Therapeutic strategies for chronic myeloid leukemia in the chronic (stable) phase

During the last four decades, the optimal first-line treatment for chronic myeloid leukemia (CML) in chronic (stable) phase has progressed from alkylating agents, to hydroxyurea (HU), and then to interferon-alfa (IFN-alpha). Treatment for younger patients with suitable donors also includes allogeneic stem cell transplantation, which offers the chance of prolonged leukemia-free survival to about 20% of all CML patients and is the only certain approach to cure. Recently, three phase II studies of imatinib mesylate (STI571), a new inhibitor specific for tyrosine kinase of the Bcr-Abl oncoprotein, have been reported. They led the Food and Drug Administration (FDA) to approve use of this agent to treat CML patients following failure of or withdrawal from IFN-alpha. The advent of imatinib also led to a reassessment of the role of allogeneic transplantation. This article reviews evidence for the safety and efficacy of imatinib and allogeneic stem cell transplantation and suggests strategic approaches to treatment in the new era of tyrosine kinase inhibition.