Background: Romiplostim, a thrombopoietin mimetic, increases platelet counts in patients with immune thrombocytopenia, with few adverse effects.
Methods: In this open-label, 52-week study, we randomly assigned 234 adult patients with immune thrombocytopenia, who had not undergone splenectomy, to receive the standard of care (77 patients) or weekly subcutaneous injections of romiplostim (157 patients). Primary end points were incidences of treatment failure and splenectomy. Secondary end points included the rate of a platelet response (a platelet count >50×10(9) per liter at any scheduled visit), safety outcomes, and the quality of life.
Results: The rate of a platelet response in the romiplostim group was 2.3 times that in the standard-of-care group (95% confidence interval [CI], 2.0 to 2.6; P<0.001). Patients receiving romiplostim had a significantly lower incidence of treatment failure (18 of 157 patients [11%]) than those receiving the standard of care (23 of 77 patients [30%], P<0.001) (odds ratio with romiplostim, 0.31; 95% CI, 0.15 to 0.61). Splenectomy also was performed less frequently in patients receiving romiplostim (14 of 157 patients [9%]) than in those receiving the standard of care (28 of 77 patients [36%], P<0.001) (odds ratio, 0.17; 95% CI, 0.08 to 0.35). The romiplostim group had a lower rate of bleeding events, fewer blood transfusions, and greater improvements in the quality of life than the standard-of-care group. Serious adverse events occurred in 23% of patients (35 of 154) receiving romiplostim and 37% of patients (28 of 75) receiving the standard of care.
Conclusions: Patients treated with romiplostim had a higher rate of a platelet response, lower incidence of treatment failure and splenectomy, less bleeding and fewer blood transfusions, and a higher quality of life than patients treated with the standard of care. ( ClinicalTrials.gov number, NCT00415532.).