Prognostic Factors and Clinical Outcomes in Patients with Blast Phase Chronic Myeloid Leukemia.

Background: Given the low incidence of patients with advanced chronic myeloid leukemia (CML), comprehensive clinical characteristics and outcomes of cohort studies of patients diagnosed with blast phase chronic myeloid leukemia (BP-CML) are limited. We examined the clinical features of blast phase CML, including the TKI selection, treatment response, and whether they have had hematopoietic stem cell transplantation (HSCT) or not.

Methods: We performed a retrospective cohort study, including BP-CML patients diagnosed in our center from January 2013 to December 2022. Clinical features, treatment therapy, and overall survival (OS) were investigated.

Results: Out of the 11 patients, 2 were myeloid type, eight patients were B-lymphoid, and one was T-lymphoid. Four patients suffered from chromosome abnormalities. Four patients were identified with BCR-ABL1 kinase domain mutation, including T315I, E255K, M244v, and E279K. The overall CR, CRi, PR, and MLFS rates were 9%, 54%, 27%, and 9%, respectively. The median follow-up was 21 months (9.5 - 33 months). At the end of the follow-up time, seven patients died. CML patients with lymphoids tended to get a better OS than patients with a type of myeloid, but the difference was not statistically significant (p > 0.05). Patients who received HSCT had an improved OS by two years compared to those who had not received HSCT.

Conclusions: The prognosis of BP-CML patients was poor. Given the rarity of BP-CML and the limitation of clinical trial data, large-scale multi-center prospective studies are urgently needed to confirm and improve the treatment of patients with BP-CML in the future.