P208 | UPDATED PREVALENCE OF CHRONIC MYELOID LEUKAEMIA IN LOMBARDY IN 2024: A MODEL WITH GLOBAL IMPLICATIONS

Lombardy represents the largest region in Italy by population, with a stable population of roughly 10 million inhabitants. It serves as a strong model for the rest of Italy and for many non-European and European countries of medium size, such as Sweden or Belgium. The CML subcommittee of the Lombardy Haematology Network (REL-CML) conducted a study at the beginning of 2023. Prevalence was calculated based on direct input from the 21 centres participating in REL-CML, while prescription records of Tyrosine Kinase Inhibitors (TKIs) collected from the ARIA regional registry were used to estimate the number of CML patients being followed in smaller centers not participating in REL-CML. A total of 2,285 patients were registered, representing a prevalence of 0.23‰. These data were compared to a similar census conducted in 2005, at the beginning of the TKI era, where a prevalence of 0.029‰ was calculated. This indicates that an almost 10 times increase took place during this period of time.Imatinib represents the most frequently prescribed first‐line TKI; in 2022, its use represented 75% of all first-line prescriptions. An increased concentration of CML patient care in specialized REL centers, with a decreased dispersion of patients in smaller centers, was also evident over this 18-year period. Since REL-CML centers manage over 90% of all CML patients in Lombardy, a series of logistical practices were agreed upon and shared among the 21 centers, aimed at optimizing the care of CML patients. Nineteen percent of patients discontinued treatment, highlighting persisting logistical and biological challenges. This underscores the need for more successful strategies to achieve such an important goal, as well as the necessity for safe drugs that can be used for many years. The analysis of CML prevalence trends between 2022 and 2024 will be presented, along with data on the proportion of patients who discontinued treatment, providing further insights into the evolving management of CML.