The purpose of this clinical trial is to learn about the safety and pharmacokinetics (pharmacokinetics helps us understand how the drug is changed and eliminated from body after participant take it) of the study medicine (called PF-08057418) in healthy people.

This study is seeking participants who are healthy adults.

Everyone who participates in this study will receive the study medicine. The study medicine may be given as a solution or as a tablet. Participants will be dosed once a week for 5 weeks.

The investigator will examine the experiences of people receiving the study medicine. This will help us determine if the study medicine is safe.

Participants will be involved in this study for up to 13 weeks from screening to follow-up visit. Participants stay in the study clinic for the 5 week dosing duration of the study, with two follow-up visits subsequently, either in person or by telephone call.

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).

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.