Carbidopa-Levodopa (CD-LD) ER Alone or in Combination With CD-LD IR to IPX066 Followed by IPX066 Extension Safety Study

The study had three distinct parts and is described as follows: Part 1: * To evaluate the dose conversion from CD-LD ER taken alone or in combination with CD-LD IR to IPX066 in subjects with advanced PD * To evaluate the utility of the Objective Parkinson's Disease Measurement (OPDM), an exploratory computer-based system, in assessing dexterity and mobility in a subset of PD subjects. Part 2: • To evaluate the long-term safety and clinical utility of IPX066 under open-label conditions in eligible subjects who successfully completed Part 1 of the study. Part 3: • To further evaluate the long-term safety of IPX066 in eligible subjects who successfully completed Part 2.