Chronic myeloid leukaemia represents a model disease where the identifi cation of driving molecular mechanisms and their targeted therapy has led to dramatic improvement in treatment outcomes. Nevertheless, a small proportion of patients still experience therapy failure followed by disease progression into a blast phase with poor outcomes even on intensive therapy.
This review focuses on the current state of knowledge regarding the pathobio logy of the blast phase and its fundamental characteristics, including blockade of cell diff erentiation, genetic instability, the occurrence of chromosomal aberrations and somatic mutations, and their impact on disease prognosis. The article also provides a brief overview of the current treatment options for the blast phase, its challenges, and possible perspectives.