Changes in chronic myeloid leukemia treatment modalities and outcomes after introduction of second-generation tyrosine kinase inhibitors as first-line therapy: a multi-institutional retrospective study by the CML Cooperative Study Group

Abstract

This study investigated changes in treatment modalities and outcomes of chronic myeloid leukemia in the chronic phase (CP-CML) after the approval of second-generation tyrosine kinase inhibitors (2G-TKIs) for first-line therapy. Patients were grouped into those who underwent TKI therapy up to December 2010 (imatinib era group, n = 185) and after January 2011 (2G-TKI era group, n = 425). All patients in the imatinib era group were initially treated with imatinib, whereas patients in the 2G-TKI era group were mostly treated with dasatinib (55%) or nilotinib (36%). However, outcomes including progression-free survival, overall survival, and CML-related death (CRD) did not differ significantly between groups. When stratified by risk scores, the prognostic performance of the ELTS score was superior to that of the Sokal score. Even though both scoring systems predicted CRD in the imatinib era, only the ELTS score predicted CRD in the 2G-TKI era. Notably, the outcome of patients classified as high-risk by ELTS score was more favorable in the 2G-TKI era group than in the imatinib era group. Thus, expanding treatment options may have improved patient outcomes in CP-CML, particularly in patients classified as high-risk by ELTS score.

Keywords: Chronic myeloid leukemia; ELTS score; Sokal score; Treatment modality; Tyrosine kinase inhibitor.