Efficacy of Isradipine in Early Parkinson Disease

The study will enroll 336 participants in this multi-center study at approximately 56 sites across the US and Canada. In this study, we are comparing 10 mg of Isradipine to Placebo for treatment of newly diagnosed PD patients. Isradipine has been approved by the Food and Drug Administration (FDA) to treat high blood pressure but is considered investigational in this study, as it has not been approved for use in patients with PD.Isradipine can affect the function of specialized channels that are present in the types of brain cells that are affected in PD patient. These cells are usually responsible for making dopamine, which is depleted in patients with PD. Isradipine may block the damage caused by the flow of certain chemicals through these channels. Laboratory data has showed that Isradipine may prevent the development of Parkinson-like symptoms in animal studies. Isradipine has been evaluated in some patients with PD. The first study with isradipine controlled release (CR) in patients with early PD and normal blood pressure found that the drug was reasonably well tolerated and safe. The controlled release formulation of isradipine is not available for use and therefore this study is using the immediate release formulation. Eligible participants will be followed for up to 36 months and will be expected to complete 12 in-person visits and 4 telephone visits. The study visits will include clinical assessment of motor, neuropsychiatric and cognitive testing as well as collection of blood and urine samples. Study drug will taken twice daily, in the morning and in the evening with or without food. Prior to taking study drug, study participants will be required to take their blood pressure with a home blood pressure device provided to them for use in this study.