November 20, 2015

Tasigna: The First Drug to Reverse Symptoms of Parkinson's Disease?

Image result for nilotinib

At their best, drugs and treatments for Parkinson's disease (PD) only slow the progression of the disease. But now a small clinical trial has shown that a cancer drug already approved by the FDA may have the potential to reverse PD symptoms, both motor and non-motor.

The new hope was announced at the recent meeting of the Society for Neuroscience by researchers at the Georgetown University Medical Center. Using a drug developed for leukemia patients, the scientists cut the dose, and gave it to 12 patients who had either advanced PD with dementia or the related Lewy body dementia.

See yesterday's post for a discussion of these two types of dementia.

The drug is nilotinib, marketed as Tasigna by Novartis. It works to stimulate the cellular clearance system, or "garbage disposal." In leukemia, it helps clear out cancer cells. In Parkinson's, the researchers thought it might also work in smaller doses to tame the neurotoxic proteins found in patients with Parkinson's, Alzheimer's, and related illnesses.

A Very Unexpected Surprise
The researchers found that one small dose a day -- instead of the two heftier doses given cancer patients -- would do the job.

Initially, the goal of this study was to check for safety and rule out the danger of serious side effects from the drug. For its cancer application, nilotinib wasn’t designed to enter the brain. This new study aimed to see if the drug could cross the blood-brain barrier in amounts that were both safe and effective.

The researchers soon realized that this experimental treatment was yielding unexpected -- and very positive -- results.

Dr. Fernando Pagan, director of the Movement Disorders Program at Georgetown, explained his team’s surprise: study subjects began displaying significant improvements in both cognitive and motor functions… a result unheard of in advanced cases of Parkinson's Typically, treatments to improve one set of those symptoms only exacerbated the other.

 Pagan reported that one patient with communications problems – both speaking and understanding -- suddenly began talking and high-fiving his nurses during the trial. "He was even able to crack a few jokes and help with his care," Pagan said.

Nilotinib’s Hefty Price Tag
The cost of nilotinib for treating leukemia is about $10,360 a month -- for 800mg daily! The dosages for the Georgetown study were 150mg and 300mg daily. My desk calculator indicates the monthly costs for those amounts would be about $2,000 and $3,900, respectively.

Study Caveats
Last Tuesday night, I attended a talk by Dr. Pagan. His appearance was part of the monthly lecture series sponsored by the Parkinson's Foundation of the National Capital Area.

Much of the well-attended meeting was devoted to the nilotinib study. Dr. Pagan readily acknowledged that the study involved only 12 patients, a very small sample. In addition, all subjects took the drug, and nobody received a placebo.

The gold standard element for drug efficacy trials is "double-blind," where neither participants nor investigators know who gets the drug and who gets the placebo. Historically, Parkinson's trials that are not double-blind are very compromised by the placebo effect.

What's Next?
The Georgetown hospital researchers now plan a larger clinical trial they hope will begin early in 2016. Pagan said this next study will involve 60-70 patients, and will include a placebo control group.

The Georgetown team had a tough time funding the first study. The usual money sources weren’t available, since the notion of using a cancer drug to treat neurological diseases sounded too risky. As a result, the research team raised $500,000 from two sources: hopeful patients and a foundation. They then secured a matching grant from the Georgetown-Howard Universities Center For Clinical and Translational Science. 

Pagan and his team hope to have better luck funding their next round of clinical trials.

I asked Dr. Pagan how long it would take for the drug to become available to PD patients, assuming the expanded trial confirms initial findings. "Three to five years," he said.

I wish I had thought to ask Dr.Pagan why the clinical trial was limited to Parkinson's patients who had dementia and whether others with Parkinson's could anticipate receiving similar benefits from the drug. I will try researching this further.

2 comments:

Chelsea said...

Any new info on this? In particular we'd love to hear from anyone who has decided to take the drug voluntarily on an off-label basis. We will probably do this after discussing it further with our neurologist.

Anonymous said...

Any news??

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