Comparative Polysomnographic Study of Oxycodone/Naloxone or Pramipexole for the Treatment of Restless Legs Syndrome

INTERVENTION: Trade Name: Targin ® 5mg/2,5 mg Pharmaceutical Form: Prolonged‐release tablet Trade Name: Targin ® 10mg/5 mg Product Name: oxycodone/naloxone Pharmaceutical Form: Prolonged‐release tablet Trade Name: MIRAPEXIN 0,088 mg Product Name: pramipexole Pharmaceutical Form: Tablet Trade Name: MIRAPEXIN 0,18 mg Product Name: pramipexole Pharmaceutical Form: Tablet CONDITION: Restless legs syndrome ; MedDRA version: 18.0 Level: PT Classification code 10058920 Term: Restless legs syndrome System Organ Class: 10029205 ‐ Nervous system disorders Therapeutic area: Diseases [C] ‐ Nervous System Diseases [C10] PRIMARY OUTCOME: Main Objective: To compare efficacy and safety of OXN‐PR (Oxycodone/Naloxone prolonged release tablets, Targin®) and pramipexole (PRA) in subjects with idiopathic Restless Legs Syndrome (RLS); The primary objectives of the study will be the comparison between the study medications based on Sleep Efficiency as measured by PSG. Primary end point(s): The primary endpoints is the difference between treatments in Sleep Efficiency, as measured by PSG. Sleep Efficiency is the ratio of time spent asleep (total sleep time) to the amount of time spent in bed. An increase in Sleep efficiency at the end of the treatment period with respect to baseline is expected. Secondary Objective: The secondary objectives will be to compare the the effects of the two treatments on the Periodic Limb Movements Index (PLMI) as measured by PSG and to compare the effects of the two treatments on a number of objective sleep quality indicators and subjective ratings .The following secondary variables will be measured: ; • Sleep latency; • Total Sleep Time; • IRLS (International Restless Legs Syndrome Study Group Rating scale) ; • Pittsburg Sleep Quality Index; • Epworth Sleepiness Scale ; • CGI Improvement ; • RLS quality of life ; Timepoint(s) of evaluation of this end point: End of the treatment period (nights 15 ‐16) SECONDARY OUTCOME: Secondary end point(s): The primary secondary endpoint is the difference between treatments in PLMI (Periodic Limb Movements Index), as measured by PSG at the end of the treatment period, with respect to baseline. ; The following secondary variables will be measured: ; • Sleep latency (onset of sleep from time the lights are turned off); • Total Sleep Time (TST); • PLMS Awakening Index (PLMSAWI: number of awakenings with PLMs during sleep/TST) ; • Total time in sleep stages (absolute and relative) ; • IRLS (Information Restless Legs Syndrome) rating scale ; • CGI (Clinical Global Improvement) ; • Pittsburg Sleep Quality Index (PSQI); • Epworth Sleepiness Scale (ESS); In addition, the RLS Quality of Life (RLS‐QoL) questionnaire will be used to measure changes in quality of life. ; Timepoint(s) of evaluation of this end point: End of the treatment period (morning of day 17) INCLUSION CRITERIA: • Subject is informed and given ample time and opportunity to think about her/his participation and has given her/his written informed consent; • Subject understands the investigational nature of the trial and is willing and able to comply with the trial requirements; • Subject is able to take the trial tablets correctly and consistently; • Subject is male or female, and is =18 and = 75 years of age; • Subject meets the diagnosis of idiopathic RLS based on the 4 essential clinical features according to the IRLSSG (Allen et al, 2003): o An urge to move legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs (the urge to move can be present without uncomfortable sensations. Arms or other body parts can also be affected.); o The urge to move or unpleasant sensations begin or worsen during periods of rest or inactivity such as lying or sitting; o The urge to move or unpleasant sensations are partially or