Study to Determine the Effect of 14 Days Dosing With Darapladib (SB-480848) on Carotid Plague Composition in Patients With Planned Carotid Endarterectomy

Inclusion Criteria: * Male or female, \>35 years of age * Females of childbearing potential must be using approved contraceptive measures * Male patients must be willing to abstain from sexual intercourse or use a form of contraception if engaging in sexual intercourse with a woman who could become pregnant * Planned carotid endarterectomy within a timeframe compatible with recruitment for the study and able to comply with the requirements of the study, as deemed by the investigator * Written, informed consent to participate Exclusion Criteria: * Recent myocardial infarction (within the previous 4 weeks) * Currently taking corticosteroids, warfarin, digoxin or a potent CYP3A4 inhibitor * Recent (\<3 months) or ongoing acute infection or significant trauma associated with bruising and/or taking antibiotics. Prophylactic antibiotics for surgery are allowed * Change in dose of lipid-lowering therapy during the previous 4 weeks from randomisation * History of chronic liver disease (e.g. cirrhosis, hepatitis) OR ALT OR AST ≥1.5 times the upper limit of normal (ULN) at screening * Diagnosis of systemic lupus erythematosis (SLE) or rheumatoid arthritis (RA) * Clinically significant anaemia * History of severe renal impairment (serum creatinine \>1.8mg/dL) * Unstable angina * History of asthma , anaphylaxis or anaphylactoid reactions, severe allergic responses * Abuse of alcohol or drugs within the last 6 months * Any factor or clinical disease state that, in the investigator's opinion, would preclude completion of a safe surgical procedure and/or completion of the study * Use of an investigational drugs within 30 days or 5 half-lives of their last dose prior to starting the study, whichever is the longest