New data published in the August issue of SLEEP show that patients with primary Restless Legs Syndrome (RLS) and with periodic leg movements during sleep (PLMS), have fewer awakenings resulting from involuntary kicks when treated with GlaxoSmithKline's Requip (ropinirole HCl).

Patients also reported better sleep adequacy as defined by feeling rested upon waking in the morning. Objective measurements showed that PLMS significantly decreased from nearly 49 per hour to 12 per hour in the group treated with Requip compared to a decrease of 36 per hour to 34 per hour in the placebo group (P < 0.0001), release from GSK said.

In the study, patients treated with Requip also experienced a significant reduction in the number of times PLMS woke them from sleep, termed PLMA (PLM with arousal), from 7 per hour to 2.5 per hour (p =0.0096). Requip is under review by the US FDA for the treatment of RLS. There is no currently approved treatment for RLS in the United States.

"The RLS patients in our study suffered from involuntary movements of their legs that often disrupted their sleep. These leg movements are often associated with RLS. These new study results show that patients who were given Requip had significant reductions in the number of leg movements, resulting in fewer awakenings from sleep," stated Clete A Kushida, director of the Stanford University Centre for Human Sleep Research and an author of the study.

PLMS are involuntary movements of the legs during sleep and are a feature seen in over 80 per cent of patients with RLS. Restless Legs Syndrome, a condition that affects up to ten percent of the population, is a neurologic movement disorder characterized by an irresistible urge to move the legs and by uncomfortable or sometimes unpleasant sensations in the legs often described as creeping-crawling, burning or twitching.

In this study, 65 patients with at least moderately severe RLS and PLMS who met the International RLS Study Group criteria for RLS and had 5 PLMS per hour on a screening polysomnogram were included in the study.
Patients aged 18 to 79 were enrolled from 15 referral centres and were randomized to receive Requip (0.25 to 4mg per day) or placebo. Participants were titrated to their effective dose of medication and received treatment for 12 weeks. Polysomnography simultaneously records multiple physiologic parameters related to sleep and wakefulness and is used to objectively evaluate abnormalities in sleep.

At 12 weeks, Requip significantly improved patients' ability to sleep. Both the primary endpoint (PLMS per hour) and secondary endpoint variable (PLMA per hour) showed large and statistically significant differences in favour of Requip over placebo. With Requip, PLMS per hour were significantly decreased from 48.5 per hour to 11.8 per hour, compared with a decrease from 35.7 per hour to 34.2 per hour in the placebo group (p < 0.0001).

Further, at a mean dose of 1.8 mg per day, Requip effectively reduced PLMS to normal levels (=5 per hour) for more than half of the patients (53.6 per cent) versus 14.8 per cent of patients on placebo. Among other sleep variables, the ability to initiate sleep (known as sleep latency) was significantly improved in patients receiving Requip compared to the placebo group. Average sleep latency in the group treated with Requip decreased from 16.7 to 6.6 minutes compared with an increase in the placebo group from 8.9 to 14.4 minutes (p < 0.01), the release explained.

Requip is a second-generation dopamine agonist that directly stimulates post-synaptic dopamine receptors in the brain.