The purpose of this study is to investigate the effect of co-administration with erythromycin on the time course of PH-797804 concentration in the blood following dosing by oral immediate release tablet formulation.

Inclusion Criteria:

• Healthy male subjects and/or healthy female subjects of non-child bearing potential between the ages of 21 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 measurements, 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).

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).
• A positive urine drug screen.
• History of regular alcohol consumption exceeding 21 drinks/week for males.