Drug Interaction Report

MONITOR: Coadministration of tafasitamab with drugs that can affect hemostasis such as anticoagulants, platelet inhibitors, thrombin inhibitors, thrombolytic agents, dextrans, and nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of bleeding. Use of tafasitamab has been associated with serious or severe myelosuppression including thrombocytopenia, anemia, and neutropenia. In the L-MIND clinical efficacy study in which tafasitamab was given with lenalidomide for up to 12 cycles followed by tafasitamab monotherapy, the total incidence of thrombocytopenia during the combination therapy phase was 31%, with Grade 3 and Grade 4 thrombocytopenia occurring in 12% and 6% of subjects, respectively. After patients were switched to tafasitamab alone in the extended monotherapy phase, the incidences of haematological events including thrombocytopenia decreased by at least 20%.

MANAGEMENT: When possible, consideration should be given to withholding concomitant medications that may increase bleeding risk in patients treated with tafasitamab. Close clinical and laboratory monitoring for bleeding complications is recommended if concomitant use is unavoidable. Refer to the product labeling for guidance on frequency of laboratory monitoring and dose modifications or withholding recommendations for platelet counts below 50,000/mcL. Patients should be advised to promptly report any signs of unusual bleeding or bruising to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, red or brown urine, or red or black stools.

ADJUST DOSING INTERVAL: Food reduces the oral bioavailability of betrixaban. When administered with a low-fat (900 calories; 20% fat) or high-fat (900 calories; 60% fat) meal, betrixaban peak plasma concentration (Cmax) and systemic exposure (AUC) decreased relative to administration in the fasting state by an average of 70% and 61%, respectively, with the low-fat meal and 50% and 48%, respectively, with the high-fat meal. The effect of food on betrixaban pharmacokinetics could be observed for up to 6 hours after meal intake.

MANAGEMENT: The manufacturer recommends taking betrixaban at the same time each day with food.