The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of single ascending doses of PF-06852231 after first-time administration to healthy adult subjects. The safety, tolerability, and pharmacokinetics of an active metabolite (PF-06892787) will also be evaluated in this study.

Inclusion Criteria:

1. Healthy female subjects of non-childbearing potential and male subjects, who at the time of screening are between 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 electrocardiogram, or clinical laboratory tests.
2. Body mass index of 17.5 to 30.5 kg/m2; and a total body weight >50 kg (110 lb).
3. Subjects who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, and other study procedures.

Exclusion Criteria:

1. Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).

2. Treatment with an investigational drug within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of investigational product (whichever is longer).

3. Screening supine BP greater than or equal to 140 mm Hg (systolic) or greater than or equal to 90 mm Hg (diastolic), following at least 5 minutes of supine rest. If BP is greater than or equal to 140 mm Hg (systolic) or greater than or equal to 90 mm Hg (diastolic), the BP should be repeated 2 more times and the average of the 3 BP values should be used to determine the subject's eligibility.

4. Screening supine 12-lead ECG demonstrating a corrected QT (QTc) interval >450 msec or a QRS interval >120 msec. If QTc exceeds 450 msec, or QRS exceeds 120 msec, the ECG should be repeated 2 more times and the average of the 3 QTc or QRS values should be used to determine the subject's eligibility.

5. Subjects with ANY of the following abnormalities in clinical laboratory tests at screening, as assessed by the study-specific laboratory and confirmed by a single repeat test, if deemed necessary:

   • Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) level greater than or equal to 1.5x upper limit of normal (ULN);
   • Total bilirubin level greater than or equal to 1.5x ULN; subjects with a history of Gilbert's syndrome may have direct bilirubin measured and would be eligible for this study provided the direct bilirubin level is less than or equal to ULN.

6. Use of prescription or nonprescription drugs and dietary supplements within 7 days or 5 half-lives (whichever is longer) prior to the first dose of investigational product.

7. Unwilling or unable to comply with the criteria in the Lifestyle Requirements section of this protocol.

8. Other acute or chronic medical or psychiatric conditions

Information relating to our policy on data sharing and the process for requesting data can be found at the following link: http://www.pfizer.com/research/clinical\_trials/trial\_data\_and\_results/data\_requests