Acute Leukemia French Association Research Articles

Minimal Residual Disease Assessed by WT1 Expression and NPM1 Mutations Specific RQ-PCR Assays Identifies Patients with Distinct Outcomes in the ALFA 0701 Trial and Is Decreased by Treatment with Gemtuzumab Ozogamicin

AbstractAbstract ▪659▪This icon denotes a clinically relevant abstract Background:NPM1 mutations and WT1 expression are frequently identified in acute myeloid leukemia (AML). Both markers have been reported as suitable molecular target for minimal residual disease (MRD) monitoring. Recently, Gemtuzumab Ozogamicin (GO) has been shown to improve event free survival and overall survival in adult AML. Aims:To follow MRD in AML patients with NPM1 mutations (NPM1mut) and/or WT1 expression (WT1+) and treated in the randomized ALFA 0701 GO trial conducted by the Acute Leukemia French Association (Castaigne et al, Lancet 2012), in order to validate their prognostic significance and to evaluate the effect of GO on MRD response. Methods:The ALFA 0701 trial included 278 patients aged 50–70 years with newly-diagnosed de novo AML, randomized to receive or not five doses of 3 mg/m2 GO, on day 1, 4 and 7 of standard induction chemotherapy and on day 1 of two consolidation chemotherapy courses, respectively. A total of 77 NPM1mut (35 in control arm, 42 in GO arm) and 178 WT1+ (87 in control arm, 91 in GO arm) AML patients were studied. WT1 + at diagnosis was defined as a ratio WT1/ABL transcript above 25% in bone marrow (BM) or 5% in peripheral blood (PB) samples. PB and BM samples were collected at diagnosis, after induction and after each consolidation course. MRD levels were assessed using cDNA-based real-time quantitative PCR (RQ-PCR) and reported as the ratio NPM1mut or WT1 transcript/100 ABL transcript. Occurrence of a MRD level below the threshold (NPM1mut <0.1% and WT1 transcript < 0.5% in PB) was defined here as a good MRD response. The prognostic value of MRD was assessed by comparing the outcome of good versus poor MRD responders after induction in terms of cumulative incidence of relapse (CIR) at 18 months. Effect of GO was then evaluated by comparing MRD response in both treatment arms. Results:178 patients (favorable cytogenetics: 4%, intermediate: 69%, unfavorable: 27%) were WT1+. WT1 transcript levels at diagnosis had no prognostic impact on complete remission (CR) rate or CIR. In the 104 patients who achieved CR, post-induction WT1 MRD level was predictive of relapse: 18-month CIR was 70% (95%CI: [49% - 84%]) in poor responders (n=31) versus 38% [26% - 50%] in good responders (n=73) (p=0.0001). When adjusted on cytogenetics, randomization arm and FLT3-ITD status, WT1 MRD remained independently associated with relapse (HR: 2.43, [1.25 – 4.75], p=0.009).Similarly, NPM1mut transcript levels at diagnosis had no prognostic impact on CR rate or CIR. Among the 67 NPM1mut patients who achieved CR, post-induction NPM1mut MRD level was predictive of relapse: 18-month CIR was 64% [45% – 70%] in poor responders (n=50) versus 25% [10% – 42%] in good responders (n=17) (p=0.0007). When adjusted on randomization arm and FLT3-ITD status, NPM1 MRD remained independently associated with relapse (HR: 4.2, [1.2 – 14.3], p=0.02).We were able to evaluate both MRD markers in 53 patients after induction (NPM1+/WT1+ n=16, NPM1+/WT1- n=24, NPM1-/WT1- n= 13). 18-month CIR was significantly different in the 3 groups (respectively 69% [38% - 87%], 40% [19% - 60%] and 25% [5% - 51%], p=0.008). In patients with poor MRD response assessed by NPM1mut, the presence of a positive WT1 MRD level was associated with a higher CIR.NPM1 MRD good response was more frequently observed in GO arm as compared to control arm (OR: 4.38 [2.12 – 9.03], p<0.0001). The rate of good NPM1 MRD response was 41% versus 7% after induction, 76% versus 35% and 93% versus 62% after first and second consolidation in GO and control arms respectively. WT1 MRD good response was more frequently observed in GO arm, although not reaching statistical significance (OR: 1.84 [0.89 – 3.77] p=0.098). The rate of good WT1 MRD response was 76% versus 65% after induction, 87% versus 66% and 87% versus 80% after first and second consolidation, respectively in GO and in control arms (figure 1). Conclusion:Our study confirms the predictive value of MRD based on NPM1 mutations and WT1 expression in patients treated in the ALFA 0701 randomized trial. In multivariate analysis, WT1 and NPM1 MRD levels remained independent prognostic factors for relapse. We showed that treatment with GO significantly improved MRD response in adult AML. [Display omitted] Disclosures:Castaigne:Wyeth: Consultancy.

