 Discontinuation of romiplostim must be approached with great caution, as a rapid decrease in the platelet count may occur, possibly leading to bleeding diathesis.In well designed, 24-week, Phase III trials, romiplostim was significantly more effective than placebo in achieving the primary endpoint of a protocol-defined durable platelet response in nonsplenectomized or splenectomized adults with chronic immune thrombocytopenic purpura.Romiplostim's effect is to stimulate the patient's megakaryocytes to produce platelets at a more rapid than normal rate, thus overwhelming the immune system's ability to destroy them.