Parkinson's Disease Isradipine Safety Study

The objective of this study is to establish the safety and tolerability of isradipine,
sustained release preparation in patients with PD. This study is a logical continuation of
the project that is being completed now and is conducted in preparation to NIH submission of
the pivotal study on the efficacy of this agent for neuroprotection in PD. This study is
conducted in parallel with Dr. Surmeier's work on further development of the preclinical
data. The focus of his work now is to establishing the correlation between the dose that
demonstrated neuroprotective effect in animal model and the dose used for clinical practice.

Hypothesis 1: Patients with PD will be able to tolerate isradipine across the FDA
recommended dose range. We expect 10% attrition due to hypotensive effect of the agent.

Hypothesis 2: Patients with PD and concomitant stable hypertension will be able to tolerate
isradipine provided that the dose of the concomitant antihypertensive agent is adjusted
based on the blood pressure reading.