Most people associate Parkinson’s with tremors and other motor symptoms. But for some, the disease gives rise to something more terrifying, and much more hidden: psychosis.
On Tuesday, an advisory committee to the Food and Drug Administration voted 12-2 in favor of approving the first antipsychotic drug specifically designed to combat the hallucinations, illusions, and delusions experienced by Parkinson’s patients.
The FDA does not have to follow the panel’s advice, but it usually does. A final regulatory decision on the drug — which is manufactured by San Diego-based Acadia Pharmaceuticals Inc. under the brand name Nuplazid — will be made by May 1.
The drug could offer an important new option for those battling the disorder, said Dr. Rachel Dolhun, a spokeswoman for the Michael J. Fox Foundation for Parkinson’s Research. “We’re in kind of a quandary here with our current therapies.”
But that hope is tempered by significant uncertainty surrounding price and effectiveness.
If approved, Nuplazid would undoubtedly cost far more than existing antipsychotic medicines, which, although designed for treating schizophrenia, are often given to Parkinson’s patients and are available as generics.
And in clinical testing, Nuplazid (which is known generically as pimavanserin) showed only modest improvements over placebo, and was evaluated in a way that makes it difficult to compare against other treatments.
Physicians involved in the trial stand by the drug, nonetheless.
Dr. Jeffrey Cummings, a neurologist at the Cleveland Clinic Lou Ruvo Center for Brain Health in Las Vegas, said he was struck by some of his patients’ “dramatic” responses.
“Of course, families will also respond to placebos, and that’s why we don’t approve drugs based on anecdotal reports,” said Cummings, who has taken consulting fees from Acadia. “But when families are saying this really made a difference for his life and our lives together, for me it was a pretty impressive study.”
Parkinson’s psychosis usually occurs in the latter stages of the disease, and generally involves nonthreatening visual hallucinations.
Cynthia Hatfield, a 72-year-old former banker living in Westerly, R.I., several times a week sees a calico cat resembling one she’d owned many years ago.
For years, her hallucinations included a menagerie of small animals. “Chipmunks and little squirrels and cats, and a little mouse would come out every once in a while,” she said. “I actually enjoy seeing them.”
The stakes are higher for those who experience frightening hallucinations or paranoid delusions. Studies have shown that psychosis, more than any other reason, causes Parkinson’s patients to move to nursing homes.
To avoid this fate, doctors will often try to dial down conventional Parkinson’s medications, which work to control tremors and other movement problems by targeting the same neurotransmitters in the brain that can also trigger psychosis. That’s a fraught approach for those with advancing physical symptoms.
The most common alternative: giving antipsychotic medications that are FDA-approved for treating schizophrenia or bipolar disorder, but not Parkinson’s. Doctors believe antipsychotics like Seroquel or Clozaril have some effect on Parkinson’s psychosis, and can help ease anxiety and sleeplessness as well, but clinical studies have failed to show an effect on Parkinson’s psychosis.
Thus the high hopes for Nuplazid even if those hopes rest on a somewhat shaky foundation, largely composed of a single Phase 3 trial that focused on 199 Parkinson’s patients and lasted just six weeks.