2026 Eastern States Conference

Authors
Katherine Gordon, PharmD, Aubrie Mason, PharmD, BCPPS, Timothy Olson, MD, PhD, Hope DiTaranto, PharmD, Christopher Phillips, PharmD
Learning Objective
At the conclusion of this presentation participants will be able to describe romiplostim dosing patterns and clinical response in pediatric hematopoietic stem cell transplant patients with treatment-related thrombocytopenia.
Background/Objective
The objective of this study is to describe romiplostim dosing in pediatric hematopoietic stem cell transplant patients and characterize response, including time to platelet recovery, treatment failure, and adverse outcomes.
Methods
This descriptive retrospective cohort study included patients aged >1 year and <25 years who received romiplostim for post-hematopoietic stem cell transplant (HSCT) treatment-related thrombocytopenia while inpatient between May 31, 2018 and May 31, 2025. Data collected included demographics, romiplostim dosing, platelet counts, transfusions, safety events, and treatment failure. Outcomes were assessed from romiplostim initiation to discontinuation, with safety and treatment failure monitored for up to one year afterward. The primary endpoint of this study was the romiplostim dose required to achieve platelet response. Secondary endpoints included time to response, treatment failure, and safety outcomes. Descriptive statistics were used, and the primary endpoint was summarized as a distribution stratified by HSCT type.
Results
Eleven patients received romiplostim for post-HSCT treatment-related thrombocytopenia. Seven patients (63.6%) achieved response. Among responders, median starting dose was 3 (IQR 1.1 – 4) mcg/kg weekly, with median dose of 8 (IQR 4.5 – 10) mcg/kg weekly and median escalation of 0.5 (IQR 0.4 – 0.9) mcg/kg/week. Median time to response was 6 (IQR 5.6 – 6.5) weeks. Median platelet count increased from 19 (IQR 18.5 – 27) to 69.6 (IQR 57 – 99.4). One patient experienced a safety event of thrombocytosis.
Conclusion
Patients who responded to romiplostim post-HSCT required higher doses to achieve response compared to FDA approved indications. The dosing strategy generally represented a gradual increase in dose followed by discontinuation after observed clinical response. Despite higher dosing, treatment was well tolerated, supporting its potential role as a safe and effective option in this population.
Self Assessment Questions
True/False: In a single retrospective cohort study, post-HSCT patients required a higher romiplostim doses to achieve response and had a higher rate of adverse effects as compared to other indications.