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July 8 (Reuters) - Intra-Cellular Therapies Inc said on Monday its lead drug failed to meet the main goal of one of two late-stage studies in patients with major depressive episodes associated with bipolar disorder.
The company's shares fell 6.5% before the opening bell.
The treatment, lumateperone, which is being studied as a monotherapy for the condition, failed to show statistically significant improvement in the disease condition compared to placebo in the trial, the company said.
The study, conducted only in the United States, tested two doses of the treatment against placebo in 554 patients.
However, a second study which tested the treatment in 381 patients, met the main goal of statistically greater improvement over placebo.
Bipolar disorder is characterized by varying episodes of mania and depression and affects about 2.8% of the U.S. population aged 18 and older, according to the National Institute of Mental Health.
Intra-Cellular also awaits FDA approval of lumateperone as a treatment for schizophrenia. (Reporting by Manojna Maddipatla in Bengaluru; Editing by Maju Samuel)