Notes from AAN 2010: Part I

From James Beck Ph.D., Director of Research Programs

Sorry for the delay in postings. As you will see in the next several posts, I have been a bit busy attending scientific meetings that have a direct impact upon Parkinson's.

The American Academy of Neurology annual meeting was held recently in Toronto. This a large international meeting where neurologists come together to learn and share new scientific progress (largely clinical) related to diseases of the nervous system. I already covered some of the new findings related to imaging and PD in my interview with David Eidelberg, M.D.,, but I wanted to share a couple of other brief things that you might find relevant, the first of which I'll include below. Look for another update next week.

A troubling non-motor feature of PD is psychosis, which is often experienced in the form of hallucinations. Yet, treatments for it have been limited. One drug that is in development for this is pimavanserin. At the AAN meeting, the results of a Phase III trial using this drug were reported by Joseph Friedman, M.D., of Brown University. Though the drug was well-tolerated, the outcome of this safety and efficacy study were negative (a rarity to find negative results reported at all). The trial missed its primary endpoint on reduced psychosis—that is the drug worked no better than the placebo.

What was interesting is that Dr. Friedman suggested that the trial failure may have been due to a greater than expected placebo effect, meaning people taking a sugar pill reported a similar reduction in symptoms as those taking the experimental medication. (Not so unusual for therapies treating motor symptoms in PD, but less common here.) In particular, non-North American study sites (i.e., Eastern Europe and India in particular) reported a much greater placebo effect than North American study sites. It is likely the results from those sites altered the final results while just using data from the North American sites suggested a more positive outcome of the drug.

Apparently, there were differences in how clinicians interacted with their patients and this attests to the difficulty in international clinical trials for some diseases. Nevertheless, Dr. Friedman indicated that the company behind the drug, Acadia Pharmaceuticals, is still pursuing the drug candidate with a revised Phase III study. It will be interesting to see whether the new Phase III trial to be conducted in North America only will end with different, more positive results.

For those interested in Dr. Friedman's work, he recently presented a one-hour PD ExpertBriefing with PDF on a different topic. View this seminar, entitled Fatigue, Sleep Disorders and Parkinson's Disease, on the PDF website.

Also, check back on Monday for news about pharmacy errors in Parkinson's.