Prognostic Value of Clonal Evolution at the Time of Diagnosis in Patients with Chronic Myeloid Leukemia Treated with Frontline Tyrosine Kinase Inhibitors

Abstract Introduction: Additional cytogenetic clonal evolution (CE) is a known risk factor for a poor prognosis in chronic myeloid leukemia (CML). However, its prognostic significance in the setting of new tyrosine kinase inhibitor (TKI) remains unclear. We sought to analyze the baseline characteristics and clinical outcome in chronic phase (CP) CML pts with or without CE treated on frontline TKI clinical trials in a single institution. Methods: Patients (pts) with Ph-positive CML in CP with or without CE at the time of diagnosis receiving initial therapy with imatinib 400 mg/d, imatinib 800 mg/d, dasatinib 100 mg/d, nilotinib 800 mg/d or ponatinib 30 or 45 mg/d in consecutive or parallel clinical trials at a single institution were analyzed. Overall survival (OS), transformation free survival (TFS), event free survival (EFS), failure free survival (FFS) were analyzed from the start of therapy by Kaplan-Meier method. Clonal evolution (CE) was defined by the presence of any cytogenetic abnormality other than a single Ph, variant Ph chromosome or loss of Y chromosome. Also we analyzed CML pts with CE with regard 'major route' abnormalities vs other. The major route abnormalities includes trisomy 8 (+8), trisomy 19 (+19), isochromosome 17q10 (i17q) and additional Ph chromosome. Results: A total of 603 pts were analyzed including 579 pts in CP without CE and 24 pts with CE. Pts in CP without CE received initial therapy with imatinib-400 (n=70), imatinib-800 (n=200), dasatinib (n=138), nilotinib (n=122), or ponatinib (n=49), and pts with CE received imatinib-400 (n=2), imatinib-800 (n=7), dasatinib (n=10), nilotinib (n=4), and ponatinib (n=1). Pts with CP were usually older, female and have a higher WBC (P Conclusion: Additional cytogenetic CE at the time of diagnosis among patients with CML in CP is associated with a similar favorable outcome as those without CE when treated with TKI. The type of additional CE (major route vs other) does not seem to impact outcome. Patients with CML-CP with CE at the time of diagnosis can thus be treated with TKI as all other pts with CP with no need for consideration for SCT unless there is clear evidence of failure. Disclosures Jabbour: ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy. Ravandi: BMS: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding. DiNardo: Abbvie: Research Funding; Agios: Other: advisory board, Research Funding; Daiichi Sankyo: Other: advisory board, Research Funding; Novartis: Other: advisory board, Research Funding; Celgene: Research Funding. Daver: Ariad: Research Funding; Sunesis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Karyopharm: Honoraria, Research Funding; BMS: Research Funding; Kiromic: Research Funding; Otsuka: Consultancy, Honoraria. Cortes: ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding.