The goals of this study are to evaluate the safety and tolerability of multiple ascending doses of PF-04634817 administered orally to healthy adult subjects. In additional, the plasma and urinary pharmacokinetics of multiple ascending doses of PF-04634817 administered orally to healthy adult subjects will be evaluated. Finally, the effect of multiple doses of PF-04634817 on circulating monocytes will be explored.

Inclusion Criteria:

• Healthy male and female (of non-childbearing potential) subjects between the ages of 18 and 55 years, inclusive.
• Body Mass Index (BMI) of 17.5 to 30.5 kg/m2; and a total body weight >50 kg (110 lbs).

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease;
• Treatment with an investigational drug within 30 days or 5 half-lives (whichever is longer) preceding the first dose of study medication;
• Use of tobacco- or nicotine-containing products in excess of the equivalent of 5 cigarettes per day;
• Nursing females;
• Females of childbearing potential.