Pramipexole Versus Placebo in Parkinson's Disease (PD) Patients With Depressive Symptoms

A Randomized, Double-blind, Placebo-controlled, Parallel Group Efficacy Study of Pramipexole and Placebo Administered Orally Over a 12 Week Treatment Phase in Parkinson's Disease Patients With Stable Motor Function and Depressive Symptoms

Parkinsons Disease (PD) is caused by a decrease of dopamine in a particular part of the brain. Dopamine is a messenger substance (neurotransmitter) that is used by the cells of the brain (nerve cells) to control and harmonize muscle movements. Consequently, the main manifestations of the disease affect movement and include tremor, muscular rigidity, slowness in performing movements and loss of balance.

However, the disease affects also other, non motor functions and may cause other disorders, such as depression. Depression may be a reaction to the disability caused by the disease, but many studies show that depression is more common in PD than in other chronic debilitating illnesses. Moreover, there is also a biological explanation for the phenomenon: dopamine is also used in brain circuits involved in the experience of pleasure, and loss of pleasure in daily physical or social activity is one of the key manifestations of depression.

The objective of the study is to assess whether pramipexole, at doses approved for the treatment of PD symptoms, is more effective than placebo in resolving depressive symptoms in PD patients.

Also data on the safety of the product in the disease will be collected.

Inclusion Criteria:

1. 15-item Geriatric Depression Scale (GDS) > or = 5
2. Unified Parkinson's Disease Rating Scale (UPDRS) Part I Score on Question #3 > or = 2
3. Folsteins Mini-Mental State Examination (MMSE) score > 24
4. Male or female patient with PD (UK PD Brain Bank criteria).
5. Patients diagnosed with idiopathic PD, Stage I-III by the Modified Hoehn and Yahr Scale and optimally controlled PD symptoms .
6. Male or female patients aged 30 - 80 years.
7. Ability to provide written informed consent.
8. Women of childbearing potential must have a negative serum beta-humanchoriongonadotropin (Beta-HCG) pregnancy test at the Screening visit unless surgically sterile or last menstruation >or = 12 months prior to signing informed consent.
9. Women of childbearing potential must be using an accepted contraceptive.
10. Patients who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.

Exclusion Criteria:

1. Previous history of allergic response, lack of efficacy or complications with pramipexole or its excipients.
2. History of suicidal attempts in the last twelve months; presence of suicidal tendencies/potential.
3. Atypical PD syndromes due to drugs, metabolic disorders, encephalitis or degenerative diseases.
4. History of PD stereotactic brain surgery.
5. Surgery within 180 days of randomization that would negatively impact the patients participation in the study.
6. History of active epilepsy within the past year.
7. Current psychotherapy or behavior therapy while participating the trial
8. Symptomatic orthostatic hypotension prior to randomization.
9. Malignant melanoma or history of previously treated malignant melanoma.
10. Patients who have received typical neuroleptics, metoclopramide, alpha methyldopa, methylphenidate, reserpine, selegiline or amphetamine derivatives within the past 3 months.
11. Patients who have received dopamine agonists within the past 30 days
12. Electroconvulsive therapy during the 90 days preceding the screening visit (Visit 1).
13. Patients who are currently lactating.
14. Participation in other investigational drug studies or use of other investigational drugs within the previous 30 days prior to randomization.
15. Any other laboratory assay abnormality, which could interfere with patient participation or interpretation of results, or could increase the risk for the patient
16. Any other clinically significant medical/psychiatric condition, which could interfere with patient participation or interpretation of results, or could increase the risk for the patient