Practical issues surrounding the explosion of tyrosine kinase inhibitors for the management of chronic myeloid leukemia

The advent of tyrosine kinase inhibitors (TKIs) has drastically changed the treatment outcome of chronic myeloid leukemia (CML). Imatinib was the first TKI approved, and has been considered the standard of care for more than a decade. Second generation compounds, namely dasatinib and nilotinib, are highly effective in newly diagnosed patients as well as those who fail imatinib. Bosutinib and ponatinib have also become available as second line options. With five agents from which to choose, selecting a TKI has become a challenge. Multiple tests are now available to determine a patient's disease status, making the ideal monitoring strategy unclear. The gold standard for response to TKI therapy remains the achievement of complete cytogenetic response. This review will discuss the practical aspects of selecting a TKI and monitoring a patient once on therapy, including when to consider a treatment change. Other relevant issues, including cost, compliance, role of allogeneic hematopoietic cell transplantation, and discontinuation of TKIs will also be covered.