Reprise: Gemtuzumab Ozogamicin for Older Patients With Acute Myeloid Leukemia

Reprise: Gemtuzumab Ozogamicin for Older Patients With Acute Myeloid Leukemia

Infectious complications in adult acute myeloid leukemia: analysis of the Acute Leukemia French Association-9802 prospective multicenter clinical trial

Infections are a major complication in patients with acute myeloid leukemia undergoing intensive chemotherapy. They remain a major cause of therapy-associated morbidity and mortality, and represent a frequent cause of treatment withdrawal. An analysis of the medical charts of 459 younger adults included in the multicenter Acute Leukemia French Association (ALFA)-9802 trial showed that 1369 febrile episodes occurred among the 459 registered patients, including fever without identifiable source (23%) and clinically or microbiologically documented infections (77%). Bloodstream infections occurred in 314 episodes, including 129 documented episodes with Gram-positive and 96 with Gram-negative pathogens. Pulmonary infection was diagnosed in 144/1054 documented infectious episodes (14%). Invasive fungal infection was probable or proven in 116 patients. In all, 15 patients died of infection-associated complications, of whom seven died during early induction therapy, one during salvage therapy and seven during consolidation therapy. Better supportive care strategies may improve overall survival in patients undergoing chemotherapy for acute myeloid leukemia.

Prognostic significance of DNA methyltransferase 3A mutations in cytogenetically normal acute myeloid leukemia: a study by the Acute Leukemia French Association

Recently, DNA methyltransferase 3A (DNMT3A) mutations have been identified in acute myeloid leukemia (AML), the highest frequency being found within cytogenetically normal (CN) AML. In this study, diagnostic samples from 123 adults younger than 60 years with primary CN-AML homogeneously treated in the Acute Leukemia French Association-9801 and -9802 trials were screened for mutations in DNMT3A-conserved domains by direct sequencing. Patients were also assessed for the presence of FLT3 (fms-like tyrosine kinase receptor-3), NPM1 (nucleophosmin), CEBPA, WT1 (Wilms tumor 1), IDH1 (isocitrate dehydrogenase 1) and IDH2 mutations. Thirty-eight mutations were detected in 36 patients (29%): 36 nucleotide substitutions, mostly affecting amino-acid residue R882 and two frameshift deletions. DNMT3A mutations were significantly associated with the French-American-British subtypes M4/M5 and the presence of NPM1 mutations. In the whole cohort, DNMT3A mutated patients had a shorter event-free survival (5-year EFS: 13% vs 32%, P = 0.02) and overall survival (5-year OS: 23% vs 45%, P = 0.02) compared with DNMT3A wild-type patients. In multivariate analysis including age, white blood cell count, NPM1/FLT3-internal tandem duplication/CEBPA risk group and DNMT3A mutational status, the presence of a DNMT3A mutation remained an independent adverse prognostic factor for EFS and OS, suggesting that testing for DNMT3A mutations could help further improve risk stratification in CN-AML.

Minimal residual disease monitoring based on FLT3 internal tandem duplication in adult acute myeloid leukemia

FLT3 internal tandem duplication (FLT3-ITD) is usually considered as a bad marker for minimal residual disease (MRD) follow-up in acute myeloid leukemia (AML). Our objective was to evaluate the suitability of FLT3-ITD as a target for MRD detection by real-time quantitative PCR, in comparison with two other molecular MRD markers, NPM1 mutation and WT1 overexpression, in 20 adult AML patients treated in Acute Leukemia French Association (ALFA) trials. Overall, these 3 MRD markers showed comparable kinetics in 17/20 (85%) cases. Furthermore, we found that FLT3-ITD MRD levels after induction chemotherapy are predictive of complete remission duration.

Prognostic Significance of DNA Methyltransferase 3A Mutations in Cytogenetically Normal Acute Myeloid Leukemia: A Study by the Acute Leukemia French Association

