people, had been removed from the brain. Ultimately, the reduction in plaque totaled 75 per cent.

To measure memory, researchers gave the mice a series of tests both before and after receiving the drug. In one test mice with Alzheimer’s walked into a cage where they had previously been given a painful electrical shock. But after being given bexarotene, they remembered the shock and would not enter the cage.

In another test, researchers placed tissues inside a cage with the mice. Normally, mice would instinctively use tissues to form a nest. Mice affected by Alzheimer’s, however, no longer know how to do this. After treatment with the drug, the Alzheimer’s mice followed their nesting instinct and created a nest with the paper.

Also, pathology tests on the mice showed bexarotene dramatically lowered the levels of amyloid beta in the brain.

“This is a particularly exciting and rewarding study because of the new science we have discovered and the potential promise of a therapy for Alzheimer’s disease,” lead researcher Gary Landreth said in a news release.

But he also cautioned that results in mice don’t necessarily translate to humans. “We need to be clear; the drug works quite well in mouse models of the disease. Our next objective is to ascertain if it acts similarly in humans. We are at an early stage in translating this basic science discovery into a treatment.”

Researchers hope to move into clinical trials in healthy humans within the next two months, CNN reports. One huge advantage of bexarotene is that it’s already been approved by the Food and Drug Administration for use in humans — which means the researchers can begin human trials sooner than if it were a new drug. People participating in the trial would be given the standard dose that cancer patients are usually given.