Second-Generation BCR-ABL Kinase Inhibitors in CML

Abstract

To the Editor: For patients with newly diagnosed chronic myeloid leukemia (CML) in the chronic phase, a complete cytogenetic response at 12 months is widely accepted as an optimal response.1 This response was used as a primary end point in the trial of dasatinib versus imatinib by Kantarjian et al. (June 17 issue).2 Although a major molecular response at 18 months is also considered an optimal response,1 Saglio et al.,3 in the same issue of the Journal, reduced the time to 12 months. We would be grateful if the authors could explain whether a major molecular response at 12 months is a valid surrogate in trials of first-line treatments for CML in the chronic phase and how we should evaluate the treatment response when a patient does not reach this goal in daily clinical practice.