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Study Shows Ropinirole is an Effective Treatment for Parkinson's Disease Ropinirole Offers Long-Term Control of Motor Symptoms and Delays Need for Levodopa Therapy <> /ADVANCE/ BOSTON, April 16 /PRNewswire/ via Individual Inc. -- Patients with early Parkinson's disease can achieve effective control of motor symptoms when treated with ropinirole (Requip(TM), SmithKline Beecham), according to a new twelve month study. The study also showed that significantly more patients treated with ropinirole did not require supplemental treatment with levodopa compared to placebo-treated patients. Ropinirole is an important development in the treatment of Parkinson's disease. Unlike currently available dopamine agonists, ropinirole has demonstrated efficacy in placebo-controlled clinical trials when used as early monotherapy and may offer a new approach to treating Parkinson's disease. These results were presented today at the 49th annual meeting of the American Academy of Neurology (AAN) in Boston. "This study is very encouraging because a new drug that can control the symptoms of early Parkinson's disease with manageable side effects would offer a significant treatment benefit," said Kapil Sethi, M.D., associate professor, department of neurology, Medical College of Georgia. "Because long-term treatment with levodopa, the standard treatment for Parkinson's disease, is limited by its potentially disabling side effects, there is a great need for new drugs that can be used in the early stages of the disease. In addition, ropinirole appears to offer a good side effect profile, which is good news for patients." A Need For New Agents to Treat Early Parkinson's Disease Parkinson's disease patients suffer from a deficiency of dopamine in the brain. Levodopa, which is a precursor of dopamine, is administered as a form of replacement therapy. Although this drug is very effective initially, after long-term use many patients develop disabling side effects which include dyskinesias (involuntary movements such as twitching, nodding or jerking), neuropsychiatric problems (e.g. hallucinations) and fluctuations of motor response. Dopamine agonists are also administered to correct the dopamine deficiency in Parkinson's disease patients and thereby reduce symptoms. These drugs mimic the effects of dopamine by binding to and stimulating dopamine receptors in the brain. A reduced level of dopamine at these receptors is believed to cause the motor symptoms of Parkinson's disease. Ropinirole is a second- generation, non-ergot dopamine agonist that selectively binds to the D2 family of receptors. Clinical studies have shown the effectiveness of ropinirole in improving the motor symptoms of Parkinson's disease, either as early monotherapy or in the later stages as adjunctive therapy with levodopa in patients experiencing motor fluctuations. Currently available dopamine agonists are indicated for use only in advanced Parkinson's disease. Ropinirole Demonstrates Long-Term Benefits For Early Parkinson's Patients The results presented today were from a continuation of an initial six month, double blind, placebo-controlled clinical trial. In the initial six month trial, which was presented at last year's AAN meeting, patients treated with ropinirole showed significant improvement in motor function, and significantly fewer of these patients required supplemental levodopa therapy compared to the placebo patients. Patients who satisfactorily completed the initial trial were eligible for enrollment in the double blind, placebo- controlled, six month extension study. A total of 147 patients elected to enter the extension study. Investigators assessed the efficacy of ropinirole over the entire twelve month period. A statistically significantly greater proportion of patients in the ropinirole group (44 percent) received monotherapy for twelve months without the need for levodopa, compared to the placebo group (22.4 percent). In addition, fewer patients treated with ropinirole (19 percent) required additional symptomatic therapy with levodopa compared to patients in the placebo group (45.6 percent) at the end of the twelve month period. This difference was also statistically significant. "What is important about this study is that the treatment benefits of ropinirole lasted for an entire twelve month period. Not only were we able to avoid giving patients additional drugs, but we also saw sustained improvements in motor functioning. This is very promising because Parkinson's disease patients typically get worse over time as the disease progresses. Further studies are necessary to determine if newer dopamine agonists may actually alter the natural course of Parkinson's disease and delay the progression of this debilitating disease," said Dr. Sethi. Ropinirole was well-tolerated over the entire twelve month period. The most common adverse experiences in the initial study were expected side effects primarily related to the stimulation of dopamine receptors (nausea, dizziness, somnolence). The frequency of these adverse experiences remained low during the six month follow up study. In addition, the incidence of hallucinations was low in both ropinirole-treated patients and patients treated with placebo (7.2 percent and 2.6 percent, respectively). A Progressive Neurodegenerative Disorder Parkinson's disease, which affects between 500,000 and 1,000,000 Americans, is a chronic and progressive neurological disorder that causes uncontrollable tremors, rigidity of the muscles and other severe motor impairments. Parkinson's disease results from the death of nerve cells in a critical area of the brain called the substantia nigra. These nerve cells normally produce dopamine, a chemical messenger that plays an important role in motor control by transmitting signals between the substantia nigra and another critical area of the brain called the striatum. Dopamine depletion results in an impaired ability to initiate and control movements. Requip(TM) is currently under review at the U.S. Food and Drug Administration (FDA) for treatment of Parkinson's disease, both as early monotherapy and as adjunctive treatment with levodopa. The Medical College of Georgia (MCG) is the state of Georgia's health sciences university with schools of allied health sciences, dentistry, graduate studies, medicine and nursing as well as the MCG hospital and clinics and the children's medical center. SOURCE Medical College of Georgia /CONTACT: Anna Frable of Cohn & Wolfe, 212-598-3692/ [Copyright 1997, PR Newswire]