GlaxoSmithKline announced that its supplemental new drug application (sNDA) for Requip (ropinirole HCl) for the treatment of Restless Legs Syndrome (RLS) has been filed by the U.S. Food and Drug Administration (FDA). If approved by the FDA, Requip will become the first and only drug indicated for the treatment of RLS in the U.S. Currently, Requip is approved by the FDA and marketed for the treatment of the signs and symptoms of idiopathic Parkinson's disease.

RLS is a neurological disorder that is characterized by an uncontrollable urge to move the legs and painful or distressing sensations in the legs, often described as creepy-crawly or twitching, that occur during rest and are relieved through movement. Because symptoms most often appear during rest in the evening or at night, RLS can lead to appreciable sleep disturbances.

"Millions of Americans suffer from Restless Legs Syndrome, but to date, no medicine is approved to treat it," said Reijo Salonen, GSK Vice President of Clinical Development and Medical Affairs for neurology. "For many of these patients, Requip, if approved, could provide relief from the distressing symptoms of Restless Legs Syndrome and have a positive impact on patients' sleep."

The sNDA for Requip is supported by data including three 12-week double-blind studies. In two of the studies, Requip significantly improved symptoms of RLS and was generally well-tolerated. The third study showed that Requip significantly reduced periodic leg movements of sleep (PLMS), a primary motor symptom associated with this disorder that contributes to the sleep disturbances seen in RLS. The most commonly reported adverse events with Requip in these studies were nausea (38% Requip, 8% placebo), headache (22% Requip, 21% placebo), and vomiting (12% Requip, 2% placebo).

In the treatment of Parkinson's disease, Requip is generally well tolerated. In studies for Parkinson's disease, the most commonly reported side effects are nausea, somnolence, dizziness, headache and dyskinesia. Patients are advised to talk to their doctor about whether they have the potential to develop the sedating effects associated with Requip, which include somnolence, and the possibility of falling asleep while engaged in activities of daily living, including operation of a motor vehicle. Fainting or low blood pressure may occur during initial treatment or with an increase in dose. Hallucinations may occur at anytime during treatment. Requip may potentiate the side effects of L-dopa and may cause and/or exacerbate pre-existing dyskinesias.