The non-dopaminergic drug pimavanserin reduces psychotic symptoms in patients with Parkinson’s disease (PD) without worsening motor function, shows a randomized trial.
In a press statement, lead researcher Clive Ballard (King’s College London, UK) stressed that “the clinical benefits of pimavanserin were seen by patients, those caring for them, and independent blinded raters alike.”
Along with observed improvements in sleep, this suggests that tackling psychosis had “a broader effect on wellbeing of patients,” write Ballard and colleagues in The Lancet.
A total of 199 patients participated in the study, 185 of whom were included in the final analysis; all had a combined score of at least 6 on the neuropsychiatric inventory items delusions and hallucinations, or an individual score of at least 4.
The researchers tried to provoke a placebo effect ahead of the start of drug treatment by first providing all patients with 2 weeks of psychosocial therapy. Nevertheless, patients assigned to the placebo group still had a 14% reduction in psychotic symptoms on the PD-adapted Scale for Assessment of Positive Symptoms (SAPS) over the 6-week study period.
However, patients taking pimavanserin – a selective serotonin 5-HT2A inverse agonist – had a significantly larger 37% improvement.
In an accompanying commentary, Susan Fox (Toronto Western Hospital, Ontario, Canada) writes: “Overall, the study opens up a new therapeutic avenue in treatment of Parkinson's disease psychosis.”