Drug Interaction Report

MONITOR: Concomitant use of a human neonatal Fc receptor (FcRn) blocker like efgartigimod alfa or rozanolixizumab may decrease the plasma concentrations and therapeutic effects of medications that bind to the FcRn such as immune globulins, monoclonal antibodies, or antibody derivatives containing the human Fc domain of the IgG subclass (e.g., abatacept, aflibercept, asfotase alfa, belatacept, dulaglutide, etanercept, luspatercept, rilonacept, romiplostim, and some recombinant coagulation factors). FcRn blockers target the FcRn, a widely expressed receptor that plays a critical role in recycling and maintaining homeostatic levels of circulating IgG and other antibodies by preventing their cellular degradation. For example, reduced serum concentrations of these products are anticipated to occur if they are administered concomitantly or within 2 weeks after the administration of rozanolixizumab.

MANAGEMENT: Due to the potential for their reduced effectiveness, close monitoring is recommended if medications that bind to the human neonatal Fc receptor are required during concomitant treatment with FcRn blockers. When long-term use of such medications is required, consider discontinuing the FcRn blocker and using alternative therapies. Some authorities recommend that initiation of treatment with these products should be delayed to 2 weeks after the last dose of any given treatment cycle of either FcRn blocker. Individual product labeling should be consulted for further guidance.