Drug Interaction Report

MONITOR: Neither the leukapheresis procedure nor sipuleucel-T have been studied for use in combination with chemotherapy or immunosuppressive agents (e.g., systemic corticosteroids). Since sipuleucel-T is designed to stimulate the immune system, concurrent use of myelo- or immunosuppressive agents may alter the efficacy and/or safety of sipuleucel-T.

MANAGEMENT: Patients should be carefully evaluated to determine whether it is medically appropriate to reduce or discontinue chemotherapy or immunosuppressive agents prior to treatment with sipuleucel-T.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of pazopanib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Although not studied, the interaction may increase the risk of QT interval prolongation and torsade de pointes arrhythmia as well as severe and fatal hepatotoxicity associated with the use of pazopanib.

ADJUST DOSING INTERVAL: Food increases the oral bioavailability of pazopanib. The mechanism of interaction is unknown. Administration of pazopanib with a high-fat or low-fat meal results in an approximately 2-fold increase in peak plasma concentration (Cmax) and systemic exposure (AUC).

MANAGEMENT: Patients treated with pazopanib should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. Pazopanib should be administered at least one hour before or two hours after a meal.