Company's R&D Update Today Unveils Rich Development Pipeline of Compounds Meeting Important Medical Needs

KENILWORTH, N.J., Nov. 24 /PRNewswire-FirstCall/ -- Schering-Plough Corporation (NYSE: SGP) today revealed top-line results of a long-term Phase III clinical study of its psychopharmacologic agent SAPHRIS(TM) (asenapine) demonstrating efficacy and safety in preventing relapse of schizophrenia. In this trial, asenapine was statistically significantly more effective than placebo in preventing relapse, as measured by the primary endpoint of the trial estimated through Kaplan-Meier curves. At the 26 week endpoint, 47 percent of the placebo-treated patients relapsed, compared with only 12 percent of the asenapine-treated patients (p<0.0001). Asenapine was generally well tolerated, with somnolence and insomnia being the most frequently reported adverse events in the initial open-label treatment phase (occurring in more than 10 percent of patients).

The top-line data were presented today at the company's 2008 R&D Update meeting being hosted for analysts and portfolio managers at company headquarters. The company plans to submit results of the trial for presentation at a future medical meeting.

"Schizophrenia is a serious disease affecting millions of people worldwide, and there is a need for effective new medications with acceptable safety and tolerability profiles," said Thomas P. Koestler, Ph.D., executive vice president and president, Schering-Plough Research Institute. "Asenapine is an important late-stage compound in the Schering-Plough development pipeline, and we are encouraged by the top-line data we are sharing today. We believe that asenapine may have the potential to help relieve the burden of schizophrenia."

Asenapine, administered as a fast-dissolving sublingual tablet, is a novel compound with a unique human receptor signature. Schering-Plough anticipates a filing for the approval of asenapine in Europe in 2009 for treatment of schizophrenia, and treatment of manic episodes associated with bipolar 1 disorder. Asenapine is currently under review by the U.S. Food and Drug Administration (FDA) for the treatment of schizophrenia and acute manic or mixed episodes associated with bipolar I disorder. The company acquired asenapine in November 2007 through its acquisition of Organon BioSciences, which developed the product.

The Phase III study was a placebo-controlled, double-blind, clinical trial with a randomized withdrawal design that evaluated the efficacy and safety of sublingually administered asenapine (5 or 10 mg BID) compared to placebo in the prevention of relapse in patients with schizophrenia. A total of 700 patients entered the open-label treatment with asenapine for up to 26 weeks. Of these, a total of 386 patients met criteria for stabilization on asenapine and were randomized to treatment in the 26-week double-blind placebo-controlled phase of the trial.

Schering-Plough is an innovation-driven, science-centered global health care company. Through its own biopharmaceutical research and collaborations with partners, Schering-Plough creates therapies that help save and improve lives around the world. The company applies its research-and-development platform to human prescription, animal health and consumer health care products. Schering-Plough's vision is to "Earn Trust, Every Day" with the doctors, patients, customers and other stakeholders served by its colleagues around the world. The company is based in Kenilworth, N.J., and its Web site is www.schering-plough.com.

SCHERING-PLOUGH DISCLOSURE NOTICE: The information in this press release includes certain "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including statements relating to the plans for, the potential of and the potential market for asenapine. Forward-looking statements relate to expectations or forecasts of future events. Schering-Plough does not assume the obligation to update any forward-looking statement. Many factors could cause actual results to differ materially from Schering-Plough's forward-looking statements, including uncertainties in the regulatory process, among other uncertainties. For further details about these and other factors that may impact the forward-looking statements, see Schering-Plough's Securities and Exchange Commission filings, including Part II, Item 1A. "Risk Factors" in the third quarter 2008 10-Q, filed Oct. 29, 2008.

SOURCE Schering-Plough Corporation