| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated  | 
| idiopathic Parkinson's disease | 
 
 
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| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| E.1.2 | Version  | 12.0 | 
 
| E.1.2 | Level  | PT | 
 
| E.1.2 | Classification code  | 10061536 | 
 
| E.1.2 | Term  | Parkinson's disease | 
 
 
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| E.1.3 | Condition being studied is a rare disease  |  No  | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial  | 
| The primary objective of this study is to test whether piribedil is superior to continued pramipexole or ropinirole treatment regarding improvement of reduced vigilance in patients with Parkinson’s disease.  | 
 
 
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| E.2.2 | Secondary objectives of the trial  | 
The secondary objectives of this study are: - to evaluate the effects of piribedil on cognitive functions; - to evaluate the safety of piribedil; - to evaluate the tolerability of piribedil. 
 | 
 
 
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| E.2.3 | Trial contains a sub-study  |  No  | 
| E.3 | Principal inclusion criteria  | 
- Male or female Caucasian patients aged 35 to 80 years; - Patients with idiopathic Parkinson's disease; - Hoehn & Yahr stages 1 to 4; - Stable medication with anti-parkinsonian medication, including stable treatment with pramipexole or ropinirole, for at least 4 weeks prior to Screening; - Significant daytime sleepiness: Epworth Sleepiness Scale score equals or is greater than 11 under previous therapy with pramipexole or ropinirole; - Patients who have read and understood the patient information sheet and have provided a signed written informed consent form; - Patients are considered to be compliant to the study regimen. 
 | 
 
 
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| E.4 | Principal exclusion criteria | 
- Treatment of Parkinson’s disease with any dopamine agonist other than pramipexole or ropinirole within 4 weeks prior to Screening; - Known hypersensitivity to Clarium or its excipients;  - Patients with daytime sleepiness caused by other factor’s than Parkinson’s disease, i.e., idiopathic narcolepsy, shift work, severe alcohol abuse, obstructive diseases, sleep apnea syndrome, or Periodic limb movement disorder; - Secondary and atypical Parkinson syndrome; - Depression (Beck Depression Inventory score greater than 16); - Dementia (Mini-Mental State Examination score equal to or smaller than 24); - Severe disability in extremities which could influence clinical assessments; - Clinically significant disease concerning the lung, liver or kidney; - Any acute or chronic infection that may influence the outcome of the study; - Cardiovascular shock; - Acute myocardial infarction; - Congestive heart failure NYHA class III or IV;  - Uncontrolled arterial hypertension (diastolic blood pressure equal to or greater than 105 mmHg) or clinically relevant hypotension; - Evidence of clinically active cancer; - Color vision defect that may have impact on assessment of FWIT; - History of substance abuse; - Intake of benzodiazepines (or derivates) if not at stable dose for at least 4 weeks prior to Screening; antiallergic agents (H1 receptor antagonists, except selective, non-sedating H1-antihistamines, e.g. loratadine and others), substances with psychostimulant properties (e.g., amphetamine, modafinil), or antidepressants if not at stable dose for at least 2 months prior to Screening; - Current treatment with neuroleptic agents (except for clozapine); - Female patients who are pregnant or lactating; - Female patients of childbearing potential who do not use a highly effective method of birth control (failure rate less than 1% per year when used consistently and correctly), e.g., implants, injectables, combined oral contraceptives in combination with a barrier method, some intrauterine contraceptive devices, sexual abstinence, or a vasectomized partner; - Mental condition rendering the patient unable to understand the nature, scope and possible risks of the study; - Patient has a history of or is suspicious of unreliability, poor co-operation or non-compliance with medical treatment; - Patients are currently or previously (within the last 28 days) participating in another study of an investigational drug; - Patients who were previously enrolled in this study; - Patients with known Hepatitis B or C or HIV infection;  - Patients who are employees of the sponsor or patients who are employees or relatives of the investigator.  
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| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| Parameter ‘median reaction time during second 15 minutes (minutes 16-30)’ of the subtest ‘vigilance’, visual test condition ‘moving bar’ of the Test battery for Attention Performance (TAP) | 
 
 
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| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis |  No  | 
| E.6.2 | Prophylaxis |  No  | 
| E.6.3 | Therapy |  Yes  | 
| E.6.4 | Safety |  Yes  | 
| E.6.5 | Efficacy |  Yes  | 
| E.6.6 | Pharmacokinetic |  No  | 
| E.6.7 | Pharmacodynamic |  No  | 
| E.6.8 | Bioequivalence |  No  | 
| E.6.9 | Dose response |  No  | 
| E.6.10 | Pharmacogenetic |  No  | 
| E.6.11 | Pharmacogenomic |  No  | 
| E.6.12 | Pharmacoeconomic |  No  | 
| E.6.13 | Others |  No  | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) |  No  | 
| E.7.1.1 | First administration to humans |  No  | 
| E.7.1.2 | Bioequivalence study |  No  | 
| E.7.1.3 | Other |  No  | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) |  No  | 
| E.7.3 | Therapeutic confirmatory (Phase III) |  Yes  | 
| E.7.4 | Therapeutic use (Phase IV) |  No  | 
| E.8 Design of the trial | 
| E.8.1 | Controlled |  Yes  | 
| E.8.1.1 | Randomised |  Yes  | 
| E.8.1.2 | Open |  Yes  | 
| E.8.1.3 | Single blind |  No  | 
| E.8.1.4 | Double blind  |  No  | 
| E.8.1.5 | Parallel group |  Yes  | 
| E.8.1.6 | Cross over  |  No  | 
| E.8.1.7 | Other |  Yes  | 
| E.8.1.7.1 | Other trial design description | 
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| E.8.2 |  Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) |  Yes  | 
| E.8.2.2 | Placebo  |  No  | 
| E.8.2.3 | Other |  No  | 
| E.8.3 | 
                                The trial involves single site in the Member State concerned
                             |  No  | 
| E.8.4 |  The trial involves multiple sites in the Member State concerned  |  Yes  | 
| E.8.4.1 | Number of sites anticipated in Member State concerned | 8 | 
| E.8.5 | The trial involves multiple Member States |  No  | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA |  No  | 
| E.8.6.2 | Trial being conducted completely outside of the EEA |  Information not present in EudraCT  | 
| E.8.7 | Trial has a data monitoring committee |  No  | 
| E.8.8 | 
                        Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial
                     | 
| Last Patient's Last Visit | 
 
 
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| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 1 | 
| E.8.9.1 | In the Member State concerned months | 1 | 
| E.8.9.1 | In the Member State concerned days | 0 | 
| E.8.9.2 | In all countries concerned by the trial years | 0 | 
| E.8.9.2 | In all countries concerned by the trial months | 0 | 
| E.8.9.2 | In all countries concerned by the trial days | 0 |