The Society for Neuroscience annual meeting, which took place last week in Chicago, IL, is a place where the latest preliminary data in neuroscience is presented. True to form, there was an interesting abstract presented by Fernando Pagan, M.D. and colleagues from Georgetown University Hospital which suggested a potential treatment for those with Parkinson’s disease (PD). At the heart of the presentation, Dr. Pagan and colleagues reported that in a small trial, an anti-cancer drug called nilotinib was able to reverse both the movement symptoms and cognitive decline of people with PD involved in the study.
First, the potential is incredibly exciting. We all know that the PD community urgently needs better treatments and certainly, the idea of repurposing drugs might be the quickest way to find those drugs and get them in the hands of those who need them.
But it is also a good point to slowdown. Why? It is very early days. As others have pointed out, the study was a "non-randomized, non-blinded, non–placebo-controlled study that looked at [only] 12 patients.” Additionally, the full data has not been published, meaning there is not yet a way for the foundation team to review and analyze it. In absence of hard data, keeping in mind how powerful the placebo effect can be in PD and the desire by all to see the drug be successful, these claims deserve caution.
The good news is that there is compelling evidence from the lab suggesting that nilotinib could impact Parkinson’s disease – at least in a mouse. The other good news is that nilotinib, despite being a drug with nasty side effects such as heart attacks and sudden death all listed in its black box warning, did not cause harm in the 12 participants who took it.
That said, we need to know more about its impact in Parkinson’s disease in larger studies. But the road is long even for this already FDA-approved drug. For example, dosing could be an issue. The doses Dr. Pagan and colleagues provided to people with PD in the study were only about 25 percent of a typical dose for a cancer patient. But in the initial animal studies mentioned above, the doses were significantly higher. If doses are increased, there is concern about adverse events (like those described above), which not only present pitfalls for people with PD, but also can make larger studies more difficult.
At the foundation, we await the published results of this study, and remain hopeful about its future. But ours is a cautious hope because we have seen this excitement before when potentially promising therapies have been heralded to the rafters yet have crumbled when more rigorously examined.
Don’t get me wrong — we all should hold out hope that nilotinib will prove to be effective. But it is important to remember the disappointment of past miracle drugs and wait until the evidence has been gathered, lest we feel double-crossed before we do the double-blind.
My fingers are crossed.
James Beck, Ph.D., has led the scientific affairs of the Parkinson's Foundation since 2008. Dr. Beck oversees the foundation’s research strategy and programs, including management of grants that support research centers, individual investigators, fellows and collaborative projects.