Blast phase (BP) of chronic myeloid leukemia (CML) still represents an unmet clinical need with a dismal prognosis. Due to the rarity of the condition and the heterogeneity of the biology and clinical presentation, prospective trials and concise treatment recommendations are lacking. Here we present the analysis of the European LeukemiaNet Blast Phase Registry, an international collection of the clinical presentation, treatment and outcome of blast phases which had been diagnosed in CML patients after 2015. Data reveal the expected heterogeneity of the entity, lacking a clear treatment standard. Outcomes remain dismal, with a median overall survival of 23.8 months (median follow up 27.8 months). Allogeneic stem cell transplantation (alloSCT) increases the rate of deep molecular responses. De novo BP and BP evolving from a previous CML do show slightly different features, suggesting a different biology between the two entities. Data show that outside clinical trials and in a real-world setting treatment of blast phase is individualized according to disease- and patient-related characteristics, with the aim of blast clearance prior to allogeneic stem cell transplantation. AlloSCT should be offered to all patients eligible for this procedure.

• MeSH
• Blast Crisis * pathology   MeSH
• Leukemia, Myelogenous, Chronic, BCR-ABL Positive * drug therapy   pathology   therapy   mortality   MeSH
• Adult MeSH
• Transplantation, Homologous MeSH
• Tyrosine Kinase Inhibitors * therapeutic use   MeSH
• Middle Aged MeSH
• Humans MeSH
• Disease Management MeSH
• Survival Rate MeSH
• Adolescent MeSH
• Young Adult MeSH
• Follow-Up Studies MeSH
• Prognosis MeSH
• Registries * MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Hematopoietic Stem Cell Transplantation methods   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Europe MeSH
• Names of Substances
• Tyrosine Kinase Inhibitors * MeSH

Treatment of chronic myeloid leukemia has improved significantly with the introduction of tyrosine kinase inhibitors (TKIs), and treatment guidelines based on numerous clinical trials are available for chronic phase disease. However for CML in the blast phase (CML-BP), prognosis remains poor and treatment options are much more limited. The spectrum of treatment strategies for children and adolescents with CML-BP has largely evolved empirically and includes treatment principles derived from adult CML-BP and pediatric acute leukemia. Given this heterogeneity of treatment approaches, we formed an international panel of pediatric CML experts to develop recommendations for consistent therapy in children and adolescents with this high-risk disease based on the current literature and national standards. Recommendations include detailed information on initial diagnosis and treatment monitoring, differentiation from Philadelphia-positive acute leukemia, subtype-specific selection of induction therapy, and combination with tyrosine kinase inhibitors. Given that allogeneic hematopoietic stem cell transplantation currently remains the primary curative intervention for CML-BP, we also provide recommendations for the timing of transplantation, donor and graft selection, selection of a conditioning regimen and prophylaxis for graft-versus-host disease, post-transplant TKI therapy, and management of molecular relapse. Management according to the treatment recommendations presented here is intended to provide the basis for the design of future prospective clinical trials to improve outcomes for this challenging disease.

• MeSH
• Leukemia, Myeloid, Acute * MeSH
• Blast Crisis therapy   MeSH
• Leukemia, Myelogenous, Chronic, BCR-ABL Positive * drug therapy   diagnosis   MeSH
• Child MeSH
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Graft vs Host Disease * MeSH
• Prognosis MeSH
• Hematopoietic Stem Cell Transplantation * MeSH
• Check Tag
• Child MeSH
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Publication type
• Journal Article MeSH
• Review MeSH