[Results of imatinib therapy in late-stage chronic myeloid leukemia after treatment with interferon-alpha].
ABSTRACT Chronic myelogenous leukemia is characterised by the presence of Philadelphia translocation and consecutive expression of bcr-abl oncogene with enhanced tyrosine kinase activity, which is known to be the essential pathogenetic event in the disease. Imatinib (Glivec, formerly STI571) is a highly selective inhibitor of the bcr-abl tyrosine kinase which has shown a promising therapeutic activity in chronic myeloid leukemia as the first molecularly targeted antinoplastic treatment.
Between January 2001 and October 2001, 54 patients with chronic phase CML, resistant or intolerant to interferon-alpha were enrolled into the Novartis Expanded Access Study (Protocol 0113). Patients characteristics were as follows: male/female: 32/22, median age: 49 years (range: 22-75), median duration of disease: 44 months (range: 3-152). All patients received 400 mg imatinib orally.
Complete hematologic response was obtained in 53 patients (96%) within 4 weeks. Major cytogenetic response (< 35% Ph+ metaphasis) was achieved after 6 months in 62.9%, and after 12 months in 64.8% of patients. Three patients progressed during the treatment (loss of complete hematologic response or cytogenetic response 1, blastic phase 2). The treatment was well tolerated, with mild side effects. Main non-hematologic side effects were weight gain and fluid retention.
The results confirm that imatinib is highly active in inducing complete hematologic response and major cytogenetic response in most patients who failed interferon-alpha. Treatment was well tolerated with rare and mild adverse events and impressive improvement of quality of life.