Imatinib treatment in chronic myelogenous leukemia: What have we learned so far?

Imatinib mesylate is currently the standard therapy for chronic myelogenous leukemia patients. Despite the remarkable results achieved with imatinib, the emergence of resistance to this drug has become a significant problem. Actually, two other second-generation tyrosine kinase inhibitors have been used for resistant/intolerant patients to imatinib. With the availability of oral tyrosine kinase inhibitors for the treatment of chronic myelogenous leukemia, questions relating to adherence to prescribed therapy have become an important issue. It has been demonstrated that the effectiveness of the treatment with imatinib requires high compliance to the prescribed dose of the drug for an indefinite period of time, whereas reduced adherence to therapy has been associated with delay in achieving cytogenetic or molecular response and/or possible development of resistance. The aim of this review is to discuss the importance of adherence, and the possible tools that we have to measure it, to improve our knowledge on possible underlying causes of non-adherence and the impact of non-adherence on hospitalization risk and healthcare cost through a systematic review of the data published to date.