A Study to Learn How Different Amounts of the Study Medicine Called PF-07985631 Are Tolerated and Act in the Body of Healthy Adults

Inclusion: 1. Between 18 and 45 years of age who are overtly healthy. 2. Japanese/Chinese and multiple dose cohorts only: Adult participants 18 to 55 years of age who are overtly healthy may be eligible at the discretion of PI. 3. Japanese/Chinese cohorts only: Participants must have 4 biological Japanese/Chinese grandparents who were born in Japan/China. Exclusion: 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. Participants with a history of allergic or anaphylactic reaction with any investigative biologic agents. 3. History of infections requiring treatment within 28 days prior to Day 1 or any active infection at Day 1. 4. Active or latent infection with tuberculosis. 5. History of recurrent urinary tract infections AND/OR sinopulmonary infections AND/OR gastrointestinal infections requiring antibiotic treatment. 6. Known fever within the 7 days prior to dosing. 7. Active gastrointestinal (GI) tract ulcerations or GI bleeding. 8. Vaccination within 6 weeks prior to Day 1 dosing or planned vaccination during the study. 9. Positive urine drug test. 10. Screening supine blood pressure (BP) ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic). 11. Estimated glomerular filtration rate (eGFR) \<75 mL/min/1.73 m². 12. Chest X-ray showing any active disease in the chest, or pulmonary nodules \>0.5 cm in diameter that have not been previously evaluated, cavitary lesions or evidence of bronchiectasis. 13. Standard 12 lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results. 14. Positive stool hematest at screening or admission. 15. Participants with ANY of the following abnormalities in clinical laboratory tests at screening: * Alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin (direct and total) ≥1.05 × upper limit of normal * Immunoglobulin G, Immunoglobulin M, Immunoglobulin A below the lower limit of normal (LLN) * Total white blood cell (WBC) below the LLN * Lymphocyte count below the LLN * Platelet count below the LLN * Hemoglobin below the LLN