Vancouver, Canada - A landmark, multinational, 5-year study shows that the dopamine-agonist ReQuip® (ropinirole hydrochloride, SmithKline Beecham) is associated with a much lower incidence of dyskinesias than L-dopa, and has comparable efficacy to L-dopa in the management of early Parkinson's Disease. The results of this exciting study are released today for the first time at the XIII International Congress on Parkinson's Disease (ICPD), Vancouver, 24-28 July, 1999.
"This landmark study should affect the future management of Parkinson's Disease. The data demonstrate that ropinirole is a first-line option for the initial treatment of early Parkinson's Disease," commented lead author of the study, Professor Olivier Rascol, Professor of Pharmacology at the Centre Hospitalier Universitaire, Toulouse, France.
"This is important news for patients, as we can now hope for good control of their symptoms with less risk of dyskinesias," concluded Dr Donald Calne, Chairman of the ICPD, and Director of the Neurodegenerative Disorders Centre, University of British Columbia, Vancouver, Canada.
The 268 patients participating in this double-blind controlled study, conducted in Europe, Israel and Canada, were randomised to receive either ReQuip® or L-dopa -- the current standard therapy. Both treatment groups were allowed to receive supplementary L-dopa if required.
The study demonstrated that the probability (odds ratio) of developing dyskinesias was 3.8 times higher for patients receiving L-dopa (incidence 46%) than for patients receiving ReQuip®, either alone or with additional L-dopa (incidence 20%). In patients who completed the trial on ReQuip® alone, the benefit was found to be even greater, with the relative probability of dyskinesias 15.2 times higher in the L-dopa group (incidence 36%) than the ReQuip® group (incidence 5%).
Over the 5-year study period, both groups of patients experienced similar control of their symptoms. A third of those in the group randomized to receive ReQuip® completed the 5-year study without the need for L-dopa, achieving satisfactory control with ReQuip alone.
Patients in the group receiving ReQuip® supplemented with additional L-dopa, required a much lower dose of L-dopa to control disease symptoms, compared to those treated with L-dopa alone (427 mg/day vs 753 mg/day). The mean daily dose of ReQuip® in patients completing all 5 years of the study was 16.5 mg3, highlighting the importance of continued dose titration over time for optimal therapeutic benefit. The maximum recommended daily dose of ReQuip® is 24 mg.
Apart from differing significantly in terms of dyskinesias, both ReQuip® and L-dopa were tolerated equally well during the study. Overall, an equal proportion of patients withdrew from both treatment groups. CNS adverse experiences were reported by 23% of patients given ReQuip® and by 16% of those who received L-dopa. This difference was not statistically significant.
Note to editors
ReQuip® is currently registered in over 30 countries.
SmithKline Beecham -- one of the world's leading healthcare companies -- discovers, develops, manufactures, and markets pharmaceuticals, vaccines, over-the-counter medicines, and health-related consumer products, and provides healthcare services including clinical-laboratory testing, disease management, and pharmaceutical-benefit management.
- ReQuip® was developed and is manufactured by SmithKline Beecham. ReQuip® is a dopamine agonist -- it stimulates dopamine receptors -- whereas L-dopa (levodopa) is a chemical precursor of the neurotransmitter dopamine found to be lacking in certain parts of the brain in patients with Parkinson's Disease. ReQuip®, unlike L-dopa, does not require conversion to dopamine and is immediately available to act on dopamine receptors.
- Dyskinesias are involuntary movements such as twitching or jerking that are a common and debilitating side effect of therapy with L-dopa.
- Rascol O., on behalf of the 056 Study Group. Ropinirole reduces the risk of dyskinesia when used in early Parkinson's Disease. Abstract accepted at XIII International Congress On Parkinson's Disease, Vancouver, Canada, July 24-28 1999.