A Study to Evaluate Fixed Dose Carbidopa/Levodopa/Entacapone Versus Immediate Release Carbidopa/Levodopa

Inclusion Criteria: * Aged 30 to 80 years, inclusive, at time of Parkinson's disease diagnosis * Idiopathic Parkinson's disease with at least 2 cardinal signs of disease: resting tremor, bradykinesia or rigidity * Parkinson's disease impairment warranting treatment with a levodopa formulation according to the investigator's assessment Exclusion Criteria: * History, signs or symptoms suggesting the diagnosis of atypical or secondary Parkinsonism due to drugs, metabolic disorders, encephalitis or other neurodegenerative diseases * History of stereotaxic brain surgery for PD (e.g., pallidotomy, deep brain stimulation, tissue transplant) * Diagnosis of Parkinson's disease for more than 5 years prior to Screening * Previous use of levodopa in any formulation, entacapone or tolcapone for more than 30 days or anytime within 4 weeks (28 days) prior to baseline * Use of a dopamine agonist within 4 weeks (28 days) prior to baseline