Abstract 2506 Introduction:The development of massively parallel sequencing technologies has led to the identification of somatic DNA methyltransferase 3A (DNMT3A) gene mutations in acute myeloid leukemia (AML), with the highest frequency being found in cytogenetically normal (CN) AML. DNMT3A mutations have been suggested to predict poor clinical outcome in AML, but only few data are available on their prognostic significance within CN-AML. The aim of this study was to determine the frequency, the main associated features, and the prognostic significance of DNMT3A mutations in CN-AML. Patients and methods:This retrospective study was performed in 123 young adult patients (16–60 years) with previously untreated primary CN-AML and enrolled on two concomitant protocols of the Acute French Leukemia Association (ALFA), the ALFA-9801 and ALFA-9802 trials. DNMT3A mutations were screened on genomic DNA by PCR and direct Sanger sequencing. We focused our screening on the 3 conserved domains of DNMT3A (the proline-tryptophane-tryptophane-proline (PWWP) domain, the ADD-type zinc finger domain, and the C5-methyltransferase domain), corresponding to exons 8–9 and 11–23. The patients were also assessed for the presence of FLT3 internal tandem duplication (FLT3-ITD), FLT3 tyrosine kinase domain (FLT3-TKD), NPM1, CEBPA, WT1, IDH1, and IDH2 mutations. Results:Thirty-eight DNMT3A mutations were identified in 36 of the 123 (29%) patients. These alterations consisted of 36 nucleotide substitutions and 2 frameshift deletions. Thirty out of 36 (83%) nucleotide substitutions affected the amino acid residue R882 (R882H, n = 21; R882C, n = 7; R882P, n = 2), 5 represented other missense alterations, and 1 was a nonsense mutation. Two patients exhibited 2 heterozygous missense mutations in different exons, and one patient had a homozygous missense mutation. DNMT3A mutated and wild-type cases did not differ in terms of age, gender, and white blood cell (WBC) count at presentation. DNMT3A mutations were strongly associated with the French-American-British (FAB) subtypes M4/M5 (P =.0002) and the presence of NPM1 mutations (P =.0006), and tended to often co-occur with IDH1R132 mutations (P = .09). In the entire cohort, complete remission rate was found lower in DNMT3A mutated patients than in DNMT3A wild-type patients, but without reaching statistical significance (80% vs 90%, P =.24). DNMT3A mutated patients had a shorter event-free survival (5-year EFS: 13% vs 32%, P =.02) and overall survival (5-year OS: 23% vs 45%, P =.02) compared to DNMT3A wild-type patients. We next performed subgroup analysis according to the NPM1/FLT3-ITD genotypes. In patients with the non-favorable genotypes, that is NPM1 mutated/FLT3-ITD positive, NPM1 wild-type/FLT3-ITD positive, NPM1 wild-type/FLT3-ITD negative (n = 86), 18 (21%) had a concomitant DNMT3A mutation. In this high-risk subgroup of CN-AML, DNMT3A mutations conferred a worse clinical outcome (5-year EFS: 0% vs 23%, P =.02; 5-year OS: 14% vs 37%, P =.06). In patients with the favorable genotype NPM1 mutated/FLT3-ITD negative (n = 37), 18 (49%) were found to display a concomitant DNMT3A mutation. Within this favorable subgroup, patients carrying a DNMT3A mutation had a significantly inferior EFS and OS compared to DNMT3A wild-type patients (5-year EFS: 25% vs 65%, P =.01; 5-year OS: 29% vs 76%, P =.02). Furthermore, in multivariate analysis including age, WBC count, NPM1/FLT3-ITD genotypes, and DNMT3A mutational status, the presence of a DNMT3A mutation remained an independent adverse prognostic factor for EFS (hazard ratio = 2.29; 95% CI, 1.42 to 3.70; P =.0007) and OS (hazard ratio = 2.34; 95% CI, 1.37 to 4.00; P =.002). Conclusion:DNMT3A mutations are one of the most common gene mutations in CN-AML and independently predict poor clinical outcome. Testing for DNMT3A mutations could help further improve risk stratification in CN-AML. Disclosures:No relevant conflicts of interest to declare.

Fractionated Doses of Gemtuzumab Ozogamicin (GO) Combined to Standard Chemotherapy (CT) Improve Event-Free and Overall Survival in Newly-Diagnosed De Novo AML Patients Aged 50–70 Years Old: A Prospective Randomized Phase 3 Trial From the Acute Leukemia French Association (ALFA)

Abstract 6 Aim.GO is a potent antibody-directed chemotherapy against CD33 antigen. Two MRC and SWOG Phase 3 studies have compared standard CT alone or combined with one single GO infusion (at 3 and 6 mg/m2, respectively) in younger adults with AML with contradictory results (Burnett, JCO 2011; Petersdof, Blood 2009). We have shown in relapsed AML Phase 2 studies that fractionated infusion of GO 3 mg/m2 on day 1, 4 and 7 was effective and might be safely combined to standard 3+7 DNR/AraC induction (Taksin, Leukemia 2007; Farhat, AJH, accepted). Here, we report the results of the prospective open label randomized multicentric Phase 3 ALFA 0701 trial (ClinicalTrial.gov ID, NCT00927498) designed to evaluate the efficacy and safety of adding this fractionated GO schedule to standard front-line chemotherapy in older AML pts. Methods.Eligible patients (pts) were adults aged 50–70 years old with previously untreated de novo AML. Pts were randomized to receive induction with DNR 60 mg/m2/d on day 1–3 and AraC 200 mg/m2/d CI on day 1–7, without (DA arm) or with GO at 3 mg/m2/d on day 1, 4 and 7(DAGO arm). Pts with persistent marrow blasts at day 15 received additional DNR 35 mg/m2/d on day 1–2 and AraC 1g/m2/12h on day 1–3. Pts achieving CR/CRp received two consolidation courses with DNR 60 mg/m2/d on day 1 and AraC 1 g/m2/12h on day 1–4, ± GO at 3 mg/m2/d on day 1 according to the randomization arm. The primary study objective was event-free survival (EFS). The study was designed to detect a 25% to 40% EFS gain at 3 years, (two-sided test, power 80%, type I error 5%). Secondary objectives were response rate, disease-free survival (DFS), overall survival (OS), and safety. Results.From March 2008 to November 2010, the required sample of 280 pts (median age, 62 years) was enrolled. Nine pts did not satisfy for inclusion criteria and were excluded from analysis. Cytogenetics was favorable (N=9), intermediate (N=177), adverse (N= 57), not done/failure (N=28). Overall, 52 pts had a favorable NPM1+ w/o FLT3-ITD genotype. The two treatment arms were well matched for all pre-treatment characteristics including age, sex, ECOG-PS, WBC, cytogenetics and molecular characteristics. CR+CRp was achieved in 220/271 pts (77%): 100/134 (75%) in the control DA arm versus 110/137 (80%) in the DAGO arm (P=0.31). There were 5/134 (4%) induction deaths in DA arm and 9/137 (6%) in DAGO arm (P=0.41). Primary resistant AML rate was 29/134 (22%) after DA versus 18/137 (13%) after DAGO (P=0.08). At 2 years, EFS was estimated at 15.6% in DA arm versus 41.4% in the DAGO arm (P=0.0018), while DFS was 18.1% in DA arm and 48.5% in the DAGO arm (P=0.0009). This significant benefit in EFS (primary objective) was observed in pts aged <65 years (P=0.035) as well as in older pts (P=0.019), and persisted after censoring the 39 pts who received allogeneic stem cell transplantation in first CR/CRp at transplant time (P=0.015). Subgroup analysis showed that EFS benefit persisted in pts with favorable/intermediate karyotype (P=0.0008) while not in those with adverse karyotype (P=0.25). Interestingly, EFS benefit was still observed when excluding favorable pts (favorable karyotype or genotype) from the comparison (P=0.0017). Finally, in the whole patient population, this gain in EFS translated into a longer OS (median, 25.4 versus 15.3 months in DAGO versus DA pts; P=0.037). Besides treatment arm, cytogenetics and favorable genotype were the only factors predictive of outcome. After adjustment on these factors, DAGO treatment remained significantly associated with longer EFS (P=0.009), DFS (P=0.003), but not OS (P=0.14). The rate of fatal adverse events at least possibly attributable to treatment was 9/134 (6.7%) in the DA and 12/137 (8.7%) in the DAGO arm (P=0.65). Prolonged grade ≥ 3 thrombocytopenia was observed in 19 DAGO pts, either after induction (N= 4) or first consolidation (N=15). Three liver VOD were observed in the DAGO arm (2 during induction, 1 during first consolidation), 2 being associated with a fatal issue. No difference was observed between both arms in the incidence of severe sepsis (DAGO 18.9%, DA 14%), as well as in the rate of intensive care unit admission during the course of therapy (DAGO 14.5%, DA 12.6%). Conclusion.The addition of fractionated doses of GO (3 mg/m2/d on day 1, 4, and 7) to standard CT significantly improves EFS and to a less degree OS in AML pts aged 50–70 years old. The main toxicity observed with GO was prolonged thrombocytopenia in 19 patients and 3 episodes of VOD. Disclosures:Castaigne:Pfizer/Wyeth: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Off Label Use: Gemtuzumab Ozogamicin is available in Europe as a compassionate treatment for relapsed AML. In this study patients GO was used in front-line treatment.

