Schering-Plough Reports Preladenant Meets Primary Endpoint in Phase II Dose-Finding Trial for Parkinson's Disease

KENILWORTH, N.J., Nov. 24 /PRNewswire-FirstCall/ -- Schering-Plough Corporation (NYSE: SGP) today reported that preladenant, its novel and selective adenosine2a receptor antagonist, met the primary endpoint in a Phase II dose-finding trial in patients suffering from moderate to severe Parkinson's disease experiencing motor fluctuations and abnormal involuntary movements (dyskinesias). The trial results were presented today at the company's 2008 R&D Update meeting being hosted for analysts and portfolio managers at company headquarters.

The dose-finding study was a randomized, placebo-controlled, double-blind, multicenter, multinational clinical trial that evaluated the efficacy and safety of four different doses (1, 2, 5 or 10 mg BID) of preladenant compared to placebo in the treatment of patients with moderate to severe Parkinson's disease with motor fluctuations and dyskinesias. All patients were on a stable regimen of standard treatments with L-DOPA and other adjunctive treatments, such as dopamine agonists and/or entacapone, but were still experiencing motor fluctuations and dyskinesias. The previous treatment was continued throughout the trial, in which the study medication was given as an adjunctive therapy.

A total of 253 patients were randomized into the trial, with the treatment phase lasting 12 weeks. Preladenant was statistically significantly more effective than the control group at the doses of 5 and 10 mg BID, respectively, in reducing the "off"-time, the primary endpoint of the trial.

In addition, preladenant significantly increased the "on"-time at the same doses of 5 and 10 mg BID, a secondary endpoint of the study. Importantly, this improvement in "on"-time was not associated with a proportional overall increase in dyskinesias. Preladenant was found to be safe and well tolerated. The most common adverse events reported in this trial were parkinsonism, dyskinesia and somnolence, which occurred with approximately the same frequency in the preladenant arms as in the control group.

"We are very excited about these compelling Phase II data that show statistically significant and clinically relevant effects on both 'off'- and 'on'-times in Parkinson's patients who, while continuing on current therapies, came into the study still experiencing profound motor fluctuations that make simple daily tasks extremely burdensome," said Ismail Kola, Ph.D., senior vice president, Discovery Research and Early Clinical Research, Schering-Plough Research Institute, and Schering-Plough's Chief Scientific Officer. He noted that levodopa, or L-DOPA, a longstanding therapy used to treat Parkinson's for some 50 years, has been valuable for many patients, but it loses its effectiveness with time and can be associated with adverse effects. "We believe preladenant with its novel mechanism has the potential to provide significant benefits to a patient population where there has long been a desperate need for new treatment options," added Kola.

The company expects to report on the results of this trial at the Movement Disorder Society's 13th International Congress of Parkinson's Disease and Movement Disorders in Paris in June 2009. The company added that it is continuing a Phase II extension trial with preladenant and preparing for the initiation of its Phase III clinical development program in Parkinson's disease.

Preladenant represents a different and novel approach in comparison to current dopaminergic treatment options. Its pharmacological profile as both a potent and selective adenosine type 2a receptor antagonist has previously been shown to have beneficial effects on the brain regions affected in Parkinson's disease, raising hope that preladenant could represent a novel choice in the treatment of movement disorders without some of the complications of standard dopaminergic treatments.

Parkinson's disease is an age-related, progressive, degenerative brain disease that currently affects one out of 100 people over the age of 60 (approximately 500,000 people in the U.S. alone). It is believed to be caused by a loss of nerve cells in the midbrain. The resulting symptoms include tremor, abnormal gait and posture, loss of balance, muscle stiffness and slowness of movements. These symptoms often severely compromise a patient's ability to lead a normal life. All currently available treatment options enhance directly or indirectly the effect of the neurotransmitter dopamine in the brain. While these treatments are often effective in the initial phase of the disease, their ability to control the symptoms of Parkinson's disease declines over time. Moreover, after several years of therapy these medications frequently induce additional troublesome and disabling motor fluctuations that can last several hours per day. At this stage, patients often experience periods of loss of movement control during the day (so-called "off"-time), which alternates with periods of relatively good motor functions (so-called "on"-time).

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 preladenant. 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 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 October 29, 2008.

SOURCE Schering-Plough Corporation