THE SPARK: The San Diego company said the drug met a series of secondary goals in the clinical trial. According to a scale that measures patients' improvement during treatment, about twice as many patients who took pimavanserin were rated "very much improved" or "much improved" compared to patients who took a placebo. Patients who took the drug also improved based on a clinical measurement called the Scale for the Assessment of Positive Symptoms, or SAPS, and on a simpler version of SAPS Acadia developed.
Acadia said patients treated with pimavanserin were less likely to suffer hallucinations and delusions.
THE BIG PICTURE: In November Acadia said pimavanserin had met its main goal in the trial, reducing psychosis as measured by one of the disease scales. It also said pimavanserin did not affect patients' motor control, while patients who took the drug slept better at night, were more awake during the day, and were less of a burden to caregivers.
According to the company, up to 60 percent of Americans with Parkinson's disease develop psychosis and there is no approved therapy to treat the condition. The company said anti-psychotic drugs are sometimes used to treat the psychosis, but those drugs can increase the risk of death and can cause side effects like the loss of motor control.
Pimavanserin is Acadia's most advanced experimental drug. The company does not have any approved products.
THE ANALYSIS: Jefferies & Co. analyst Thomas Wei said he still expects pimavanserin to be approved, and said it helps that patients improved according to the full SAPS scale along with its streamlined version of the scale.
Wood kept a "Buy" rating on Acadia shares with a price target of $13.
SHARE ACTION: Acadia shares rose 25 percent, or $1.67, to $8.32 in morning trading. The stock is now trading at its highest prices since June 2008. The shares closed at $2.30 before Acadia reported the initial results from the trial.