The New England Journal of Medicine Publishes Results from the Phase 3 HARMONY Study Evaluating Pimavanserin in Patients with Dementia-Related Psychosis

Acadia Pharmaceuticals Inc. (Nasdaq: ACAD) announced today that the New England Journal of Medicine published results from the Phase 3 HARMONY study, an international, double-blind, placebo-controlled relapse prevention trial in 392 patients evaluating pimavanserin as an investigational treatment in patients with hallucinations and delusions associated with dementia-related psychosis (DRP). The study included patients across five subgroups of dementia: Alzheimer’s disease, dementia with Lewy bodies, frontotemporal dementia, Parkinson’s disease dementia, and vascular dementia.

The HARMONY study was stopped early due to positive efficacy at the pre-planned interim analysis upon recommendation of the trial’s independent data safety monitoring board. HARMONY met its primary endpoint by significantly reducing the risk of relapse of psychosis by 2.8 fold compared to placebo in the double-blind period (hazard ratio (HR)=0.35, two-sided p=0.005; one-sided p=0.0023). The study also met its secondary endpoint by significantly reducing the time to trial discontinuation for any reason (HR=0.45, two-sided p=0.005; one-sided p=0.0024). The data from the HARMONY study demonstrates that patients with DRP who had responded to pimavanserin had a significantly lower risk of relapse of psychosis with continuation of pimavanserin compared to placebo up to 26 weeks.

“The relapse prevention design of the HARMONY study mirrors exactly what we do in clinical practice. This landmark trial showed that when patients responded to pimavanserin and then continued treatment, they were almost three times less likely to develop recurrence of their hallucinations and delusions than those patients who discontinued pimavanserin treatment,” said the study’s lead author, Dr. Pierre N. Tariot, Banner Alzheimer’s Institute director. “This is a substantial finding and a significant advance for a critical public health need in our field. There is no FDA approved treatment for DRP, and the majority of antipsychotics currently used off-label have equivocal efficacy and may accelerate cognitive decline.”

Pimavanserin was well-tolerated over the nine-month study duration. In a pre-specified analysis, pimavanserin was not associated with a decline in cognition as measured by Mini-Mental State Examination (MMSE) or the onset or worsening of motor symptoms as measured by Extrapyramidal Symptom Rating Scale A (ESRS-A).

“The HARMONY study findings demonstrated three important results. First, in the 12-week open-label period, pimavanserin treatment showed a sustained reduction of psychotic symptoms. Second, in the 26-week double-blind period, patients on pimavanserin had a nearly three-fold reduction of risk of psychosis relapse compared to patients on placebo. Third, pimavanserin was well-tolerated by elderly patients with DRP,” said Steve Davis, Chief Executive Officer of Acadia. “We are very pleased that the New England Journal of Medicine has chosen to publish the important results of this study.”