Older Patients with Acute Myeloid Leukemia (AML) in First Relapse: Impact of Genetics and of Salvage Therapy. A Study of the Acute Leukemia French Association (ALFA)

Abstract 253 Aim.AML in older patients constitutes the majority of AML cases, still associated with a high relapse rate after intensive chemotherapy (ICT). Relapsing patients are frequently targeted for new drug development, but few data are available on their outcome and optimal management. With the aim to provide historical data for future drug evaluation, we retrospectively analyzed a cohort of 393 patients aged ≥50 years in first relapse after prospective inclusion in ALFA 9801 (NCT00931138) and 9803 (NCT00363025) ICT trials. Patients.Median age was 64 years (50–82). Median duration of first complete remission (CR1) was 9 months (1–69). Twelve patients had prior allogeneic stem cell transplantation. At diagnosis, cytogenetics was as follows: 16 favorable (4%), 240 intermediate (61%), 76 adverse (19%), and 61 failed or not done (16%), 173 patients having a normal karyotype (NK). Twenty-nine of 174 patients tested at diagnosis had FLT3-ITD (17%), while the incidence of NPM1, CEBPA, IDH1, IDH2 or WT1 mutation was 24%, 4%, 9%, 10% and 2%, respectively. Among 86 NK-AML patients tested, 24 had a favorable genotype (NPM1 or CEBPA mutation without FLT3-ITD). At relapse, median WBC was 3.4 × 109/L and ECOG-PS >1 in 28% of patients. Relapse management was best supportive care (BSC, 32%), low-dose cytarabine (LDAC, 12%), ICT (38%), ICT combined with gemtuzumab ozogamicin (GO, 5%), or GO alone (10%). As expected, patients who received LDAC or BSC were significantly older and tended to have more frequent unfavorable karyotype. Conversely, patient and AML characteristics were comparable in the ICT, ICT+GO, and GO subsets. Results.Complete remission (CR) rate was 31% and median post-relapse survival was 6.8 months (0%, 17%, 53%, 80%, 42.5% and 3.2, 5.6, 9, 19.8, 8.9 months in BSC, LDAC, ICT, ICT+GO, and GO subsets, respectively). CR2 rate and post-relapse survival were comparable in both GO and ICT subsets, while CR2 rate was higher (P=0.02) and survival longer (P=0.04) in the ICT+GO versus the ICT subset. Median post-relapse survival was 17.3 months in patients who achieved CR2 versus 4.2 months in those who did not (p<0.001). In univariate analysis, age, CR1 duration, WBC, ECOG-PS, and favorable karyotype influenced both CR2 rate and post-relapse survival. Median post-relapse survival reached 16.2 months in patients with favorable karyotype versus 6.2 months in other patients (P<0.001). The presence of FLT3-ITD at diagnosis was associated with shorter post-relapse survival (3 versus 7 months, P=0.03). Interestingly, outcome was similar in NK patients with or without a favorable genotype, as well as in patients with an intermediate or even an adverse karyotype. Besides favorable karyotype, multivariate analysis allowed to identify CR1 duration <12 months (HR, 1.8; P<0.001), ECOG-PS ≥2 (HR, 2.0; P>0.001), age (P=0.001) and WBC (P=0.03), but not FLT3-ITD, as independent factors for shorter survival. To evaluate the role of the different management options, which were dependent of patient and disease characteristics as well as physician’s choice, we matched patients treated intensively (ICT/ICT+GO/GO) to those not treated intensively (LDAC/BSC) using a propensity score. This methodology allows comparing both approaches by reducing the multidimensional covariates associated with the intensive option to a single one-dimensional score used for patient matching. In 76 patient pairs, intensive salvage (HR, 0.49, P<0.001), good ECOG-PS (HR, 0.44, P<0.001), and CR1 duration ≥12 months (HR, 0.55, P=0.001) were associated with longer post-relapse survival. The benefit associated with intensive treatment was more marked in patients with CR1 duration ≥12 months (1-year post-relapse survival, 58% versus 24%; P=0.001) than in those with CR1 duration <12 months (1-year post-relapse survival, 25% versus 13%; P=0.09). Conclusion.If, as expected, favorable karyotype and longer CR1 duration predicted better post-relapse outcome in older AML patients, other karyotypes or genotypes did not. Patients with CR1 duration ≥12 months did benefit from intensive salvage. Intensive treatment should thus remain the current control arm in trials evaluating new alternatives in late relapsing patients, while LDAC/BSC may still be considered as an adequate control arm in patients relapsing within the first year of CR1. Results observed with GO-containing salvage also suggest that GO studies should be actively pursued in this setting. Disclosures:No relevant conflicts of interest to declare.

