Suboptimal response in chronic myeloid leukemia patients treated with imatinib: early identification and new therapeutic challenges.

In 2006 European LeukemiaNet proposed recommendations to define several categories of chronic myeloid leukemia patients treated front-line with imatinib. In 2009 an update of these recommendations was published: whereas it is clear how important is to switch rapidly to a second line of treatment in failure patients, the correct treatment of patients with sub-optimal response is still a matter of debate. Several groups have indeed shown that prognosis of patients with sub-optimal cytogenetic response is similar to that of failure patients, whereas lack of data exists for patients with sub-optimal molecular response at 18 months. In this article, we overview studies demonstrating prognostic implications of being suboptimal responders to imatinib as well as results of recent clinical trials testing new generation tyrosine kinase inhibitors in this setting.