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Added Pimavanserin Shows Positive Trends in Schizophrenia but Misses Primary Endpoint in Trial

July 31, 2019

Although adding pimavanserin to antipsychotic treatment in adults with schizophrenia showed a consistent trend in improvement of symptoms, results from a phase 3 study did not achieve statistical significance on the trial’s primary endpoint, Acadia Pharmaceuticals announced.

“Unfortunately, we did not achieve a statistically significant reduction in the Positive and Negative Syndrome Scale (PANSS) total score in this study,” said Acadia Pharmaceuticals president Serge Stankovic, MD, in a company press release. “We are pleased with the improvement in negative symptoms observed in this study. We look forward to completing our ongoing ADVANCE trial evaluating pimavanserin in schizophrenia patients with predominant negative symptoms.”

The 6-week, phase 3 ENHANCE study evaluated once-daily pimavanserin as an adjunctive treatment in adults with schizophrenia who had inadequate response to their current antipsychotic. Some 396 outpatients with moderate to severe psychotic symptoms were randomized to either pimavanserin or placebo added to their current treatment, which included risperidone, olanzapine, and aripiprazole.

In addition to a trend of improved psychotic symptoms with added pimavanserin, researchers observed a positive trend on the Clinical Global Impression-Severity (CGI-S) score, Acadia Pharmaceuticals reported. In a pre-specified subgroup analysis by study region, consistent positive results were demonstrated on PANSS total score as well as CGI-S score.

In the full analysis set, pimavanserin showed significant improvements in two measures of negative symptoms: the PANSS negative symptoms scale sub-score and the PANSS Marder negative factor score.

Adjunctive pimavanserin is currently being evaluated for the treatment of patients with predominant negative symptoms in the 26-week, phase 2 ADVANCE study. The trial’s primary endpoint is change from baseline on the Negative Symptom Assessment-16 total score. Results are expected by the end of the year.

—Jolynn Tumolo


ACADIA Pharmaceuticals announces top-line results from phase 3 ENHANCE trial of pimavanserin as adjunctive treatment for patients with schizophrenia [press release]. San Diego, California: ACADIA Pharmaceuticals; July 22, 2019.

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