Nuplazid’s Risks in Treating Parkinson’s Psychosis Don’t Appear Exceptionally High, Experts Say

The controversy surrounding Nuplazid (pimavanserin), Acadia Pharmaceuticals‘ approved treatment for psychosis in Parkinson’s patients, has made its way to scientific journals. But experts appear to take a more questioning view of the medication’s risks than that aired by general media.

A clinical trial comparing the effectiveness and benefits of Nuplazid to other antipsychotics used to treat these patients would be warranted, and ideally pit the medication against clozapine, an editorial in The Lancet said. But the piece also noted that clozapine, a schizophrenia treatment, is not approved for Parkinson’s disease and is used off-label, complicating matters.

The editorial, “Difficult choices in treating Parkinson’s disease psychosis,” was published on May 29.

Focusing on the “relative risk of pimavanserin” in comparison to psychosis medications like clozapine and quetiapine, it also noted that “it is important to remember that safety concerns were expected and deaths can occur commonly in patients with Parkinson’s disease psychosis — a fact acknowledged by the FDA during its assessment — because these patients are frail, and are usually in the end stages of the disease.”

Still, the editorial recommended that a randomized clinical trial assessing Nuplazid’s risks and benefits in Parkinson’s patients be pursued, and research “continue into novel drugs for psychosis in frail populations.”

In the journal Neurology Today, meanwhile, three neurologists questioned reports of an unusual risk to Parkinson’s patients being treated with Nuplazid for psychosis.

“In my personal experience with pimavanserin, it is effective in a majority of PD [Parkinson’s] psychosis patients,” said Rajesh Pahwa, MD, a professor of neurology and chief of the Parkinson & Movement Disorders Division at the University of Kansas Medical Center in Kansas City. “We need to further study the reports of increased mortality, but in a scientific manner.”

The journal’s “Article in Brief,” published June 7, recounted the controversy concerning Nuplazid, the first medication approved by the U.S. Food and Drug Administration to treat Parkinson’s psychosis, or disease-related hallucinations and delusions, in 2016.

Nuplazid works differently from other anti-psychotic medications in that it does not block dopamine — a brain neurotransmitter crucial to movement and motivation, and the target of treatments for Parkinson’s movement difficulties — focusing instead on a subfamily of serotonin receptors (5 HT2A) of importance to cognition, memory, and the ability to learn.

The news channel CNN reported in April that the FDA’s Adverse Event Reporting System (FAERS) showed a total of 700 deaths, including 500 in Parkinson’s patients in which the medication was the only agent likely involved.

The FDA initially responded by noting that “FAERS data by themselves are not an indicator of the safety profile of the drug or biologic,” and emphasizing it had placed a “boxed warning” on Nuplazid highlighting its risks. A boxed warning is the strictest warning on product labeling that can be given an approved medication, but one — warning of an increased risk of mortality and morbidity in people with dementia — given on all antipsychotics, The Lancet commentary noted.

Later, the FDA acknowledged that is was continuing to keep close watch on Nuplazid and its use in Parkinson’s patients. The CNN report led to a 20 percent drop in Acadia’s stock in the days after its airing.

But, as Pahwa argued, the U.S. Medicare database show that mortality rates (per 100 patient years) are 7.3 for Parkinson’s patients without psychosis, and 28 for patients with psychosis — with a mortality rate of 18.6 for those using quetiapine off-label, compared to 12.4 in post-marketing data for pimavanserin.

Joseph Jankovic, MD, director of the Parkinson’s Disease Center at Baylor College of Medicine in Houston, told Neurology Today that his patients largely have responded well to Nuplazid treatment.

“While not all patients are completely satisfied, many of my patients have experienced marked improvement in their visual hallucinations, paranoia, and other psychotic symptoms,” Jankovic said. “I suspect that the death rates in elderly patients with advanced PD and psychosis are higher than in a control population without these problems, so it’s not surprising to see deaths in such patients who are taking pimavanserin, but the cause-effect relationship has not been established.”

He preferred to recommend that physicians simply continue to closely monitor their patients.

A similar view was voiced by Cynthia Comella, MD, a professor of neurology at Rush University Medical Center’s Parkinson’s Disease and Movement Disorders Section in Chicago.

“I think it is too soon to be concerned specifically about this drug,” Comella said. “I feel that we need to be cautious with all of these drugs. I especially have concerns prescribing them in elderly patients because they are more fragile and usually have additional disorders and health conditions.”

According to the Neurology Today article, Pahwa has received consulting fees from about a dozen pharmaceuticals and government agencies including Acadia, but no research grants from Acadia. Jankovic and Comella reported no conflicts of interest.