Romiplostim for chemotherapy induced thrombocytopenia in pediatric cancers

Chemotherapy-induced-thrombocytopenia (CIT) compromises cancer care, but data on its management in children is scarce. Romiplostim, a thrombopoietin-receptor-agonist, has shown efficacy in adults with CIT, though its role in paediatric patients remains undefined.

We conducted an investigator-initiated, open-label, randomized-controlled-trial at a tertiary center in India to evaluate prophylactic romiplostim for prevention of CIT in children aged 1-14 years with acute myeloid leukemia (AML), non-Hodgkin's lymphoma (NHL), and solid-tumors receiving myelosuppressive chemotherapy. Patients were randomly assigned (1:1) to receive romiplostim (3 μg/kg-subcutaneously) or standard-care. The primary outcome was platelet recovery (≥100 × 10⁹/L and transfusion-free for 72 hours) within 3-weeks. Secondary outcomes included bleeding, transfusion requirements, chemotherapy delays, and immature platelet fraction percentagecIPF%) trends.

From March 2023 to October 2024, 93 patients (median age, 3 years; interquartile range [IQR], 2-5) were randomized (47 intervention, 46 control). Platelet recovery occurred in 91.3% and 88.1%, respectively (risk difference, 3.2 percentage points; 95% confidence interval [CI], -9.5 to 15.9; P = 0.73). Clinically significant bleeding (≥WHO grade 2) occurred in none of 46 patients in romiplostim group and 6 of 43 (14%) in control group (absolute risk difference,-14 percentage points; 95% CI, -27 to -2; P = 0.01). Median platelet transfusion volume was lower with romiplostim (19.3 vs. 29.6 mL/kg; median difference, -10.3 mL/kg; 95% CI, -21.5 to 0.9; P = 0.06, rank-biserial correlation= 0.35). Romiplostim significantly increased IPF% on day-16 from baseline (258% vs. 47.7%, p = 0.016, Cohen's h = 2.41). No thrombotic events occurred.

Prophylactic romiplostim didn't hasten platelet recovery in pediatric patients receiving myelosuppressive chemotherapy but was associated with reduced bleeding and had lower transfusion requirements. There was a significant relative immature platelet fraction percentage (IPF)% increment on day 16 in the romiplostim arm in comparison to the control arm, reinforcing the biological plausibility of romiplostim's effect on megakaryocyte stimulation.

Clinical Trials Registry of India: CTRI/2023/02/049906.