U.S. Food and Drug Administration staff members said on Friday Acadia Pharmaceuticals Inc's drug to treat psychosis associated with Parkinson's disease was an effective treatment for the condition.

The drug, Nuplazid, is a new chemical compound and could be the first drug specifically approved in the United States for Parkinson's disease psychosis (PDP). (1.usa.gov/1PuYUCe)

Parkinson's disease is typically associated with impaired motor function.

However non-motor symptoms, such as psychosis characterized by hallucinations and delusions, occur in about 25 percent of Parkinson's patients, said Alan Carr, an analyst with investment banking and asset management firm Needham & Co.

This translates into an addressable population of 250,000 for the drug in the United States, according to Carr.

Nuplazid was granted the FDA's breakthrough therapy status in 2014 on the basis of a late-stage study that showed it reduced psychosis symptoms, with a relatively clean safety profile. (bit.ly/1PuZPCO)

FDA scientists released their report ahead of a meeting on Tuesday of an independent medical advisory panel. While the FDA is not obligated to follow the panel's recommendations, it typically does so. The FDA is slated to decide on the treatment's approval by May 1.

Nuplazid will likely win approval and be adopted as the treatment of choice, some industry analysts have said. 



"While the applicant will present evidence that the treatment effect represents a clinically meaningful change," writes Mitchell Mathis, director of the division of psychiatry products, "the Division's medical officer will present his interpretation of the same data and reach a different conclusion." 


None of that seemed to spook investors, though. Acadia's shares shot up 25% in early trading on Monday.

Analysts have pegged 2020 revenue from Nuplazid at $1.4 billion, making this one of the top drug prospects up for review this year. The FDA has designated the therapy as a "breakthrough" drug warranting a quick response from regulators.


"Serious adverse events (AEs) occurred in 16/202 (7.9%) patients taking pimavanserin 34 mg versus 8/231 (3.5%) placebo-treated patients" in the studies, noted the FDA review. And it was also clear to the regulators that the rate of AEs increased with the dosage of the drug. But that's also not necessarily damning. This is a patient population, after all, that suffers a high mortality rate, as well as adverse events. The regulators were also unable to explain the differences.


States the FDA: "As with the disproportionate increase of serious adverse events in the pimavanserin 34 mg daily group compared to the placebo group, there is no obvious unifying pathophysiologic process or unique adverse event that drives or dominates this disproportion."