Imatinib mesylate experience of young patients with chronic myeloid leukemia in chronic phase—Care to cure

Abstract

7072 Background: Chronic myeloid leukemia (CML) with introduction of imatinib has been transformed into a chronic illness. The options of treatment in a patient less than 35 years include imatinib or allogenic stem cell transplantation. Hence we studied this unique subset to look at the response rates, adverse effects, progression free survival, and overall survival with imatinib mesylate. Methods: 477 patients with Philadelphia positive CML in chronic phase were retrospectively analyzed from January 2002 to December 2007 at Cancer Institute (WIA), Chennai, India. Standard criteria were used for response evaluation and adverse effects. Results: A total of 248 young CML patients with age less than 35 years (51.9%) were diagnosed in chronic phase. The median age of study population was 27 years (4–35). The male to female ratio was 1.9: 1. Risk stratification was done using Sokal index and were classified into low (32.3%), intermediate (50.4%), and high (17.3%). All patients received imatinib 400 mg as the initial dose. Complete hematological remission (CHR) was seen in 96.7%.Cytogenetic (FISH) and molecular (RTPCR) monitoring was possible in 53.2% and 17.3%, respectively. 72% of the patients had major cytogenetic response. Major molecular response was seen in 34.8% while complete molecular response occurred in 23.2% of the patients. Primary and secondary imatinib failure was seen in 3.1% and 16.9%, respectively. 6.7% had grade 3 and grade 4 hematological toxicities. The other common non hematological toxicities included pedal edema (13.7%), hypo or hyper pigmentation (60.0%), hyalgia (14.5%), diarrhea (1.6%), and liver dysfunction (1.6%). None of the patients discontinued imatinib due to toxicities. The 3-year DFS and OS was 86.2% and 89.5%, respectively. Patients with male sex (p = 0.04), spleen > 8 cm (p = 0.02), high sokal index (p = 0.02), and loss of CHR (p < 0.001) were associated with poor outcome. Conclusions: Imatinib in young patients have an excellent tolerance and response. A small subset does not respond to therapy or develop resistance during treatment. Hence it is essential to identify these poor responders and to offer stem cell transplantation at the earliest. No significant financial relationships to disclose.