* Lurasidone significantly better than placebo in study
* Discontinuation rate similar to placebo
* Company to seek U.S. FDA approval in early 2010
By Bill Berkrot
NEW YORK, Aug 26 (Reuters) - Japan's Dainippon Sumitomo Pharma Co Ltd <4506.T> said its experimental schizophrenia drug, lurasidone, was significantly better than placebo in a pivotal late-stage clinical trial, according to data released on Wednesday.
The company said it plans to submit its application seeking U.S. approval to sell the medicine early next year.
Patients with acute schizophrenia in the 478-subject, six-week, Phase III trial received either 40 milligrams or 120 milligrams of lurasidone daily or a placebo.
Both doses of the drug proved to be statistically significantly better than placebo in the primary goal of the study, which was 30 percent or better improvement in the Positive and Negative Syndrome Scale, the company said.
Fifty-three percent of patients who received 40 mg of lurasidone and 47 percent of those on the 120 mg dose achieved the primary goal compared with 38 percent on placebo.
Both doses of lurasidone were also significantly more effective than placebo on a secondary measure used to test antipsychotic drugs called the Clinical Global Impressions Severity scale, the company said.
In previous trials, lurasidone was also tested at 80 mg and Dainippon Sumitomo said it would submit all three doses for FDA approval.
Lurasidone belongs to a class of drugs known as atypical antipsychotics and works by blocking serotonin receptors in the brain. If approved, it would join an already crowded field of such treatments.
"We're still searching for the right drug for many of these patients. There's no one size fits all," Dr Herbert Meltzer, one of the study's lead investigators and professor of psychiatry at Vanderbilt University School of Medicine, said in a telephone interview.
Patients in the trial had been diagnosed with schizophrenia on average for more than 13 years and most had been previously hospitalized prior to entering the study.
"If you look at the weight gain, the lipid changes, it's among the most benign of any antipsychotic drugs, clearly better than olanzapine, clozapine and Seroquel," Meltzer said.
Olanzapine is the chemical name for Eli Lilly and Co's
Zyprexa and similar drugs can cause significant weight gain and have been linked to increased risk of diabetes.
But "this class of drugs as a whole is so superior to the first generation drugs," said Meltzer, who plans to present the data from the lurasidone trial at a major medical meeting in December.
Lurasidone was well tolerated with a discontinuation rate nearly identical to placebo -- 40 percent versus 39 percent -- and the adverse events were generally mild, such as restlessness and sleepiness.
"From the point of view of efficacy and side effect profile, once a day administration, the fact that the lower dose works as well as the higher dose, I think this is going to have a very good chance of major acceptance among my colleagues," Meltzer added. (Reporting by Bill Berkrot; editing by Andre Grenon)