Drug Interaction Report

MONITOR: Coadministration with inhibitors of CYP450 3A4 and/or P-glycoprotein (P-gp) may increase the plasma concentrations of tepotinib, which may increase the incidence and severity of adverse reactions such as interstitial lung disease/pneumonitis, hepatotoxicity, edema, nausea, vomiting, diarrhea, constipation, and musculoskeletal pain. Tepotinib is a substrate of both CYP450 3A4 isoenzyme and P-gp efflux transporter. However, the effect of CYP450 3A4 or P-gp inhibitors on tepotinib has not been studied clinically.

MANAGEMENT: Caution is advised when tepotinib is used with inhibitors of CYP450 3A4 and/or P-gp. Patients should be monitored for increased adverse effects, and the tepotinib dosage adjusted as necessary.

ADJUST DOSE: Smoking tobacco may decrease the steady-state systemic exposure of istradefylline by 38% to 54%.

MANAGEMENT: The possibility of reduced therapeutic effects of istradefylline should be considered in smokers. The manufacturer recommends an istradefylline dosage of 40 mg once daily in patients who smoke 20 or more cigarettes (or the equivalent amount of another tobacco product) per day.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of tepotinib. When tepotinib was administered after a high-fat, high-calorie meal (approximately 800 to 1000 calories; 150 calories from protein, 250 calories from carbohydrate, 500 to 600 calories from fat), tepotinib peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 2-fold and 1.6-fold, respectively, compared to administration under fasted conditions.

MANAGEMENT: Tepotinib should be administered with food at approximately the same time each day.