New Phase 3 Data Showed PRISTIQ Significantly Reduced Symptoms Of Major Depressive Disorder Versus Placebo

Main Category: Depression
Also Included In: Psychology / Psychiatry;  Clinical Trials / Drug Trials;  Pharma Industry / Biotech Industry
Article Date: 13 Dec 2007 - 0:00 PDT

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Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE), announces that data from two Phase 3 clinical studies of PRISTIQ(TM) (desvenlafaxine), an investigational serotonin-norepinephrine reuptake inhibitor (SNRI), showed that adult patients who received a 50 mg/day dose of PRISTIQ for the treatment of major depressive disorder (MDD) experienced a statistically significant reduction in the symptoms of major depression compared to placebo. The two studies, which evaluated efficacy and safety of PRISTIQ for the treatment of MDD at fixed doses of 50 mg/day and 100 mg/day, will be presented today at a major medical meeting. This will be the first time an analysis of the 50 mg/day dose for PRISTIQ for the treatment of MDD is presented.

In both studies, discontinuation rates due to adverse events (AEs) for PRISTIQ 50 mg/day were similar to placebo. In the two studies, the rates of discontinuation due to AEs for placebo and PRISTIQ 100 mg/day were three percent and seven percent, respectively.

"These findings show that PRISTIQ has the potential to reduce symptoms of MDD at doses as low as 50 mg once daily," says Philip Ninan, M.D., Vice President, Neuroscience, Global Medical Affairs. "The response rates of patients in the 50 mg/day dose groups are similar to the rates seen at higher doses. We are also encouraged by the tolerability profile shown in the two studies presented at this meeting. Notably, subjects in the 50 mg/day dose groups were not titrated from a lower dose when initiating therapy."

Wyeth submitted in August 2007 the results of the two studies to the U.S. Food and Drug Administration (FDA) as part of its complete response to the FDA approvable letter it received in January 2007 for PRISTIQ for the treatment of MDD. FDA action on the application is expected during the first quarter of 2008. The clinical data for PRISTIQ presented at the meeting represent only a portion of the data from the ongoing clinical development of PRISTIQ and are not necessarily representative of the totality of data and other information that may affect further development, regulatory review and/or commercialization of PRISTIQ.

More About the Studies

Poster 145: Liebowitz M., et al. Evaluation of the Efficacy and Safety of Fixed Doses of Desvenlafaxine Succinate at 50 mg and 100 mg in Outpatients with Major Depressive Disorder in 2 Placebo-Controlled Trials

Data presented are from two identically designed multicenter, randomized, double-blind, placebo-controlled, eight-week studies, one conducted outside of the United States involving 483 adult patients, and one in the U.S. with 447 adult patients. Primary efficacy in both trials was determined based on change from baseline score on the 17-item Hamilton Depression Rating Scale (HAM-D17). Patients in both desvenlafaxine groups started treatment at 50 mg/day. For the 100 mg/day group, the dose was increased to 100 mg/day on the eighth day of the study.

Efficacy Analysis

The results of both trials showed that at the 50 mg/day dose, desvenlafaxine was associated with a significant reduction in the symptoms of MDD as measured by HAM-D17 scores over eight weeks compared with placebo (ex-US: p=0.002, 50 mg = -13.2, placebo = -10.7; U.S.: p=0.018, 50 mg = -11.5, placebo = -9.5). While the 100 mg/day dose showed a statistically significant improvement in the international study versus placebo (p<0.001, 100 mg = -13.7), this dose did not statistically separate from placebo in the U.S. study (p=0.065, 100 mg = -11.0).

Safety Analysis

In the U.S. study, rates of discontinuation due to AEs for the placebo, desvenlafaxine 50 mg/day and desvenlafaxine 100 mg/day groups were 3 percent, 3 percent and 7 percent, respectively. In the international study, these rates for the placebo, desvenlafaxine 50 mg/day and desvenlafaxine 100 mg/day groups were 3 percent, 5 percent and 7 percent, respectively.

Adverse events in both of these studies that were reported by at least five percent of the subjects and twice the rate of placebo included asthenia, anorexia, anxiety, dizziness and insomnia. Events also reported by at least five percent of the subjects and twice the rate of placebo in the international study were nausea, somnolence and abnormal ejaculation; and in the U.S. study they were constipation, dry mouth, myalgia, impotence and sweating. In the U.S. study, nausea was not among the adverse events reported by at least five percent of the subjects and twice the rate of placebo.

"Major depressive disorder is a chronic and disabling disease that can cause significant distress and impair an individual's daily functioning," says Michael Liebowitz, M.D., lead author of the poster and a professor of clinical psychiatry. "Unfortunately, research and clinical practice suggest that a large percentage of patients with major depression do not respond to initial antidepressant therapy, leaving these patients still struggling with symptoms of depression. Clearly, there is a need for additional treatment options."

Desvenlafaxine was discovered and developed by Wyeth Research. As a leader in neuroscience, the Company is committed to discovering and developing a broad range of treatments for mental illness.

About Antidepressants

Antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and SNRIs, increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents and young adults in short-term studies of Major Depressive Disorder (MDD) and other psychiatric disorders. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber.

About Wyeth Pharmaceuticals

Wyeth Pharmaceuticals, a division of Wyeth, has leading products in the areas of women's health care, infectious disease, gastrointestinal health, central nervous system, inflammation, transplantation, hemophilia, oncology, vaccines and nutritional products.

Wyeth is one of the world's largest research-driven pharmaceutical and health care products companies. It is a leader in the discovery, development, manufacturing and marketing of pharmaceuticals, vaccines, biotechnology products and non-prescription medicines that improve the quality of life for people worldwide. The Company's major divisions include Wyeth Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal Health.

The statements in this press release that are not historical facts are forward-looking statements based on current expectations of future events and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. In particular, clinical trial data are subject to differing interpretations and regulatory agencies, including the FDA, may not share our views of data or its sufficiency to support regulatory approval for a product candidate or indication. Other risks and uncertainties include the inherent uncertainty of the timing and success of, and expense associated with, research, development, regulatory approval and commercialization of our products and pipeline products (including with respect to future FDA action regarding our NDA for PRISTIQ for the treatment of MDD, as to which no assurance can be given); government cost-containment initiatives; restrictions on third-party payments for our products; substantial competition in our industry, including from branded and generic products; data generated on our products; the importance of strong performance from our principal products and our anticipated new product introductions; the highly regulated nature of our business; product liability, intellectual property and other litigation risks and environmental liabilities; uncertainty regarding our intellectual property rights and those of others; difficulties associated with, and regulatory compliance with respect to, manufacturing of our products; risks associated with our strategic relationships; economic conditions including interest and currency exchange rate fluctuations; changes in generally accepted accounting principles; trade buying patterns; the impact of legislation and regulatory compliance; risks and uncertainties associated with global operations and sales; and other risks and uncertainties, including those detailed from time to time in our periodic reports filed with the Securities and Exchange Commission, including our current reports on Form 8-K, quarterly reports on Form 10-Q and annual report on Form 10-K, particularly the discussion under the caption "Item 1A, Risk Factors." The forward-looking statements in this press release are qualified by these risk factors. We assume no obligation to publicly update any forward- looking statements, whether as a result of new information, future developments or otherwise.

For more information, visit http://www.Wyeth.com.

Wyeth Pharmaceuticals
http://www.wyeth.com