Imatinib mesylate as first‑line therapy in patients with chronic myeloid leukemia in accelerated phase and blast phase: A retrospective analysis.

INTRODUCTION: Imatinib is a bcr‑abl tyrosine kinase inhibitor which has revolutionized the treatment for chronic myeloid leukemia (CML). Even though there is much data on CML chronic phase, there is limited data on imatinib‑naïve advanced phase CML. MATERIALS AND METHODS: We retrospectively analysed 90 patients with advanced phase CML (accelerated phase [AP]: 51 and blast crisis [BC]: 39), patients who received imatinib as frontline therapy. RESULTS: The median age of presentation in CML‑AP and CML‑BC were 32 years (12‑61) and 39 years (8‑59), respectively. Imatinib at 600 mg/day was initiated within 2 weeks of diagnosis. Median time to complete hematological response in both CML‑AP and CML‑BC was 3 months (CML‑AP: 1‑9 months and CML‑BC: 1‑14 months). At 6 months 30 (59%) CML‑AP and 15 (38%) CML‑BC patients achieved major cytogenetic response (MCyR), of them 24 (47%) and 10 (25.6%) being the complete cytogenetic response, respectively. At a median follow‑up of 41 months, the median overall survival in CML‑AP was 61 months, but in CML‑BC it was 14 months. The median progression‑free survival and event‑free survival were 30 months and 23 months in CML‑AP and 14 and 12 months in CML‑BC, respectively. On univariate analysis, performance status (PS), spleen size, and MCyR predicted survival in AP, whereas in BC, platelet count, PS, and early MCyR were predictive. Non‑hematologic and hematologic adverse events were observed in 80% and 60% of patients, respectively. Dose was reduced in 10% of patients for grade IV toxicity and interrupted in 30% for grade III toxicity. CONCLUSION: Front‑line imatinib is an option in advanced phases of CML especially in CML‑AP in low‑resource countries, where stem cell transplantation and alternate TKIs are not available.