SAN DIEGO ( TheStreet) -- Acadia Pharmaceuticals' (ACAD - Get Report) experimental drug pimavanserin reduced psychotic episodes in patients with Parkinson's disease compared to a placebo, achieving the primary endpoint of a phase III study, the company said Tuesday.
Shares of Acadia were UP 145% to $5.64 in early Tuesday trading.
Acadia needs to conduct another phase III study of pimavanserin in Parkinson's patients in order to confirm Tuesday's results. Two previous late-stage studies of the drug failed to demonstrate a significant reduction in psychotic episodes.
Treatment with a 40 mg dose of pimavanserin resulted in a 5.79-point reduction in psychotic behavior compared to a 2.73-point reduction in patients treated with a placebo. The 3.06-point difference in the two arms of the phase III study was statistically significant.Reduction in psychotic behavior focused mostly on hallucinations and delusions and was assessed using a 9-item scale adapted from the Scale for the Assessment of Positive Symptoms (SAPS). Pimavanserin achieved its antipsychotic effects without worsening motor function in Parkinson's patients, meeting a key secondary endpoint of the trial. The pimavanserin data are "better than I expected," said Zacks analyst Jason Napodano, in a twitter post reacting to the Acadia study results. The U.S. market opportunity for pimavanserin in Parkinson's disease psychosis is $300-400 million, he adds. -- Reported by Adam Feuerstein in Boston. Follow @AdamFeuerstein