A case of successful treatment with eltrombopag for severe immune-related thrombocytopenia induced by atezolizumab:Case report.

Immune checkpoint inhibitors (ICIs) have shown impressive anti-tumor effects against multiple types of malignancies. Among the wide variety of immune-related adverse events (irAEs), immune-related thrombocytopenia (ITP) is relatively rare but often clinically significant and life-threatening. However, the appropriate treatment for severe ITP has not been determined. We herein report an 82-year-old male patient with non-small-cell lung cancer who developed severe ITP three weeks after starting the third course of atezolizumab. The initial combination therapy with high-dose prednisolone, intravenous immunoglobulin and platelet transfusion was ineffective. However, additional treatment with eltrombopag, a thrombopoietin receptor agonist, resulted in remarkable improvement in the thrombocytopenia. J. Med. Invest. 70 : 516-520, August, 2023.