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

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.

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.

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.

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.