Drug Interaction Report

MONITOR: Coadministration with mosunetuzumab may increase the plasma concentrations of drugs that are substrates of CYP450 isoenzymes. Initiation of mosunetuzumab treatment causes transient release of cytokines that may suppress CYP450 isoenzymes, although the potential for interaction has not been studied. According to the manufacturer, the highest drug-drug interaction risk would be after the first dose of the first cycle, up to 14 days after the second 60 mg dose on the first day of the second cycle, as well as during and after cytokine release syndrome.

MANAGEMENT: Caution is advised when mosunetuzumab is prescribed to patients receiving drugs that are metabolized by CYP450 isoenzymes, particularly those with a narrow therapeutic index such as carbamazepine, colchicine, cyclosporine, disopyramide, phenytoin, quinidine, theophylline, warfarin, macrolide immunosuppressants, vinca alkaloids, and some narcotic analgesics. Clinical laboratory monitoring are recommended following the initiation of mosunetuzumab, and the individual dosage of the concomitant agents adjusted as needed.

GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered everolimus. The mechanism is inhibition of CYP450 3A4 and P-glycoprotein activity in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients treated with everolimus should avoid consumption of grapefruit and grapefruit juice.