This is a Phase 1, randomized, 2 way crossover, open-label study of the effect of multiple-dose PF 06651600 on single-dose oral contraceptive (OC) pharmacokinetics (PK) in healthy female subjects. Subjects will be randomized to 1 of 2 treatment sequences. A total of 28 healthy female subjects (14 in each treatment sequence) will be enrolled in the study. Each treatment sequence will consist of 2 periods.

Inclusion Criteria:

Participants are eligible to be included in the study only if all of the following criteria apply:

Age and Sex:

1. Female participants of non childbearing potential who, at the time of screening, are between the ages of 18 and 60 years, inclusive.
2. Female participants who are healthy as determined by medical evaluation including detailed medical history, full physical examination, including blood pressure (BP) and pulse rate measurement, 12 lead ECG, or clinical laboratory tests.
3. Participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.
4. Body mass index (BMI) of 17.5 to 35 kg/m2; and a total body weight >50 kg (110 lb).

Exclusion Criteria:

1. Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, dermatological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).
2. Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy, appendectomy).
3. Known immunodeficiency disorder, including positive serology for human immunodeficiency virus (HIV) at screening, or a first-degree relative with a hereditary immunodeficiency.
4. Infection with hepatitis B or hepatitis C viruses -

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.