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 \< 24 at screening visit. * Any psychiatric disorder according to DSM-V Diagnostic and Statistical Manual of Mental Disorders, 5th edition criteria that could prevent compliance or completion of the study and/or put the patient at risk if he/she takes part in the study. * History of psychosis, except history of drug induced hallucinations (provided the investigator considers that participation to the trial would not represent a significant risk for the patient). * History of deep brain stimulation. * History of nucleus lesioning. * Clinically significant electrocardiogram (ECG) abnormalities at screening visit, according to investigator's judgement. * Clinically significant hypotension (i.e. supine systolic blood pressure \< 90 mmHg) and/or symptomatic orthostatic hypotension (i.e. clinical symptoms of orthostatic hypotension associated with a decline ≥ 20 mmHg in systolic blood pressure and a decline ≥ 10 mmHg in diastolic blood pressure, at 1 minute after standing compared with the previous supine systolic and diastolic blood pressure obtained after 5 minutes of quiet rest) at screening or randomization visit. * Major surgery (major according to the investigator's assessment) performed within 12 weeks prior to randomization or planned within 12 months after screening, e.g. hip replacement. * Any other clinically significant disease, whether treated or not, that could put the patient at risk or could prevent compliance or completion of the study. * Serious Sleep Apnea Hypopnea Syndrome (i.e. the scoring of question 15 in Parkinson's Disease Sleep Scale 2nd version (PDSS-2)≥ 3, that means frequency is at least 4 to 5 days during the past week ) * Any documented active or suspected malignancy or history of malignancy within 5 years prior to screening, except appropriately treated basal cell carcinoma of the skin or in situ carcinoma of uterine cervix. * Serum levels of Aspartate Aminotransferase (AST)(SGOT), Alanine Aminotransferase (ALT)(SGPT), alkaline phosphatases or total bilirubin \>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 drug considered likely to interfere with the safe conduct of the trial. * Previous enrolment in this trial. * Currently enrolled in another investigational device or drug trial, or less than 30 days since ending another investigational device or drug trial(s), or receiving other investigational treatment(s). * Chronic alcohol or drug abuse or any condition that, in the investigator's opinion, makes them an unreliable trial patient or unlikely to complete the trial. * Women who are pregnant, nursing, or who plan to become pregnant in the trial.