Search

We evaluated responses to the treatment and long-term outcomes of chronic myeloid leukemia patients treated with imatinib as first-line treatment in routine clinical setting from two countries with centralized tyrosine kinase inhibitors (TKIs) treatment. We assessed prognostic significance of European LeukemiaNet (ELN) 2006- and 2009-defined responses and the prognostic value of molecular responses at defined time points on 5-year survivals. Among the cumulative rates of incidence of hematologic, cytogenetic, and molecular responses and all important survival parameters, we evaluated the prognostic significance of different BCR-ABL transcript-level ratios (≤1%; >1%-≤10%; >10%) at 3, 6, 12, and 18 months (n = 199). The ELN optimal response criteria and their predictive role were significantly beneficial for event-free survival at all given time points. We found significant improvement in survivals of patients with BCR-ABL lower than 10% in the 6th and 12th months. Significantly better outcome was found in patients who achieved major molecular response (MMR) in the 12th month. The cumulative incidences of complete cytogenetic response (CCyR) and MMR were significantly associated with the molecular response in the 3rd month. The ELN response criteria and their predictive role were helpful at given time points; however, the 2009 definition did not significantly alter the prognostic accuracy compared with that of the 2006 definition. The significant value was observed for cytogenetic responses at the 6th and 12th month. Moreover, progression-free and event-free survivals were improved with MMR at the 12th month.

Imatinib (IM) dramatically improved the prognosis of chronic myeloid leukemia (CML), particularly with newly diagnosed patients in a chronic phase (CP) [1]. The most robust source of data about IM efficacy in this setting is the IRIS trial. However, every day clinical practice data are still scarce. We analyzed IM efficacy and safety in the first-line therapy of 152 consecutive adult CP-CML patients from a defined region. The estimated 4-year cumulative incidences of complete hematologic, complete cytogenetic, major, and complete molecular responses were 95.3%, 80.6%, 65.4%, and 39.2%, respectively. The 4-year probability of overall and progression-free survival (PFS) defined as with the IRIS [2] was 91.5% and 78.1%, respectively. We thus confirmed very good IM efficacy also in patients not participating in clinical trials. However, the estimated 4-year event-free survival (EFS), which also counted failure events according to valid recommendations [3] or IM discontinuation due to intolerance, was only 60.7%. The 4-year probability of an alternative treatment-free survival, our newly defined parameter, which better reflects the proportion of patients remaining on IM despite an event, was 67.6%. Therefore, more appropriate selection and unification of survival analyses end-points is desirable to describe and compare IM real efficacy.