The study is a 2-arm, open-label, repeat-dose, single sequence, crossover, study designed to evaluate the effects of ketoconazole (Arm A) and esomeprazole (Arm B) on the pharmacokinetics (PK) of oral pazopanib in subjects with solid tumor malignancies. This study will compare the PK parameters of oral pazopanib and its metabolite concentrations when given alone and when co-administered with either ketoconazole (Arm A) or esomeprazole (Arm B). Safety assessments (physical examinations, vital signs, 12-lead electrocardiograms, Eastern Cooperative Oncology Group performance status, clinical laboratory assessments, and monitoring of adverse events) will also be evaluated during the study.