PF 06412562 in Subjects With Advanced Stage Parkinson's Disease

The investigators are conducting a randomized, double-blind, carbidopa/levodopa-controlled
crossover safety, tolerability, and efficacy study of the investigational compound,
PF-06412562, in advanced Parkinson's patients. The primary purpose of this study is to test
the safety and tolerability of the investigational drug PF-06412562 compared to the current
medical standard of care medication for Parkinson's disease, carbidopa/levodopa, in these
patients. This secondary purpose of this research is to find out if the investigational drug
PF-06412562 can help improve the motor (movement) function, alertness, and cognitive
(thinking) skills of people who are considered to be in the advanced-stage of Parkinson's
disease. This study will inform the field as to whether PF-06412562 is safe and
well-tolerated in advanced Parkinson's patients, and also may provide preliminary data on its
efficacy in several domains.

Inclusion Criteria:

- Diagnosis of classic PD with history of clinically meaningful response to levodopa

- Disease duration >15 years since diagnosis

- Hoehn & Yahr stage >IV "on" or "off" levodopa

- Consent signed by subject, if possible

- If subject is cognitively impaired, consent signed by power of attorney or legally
authorized subject representative

- Assent from the study subject, if possible

- Stable dose of all medications for 60 days prior to Day 1 of first week of study

Exclusion Criteria:

- Atypical parkinsonian syndrome (e.g., never responded to levodopa, and/or atypical
signs)

- Acute or unstable medical condition such as heart disease, kidney and liver failure

- History of HIV, hepatitis B and C

- Use of moderate to strong CYP 3A4 modulators (see both inhibitors and inducers in
Appendix BB)