Wyeth Pharmaceuticals, a division of Wyeth, this week presented for the first time phase 3 data and results from other studies concerning its investigational drug for major depressive disorder (MDD), desvenlafaxine succinate (DVS-233), a novel serotonin-norepinephrine reuptake inhibitor (SNRI) at the 2006 American Psychiatric Association Annual Meeting in Toronto.

Overall, the phase 3 data results showed desvenlafaxine succinate significantly improved depressive symptoms in adult patients compared to placebo. In a separate study investigating QTc prolongation involving healthy adult female subjects, desvenlafaxine succinate 200 mg and 600 mg doses did not affect the QT interval at the study's primary endpoint at eight hours post dose. Studying a drug's effect on the QT interval is one of many methods used to help determine a drug's overall safety profile.

Wyeth Research discovered and developed desvenlafaxine succinate. In December 2005, Wyeth submitted a New Drug Application (NDA) to the US FDA for desvenlafaxine succinate for the treatment of MDD.

"The phase 3 data showed that desvenlafaxine succinate can help improve symptoms in adult patients suffering with depression," says Nicholas A. DeMartinis, assistant professor and associate director of clinical operations of the Neuropsychopharmacology Treatment Research and Training Centre at the University of Connecticut Health Centre and principal investigator of the clinical trial presented in the scientific session. "Because a substantial number of patients with depression do not respond to current antidepressant treatments, it is important that new treatments continue to be developed to provide patients and physicians with additional treatment options," DeMartinis adds.

"Wyeth is pleased to be able to report these promising findings that have the potential to add value to the management and treatment of major depressive disorder," says Philip Ninan, VP, Neuroscience, Global Medical Affairs. "As a leader in neuroscience, Wyeth is committed to its continuing development of medications that help address the unmet needs of people living with mental illness," he added.