Romiplostim for CIT

Background

Retrospective chart review. N=18 pediatric patients (≤22 years) with solid tumors and chemotherapy-induced thrombocytopenia (CIT), single tertiary pediatric hospital, July 2020-December 2023.

Interventions and follow up

Treatment: Romiplostim (TPO receptor agonist), weekly SC dosing titrated to platelet count, for CIT in pediatric solid tumors
Primary endpoint: Response rate (platelet ≥75,000/µL maintained without CIT recurrence)
mFollow up: Median treatment duration variable

Results

Response rate: 70% (12/18)
Chemotherapy dose reductions: mean 2 pre-romiplostim vs 1 during romiplostim (P=.46)
Chemotherapy delays: mean 3 pre-romiplostim vs 1 during romiplostim (P=.0008)
Time to platelet recovery: 30 days pre-romiplostim vs 15 days during treatment

Adverse events

Main adverse events: No treatment-limiting adverse events reported
Thrombotic: no thromboembolic complications noted
Overall: safety profile manageable

Conclusions

Romiplostim may decrease chemotherapy dose reductions and delays in pediatric solid tumors with CIT, potentially allowing maintenance of dose intensity. The observed reduction in treatment delays (3 to 1) is clinically meaningful.

Key Limitations

Retrospective, single-institution, very small sample (N=18); no control arm; heterogeneous tumor types and chemotherapy regimens; dose-reduction difference not significant (P=.46); off-label use in pediatrics; short and variable follow-up.

Clinical Context

Romiplostim is FDA-approved for immune thrombocytopenia but its use for chemotherapy-induced thrombocytopenia, particularly in pediatrics, is off-label and investigational. These data add to a limited evidence base supporting TPO receptor agonists as a strategy to preserve chemotherapy dose intensity in CIT; prospective trials are needed before routine adoption.

References