Efficacy, Safety, Tolerability of Pramipexol ER Versus Pramipexol IR Versus Placebo in Early PD Patients

The objectives of this trial conducted in early Parkinson's Disease (PD) patients are to determine the efficacy (as measured by the change from baseline to the end of the maintenance phase in the total score for the Unified Parkinson's Disease Rating Scale (UPDRS) Parts II and III combined), safety, and tolerability of Pramipexole Extended Release (ER) (in daily doses from 0.375mg to 4.5mg q.d.) in comparison to placebo, and to test for non-inferiority between the two formulations (ER and IR) of pramipexole.

In addition, the efficacy of Pramipexole Immediate Release (IR) will be compared to placebo, for assay sensitivity


Eligibility Criteria:
Inclusion Criteria:

1. Male or female patient with idiopathic Parkinsons disease (PD) confirmed by at least two of the following signs: resting tremor, bradykinesia, rigidity.
2. Parkinsons disease diagnosed within 5 years.
3. Patients 30 years of age or older at the time of diagnosis.
4. Modified Hoehn and Yahr stage of 1 to 3.
5. Patients requiring additional therapy/ introduction of therapy (for de novo patients) to treat their parkinsonian symptoms at the time of enrollment (screening visit, V1) according to the investigators judgement.

Exclusion Criteria:

1. Atypical 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).
2. Dementia, as defined by a Mini-Mental State Exam score \< 24 at screening visit
3. Any psychiatric disorder according to Diagnostic and Statistical Manual of Mental Disorders 4th (DSM-IV)
4. History of psychosis
5. Clinically significant electrocardiogram (ECG) abnormalities at screening visit
6. Clinically significant hypotension
7. Malignant melanoma or history of previously treated malignant melanoma
8. 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
9. Pregnancy
10. Sexually active female of childbearing potential not using a medically approved method of birth control
11. Serum levels of Aspartate Aminotransferase (AST) , Alanine Aminotransferase (ALT), alkaline phosphatases or bilirubin \> 2 Upper Limit of Normal (ULN)
12. Patients with a creatinine clearance \< 50 mL/min
13. Any dopamine agonist (including pramipexole) within 4 weeks prior to baseline visit, or L-Dopa within 8 weeks prior to baseline visit.
14. Total cumulative duration of prior exposure to Levodopa of more than 3 months.
15. Any medication (including intra-muscular formulations) with central dopaminergic antagonist activity within 4 weeks prior to the baseline visit
16. Any of the following drugs within 4 weeks prior to the baseline visit: methylphenidate, cinnarizine, amphetamines.
17. Flunarizine within 3 months prior to baseline visit
18. Known hypersensitivity to Pramipexole or its excipients
19. Drug abuse (including alcohol), according to Investigators judgement, within 2 years prior to screening.
20. Participation in other investigational drug studies or use of other investigational drugs within one month or five times the half-life of the investigational drug