[Eltrombopag for the treatment of primary immune thrombocytopenia in 23 pediatric patients].

To evaluate the efficacy and safety of eltrombopag in the treatment of pediatric primary immune thrombocytopenia (ITP) . The clinical characteristics of 23 pediatric ITP patients who received eltrombopag from May 2015 to March 2019 were retrospectively analyzed. Eltrombopag started with an initial dose of 12.5-50.0 mg/d and the maximum dose was 75.0 mg/d. Among 23 children, there were 11 boys and 12 girls with median age 11.0 (2.0-17.0) years. Four cases were newly diagnosed ITP, the other 8 of persistent ITP and 11 of chronic ITP. The duration of eltrombopag application ranged from 4.5 to 95 weeks (8/23 still ongoing) . The median platelet (PLT) counts at 2 weeks, 4 weeks, 3 months and the 6 months after treatment were 40 (4-170) ×10(9)/L, 20 (4-130) ×10(9)/L, 60 (4-110) ×10(9)/L, and 70 (18-160) ×10(9)/L, which were all significantly higher than that before treatment 14 (2-82) ×10(9)/L (=-3.440, =0.001; =-1.964, =0.049; =-4.339, <0.001;=-5.794, <0.001 respectively) . The overall response rate was 60.87% (14/23 cases) . The median time to PLT count ≥30×10(9)/L was 10.5 (3-42) days. Seven patients (30.43%) responded within the first week, and 10 cases (43.48%) achieved PLT counts ≥30×10(9)/L within 2 weeks. All patients were divided into three groups according to the age (<6 years old, 6-12 years old, 13-17 years old) . The response rates were similar in three groups, as 33.33%, 60.00%, 85.71%, respectively. WHO bleeding scores as 0, 1, 2 were corresponded to 4, 12 and 7 patients before treatment. Patient numbers changed to 13, 7, 3 with bleeding scores 0, 1, 2 respectively after treatment ((2)=7.558, =0.006) . Eltrombopag was well tolerated, the common adverse events included elevated transaminase (4 cases) and serum bilirubin (4 cases) ; mild nausea (1 case) , vomiting (1 case) and dizziness (1 case) . No drug withdrawal occurred due to adverse events. Eltrombopag is safe and effective in pediatric patients with primary ITP.