This is a Phase I study to determine the effect of GW786034 (pazopanib) on P450 enzymes. This study will help determine which types of drugs may interact with GW786034.

Inclusion criteria:

• Histologically or cytologically confirmed diagnosis of advanced solid tumors.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Adequate bone marrow, renal, lung, and liver function.
• A female subject must not be pregnant and will agree not to become pregnant during the trial

Exclusion criteria:

• Any major surgery, chemotherapy, hormone therapy, investigational drugs, or radiotherapy within the last 28 days.
• Poorly controlled hypertension.
• Corrected QT (QTc) prolongation defined as a QTc interval greater than or equal to 480 msec and a prior history of cardiovascular disease, arrhythmias, or significant ECG abnormalities.
• Arterial or venous thrombi (including cerebrovascular accident), myocardial infarction, admission for unstable angina, cardiac angioplasty, or stenting within the last 3 months.
• Current use of therapeutic anticoagulation (low molecular weight heparin, oral anticoagulant agents).

Amiodarone must not have been taken for at least 6 months prior to the administration of the first dose of study drug.

• History of brain metastases.
• Has narrow-angle glaucoma which is a contraindication to midazolam use.
• History of nicotine-containing product (including cigarettes, cigars, nicotine patches) use within the past 6 months.
• A history of bleeding problems.