Drug Interaction Report

MONITOR: The use of topotecan with other cytotoxic agents is likely to result in greater myelosuppression due to additive or synergistic pharmacologic effects. Severe neutropenia and neutropenic sepsis resulting in death were reported with topotecan and cisplatin.

MANAGEMENT: Caution is advised if topotecan is used with other cytotoxic agents. Dosage reductions may be required, and bone marrow function should be closely monitored. Patients should be advised to contact their physician if they develop signs and symptoms of myelosuppression such as pallor, dizziness, fatigue, lethargy, fainting, easy bruising or bleeding, or signs of infection such as fever, chills, sore throat, body aches, and other influenza-like symptoms.

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).