[Successful treatment with fostamatinib and thrombopoietin receptor agonists in immune thrombocytopenia].

An 84-year-old man presented to our department with a chief complaint of gingival bleeding. Primary immune thrombocytopenia was diagnosed, and treatment with prednisolone, eltrombopag, and Helicobacter pylori eradication was started. Although the patient initially achieved complete remission, thrombocytopenia recurred after an episode of bacterial pneumonia. Subsequently, the dosage of prednisolone was increased, intravenous immunoglobulin and rituximab were added to the regimen, and eltrombopag was replaced with romiplostim, but platelet count failed to recover. Fostamatinib was started, but was ineffective at the initial dose. However, increasing the dose led to a rapid increase in platelet count. The patient subsequently developed pulmonary embolism, necessitating discontinuation of romiplostim and initiation of anticoagulation therapy. A decrease in platelet count 15 days after the last romiplostim injection prompted resumption of romiplostim, which led to platelet count recovery. The safety and efficacy of the combination of fostamatinib and thrombopoietin receptor agonist (TPO-RA) has not been established. In the present case, TPO-RA and fostamatinib were ineffective individually, but their combination proved effective. This combination may be considered a therapeutic approach for refractory immune thrombocytopenia, although monitoring for drastic platelet count fluctuations and thrombosis is required.