Drug Interactions between nirmatrelvir / ritonavir and revumenib

ADJUST DOSING INTERVAL: Administration with food may modestly affect the bioavailability of ritonavir from the various available formulations. When the oral solution was given under nonfasting conditions, peak ritonavir concentrations decreased 23% and the extent of absorption decreased 7% relative to fasting conditions. Dilution of the oral solution (within one hour of dosing) with 240 mL of chocolate milk or a nutritional supplement (Advera or Ensure) did not significantly affect the extent and rate of ritonavir absorption. When a single 100 mg dose of the tablet was administered with a high-fat meal (907 kcal; 52% fat, 15% protein, 33% carbohydrates), approximately 20% decreases in mean peak concentration (Cmax) and systemic exposure (AUC) were observed relative to administration after fasting. Similar decreases in Cmax and AUC were reported when the tablet was administered with a moderate-fat meal. In contrast, the extent of absorption of ritonavir from the soft gelatin capsule formulation was 13% higher when administered with a meal (615 KCal; 14.5% fat, 9% protein, and 76% carbohydrate) relative to fasting.

MANAGEMENT: Ritonavir should be taken with meals to enhance gastrointestinal tolerability.

ADJUST DOSING INTERVAL: In pharmacokinetic studies, revumenib was administered while fasting or with a low fat meal. Revumenib has not been studied with meals of higher fat content and the impact on its pharmacokinetic parameters is unknown.

MONITOR: Grapefruit, grapefruit juice, grapefruit hybrids, pomelos, star-fruit, and Seville oranges may increase the plasma concentrations of revumenib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The extent and clinical significance are unknown. In pharmacokinetic studies in patients with relapsed or refractory acute leukemia, revumenib area under the concentration-time curve (AUC) and peak plasma concentration (Cmax) increased 2-fold following concomitant use with the potent CYP450 3A4 inhibitors posaconazole, itraconazole, and voriconazole, and 2.5-fold following concomitant use with the potent CYP450 3A4 inhibitor cobicistat. However, clinically significant differences in revumenib pharmacokinetics were not observed when used concomitantly with the moderate CYP450 3A4 inhibitors fluconazole and isavuconazole. 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. Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability. Increased exposure to revumenib may increase the risk of QT interval prolongation, which has been associated with ventricular arrhythmias including torsade de pointes and sudden death.

MANAGEMENT: Due to the potential impact of high fat content meals on revumenib absorption and exposure, it is recommended that revumenib be administered while fasting or with a low fat meal (approximately 400-500 calories, with 25% of calories from fat). In addition, if grapefruit, grapefruit juice, grapefruit hybrids, pomelos, star-fruit, or Seville oranges are consumed during treatment with revumenib, assess patient tolerability and monitor for serious adverse effects (e.g., QT prolongation and torsade de pointes arrhythmia, differentiation syndrome, neutropenia, thrombocytopenia).