Basic and Clinical Studies of Levodopa/Carbidopa/Entacapone in the Treatment of Early Parkinson's Disease

Inclusion Criteria:

• Male or female and greater from 30 to 80.
• Diagnosis of idiopathic PD according to the MDS PD Diagnostic Criteria (2015).
• Hoehn-Yahr stage of 1.5-3.0 ("open" stage).
• Not on anti-PD medication or stable on anti-PD medication for at least 30 days.

Exclusion Criteria:

• Diagnosis of atypical Parkinsonian syndrome, vascular Parkinsonism or drug-inducedParkinsonism.
• History of surgery within 6 months.
• Alcoholism, drug abuse, or severe cognitive impairment (including severe Alzheimer'sdisease)
• Psychiatric illness, epilepsy, pregnancy and breastfeeding, and clinically significantconcomitant illnesses
• Participation in another clinical trial within 2 months.
• With dyskinesia.
• Any other condition that, in the opinion of the investigator, makes them ineligiblefor enrolment.