Recent progress in the management of pediatric chronic myeloid leukemia

Biological Markers of Myeloproliferative Neoplasms in Children, Adolescents and Young Adults

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic cancers characterized by hyperproliferation of the myeloid lineages. These clonal marrow disorders are extremely rare in pediatric patients. MPN is reported to occur 100 times more frequently in adults, and thus research is primarily focused on this patient group. At present, modern diagnostic techniques, primarily genetic, facilitate the identification of the biology of these diseases. The key genes are JAK2, MPL, and CALR, namely, driver mutations, which are present in approximately 90% of patients with suspected MPN. Moreover, there are more than 20 other mutations that affect the development of these hematological malignancies, as evidenced by a review of the literature. The pathogenic mechanism of MPNs is characterized by the dysregulation of the JAK/STAT signaling pathway (JAK2, MPL, CALR), DNA methylation (TET2, DNMT3A, IDH1/2), chromatin structure (ASXL1, EZH2), and splicing (SF3B1, U2AF2, SRSF2). Although rare, myeloproliferative neoplasms can involve young patients and pose unique challenges for clinicians in diagnosis and therapy. The paper aims to review the biological markers of MPNs in pediatric populations-a particular group of patients that has been poorly studied due to the low frequency of MPN diagnosis.

Bosutinib: Pediatric First Approval

Bosutinib (BOSULIF®), an orally administered BCR-ABL tyrosine kinase inhibitor (TKI) developed by Pfizer Inc., is well established in the EU and the USA as a treatment for adults with newly diagnosed (ND) chronic phase (CP) Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), and for CP, accelerated phase and blast phase Ph+ CML that is resistant or intolerant (R/I) to prior therapy. In September 2023, based on clinical data from patients aged ≥ 1 to < 18 years, bosutinib was approved in the USA for the treatment of pediatric patients aged ≥ 1 year with CP Ph+ CML that is ND or R/I to prior therapy. This article summarizes the milestones in the development of bosutinib leading to this first pediatric approval.