Althoughthe drug contains an active substance never before approved by the FDA,that substance is an active metabolite of an old drug, the atypicalantipsychotic Risperdal (risperidone), which is marketed for treatingschizophrenia.

Theeffectiveness of Invega in the acute treatment of schizophrenia wasestablished in three six-week placebo-controlled trials conducted inNorth America, Europe and Asia.

The1,665 participating adults were evaluated for the full array of signsand symptoms of schizophrenia. In the three studies using doses rangingfrom 3 mg a day to 15 mg a day, Invega was superior to the placebo. Therecommended dose range for Invega is 3 mg to 12 mg a day.

SinceInvega efficacy has not been evaluated in placebo-controlled trials forlonger than six weeks, the FDA said physicians should periodicallyreevaluate patients who use the drug for extended periods.

TheFDA cautioned that Invega belongs to the atypical antipsychotic class,and, compared with placebo, atypical antipsychotic drugs have beenassociated with an increased risk of death of in elderly patients withdementia-related psychosis.

The FDA added that Invega "is not approved for dementia-related psychosis."

Inclinical trials. commonly reported adverse events were restlessness,extrapyramidal symptoms, rapid heartbeat and sleepiness.