The purpose of this study is to learn how a certain amount of [14C] PF-06821497 is taken up into the bloodstream and removed from the body.

The study is seeking participants who are:

• Males aged 18 years or older.
• Are confirmed to be healthy after performing some medical and physical tests.
• Weigh more than 50 kilograms and have a body mass index of 16 to 32 kg per meter squared.

The study consists of two parts. In part one, all participants will receive one full dose of [14C]PF-06821497 by mouth. Part two will begin at least 14 days after the dose in part one. In part two participants will receive one full dose of PF-06821497 by mouth and one small dose of [14C]PF-06821497 by intravenous (IV) infusion. IV infusion will be directly injected into the veins.

To understand how the medicine is processed in the body, samples of blood, urine, and feces will be collected after each dose is given. This will help understand:

• How much PF-06821497 is taken up into the bloodstream when taken by mouth compared to the dose given by IV
• How the body removes it from the bloodstream.

Participants will take part in the study for about 11 weeks, including the initial evaluation and follow-up periods.

Key eligibility criteria for this study include, but are not limited to the following:

Inclusion Criteria:

• Male participants aged 18 years at screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring.
• Body mass index (BMI) of 16-32 kg/m2; and a total body weight of >50kg (110lb)
• Participants who are willing to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures

Exclusion Criteria:

• Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy, prior bariatric surgery, ileal resection, inflammatory gastrointestinal disease, chronic diarrhea, known diverticular disease).
• Chronic liver diseases including alcoholic liver disease, viral hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis, Wilson's disease, hemochromatosis, alpha-1 antitrypsin deficiency, human immunodeficiency virus, or other chronic liver disease.
• Previous administration with an investigational product (drug or vaccine) within 30 days (or as determined by the local requirement) or 5 half lives preceding the first dose of study intervention used in this study (whichever is longer). Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.
• Total [14C] radioactivity measured in plasma at screening exceeding 11 mBq/mL

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.