Clinical outcomes of allogeneic cell transplantation for patients with chronic myeloid leukemia

Area of Science:

• Hematology
• Oncology
• Stem Cell Transplantation

Background:

• Allogeneic hematopoietic cell transplantation (allo-HCT) is a critical therapy for advanced chronic myeloid leukemia (CML).
• Patients with CML in blast phase (CML-BP) or tyrosine kinase inhibitor (TKI)-resistant CML-CP often require intensive treatment options.
• Allo-HCT offers a potential curative approach for these challenging CML subtypes.

Purpose of the Study:

• To evaluate the efficacy and outcomes of allo-HCT in patients with CML-BP and TKI-resistant CML-CP.
• To identify factors influencing survival and relapse rates post-allo-HCT in these CML populations.
• To assess the impact of disease biology and cytogenetic abnormalities on allo-HCT outcomes.

Main Methods:

• Retrospective analysis of 75 patients undergoing allo-HCT across four U.S. centers (2005-2023).
• Categorization of patients into CML-BP (myeloid or lymphoid) and TKI-resistant CML-CP groups.
• Comparison of overall survival (OS) and leukemia-free survival (LFS) based on disease characteristics and cytogenetics.

Main Results:

• Median OS was 50 months for myeloid blast phase (MBP), while not reached for lymphoid blast phase (LBP) and TKI-resistant CML-CP.
• MBP exhibited higher relapse rates and inferior LFS compared to LBP and TKI-resistant CML-CP.
• Transformed MBP, de novo MBP, and presence of 7/7q- deletions were associated with worse outcomes. Post-transplant TKI maintenance showed no significant impact.

Conclusions:

• Allo-HCT is a viable treatment for CML-BP and TKI-resistant CML-CP.
• Disease biology, specifically MBP, and cytogenetic features significantly impact allo-HCT outcomes.
• Further research may refine patient selection and post-transplant strategies for improved CML management.