Prognostic Significance of Karyotype in Octogenarian Patients (Pts) with Acute Myeloid Leukemia (AML)–An International Study

Abstract 2521We asked whether a modified European LeukemiaNet (ELN) karyotype-based classification without molecular markers has prognostic significance in AML pts aged 80 to 89 years (y). We queried the German-Austrian AML Study Group (AMLSG; 7 pts), the Acute Leukemia French Association Group (ALFA; 17 pts), the German AML Cooperative Group (AMLCG; 35 pts) and the Cancer and Leukemia Group B (CALGB; 81 pts) for pts treated with intensive induction (7+3 or similar) on whom conventional karyotype analyses were completed and reviewed centrally. Of the 140 pts, including 82 (59%) men and 58 (41%) women, with a median age of 82 y (range, 80–89), 117 pts had de novo and 23 had secondary or therapy-related AML (s-AML/t-AML). There were 2 pts in the modified Favorable Group [t(8;21) and inv(16)], 67 pts in the modified Intermediate I Group [cytogenetically normal (CN-AML) pts], 44 pts in the ELN Intermediate II Group [t(9;11) and abnormalities (abn) classified as neither favorable nor adverse] and 27 pts in the ELN Adverse Group [inv(3) or t(3;3), t(6;9), t(v;11)(v;q23), -5 or del(5q), -7, abn(17p) and complex karyotype (≥3 abn)]. In order to assess the impact of karyotype on outcome, we eliminated early deaths. The complete remission (CR) rate for all 92 (66%) pts surviving beyond 30 days (d) was 46% and their median disease-free survival (DFS) was 6 months (mo); 35% were disease-free at 1 y and 12% at 3 y. Similarly, the median overall survival (OS) for pts surviving beyond 30 d was 6 mo, with 35% alive at 1 y and 11% at 3 y. There was no difference in DFS or OS based on AML type (de novo v s-AML/t-AML; Table 1). As shown in Table 2, pts in the modified Intermediate I Group had better OS than pts in the Adverse Group (P=0.03). Among CN-AML pts with molecular testing completed, 9/21 (43%) were NPM1-mutated (mut), 8/25 (32%) had FLT3-internal tandem duplication (ITD) and 1/12 (8%) was CEBPA-mut. Interestingly, FLT3-ITD did not have prognostic significance in the CN-AML cohort alive beyond 30 d (data not shown), but NPM1 mutation resulted in trends for higher CR rates (67% v 25%, P=.09) and longer OS (91 v 10 mo, P=0.07) in the CN-AML cohort alive beyond 30 d (Figure). Of note, there was no difference between the 2 larger cohorts (AMLCG and CALGB) in regards to pt characteristics or outcome in de novo pts; there were insufficient numbers of pts with s-AML/t-AML to compare the 2 cohorts. We conclude that there is a difference in accrual to clinical trials of octogenarian AML pts among the different cooperative groups. Further, CN-AML pts had better OS in octogenarian AML, and NPM1 mutation may be of prognostic significance among the CN-AML pts.Table 1:Treatment outcome by disease presentation for 92 pts alive beyond 30 dEnd Pointde novo AML (n = 78)s-AML/t-AML (n = 14)All pts (n = 92)P de novo v s-AML/t-AMLCR, no. (%)35 (45)7 (50)42 (46).78DFS.76Median, y0.50.60.5.27% Disease-free at 1 y36 (26–51)29 (4–61)35 (21–49)% Disease-free at 3 y14 (5–29)012 (4–24)OSMedian, y0.50.60.5% Alive at 1 y35 (24–46)36 (13–59)35 (25–45)% Alive at 3 y14 (6–23)011 (5–19)Table 2:Disease outcome by ELN karyotype-based classification without molecular markers for 92 pts alive beyond 30 dEnd PointIntermediate I (n = 43)Intermediate II (n = 29)Adverse (n = 20)PCR, no. (%)23 (53)13 (45)6 (30).23DFS.17*Median, y0.60.40.3% Disease-free at 1 y36 (17–56)40 (16–63)17 (1–52)% Disease-free at 3 y23 (8–41)00OS.03†Median, y0.90.40.3% Alive at 1 y43 (28–57)33 (16–50)21 (7–41)% Alive at 3 y17 (8–31)5 (0–20)5 (0–22)*Only Intermediate I compared to Intermediate II (too few pts in the Adverse Group)†This is overall P-value. Adjusted P-values were not significant for the differences between Intermediate-I and Intermediate-II Groups (P=.26) and between Intermediate-II and Adverse Groups (P=.87). There was a statistically significant difference between Intermediate-I and Adverse Groups (P=.03) [Display omitted] Disclosures:Krug:MedA Pharma: Honoraria; Novartis: Honoraria; Alexion: Honoraria; Boehringer Ingelheim: Research Funding; Sunesis: Honoraria.

