Interferon alpha in the treatment of chronic myelogenous leukemia

Fifteen years ago Talpaz and colleagues were the first to determine that natural interferon alpha (INF-alpha) induces hematologic remission in chronic phase patients with chronic myeloid leukemia (CML). Further research revealed that this agent, contrarily to conventional chemotherapy with busulfan or hydroxyurea, eliminates leukemic hematopoietic cells having Philadelphia chromosome (Ph1-positive) in about 20% of patients, leading to the phase of cytogenetic remission. Comparison of the efficiency of IFN-alpha with conventional chemotherapy was carried out in several randomized clinical trials. It was found, that IFN-alpha delays the occurrence of blastic phase of CML and prolongs patients life span. It does not create, however, a likely chance of full recovery. The results of the randomized trails, carried out in France, showed that the combination of IFN-alpha and cytarabine as compared with INF-alpha alone, increases the rate of major cytogenetic response and prolongs survival in the chronic phase of CML. IFN-alpha efficiency in acceleration and blastic transformation phases of CML has not been proven so far, although this drug may be of certain value in combination with hydroxyurea or other cytostatic agents. At present, it is more often considered that IFN-alpha should be a first line therapy in newly diagnosed CML in its chronic phase, if due to absence of appropriate donors or advanced age, allogenic bone marrow transplantation cannot be performed.