Drug Interactions between Adcetris and conivaptan

MONITOR CLOSELY: Coadministration with potent inhibitors of CYP450 3A4 may increase the plasma concentrations of unconjugated monomethyl auristatin E (MMAE), the anti-mitotic and cytotoxic component of brentuximab vedotin. Brentuximab vedotin is an antibody-drug conjugate (ADC) that releases MMAE via proteolytic cleavage, and MMAE has been shown in vitro to be primarily metabolized by CYP450 3A4. When brentuximab vedotin was administered with the potent CYP450 3A4 inhibitor ketoconazole, MMAE peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 25% and 34%, respectively, with no change in ADC exposure. Using a model-based approach to account for the fact that MMAE exposures are decreased after multiple doses by 20% to 50% compared to the first dose, the adjusted increase in MMAE AUC by ketoconazole is predicted to be 73%.

MANAGEMENT: Caution is advised when brentuximab vedotin is used concomitantly with potent CYP450 3A4 inhibitors. Close monitoring for adverse effects including neutropenia, infection, peripheral neuropathy, hepatotoxicity, pulmonary toxicity and hyperglycemia is recommended, and the dosing of brentuximab vedotin adjusted or withheld as necessary in accordance with the product labeling.