Cladribine Plus Idarubicin/Cytarabine Induction for Untreated Acute Myeloid Leukemia

Abstract 4275 Introduction:There is interest improving induction chemotherapy in acute myeloid leukemia. The PALG (Polish Adult Leukemia Group) demonstrated that the addition of cladribine to daunorubicin/cytarabine resulted in improved CR rates and overall survival in untreated AML patients <60 years of age (Blood{ASH Annual Meeting Abstracts}, Nov 2009; 114: 2055). Idarubicin has shown superiority over high dose daunorubicin in the Acute Leukemia French Association 9801 Study (J Clin Oncol 2010, 28: 808–814), and here we present results of idarubicin/cytarabine/cladribine (IAC) therapy in untreated AML. Methods:Records of all patients receiving cladribine at Saint Louis University Hospital between December 2008 and July 2011 were analyzed after identification using a pharmacy database search. We began using cladribine for all acute myeloid leukemia patients after the report of improved overall survival in December 2008 (Blood{ASH Annual Meeting Abstracts}, Nov 2008; 112: 133). All patients with untreated acute myeloid leukemia by World Health Organization (WHO) criteria were included who received induction with IAC, which consisted of: idarubicin 12mg/m2 intravenously (IV) daily day 1–3, cytarabine 200mg/m2 IV daily day 1–7 by continuous infusion, and cladribine 5mg/m2 IV daily day 1–5. Results:34 patients received the IAC regimen. International Working Group criteria were used to assess response and cytogenetic abnormalities were grouped according to SWOG criteria. Median age was 60 years (range 25–81). Age: < 60: 18/34 (53 %), ≥ 60: 16/34 (47 %). 15/34 (44 %) had ECOG performance status 1–2, and 19/34 (56 %) had performance status 3–4. Median WBC count on presentation was 11 K (range 1K–483K). Risk distribution by cytogenetics: favorable: 4/34 (12 %), intermediate: 20/34 (59 %), adverse: 10/34 (29%) and by molecular analysis with NPM1/FLT3-ITD/CEBPA: favorable: 7/34 (21 %), intermediate-1: 12/34 (35 %), intermediate-2: 5/34 (15 %), adverse: 10/34 (29 %).The ORR (CR+CRi): 22/34 (65 %). CR 21, Cri 1. ORR by age: < 60: 14/18 (78 %), ≥ 60: 8/16 (50 %). ORR by cytogenetics: favorable: 4/4 (100%), intermediate: 14/20 (70 %), adverse: 4/10 (40 %). CR/CRi in 1 course: 18/20 (90%). Treatment failure (TF): 12 (37%). Treatment failure was due to persistent leukemia in 6/12 (50 %), death in bone marrow aplasia in 5/12 (42 %), and death due to indeterminate cause in 2/12 (8 %).Further consolidation treatment was heterogenous and typically consisted of either HIDAC or allogeneic transplantation depending on risk features. The median observation time of this patient cohort was 16.7 months (range: 4.1–29.4 months). The median event-free survival and overall survival were 9.5 months (range: 1.4–17.6 months) and 16.7 months (range: 5.1–28.3), respectively. See Figures1 and2.The 30 and 60 day mortality rates were 3/34 (9 %) and 7/34 (21 %), respectively. The median time to hospital discharge in those achieving remission was 26.5 days (range: 21–80 days). The median day to achievement of a neutrophil count >500 was 23 (range 21–43) in those who achieved a CR in 1 course. The median day to achievement of platelet transfusion independence with transfusion threshold of 10K and to platelet count ≥ 50K was 21 (range 19–28) and 23 (range 20–26), respectively, in those who achieved a CR in 1 course. The median number of red blood cell and platelet transfusions in those who achieved CR in 1 course was 8 (range 2–18) and 6 (range 3–18), respectively. Death in aplasia etiologies were (all in 1st IAC induction unless otherwise noted): autopsy-proven Aspergillus infections, one disseminated day 14, one pulmonary day 16/ MDR Pseudomonas sepsis and toxic megacolon day 21/ respiratory failure of undetermined etiology with recent stroke day 16 of 2nd IAC induction. Indeterminate deaths were: shock of undetermined etiology with multiorgan failure day 16 / probable Zygomycete pulmonary infection day 37. 25/34 patients (74%) had documented infection during induction. Conclusion:We found a high complete remission rate of IAC in younger patients with an acceptable 30 day mortality rate in spite of short follow-up. We believe that the addition of cladribine to induction chemotherapy with intensified daunorubicin or idarubicin for acute myeloid leukemia warrants further study. Disclosures:Off Label Use: Cladribine was utilized off-label in this study based on prior reports of efficacy in untreated and relapsed acute myeloid leukemia patients. [Display omitted] [Display omitted]

