Multicenter Experience with Imatinib Mesylate in Newly Diagnosed Chronic Myeloid Leukemia (CML) Patients.

Imatinib mesylate (IM) is a powerful and selective p210 Bcr-Abl tyrosine kinase inhibitor that has been demonstrated to be effective for the treatment of CML. An Italian multicenter study was performed to investigate the safety, efficacy, tolerance and compliance of IM in newly diagnosed CML patients. From February 2000 through February 2007, we collected 339 CML patients in different phases of disease and previously treated with Interferon-alpha and/or other therapies. One hundred fifty-two untreated Ph⁺ CML patients received Imatinib at diagnosis at a dose of 400 mg orally per day; 88 were male and 64 female with a median age of 50 (range, 17–80) years. Complete hematological remission was achieved in 94% of patients. The estimated rate of complete cytogenetic remission (CCR) was 69% after 12 months; with a median follow up of 38 months the rate of CCR raised to 86,8%. Levels of Bcr-Abl transcripts had fallen by at least 3 log in 59% of cytogenetic remitters patients at 12 months; after a median follow up of 38 months, 26% of these patients achieved complete molecular remission (CMR). The most commonly reported adverse events after IM were edema (including peripheral and periorbital edema) (50%), muscle cramps (37,7%), diarrhea (40,7%), fatigue (38,8%); moreover in 8 (5,2%) patients grade 3–4 events were observed consisting of pancitopenia and/or elevated liver enzymes. Eight (5,2%) patients died: 2 patients for progressive disease after allografting, 2 patients of cardiac infarction, 1 patient of severe necrotic fascitis, 1 patient of metastatic colon cancer and 2 patients of blastic crisis. In summary, at 84 months 144/152 (94,7%) patients are alive and 125 (86,8%) of them are still receiving IM. Nineteen (13%) patients discontinued Imatinib: 7 patients for adverse events grade 3–4 and 12 patients for progressive disease. These data are comparable to those of IRIS study and confirm the safety and efficacy of IM in newly diagnosed patients.