A drug approved by the U.S. Food and Drug Administration for the treatment of chronic myelogenous leukemia reportedly showed promise in treating neurodegenerative diseases, according to NPR.

The study involved the use of the cancer drug nilotinib on 12 patients suffering from Parkinson's disease and Lewy body dementia. The patients were given increasing doses of the drug, from 150 to 300 milligrams, over a period of six months. During the trial, they showed improvement in motor skills, cognition and non-motor function.

"Study participants with earlier stage disease responded best, as did those diagnosed with Lewy body dementia, often described as a combination of Parkinson's and Alzheimer's diseases," said study co-author Dr. Fernando Pagan, associate professor of neurology at Georgetown University Medical Center, in a press release.

The researchers explained that nilotinib, given in smaller doses than that used for cancer treatment, effectively helped clear out the toxic buildup of certain proteins in the brain, which disrupts normal functioning both in Parkinson's and dementia patients. When the toxic buildup is cleared, normal function is restored.

"We found that, surprisingly, with a very little amount of the drug we can clear all these proteins that are supposed to be neurotoxic," said study author Charbel Moussa, director of Georgetown University's Laboratory of Dementia and Parkinsonism, to NPR.

One of the patients, retired Georgia State University professor Alan Hoffman, was diagnosed with Parkinson's disease in 1997. As his condition worsened over the years, he had more difficulty moving and focusing.

"Before the nilotinib, I did almost nothing around the house. Now, I empty the garbage, unload the dishwasher, load the washer and the dryer, set the table, even take responsibility for grilling," he said. He also began to read books and newspapers again. The improvement in his condition, he said, was "life-changing" for him and his family.

"To my knowledge, this study represents the first time a therapy appears to reverse — to a greater or lesser degree depending on stage of disease — cognitive and motor decline in patients with these neurodegenerative disorders," said Pagan. "But it is critical to conduct larger and more comprehensive studies before determining the drug's true impact."

The researchers also noted that the pilot study was conducted without a control group, and nilotinib was not compared with a placebo or other drugs used to treat Parkinson's and dementia.

The researchers presented the results of the study Saturday at Neuroscience 2015, the annual meeting of the Society for Neuroscience, which is held in Chicago from Oct. 17-21.