Fractionated doses of gemtuzumab ozogamicin with escalated doses of daunorubicin and cytarabine as first acute myeloid leukemia salvage in patients aged 50–70‐year old: A phase 1/2 study of the acute leukemia French association

This Phase 1/2 study aimed to determine optimal doses of daunorubicin (DNR; mg/m(2)) and cytarabine (mg/m(2)) to be combined with fractionated doses of gemtuzumab ozogamicin (GO, Mylotarg(®); 3 mg/m(2) on day 1, 4, and 7) satisfying safety requirements. Three dose levels of DNR/AraC were investigated namely (45, 100), (60, 100), and (60, 200). Patients included were acute myeloid leukemia in first relapse, aged 50-70 years. Hematological recovery was 31 days for neutrophil and 32 days for platelet counts. A documented infectious episode > Grade 2 occurred in 11/20 patients (55%). None of the 20 patients had signs of veno-occlusive disease. Overall, eleven patients reached complete remission (CR), two CR with incomplete platelets recovery. The results showed that combination of fractionated GO doses with DNR at 60 mg/m(2)/d for 3 days and cytarabine at 200 mg/m(2)/d for 7 days is tolerable and could be further investigated in the front-line therapy.

Comparison of high-dose cytarabine and timed-sequential chemotherapy as consolidation for younger adults with AML in first remission: the ALFA-9802 study

AbstractTo assess the value of administering timed-sequential chemotherapy (TSC; 2 therapeutic sequences separated by a 4-day interval-free chemotherapy) or high-dose cytarabine (HDAraC) cycles in consolidation therapy for acute myeloid leukemia (AML), 459 patients 15 to 50 years of age were enrolled in the prospective randomized Acute Leukemia French Association–9802 trial. Complete remission was achieved in 89%. A total of 237 patients were then randomized to either TSC consolidation (120 patients) or HDAraC consolidation cycles (117 patients). Overall, there was no significant difference between the 2 consolidation arms (5-year event-free survival [EFS]: 41% for HDAraC vs 35% for TSC), or cumulative incidence of relapse, or treatment-related mortality. Cytogenetically normal AML NPM1+ or CEBPA+ and FLT3-ITD− had the same outcome as those with favorable cytogenetics. When considering favorable and unfavorable risk groups, the trend was in favor of HDAraC. However, the difference became significant when considering intermediate cytogenetics (5-year EFS: 49% vs 29%; P = .02), especially cytogenetically normal AML (5-year EFS: 48% vs 31%; P = .04), which was related to lower relapse rate and less toxicity. This study demonstrates that TSC did not produce any benefit when used as consolidation therapy in younger adults compared with HDAraC. This trial was registered at www.clinicaltrials.gov as #NCT00880243.

Impact of post-remission therapy in patients aged 65-70 years with de novo acute myeloid leukemia: a comparison of two concomitant randomized ALFA trials with overlapping age inclusion criteria

There is no standard post-remission therapy in older patients with acute myeloid leukemia. From 1999 to 2006, the Acute Leukemia French Association group ran two concurrent randomized trials with overlapping inclusion criteria for patients aged 65 to 70 with acute myeloid leukemia, with different post-remission strategies: two intensive courses in the 9801 trial, one intensive course or six outpatient courses in the 9803 trial. We analyzed the outcome of these patients per protocol and per post-remission therapy. Two hundred and eleven patients aged 65 to 70 years with de novo acute myeloid leukemia were enrolled in trial 9801 (n=76) or 9803 (n=135). The patients in the two trials had comparable white blood cell counts (P=0.3), cytogenetics (P=0.49), and complete remission rates (70% and 57%, respectively; P=0.17). Overall survival was identical in both trials (32% and 34% at 2 years, respectively; P=0.71). Overall survival after complete remission was identical in the 103 of 130 patients who received the planned post-remission courses (n=44 with two intensive courses, n=28 with one intensive course, n=31 with six outpatient courses; 41%, 55%, and 58% at 2 years, respectively; P=0.34). Even in patients with favorable or normal karyotype (n=97), overall survival from complete remission was not improved by more intensive post-remission therapy. In patients aged 65 to 70 years with de novo acute myeloid leukemia in complete remission after standard intensive induction chemotherapy, there is no apparent benefit from intensive post-remission therapy. (ClinicalTrials.gov Identifiers: NCT00931138 and NCT00363025).

