Azacitidine (AZA) Prolongs Overall Survival in Older Patients with Acute Myeloid Leukemia (AML) with Poor Prognostic Karyotypes Compared with Conventional Care Regimens (CCR)

Background : Karyotype is the strongest independent prognostic factor for survival in AML. The randomized phase 3 AZA-AML-001 study of older patients with AML showed AZA prolonged overall survival (OS) compared with CCR (10.4 vs 6.5 months, respectively; P =0.101) (Dombret et al, Blood, 2015). In a prospective subanalysis of the study, AZA was shown to meaningfully prolong OS by 3.2 months compared with CCR ( P =0.0185) in the subgroup of patients with NCCN-defined poor-risk cytogenetics (Dohner et al, Blood , 2014: Abstract 621). Aim : This analysis evaluates treatment effects of AZA vs CCR on OS in subgroups of patients with specific cytogenetic abnormalities as well as in patient subgroups defined by cytogenetic risk per modified European LeukemiaNet (ELN) recommendations (not considering molecular markers) (Dohner et al, Blood , 2010). Methods: Patients aged ≥65 years with newly diagnosed AML (>30% bone marrow [BM] blasts), ECOG performance status score ≤2, intermediate- or poor-risk cytogenetics per NCCN 2009 criteria, and WBC count ≤15x10 9 /L were randomized to receive AZA (75 mg/m 2 /day [d] x7d/28d) or CCR: intensive chemotherapy (cytarabine 100-200mg/m 2 IV x7d + anthracycline IV x3d induction), low-dose ara-C (20mg SC BID x10d/28d), or best supportive care only. Karyotypes obtained from BM were reviewed centrally by an independent cytogeneticist. OS was evaluated in subgroups of patients with frequent specific abnormalities, including -5/del(5q), -7, -7/del(7q), abnormal (17p) or complex karyotype (based on specific abnormalities, patients may have been evaluated in more than one category). OS was also assessed for patients in ELN-defined karyotype risk subgroups: Intermediate (Int)-I (normal karyotype), Int-II (all abnormalities not classified as Favorable or Adverse), and Adverse karyotype. OS was assessed using Kaplan-Meier methods and compared using a weighted log-rank test. Results: Centrally reviewed cytogenetic data were available for 485/488 patients (99.4%). In all, 220 patients (45.4%; AZA n=114, CCR n=106) had Int-I karyotype, 111 patients (22.9%; AZA n=53, CCR n=58) had Int-II karyotype, and 154 patients (31.8%, AZA n=73, CCR n=81) had Adverse karyotype ( Figure 1 ). OS was comparable between AZA and CCR in patients with Int-I karyotype (14.1 vs 10.1 months, respectively; hazard ratio [HR] 0.83, 95%CI 0.60, 1.1; P =0.44) and patients with Int-II karyotype (8.9 vs 9.6 months; HR 1.19, 95%CI 0.79, 1.8; P =0.78). There was a significant 2.4-month median OS difference in favor of AZA in patients with Adverse karyotype (5.3 vs 2.9 months with CCR; HR 0.71, 95%CI 0.51, 0.99; P =0.046; Figure 2 ), with 1-year survival rates of 29.1% vs 14.7% for AZA and CCR, respectively. AZA was associated with longer median OS and higher 1-year survival compared with CCR for all subgroups of patients with the specific cytogenetic abnormalities under study: -5/del(5q), -7, -7/del(7q), abnormal (17p), and complex karyotype, with HRs ranging from 0.54 to 0.69( Table ). Median OS in the CCR arm was less than 3 months for each of these subgroups. Similar to what has been reported in MDS (Ravandi et al, Cancer , 2009), AML patients with chromosome 7 abnormalities responded particularly well to AZA, with an improvement in median OS of 4.1 months over CCR. Patients with complex karyotypes also had meaningful improvements in OS, with ~15% more AZA-treated patients alive at 1 year than CCR patients. Conclusions : Prognosis is dismal for older AML patients with adverse karyotypes, and is especially poor for patients with complex karyotypes. Median OS and 1-year survival in patients with ELN-defined Adverse karyotype treated with AZA were almost double those of patients treated with CCR. AZA-treated patients with the specific cytogenetic abnormalities and/or complex karyotype in this analysis had a 31-46% reduction in risk of death vs CCR, and proportions of patients alive at 1 year were 11-22% greater with AZA. These data suggest AZA should be the preferred treatment for older patients with AML and adverse karyotypes. Disclosures Seymour: Celgene: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Genentech: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity9s Board of Directors or advisory committees. Santini: Astex: Consultancy; Amgen: Consultancy; Onconova: Consultancy; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Stone: Celator: Consultancy; Novartis: Consultancy; Abbvie: Consultancy, Membership on an entity9s Board of Directors or advisory committees; Xenetic Biosciences: Consultancy; Agios: Consultancy; Amgen: Consultancy; Celgene: Consultancy, Membership on an entity9s Board of Directors or advisory committees; Karyopharm: Consultancy; Jansen: Consultancy; Pfizer: Consultancy; ONO: Consultancy; Juno Therapeutics: Consultancy; Merck: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Sunesis Pharmaceuticals: Consultancy. Al-Ali: Celgene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Morrill: Celgene: Employment, Equity Ownership. Songer: Celgene: Employment, Equity Ownership. Weaver: Celgene Corporation: Employment, Equity Ownership. Skikne: Celgene: Employment, Equity Ownership. Beach: Celgene Corporation: Employment, Equity Ownership. Dombret: Agios: Honoraria; Ambit (Daiichi Sankyo): Honoraria; Menarini: Honoraria; Menarini: Honoraria; Servier: Honoraria; Sunesis: Honoraria; Karyopharm: Honoraria; Kite Pharma.: Honoraria, Research Funding; Astellas: Honoraria; Janssen: Honoraria; Seattle Genetics: Honoraria; Roche/Genentech: Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Ariad: Honoraria, Research Funding; Novartis: Honoraria; Celgene: Consultancy, Honoraria; Jazz Pharma: Honoraria, Research Funding.