DAVID GREENE, HOST:
Now a small study with potentially big implications. The study was presented over the weekend at the Society for Neuroscience meeting in Chicago, and it has people who work with Parkinson's very excited. A cancer drug appears to help patients with Parkinson's and also a related form of dementia. NPR's Jon Hamilton reports on the preliminary but pretty dramatic results.
JON HAMILTON, BYLINE: In people with Parkinson's disease, toxic proteins build up in certain brain cells, eventually killing those neurons. Several years ago, a researcher named Charbel Moussa at Georgetown University Medical Center got an idea. He thought a drug already approved for cancer might be able to reverse this buildup of toxins in brain cells. Moussa says the drug activates a system in cells that works like a garbage disposal. It clears out unwanted proteins.
CHARBEL MOUSSA: And we found that surprisingly with a very little amount of the drug, we can clear all these proteins that are supposed to be neurotoxic.
HAMILTON: But that was in cells growing in petri dishes. So Moussa had his team try the drug on transgenic mice that developed Parkinson's disease.
MOUSSA: When we tested the transgenic mice for behavioral outcomes, we saw that the mice, which were almost completely paralyzed, they were rescued.
HAMILTON: They were moving like healthy mice again. That got the attention of Fernando Pagan, the neurologist in charge of Georgetown's Movement Disorders Program.
FERNANDO PAGAN: When I saw these mice when Dr. Moussa showed them to me, it looked like, hey, this is the type of drug that we've been looking for because it goes to the root of the problem.
HAMILTON: The drug is nilotinib, a new and very costly treatment for leukemia. Nilotinib kills cancer cells, but brain cells thrive on low doses of the drug. Pagan wondered whether nilotinib would be safe for patients with Parkinson's and a form of dementia that often accompanies the disease. So for six months, he gave tiny amounts of the drug to a dozen patients, including this man.
ALAN HOFFMAN: I'm Alan Hoffman, and I'm 64 years old - 74. And I have a Ph.D. from Michigan State University in social science education - taught there for 27 years.
HAMILTON: Now Hoffman lives in northern Virginia with his wife, Nancy. He was diagnosed with Parkinson's in 1997. By 2007, the disease had begun to affect his thinking. Nancy Hoffman says things got really bad during a trip to London.
NANCY HOFFMAN: He had more and more difficulty making sense, and he was being pretty belligerent. And I said something to him that I later cried my eyes out over doing, but I said, Alan, you have dementia.
HAMILTON: That was something Alan already suspected.
A. HOFFMAN: I knew I had dropped off. You know, people would keep giving me books and I'd have read the first chapter of about 10 of them. I had no ability to focus on it.
HAMILTON: The Hoffman's tried experimental drugs and deep brain stimulation. The treatments helped, but didn't halt the disease. Eventually, the couple came to Fernando Pagan at Georgetown, and he offered Alan a chance to enroll in the study of nilotinib. Pagan shows me a video taken at the beginning of the study. Alan is walking down a corridor as part of a timed test.
PAGAN: You can see he's slow. There's a decreased arm swing there on the right. He's a little bit wobbly when he walks.
HAMILTON: And his posture is twisted by a muscle problem called dystonia. Next, Pagan shows a video of Hoffman taking the same test after two months on nilotinib.
PAGAN: Here, he went from 15 seconds originally to eight seconds - much straighter, less dystonia and no longer using a cane.
HAMILTON: Alan Hoffman remembers that day.
A. HOFFMAN: That was a shock to everybody. I mean, I didn't expect to do it. And I was walking like a normal human being.
HAMILTON: Even more surprising, Hoffman's scores on cognitive tests began to improve. The study ended in August, but Nancy Hoffman remembers that while her husband was on the drug he did things he hadn't done in years.
N. HOFFMAN: He actually read the David McCullough book on the Wright brothers and started reading the paper from beginning to end.
HAMILTON: Pagan says everyone in the study improved, though the amount varied. Levels of toxic proteins in their blood and spinal fluid decreased, and they were able to function on lower doses of Parkinson's drugs. After the study ended, Alan Hoffman says he was OK for about three weeks.
A. HOFFMAN: The last couple of weeks has been scary. I mean...
N. HOFFMAN: There's a pretty big change. He does have more problems with his speech and he has more problems with cognition and more problems with mobility.
HAMILTON: The Hoffmans hope to get more nilotinib through a program for people who improve during experiments like this one. Meanwhile, the Georgetown team plans to try nilotinib in patients with another brain disease that involves toxic proteins - Alzheimer's. Jon Hamilton, NPR News.
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