Romiplostim as early treatment for refractory primary immune thrombocytopenia.

Romiplostim is a thrombopoietin-receptor agonist approved to treat chronic immune thrombocytopenia (ITP). We treated eight patients with acute or persistent primary ITP, severe clinical bleeding, and resistance to corticosteroids and/or intravenous immunoglobulins (IVIg). Romiplostim, initially administered at 2 or 3 μg/kg/week, was subsequently increased to achieve and maintain platelet-count responses and control bleeding. Seven patients' platelet counts rose above 30 G/L, representing ≥twofold increases, within a median of 14 days after 1-5 infusions. The weekly dose reached 9 μg/kg at week 5 for three patients; the other patients' ITPs were controlled with ≤6 μg/kg/week. No thromboembolic events occurred. Five patients received rituximab concomitantly with romiplostim, four of whom could stop romiplostim within 2 months, thereby demonstrating rituximab efficacy. All three patients treated with romiplostim alone required maintenance therapy. Thus, romiplostim represents an alternative for patients with severe acute or persistent ITP refractory to conventional therapy.