Pivotal phase III HARMONY trial stopped early for positive efficacy of pimavanserin in dementia- related psychosis

ACADIA Pharmaceuticals Inc. announced that its Phase III HARMONY study, a double-blind, placebo-controlled relapse prevention trial evaluating pimavanserin for the treatment of dementia-related psychosis, met its primary endpoint, demonstrating a highly statistically significant longer time to relapse of psychosis with pimavanserin compared to placebo in a planned interim efficacy analysis.

Upon the recommendation of the study’s independent data monitoring committee, which met to review the data from the planned interim efficacy analysis, the study will now be stopped early based on pre-specified stopping criteria requiring a one-sided p-value less than 0.0033 on the study’s primary endpoint. The Company is planning to meet with the FDA regarding a supplemental NDA submission in 2020 and the results from the HARMONY study will be submitted for presentation at upcoming medical meetings.

“Psychosis adds dramatically to the marked burden that dementia patients already carry and is one of the most challenging-to-manage aspects of the disease for caregivers,” said Jeffrey Cummings, M.D., Sc.D., Director Emeritus of Cleveland Clinic Lou Ruvo Center for Brain Health in Las Vegas. “With no approved treatment options available today for dementia-related psychosis, the pimavanserin study results represent a meaningful advance that will potentially bring us a much needed therapy for this debilitating disease.”

About the HARMONY Study : HARMONY is a Phase III study designed to evaluate the efficacy and safety of pimavanserin for the treatment of delusions and hallucinations associated with dementia-related psychosis across a broad population of patients with the most common subtypes of dementia including: Alzheimer’s disease, dementia with Lewy bodies, Parkinson’s disease dementia, vascular dementia, and frontotemporal dementia spectrum disorders.The HARMONY study included a 12-week open-label stabilization period during which patients with dementia-related psychosis were treated with pimavanserin 34 mg once daily. Dose reduction to 20 mg once daily was allowed if clinically justified within the first four weeks. Following the 12-week stabilization period, patients who met pre-specified criteria for treatment response were then randomized into the double-blind period of the study to continue their pimavanserin dose (34 mg or 20 mg per day) or switched to placebo and followed for up to 26 weeks or until a relapse of psychosis occurred. The primary endpoint in the study was time to relapse in the double-blind period. Relapse (significant worsening of dementia-related psychosis after prior stabilization) was defined in the study by one or more of the following: hospitalization due to dementia-related psychosis, significant deterioration of dementia-related symptoms on clinical scales, withdrawal from the study due to lack of efficacy, or the use of an off-label antipsychotic medication for the treatment of dementia-related delusions and/or hallucinations. All potential relapses and discontinuations in the double-blind portion of the study were adjudicated by an independent adjudication committee to determine if protocol defined relapse criteria were met.