Optimizing pediatric ITP therapy: a real-world study on plasma concentration-guided eltrombopag dosing.

Eltrombopag (ELT) is a second-line therapy for pediatric immune thrombocytopenia (ITP), but inter-individual variability in metabolism leads to wide plasma concentration differences at the same dose, affecting efficacy and adverse drug reactions (ADRs). To validate the feasibility of individualized drug regimens based on blood drug concentration guidance in pediatric persistent/chronic ITP (P/CITP) and to provide a new method of individualized treatment with eltrombopag for pediatric P/CITP. This prospective, observational cohort study enrolled 70 children with refractory persistent/chronic ITP (P/CITP) to evaluate the feasibility and value of plasma concentration–guided individualized dosing. Patients were assigned to a conventional group (dose titration by platelet counts and bleeding events) or an individualized group (dose adjustments additionally guided by ELT concentrations), with 6-month follow-up. Although no statistical significance was observed, the individualized group achieved a higher overall response rate (82.9% vs. 71.4%) and complete response rate (65.7% vs. 48.6%), with more stable platelet counts, fewer bleeding events, reduced requirements for concomitant/rescue therapy, and a lower incidence of ADRs (17.1% vs. 37.1%). Similarly, though not statistically significant, the individualized group had lower direct medical costs and improved cost-effectiveness. These findings suggest that plasma concentration-guided individualized ELT therapy may enhance therapeutic efficacy, improve safety profiles, and reduce medical costs, which represents a meaningful step toward precision medicine in the field of pediatric hematology.