Drug Interaction Report

MONITOR: Coadministration with elranatamab may increase the plasma concentrations of drugs that are substrates of CYP450 isoenzymes. Initiation of elranatamab 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 elranatamab on day 1 and up to 14 days after the 32 mg dose on day 4, as well as during and after cytokine release syndrome.

MANAGEMENT: Caution is advised when elranatamab is administered with 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 and/or laboratory monitoring is recommended following the initiation of elranatamab, and the dosage(s) of the CYP450 substrate(s) may be adjusted accordingly.