Despite significant progress being made in the management of chronic myeloid leukemia (CML) which has allowed many to live normal lifespans, mortality remains high in patients with accelerated phase (CML-AP) or blast phase (CML-BP), according a review published in the SOHO 2019 Meeting Proceedings Supplement in Clinical Lymphoma, Myeloma and Leukemia.
Patients with accelerated CML-AP or CML-BP may be initially treated with tyrosine kinase inhibitors (TKIs) to reduce the CML burden and be considered viable candidates for early allogeneic stem cell transplantation (allo-SCT). Research shows that response rates with combinations of TKIs and chemotherapy are 40% in nonlymphoid CML-BP and 70-80% in lymphoid CML-BP. Median survival times are 6 to 12 months, and 12 to 24 months, respectively. Adding TKIs to chemotherapy has enhanced the response rates and prolonged the median survival time in patients with CML-BP.
Recently, researchers assessed the outcomes of 477 patients with CML-BP who were treated with a TKI during their CML. The results showed that the median survival was 12 months with a median failure-free survival of five months. They observed that the use of TKI in conjunction with intensive chemotherapy followed by stem cell transplantation yields the best outcome.
The review noted that currently, allo-SCT stands as the only curative therapy for CML-AP and CML-BP with an average cure rate in the range of 15 to 40% and 10 to 20%, respectively, with cytogenetic clonal evolution representing the only accelerated phase criterion to exhibit a long-term event-free survival rate (approximately 60%). Otherwise, TKIs induce hematologic responses in 80% of patients and an estimated 4-year survival rates of 40 to 55% in CML-AP patients, but only a 40% response rate and a median survival of 9 to 12 months in CML-BP.
“Patients in the AP or BP should be encouraged to participate in investigational strategies to improve their prognosis,” the author wrote.