This study is to investigate the safety, tolerability and pharmacokinetics of single ascending oral doses of PF-04991532 in Japanese healthy subjects. The secondary objective is to investigate the pharmacokinetics and safety of single ascending oral doses of PF-04991532 in Western healthy subjects and to compare the pharmacokinetics between Japanese and Western healthy subjects.

Safety/Tolerability and Pharmacokinetics

Inclusion Criteria:

• Healthy male and/or female subjects of non-childbearing potential, between the ages of 18 and 55 years, inclusive (Healthy is defined as no clinically relevant abnormalities identified by a detailed medical history, full physical examination, including blood pressure and pulse rate measurement, 12 lead ECG and clinical laboratory tests).
• Body Mass Index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight > 50 kg (110 lbs).
• Japanese subjects must have four Japanese grandparents who were born in Japan.
• Mean body weight and the body weight range of Western subjects must be within ±10% of the Japanese subjects.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at time of dosing).
• Screening supine blood pressure >=140 mm Hg (systolic) or >=90 mm Hg (diastolic), on a single measurement (confirmed by a single repeat, if necessary) following at least 5 minutes of rest.
• Any condition possibly affecting drug absorption (eg, gastrectomy).
• History of regular alcohol consumption exceeding 7 drinks/week for females or 14 drinks/week for males (1 drink = 5 ounces (150 mL) of wine or 12 ounces (360 mL) of beer or 1.5 ounces (45 mL) of hard liquor) within 6 months of screening.
• Treatment with an investigational drug within 30 days (or as determined by the local requirement, whichever is longer) or 5 half-lives preceding the first dose of study medication.
• 12-lead ECG demonstrating QTc >450 msec or a QRS interval >120 msec at screening. If QTc exceeds 450 msec, or QRS exceeds 120 msec, the ECG should be repeated two more times and the average of the three QTc or QRS values should be used to determine the subject's eligibility.
• Pregnant or nursing females or women of childbearing potential.