Drug Interaction Report

MONITOR CLOSELY: Coadministration of loncastuximab tesirine with antineoplastic, immune-modulating, immuno- or myelosuppressive therapies may potentiate the risk of severe infections, myelosuppression, and/or other unintended additive immunosuppressive effects. Serious and fatal infections, including opportunistic infections, as well as myelosuppression, including neutropenia, thrombocytopenia, and anemia have been reported with the use of loncastuximab tesirine. Concomitant use may potentiate these risks. However, clinical data are not available.

MANAGEMENT: The safety and efficacy of loncastuximab tesirine use in combination with other immuno- or myelosuppressive agents have not been evaluated. Patients receiving loncastuximab tesirine should be monitored closely for the development of signs and symptoms of infection and/or myelosuppression. The manufacturers' recommendations and institutional protocols for dosage, treatment regimens, monitoring, and management of toxicities should be consulted.

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.