A Study to Learn How a Single Dose of the Study Medicine Called PF-08057418 is Tolerated in the Body of Healthy Adults.

Inclusion Criteria: * Adults 18 to 60 years of age (or the minimum age of consent per local regulations) at screening. * Healthy participants, as determined by medical history, physical examination, clinical laboratory tests, and cardiac monitoring. * Body mass index (BMI) between 16 and 32 kg/m² and body weight \>50 kg (110 lb). * Willing and able to comply with all study procedures, including scheduled visits, treatment plans, laboratory testing, and lifestyle restrictions. Exclusion Criteria: * History or evidence of clinically significant medical conditions, including but not limited to hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic diseases (excluding untreated, asymptomatic seasonal allergies at the time of dosing). * Any condition that may affect drug absorption (e.g., gastrectomy, cholecystectomy). * History of HIV infection, hepatitis B, or hepatitis C, or positive screening tests for HIV, hepatitis B core antibody (HBcAb), hepatitis B surface antigen (HBsAg), or hepatitis C antibody (HCVAb). Hepatitis B vaccination is permitted. * History of phototoxicity or photosensitivity. * Prior use of any investigational drug or vaccine within 30 days or 5 half-lives (whichever is longer) before the first study dose, or participation in another investigational study during this study. * Elevated blood pressure at screening: * 140/90 mm Hg for participants \<60 years, or * 150/90 mm Hg for participants ≥60 years, after at least 5 minutes of supine rest (average of 3 measurements). * Renal impairment, defined as estimated glomerular filtration rate (eGFR) \<75 mL/min/1.73 m². * Clinically significant ECG abnormalities, including but not limited to QT corrected for heart rate by Fridericia's cube root formula (QTcF) \>450 ms, complete left bundle branch block, evidence of myocardial infarction or ischemia, second- or third-degree AV block, or clinically significant arrhythmias. * Clinically significant laboratory abnormalities at screening, including ALT, AST, or total bilirubin ≥1.05 × ULN (participants with Gilbert's syndrome may be eligible if direct bilirubin is ≤ULN).