Preliminary experience with oral thrombopoietin-receptor agonists, primarily hetrombopag, in pediatric immune thrombocytopenia: a pilot single-center retrospective report

Background: Although thrombopoietin receptor agonists (TPO-RAs) are effective second-line treatments for pediatric immune thrombocytopenia (ITP), real-world data on newer agents like hetrombopag remain scarce. This study aimed to describe a single-center retrospective experience with oral TPO-RAs, predominantly hetrombopag, in children with ITP who were refractory to or relapsed after first-line therapy.

Methods: We conducted a single-center retrospective study of 18 children with ITP treated with oral TPO-RAs (hetrombopag, eltrombopag, or avatrombopag) at Qingdao Women and Children’s Hospital from January 2023 to June 2024. Platelet counts, bleeding grades, use of rescue therapy, and adverse events (AEs) were extracted from medical records and summarized descriptively; statistical analyses were performed.

Results: Platelet counts increased after treatment initiation, with statistically significant differences from baseline at prespecified time points (week 1, month 1, month 3, and month 6; all Holm-adjusted P≤0.005). Bleeding grades (Buchanan & Adix overall grade 0–4) did not show a statistically significant improvement at the group level (P=0.10) or individual level (P=0.056). No statistically significant associations were detected between response and selected baseline factors (age, sex, disease duration, infection status, bleeding at baseline, or antibody status), although the study was underpowered for these analyses. Most recorded AEs were mild to moderate.

Conclusions: In this preliminary, pilot-scale hetrombopag-predominant cohort, oral TPO-RA use was associated with increased platelet counts; however, the limited sample size and lack of statistically significant improvement in bleeding scores preclude definitive conclusions regarding the overall clinical utility of these agents beyond their ability to increase platelet counts. Given the retrospective design, heterogeneity of exposure, and limited sample size, the findings are hypothesis-generating and should be confirmed in prospective studies.