Acadia plummets on pimavanserin miss

Acadia Pharmaceuticals Inc. (NASDAQ:ACAD) fell US$3.84 (66%) to US$2 on Tuesday after pimavanserin missed the primary endpoint of a significant improvement in antipsychotic efficacy as measured by the Scale for the Assessment of Positive Symptoms vs. placebo for six weeks in the Phase III ACP-103-012 trial to treat Parkinson's disease psychosis (PDP). The double-blind, international trial of the small molecule serotonin (5-HT2A) receptor inverse agonist enrolled 298 patients. A second Phase III trial of pimavanserin in PDP patients is ongoing. ...