Shares in Acadia were on the rise after US regulatory advisors endorsed a drug with the potential to bring a step change in the way Parkinson’s disease is treated.

The US Food and Drug Administration’s Psychopharmacologic Drugs Advisory Committee (PDAC) voted 12-2 that the benefits of Nuplazid (pimavanserin) for treating psychosis associated with Parkinson’s disease outweigh the treatment’s risks.

The decision was based on findings of a Lancet-published Phase III clinical trial, in which the drug was associated with a -5.79 decrease in the Parkinson’s disease-adapted scale for positive assessment of symptoms (SAPS-PD) versus -2.73 for placebo.

Overall, the drug was also found to be well-tolerated, with no significant safety concerns or worsening of motor functions, although 10 patients from the group given Nuplazid discontinued the trial because of an adverse event (four due to psychotic disorder of hallucination) compared to two in the placebo arm.

According to the National Parkinson’s Foundation, about one million people in the US suffer from the progressive neurological condition, of which an estimated 40 percent experience related psychosis, characterised by hallucinations and delusions, a diminished quality of life, and significant caregiver burden.

“If approved by the FDA, Nuplazid would be the first drug indicated to treat psychosis associated with Parkinson’s disease,” noted Acadia’s chief executive Steve Davis.

The FDA should make a final decision by May 1, having assigned the drug’s application a priority review.