A Study to Learn About the Medicine Called PF-08653944 in People With and Without Reduced Liver Function

Inclusion criteria

• Adults 18 to 75 years of age, male or female.
• BMI ≥21 kg/m² and body weight >50 kg at screening.
• Group 1 (without hepatic impairment):

• No known or suspected hepatic impairment.
• Normal liver function tests (ALT, AST, bilirubin, albumin, PT within normal limits, with protocol-specified exceptions such as Gilbert's syndrome).
• Groups 2-4 (with hepatic impairment):

• Stable hepatic impairment classified as Child-Pugh Class A (mild), B (moderate), or C (severe).
• No clinically significant worsening of hepatic status within 28 days prior to screening.
• Women of childbearing potential must not be pregnant or breastfeeding and must agree to use highly effective contraception.

Exclusion criteria

• Clinically significant medical or psychiatric conditions, including recent or active suicidal ideation or behavior.
• Use of GLP-1 receptor agonists within 90 days (or 5 half-lives) prior to dosing.
• Participation in another investigational study or receipt of an investigational product within 30 days (or 5 half-lives) prior to dosing.
• For hepatic-impairment groups only:

• Hepatic carcinoma, hepatorenal syndrome, or limited life expectancy.
• Clinically active Grade 3 or 4 hepatic encephalopathy.
• Severe uncontrolled ascites, recent gastrointestinal bleeding, or history of solid organ transplant.