Margetuximab Disease Interactions

Decreases in left ventricular ejection fraction (LVEF) have been reported with agents that block HER2 activity. Patients who have received prior anthracyclines, those who received anthracycline after stopping therapy with agents that block HER2 activity, or patients who received prior radiotherapy to the chest area may be at higher risk of decreased LVEF. Therapy with these agents should be administered cautiously in patients with a previous history of heart conditions. Evaluate cardiac function before, during, and upon completion of treatment. Withhold or discontinue therapy with agents that block HER2 activity as appropriate, and for a confirmed clinically significant decrease in left ventricular function, or if the LVEF has not improved or has declined further. It is recommended to monitor overall cardiac function and LVEF by echocardiogram or MUGA scan as appropriate.

Thrombocytopenia has been reported with the use of agents that block HER2 activity. Monitor platelet counts prior to initiation of therapy and prior to each dose. If appropriate modify the dose according to clinical guidelines. Patients with decreased platelet count and patients on anti-coagulant treatment should be closely monitored during treatment with these agents.