Outcome of patients of CML in AP and BC with imatinib: A retrospective analysis of patients from India

Abstract

17531 Background: Imatinib is a very active agent in advanced phase CML. The present study assesses the impact of Imatinib therapy on the outcome of Indian patients with CML in Accelerated Phase (AP) and Blast Crisis (BC). Methods: Patients of CML in AP or BC who were treated with Imatinib based therapy between 2001 and 2006 were analyzed retrospectively. Results: A total of 65 patients who received Imatinib based treatment for CML in AP or BC were analyzed. Thirty eight (58.46 %) patients diagnosed in chronic phase (CP) were initiated on Imatinib based treatment at time of progression to AP or BC. The remaining 27 (41.53 %) patients had AP or BC of CML at initial diagnosis. At the time of start of Imatinib treatment 36 (55.38 %) patients had AP and 29 (44.61 %) were in BC. Imatinib as a single agent was used in 41 (63.07 %) patients (27 in AP and 14 in BC) and in combination with oral 6-MP and Etoposide was used in 24 (36.92 %) patients (14 in AP and 10 in BC). Hematological response (HR) was seen in 64.61% (42 out of 65) patients, complete HR in 32 (49.23 %) and partial HR in 10 (15.38 %). Cytogenetic response (CR) was noted in 21 (32.31%) patients (Complete -10, Partial -9, and Minor - 2). Twenty eight (43.07%) patients remained progression free (HR+CR in 16 and only HR in 12 patients) till the last date of follow up (median duration of follow-up was 17 months).For the whole group (n=65) the overall survival from the diagnosis of AP or BC after commencing Imatinib treatment was 65.3%, 51.6% and 34.4% at 1, 2 and 3 years respectively. The median survival was 25 months. The median survival and OS at 1 year, as expected, was significantly better for patients in AP (36 months, 77.4 %) as compared to those in BC (11 months, 48.2%)(p=0.004) and both were much longer than previously reported with non-Imatinib therapy. Outcome in patients with AP or BC was not significantly improved by addition of 6-MP and Etoposide. Temporary discontinuation of Imatinb for grade III/IV toxicity was done in 27 (41.53 %) patients for a median duration of 28 days. Conclusions: Imatinib has improved the outcome of patients with advanced phase CML. Our data also documents this in patients from India. However, Imatinib needs to be studied with newer combinations to achieve long term disease control in patients with CML, particularly those in BC. No significant financial relationships to disclose.