Delayed treatment-free response after romiplostim discontinuation in pediatric chronic immune thrombocytopenia.

We report the case of a 16-month-old patient with chronic immune thrombocytopenia (ITP) patient who experienced delayed treatment-free response (TFR) after romiplostim treatment. He received intravenous immunoglobulin every month to maintain a platelet count above 20,000/μL for 2 years. Thereafter, he received rituximab and cyclosporine as second-line therapy, with no response, followed by romiplostim. After 4 weeks of treatment, the platelet count was maintained above 50,000/μL. Following 7 months of treatment, he discontinued romiplostim, and the platelet count decreased. His platelet counts remained above 50,000/μL, without any bleeding symptoms, 2 years after romiplostim discontinuation. This is the first report of TFR after romiplostim treatment in pediatric chronic ITP.