Immunotherapy in chronic myelogenous leukemia

Chronic myelogenous leukemia is one of the leukemic disorders more responsive to immunotherapy. Interferon-based regimens were the first treatment to produce complete cytogenetic responses, and this agent has been classified as an immunotherapeutic agent. Although most patients are now treated with imatinib as first-line therapy, a combination of interferon and imatinib could increase the rate of molecular responses and prevent patients from experiencing relapse. Thus, large phase III trials are currently exploring this strategy. Allogeneic stem cell transplantation also involves the immune system, with fewer patients in relapse in case they experience graft-versushost disease. Vaccine strategies are also promising with phase II ongoing trials. These vaccine strategies include the use of oligopeptides derived from the Bcr-Abl junction. Initial results indicate a good safety profile of these therapies in patients exhibiting complete cytogenetic response and molecular responses. These 3 different approaches of immunotherapy are described herein. Although these results obtained with imatinib are promising, this tyrosine kinase inhibitor does not eradicate leukemic stem cells. Thus, immunotherapeutic strategies are still being investigated in chronic myelogenous leukemia.