The SUSTAIN Study Compares the Effects of Sustained and Immediate-release Pramipexole on the noctUrnal Symptoms of paTients With Advanced ParkInsoN's Disease Who Also Take L-Dopa

Inclusion Criteria

• Male or female patient with advanced idiopathic Parkinson's disease (PD) confirmed by at least bradykinesia and one of the following signs: resting tremor, rigidity.
• Diagnosed as Parkinson's disease, with at least 2 years' PD history.
• Of age ≥ 30 years at time of diagnosis.
• Modified Hoehn and Yahr stage of 2 to 4 at on-time.
• They must have clinically relevant sleep disturbances (i.e. Parkinson's Disease Sleep Scale 2nd version (PDSS-2) total score ≥18 at baseline).
• They must feel uncomfortable at night because they were unable to turn around in bed or move due to immobility (i.e. the scoring of question 9 in PDSS-2 ≥ 2, that means frequency is at least 2 to 3 days during the past week).
• They must have early morning off (i.e. the frequency of "feeling like bodily movements are poor when you wake up?" is at least 2 to 3 days during the past week).
• Patient must have motor fluctuations (at least 2 cumulative hours of off-time every day during waking hours, documented on a patient diary completed for 2 consecutive days before randomization visit).
• Patients must be treated with Levodopa combined with a Dopa-Decarboxylase-inhibitor (L-Dopa+) (i.e. standard and/or controlled release Levodopa/DDC inhibitor), or with a combination of L-Dopa+ and entacapone, at an optimized dose according to investigator's judgment, this dose being stable for at least 4 weeks prior to randomization visit.
• Patients must not have been treated with sustained release dopaminergic drug (i.e. sustained release Levodopa/Dopa-Decarboxylase (DDC) inhibitor) after supper, or any anti-PD medication after 9pm within 4 weeks prior to randomization visit.
• Patients must not have been treated with dopamine agonists within 4 weeks prior to randomization visit. A concomitant treatment with one or more of the following drugs will be allowed (at a stable dose for at least 4 weeks prior to randomization visit and the investigator does not intend to change this treatment during the treatment phase):
• Anti-parkinsonian anticholinergics;
• Selegiline, rasagiline, or other Monoamine Oxydase (MAO)-B-Inhibitor;
• Amantadine;
• Entacapone (or other Catechol-O-Methyltransferase (COMT)-Inhibitor).
• Male or female patients. Women of childbearing potential (WOCBP) and men able to father a child must be ready and able to use highly effective methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly. A list of contraception methods meeting these criteria is provided in the patient information.
• Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to admission to the trial.

Exclusion criteria

• Secondary parkinsonian syndromes due to drugs (e.g., metoclopramide, flunarizine), metabolic disorders (e.g., Wilson's disease), encephalitis or degenerative diseases (e.g., progressive supranuclear palsy).
• Dementia, as defined by a Mini-Mental State Exam score 2 ULN (on screening lab test).
• Patients with a creatinine clearance < 50 mL/min (estimated by the local lab / the investigator using the Modification of Diet in Renal Disease (MDRD, please refer to Appendix 10.1), and calculated on screening lab test).
• Any hypnotic medication within 4 weeks prior to the randomization visit (i.e. diazepam, clonazepam, estazolam, alprazolam, zolpidem, etc.).
• Any medication (including intra-muscular formulations) with central dopaminergic antagonist activity within 4 weeks prior to the randomization visit (i.e. typical neuroleptics, atypical antipsychotics, reserpine, methyldopa, centrally-active antiemetics, etc.).
• Any of the following drugs within 4 weeks prior to randomization visit: methylphenidate, cinnarizine, amphetamines.
• Flunarizine within 3 months prior to randomization visit.
• Known hypersensitivity to Pramipexole or its excipients.
• Patients who must or wish to continue the intake of restricted medications or any dr