Thrombopoietin receptor agonists for thrombocytopenia in pediatric
hematologic malignancies
Abstract
Background: Thrombopoietin receptor agonists (TPO-RAs) have
demonstrated efficacy in treating clinically significant
thrombocytopenia, including chemotherapy-induced thrombocytopenia (CIT)
in adults. However, data regarding their safety and efficacy in
pediatric, adolescents, and young adult (AYA) patients with hematologic
malignancies are limited. Methods: We retrospectively
identified 15 pediatric and AYA patients aged 25 years or younger with
hematologic malignancies treated with a TPO-RA at UCSF Benioff
Children’s Hospitals between 2015 and 2023. Platelet counts and
transfusion requirements were compared before and after TPO-RA therapy.
Results: The median age at TPO-RA initiation was 16 years
(range: 7-25 years). Nine patients (60%) had a history of bleeding or
comorbidity that predisposed to severe bleeding risk. Eleven patients
received romiplostim and four patients received eltrombopag. The median
platelet count significantly increased from 24 x 10
9/L at baseline to 54 x 10 9/L after
3 weeks of any TPO-RA therapy (p =0.029). Monthly platelet transfusion
requirements significantly decreased from a median of 15 to two units
after TPO-RA therapy (p=0.007). Fourteen of the 15 patients (93%)
achieved a sustained platelet count >50,000/µL within eight
weeks, with a median time to response of 3 weeks. No TPO-RA-related
adverse events were observed. Conclusion: TPO-RAs were
effective in managing refractory thrombocytopenia in pediatric and young
adult patients being treated for hematologic malignancies, with a
favorable safety profile, even among patients with multiple
comorbidities. These findings warrant further investigation through
prospective clinical trials to confirm efficacy and establish clinical
guidelines for this population.