A Safety, Tolerability and Pharmacokinetic Study of ND0611 on the Top of Different Oral Dosage Forms of Levodopa/Carbidopa in Parkinson's Disease Patients

Inclusion Criteria: 1. Men and women with idiopathic Parkinson's disease 2. Subjects must experience motor fluctuations associated with LD/CD dosing 3. Modified Hoehn and Yahr stage \< 5 4. Subjects must be taking optimized and stable levodopa/dopa decarboxylase inhibitor therapy 5. Women must be postmenopausal, surgically sterilized, or using adequate birth control. Women of childbearing potential must have a negative pregnancy test (serum beta-HCG) at screening. 6. Subjects must be age 30 or older. 7. Subjects must be willing and able to give informed consent. Exclusion Criteria: 1. Subjects with a clinically significant or unstable medical or surgical condition 2. Subjects with clinically significant psychiatric illness. 3. Pre-menopausal women, not using birth control method. 4. Subjects who have taken experimental medications within 60 days prior to baseline. 5. Subject who have undergone a neurosurgical intervention for Parkinson's disease (e.g., pallidotomy, thalamotomy, transplantation and deep brain stimulation).