Allogeneic transplantation for CML in the TKI era: striking the right balance

The management of chronic myeloid leukaemia (CML) has changed extensively over the past 15 years. Prior to the development of targeted therapies and in the absence of allogeneic haematopoetic stem-cell transplantation (HSCT), the median survival was 5-7 years. HSCT was quickly established as the standard of care for eligible patients through the 1980s and 1990s, when considerable advances were made in the optimization of conditioning regimens and supportive care. Exploiting a deeper understanding of the molecular basis of CML, the development of tyrosine kinase inhibitors (TKIs) in the late 1990s revolutionized the management of the disease. TKIs offer the prospect of long-term disease control with a simple oral therapy, and are the first-line treatment in the 21(st) century. The majority of patients treated with TKIs achieve excellent responses with sustained treatment, and some even continue to have undetectable or exceptionally low level disease upon TKI withdrawal; however, for an almost equal number of patients, an adequate response cannot be achieved with any of the currently available TKIs. For those patients who fail to respond adequately to TKIs, HSCT offers the best prospect of long-term survival.