Drug Interactions between mobocertinib and telaprevir

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of mobocertinib. The mechanism may involve inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit juice. Based on drug interaction studies using model-informed approaches, coadministration of mobocertinib with multiple doses of itraconazole or ketoconazole (strong CYP450 3A4 inhibitors) is predicted to increase the steady-state combined molar AUC (systemic exposure) of mobocertinib and its active metabolites by 374% to 419%, while coadministration with multiple doses of a moderate CYP450 3A4 inhibitor is predicted to increase this value by approximately 100% to 200%. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Elevated plasma concentrations of mobocertinib may increase the risk for adverse effects such as QT prolongation, heart failure or reduced ejection fraction, cardiomyopathy, heart block, diarrhea, rash, stomatitis, fatigue, and musculoskeletal pain.

MANAGEMENT: Patients should avoid consumption of grapefruit and grapefruit juice during treatment with mobocertinib.

ADJUST DOSING INTERVAL: Food significantly enhances the oral bioavailability of telaprevir. When given with a meal containing 533 kcal and 21 g fat, telaprevir systemic exposure (AUC) increased by 237% compared to administration under fasting conditions. The type of meal also affects the exposure to telaprevir. Relative to fasting, telaprevir AUC increased by approximately 117% with a low-fat meal (249 kcal; 3.6 g fat) and 330% with a high-fat meal (928 kcal; 56 g fat). In Phase 3 clinical trials, telaprevir doses were administered within 30 minutes of completing a meal or snack containing approximately 20 grams of fat.

MANAGEMENT: Telaprevir should be administered with food containing approximately 20 grams of fat. Patients should be advised that the fat content of the meal or snack is critical to the absorption of telaprevir. Food taken with telaprevir should be ingested within 30 minutes prior to each dose. Examples of some foods that could be taken with telaprevir include: bagel with cream cheese; half cup of nuts; 3 tablespoons of peanut butter; 1 cup of ice cream; 2 ounces of American or cheddar cheese; 2 ounces of potato chips; or half cup of trail mix.