Parkinson's Disease (PD) is a brain disorder causing shaking, stiffness, and difficulty with balance. This study focuses on people with advanced Parkinson's Disease (aPD) who respond well to a medicine called levodopa. Levodopa helps with movement problems. In this study, a new way to give medicine is being tested. It's called foslevodopa/foscarbidopa and it's given through a small tube under the skin, called a subcutaneous infusion (like a tiny straw). This helps the medicine work better over time. The study will look at different ways of setting the machine that gives the medicine, like changing the speed it goes in.

• This study watches how people do on this new treatment over time.
• You need to be part of a special support program to join.
• It's for people who already use this type of medicine for their PD.