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 109/L
at baseline to 54 x 109/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.
Short running title: “TPO-RAs for pediatric hematologic
malignancies”
Key words: Thrombopoietin receptor agonist, romiplostim,
eltrombopag, pediatric, adolescent, and young adults, leukemia,
hematologic malignancies