Drug Interaction Report

MONITOR CLOSELY: Coadministration of loncastuximab tesirine with antineoplastic, immune-modulating, immuno- or myelosuppressive therapies may potentiate the risk of severe infections, myelosuppression, and/or other unintended additive immunosuppressive effects. Serious and fatal infections, including opportunistic infections, as well as myelosuppression, including neutropenia, thrombocytopenia, and anemia have been reported with the use of loncastuximab tesirine. Concomitant use may potentiate these risks. However, clinical data are not available.

MANAGEMENT: The safety and efficacy of loncastuximab tesirine use in combination with other immuno- or myelosuppressive agents have not been evaluated. Patients receiving loncastuximab tesirine should be monitored closely for the development of signs and symptoms of infection and/or myelosuppression. The manufacturers' recommendations and institutional protocols for dosage, treatment regimens, monitoring, and management of toxicities should be consulted.

ADJUST DOSING INTERVAL: Administration with food increases the oral bioavailability of belumosudil. The mechanism has not been described. Administration of belumosudil (200 mg single oral dose) in healthy subjects, with a fatty and calorie-rich meal (approximately half of the calories were contained in the fat) increased the mean belumosudil peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 120% and 100%, respectively, compared to administration under fasting conditions. The time to reach peak concentration (Tmax) was delayed by 30 minutes. Administration of oral belumosudil 200 mg once daily with food in patients with chronic graft-versus-host disease (chronic GVHD) lead to steady-state concentrations of the drug with an accumulation ration of 1.4.

MANAGEMENT: To ensure maximal oral absorption, belumosudil should be administered with a meal, every day at the same time.