Khoảng 60% bệnh nhân được điều trị bằng imatinib 400 mg trong ngày sau khi thất bại điều trị interferon-alpha sẽ đạt được một phản ứng di truyền tế bào lớn. Điều này là hoàn toàn trong 41% (Kantarjian et al 2002). CCyR đạt được trong 75% những người được điều trị với imatinib như firstline điều trị (O'Brien et al 2003). | Clinical Features of CML 65 serve as a benchmark for the assessment of the longterm effectiveness of imatinib. Imatinib is now first-line therapy for CML except for those few who proceed directly to allograft. Around 60 of patients treated with imatinib 400 mg in CP after failing interferon-alpha therapy will achieve a major cytogenetic response. This is complete in 41 Kantarjian et al. 2002 a . CCyR is reached in 75 of those treated with imatinib as first-line therapy O Brien et al. 2003 . This study the IRIS study is the only study that has at least some details of the Sokal risk score for the patients entered. The IRIS study did not initially show a significant difference in progression-free survival among the different Sokal risk-group categories O Brien et al. 2003 . However with further follow-up the Sokal classification was shown to differentiate three groups with distinct progression-free survival probabilities Cervantes et al. 2003 . A further update of these results at 54 months of follow-up was presented at ASH 2005 Simonsson et al. 2005 . They confirm the prognostic significance of Sokal Risk Group Fig. . However in addition they show that if high-risk patients do achieve CCyR on im-atinib their survival to date seems as good as other patients achieving CCyR Simonsson et al. 2005 . Details of Hasford scores are not available for the IRIS study. Hence these traditional prognostic models need to be re-examined and possibly revised in this new era of treatment for CML. The major prognostic indicator now appears to be the depth and quality of cytogenetic and molecular responses to imatinib. There is good evidence from the IRIS Trial O Brien et al. 2003 and indeed from the earlier studies in interferon-resistant and interferon-intol erant patients Kantarjian et al. 2002 a b Marin et al. 2003 that the achievement of a major or complete cytogenetic response is associated with improved prognosis. If CCyR is achieved at 12 months a 3 log reduction in .
