Thrombopoietin Receptor Agonists in the Treatment of Chronic Resistant Primary Immune Thrombocytopenia: Efficacy and Safety Data in Real Clinical Practice

Objective: To analyze the long-term efficacy and safety of ATR in adult patients with primary resistant ITP in real-world clinical practice. Materials and methods.The article contains long-term results analysis of ATR application under real clinical practice conditions in 138 patients (40 men and 98 women) whose median age at the beginning of therapy was 59 (18-86) years. Two ATR medicines-romiplostim (100 patients) and eltrombopag (38 patients) were used. Results. During the first month of therapy, the median platelet count in the romiplostim group increased from 17.10(9)/L to 60.10(9)/L (9-600.10(9)/L), and the elethrombopag from 16.10(9)/L to 56.109/L (9-400.10(9)/L). The minimal response (reaching platelet counts over 30.10(9)/L) was achieved in 92% of cases in both groups. Partial response (achievement of platelet count more than 50.10(9)/L) was achieved in 91 and 84% of patients in the rhombostim and eltrombopag groups, respectively. The frequency of complete response (an increase in platelet counts above 100.10(9)/L) was noted somewhat more often in the rhy- ploistim group-69% compared to 47% in the eltrombopag group (P = NS). Most patients demonstrated a long-term stable effect in the form of an increase in blood platelet count to a safe level during months and years of ATR treatment. The achievement of at least partial remission for 3 months or more was 70 and 71% in romiplostim and elthrombopag groups, respectively. Patients who started ATR-therapy are currently continuing treatment: 51% - in romiplostim group and in eltrombopag group-39%. The main reason of discontinuation the initially effective therapy were the loss of platelet response, toxicity, withdrawal from treatment (withdrawal with preservation of remission) and patients death. The tolerability of drugs with long-term admission was satisfactory. The most common AE were headache, bone pain, thrombosis, increased blood pressure and petechial hemorrhagic eruptions. The overall incidence of complications did not differ significantly between the romiplostim and eltrombopag groups -15.6 and 15.8%, respectively. Conclusion. Long-term ATR-therapy using in patients with resistant chronic ITP is an effective and largely safe treatment option.