Phase three trial to evaluate pimavanserin

Acadia announces that it has initiated a new phase three trial designed to evaluate the efficacy, tolerability and safety of pimavanserin as a treatment for patients with Parkinson’s disease psychosis (PDP).

“This phase three trial builds on the signals of efficacy observed in our earlier PDP studies and uses a refined study design that we expect will help mitigate the placebo response, reduce variability and enhance sensitivity in measuring the efficacy of pimavanserin in PDP patients,” said Uli Hacksell, PhD, CEO of Acadia. “We believe pimavanserin has an ideal profile to effectively treat PDP without impairing motor function and, therefore, provides the potential for an important advance in therapy for patients suffering from this large unmet medical need.”

The phase three trial (the -020 Study) is a multi-center, double-blind, placebo-controlled study designed to evaluate the efficacy, tolerability and safety of pimavanserin in patients with PDP. The -020 Study is expected to enroll about 200 patients at clinical sites located in North America. Patients in the trial will be randomised on a one-to-one basis to two study arms and will receive oral doses of either 40 mg of pimavanserin or placebo once-daily for six weeks.

Patients also will continue to receive stable doses of their existing dopamine replacement therapy used to manage the motoric symptoms of Parkinson’s disease. The primary endpoint of the -020 Study is antipsychotic efficacy as measured using a group of nine items from the hallucinations and delusions domains of the Scale for the Assessment of Positive Symptoms (SAPS).

The primary endpoint will be assessed using centralised ratings. Motoric tolerability will be a key secondary endpoint in the trial and will be measured using Parts II and III of the Unified Parkinson’s Disease Rating Scale (UPDRS).

In addition to the -020 Study, Acadia is continuing to conduct an open-label safety extension study (the -015 Study) that enrolled patients who completed either of two earlier phase three PDP trials. Patients who complete the -020 Study also will have the opportunity to enroll in the -015 Study if, in the opinion of the treating physician, the patient may benefit from continued treatment with pimavanserin.