A Study to Investigate the Pharmacokinetics of Tirabrutinib in Participants With Mild, Moderate, and Severe Hepatic Impairment Compared to Healthy Participants

This study is examining how a drug called tirabrutinib (used to treat certain blood cancers) is processed by the body in people with varying degrees of liver damage, compared to healthy volunteers. The goal is to understand whether liver impairment affects how the drug works or is eliminated. **You may be eligible if...** - You are 18–75 years old - You have a stable, chronic liver condition classified as mild, moderate, or severe (Child-Pugh A, B, or C) - You are a healthy volunteer matched to a participant with liver impairment - Your kidney function meets the study threshold - Your BMI is between 18 and 40 **You may NOT be eligible if...** - You have unstable or rapidly worsening liver disease - You smoke more than 20 cigarettes per day - You have significant blood count or organ function abnormalities - You have taken medications that interfere with the study drug Talk to your doctor to see if this trial is right for you.