Long-Term Outcome Associated with Current Allogeneic Stem Cell Transplantation Procedures In Younger Adults with Adverse-Risk AML In First CR – A Real-Life Transplant Versus No-Transplant Analysis of the Acute Leukemia French Association (ALFA)

AbstractAbstract 3513 Purpose:Based on donor versus no-donor studies, allogeneic stem cell transplantation (SCT) is the best treatment option for younger patients with intermediate- or adverse-risk AML in first CR (Cornelissen et al. Blood 2007; Koreth et al. JAMA 2009). However, in these intent-to-treat studies, the benefit associated with SCT seems often small in the adverse-risk subgroup, probably due to a higher incidence of early relapse. In addition, the definition of the donor group has evolved with the increasing use of alternative SC sources. To assess the role of current SCT procedures in adverse-risk patients specifically, we thus performed the present real-life transplant versus no-transplant analysis. Patients and Methods:A total of 205 adults aged 50 years or less with adverse-risk AML in first CR (CR1) were included. All have reached CR1 after induction therapy within the ALFA-9000 (N=69; period 1990–1996) or ALFA-9802 (N=136; period 1999–2006) trial. Adverse-risk AML was defined as: 1) unfavorable cytogenetics, including 3q26 or 11q23 anomalies, del(7q)/-7, del(5q)/-5, and complex karyotypes (N=106); 2) initial WBC>100.109/L (N=72); 3) late CR1 achievement (N=47); and more recently 4) FLT3-ITD, after protocol amendment in 2002 (N=35). Patients with CBF-AML were excluded. Among these 205 eligible patients (median age, 38y), 102 (50%) received SCT, including 74 patients in CR1 (36%). In CR1 patients, the median time between CR and SCT (60 sibling and 14 unrelated donors, including 4 cord blood; 65 myeloablative and 9 reduced intensity [RIC] conditioning) was 88 days (5%-95% percentiles, 24–245). In patients allografted after relapse, the median time between relapse and SCT was 109 days (5%-95% percentiles, 8–205). Outcomes of transplanted versus non-transplanted patients were compared using Mantel-Byar estimates. The median follow-up was 7 years. Results:According to SCT in CR1, both transplant and no-transplant groups were comparable in terms of age, WBC, cytogenetics, and time to CR. Transplant rate in CR1 was higher in the latter 9802 trial (42% versus 25%, P=0.02), due to the increasing use of unrelated donors over time (24% versus 0%, P=0.03). Overall, Mantel-Byar estimates revealed a better outcome of patients transplanted in CR1 compared to those not transplanted in CR1. At 5 years, estimates were 43% (95%CI, 31–54) versus 20% (95%CI, 13–28) (Figure 1; P=0.05) and 41% (95%CI, 29–53) versus 26% (95%CI, 19–34) (P=0.17) for DFS and OS from CR in the transplant and no-transplant groups, respectively. Notably, SCT was associated with an impressive decrease of relapses (5-year cumulative incidence, 30% [95%CI, 21–43] versus 77% [95%CI, 69–84]; P<0.0001), attesting that a strong and long-lasting anti-AML effect can be achieved with SCT even in these patients at very high risk of relapse. Similar results were observed in various adverse-risk subsets (unfavorable, complex, or monosomal karyotypes; high WBC). In patients not transplanted in CR1, almost 20% of relapses occurred within the first 3-month period (i.e. the median time to SCT in transplanted patients). In patients relapsing without having been transplanted in CR1, SCT after relapse was, however, not able to prolong OS which was as poor as in patients not transplanted after relapse (10% at 5 years). [Display omitted] Conclusion:Even if SCT results remain unsatisfactory, this real-life study confirms its superiority over chemotherapy in patients with adverse-risk AML in CR1. With a very high short-term relapse incidence and evidence of anti-AML allogeneic effect, the study also provides a strong rationale to propose upfront early sequential regimens to these patients, combining innovative chemotherapy and RIC-SCT (Schmid et al. Blood 2006). This option will be prospectively evaluated in the next younger AML French ALFA-GOELAMS Intergroup trial. Disclosures:No relevant conflicts of interest to declare.

Prognostic Impact of Isocitrate Dehydrogenase Enzyme Isoforms 1 and 2 Mutations in Acute Myeloid Leukemia: A Study by the Acute Leukemia French Association Group

Recently, whole-genome sequencing in acute myeloid leukemia (AML) identified recurrent isocitrate dehydrogenase enzyme isoform (IDH1) mutations (IDH1m), previously reported to be involved in gliomas as well as IDH2 mutations (IDH2m). The prognosis of both IDH1m and IDH2m in AML remains unclear. The prevalence and the prognostic impact of R132 IDH1 and R172 IDH2 mutations were evaluated in a cohort of 520 adults with AML homogeneously treated in the French Acute Leukemia French Association (ALFA) -9801 and -9802 trials. The prevalence of IDH1m and IDH2m was 9.6% and 3.0%, respectively, mostly associated with normal cytogenetics (CN). In patients with CN-AML, IDH1m were associated with NPM1m (P = .008), but exclusive of CEBPAm (P = .03). In contrary, no other mutations were detected in IDH2m patients. In CN-AML patients, IDH1m were found in 19% of favorable genotype ([NPM1m or CEBPAm] without fms-related tyrosine kinase 3 [FLT3] internal tandem duplication [ITD]) and were associated with a higher risk of relapse (RR) and a shorter overall survival (OS). Favorable genotype in CN-AML could thus be defined by the association of NPM1m or CEBPAm with neither FLT3-ITD nor IDH1m. In IDH2m CN-AML patients, we observed a higher risk of induction failure, a higher RR and a shorter OS. In multivariate analysis, age, WBC count, the four-gene favorable genotype and IDH2m were independently associated with a higher RR and a shorter OS. Contrarily to what is reported in gliomas, IDH1m and IDH2m in AML are associated with a poor prognosis. Screening of IDH1m could help to identify high-risk patients within the subset of CN-AML with a favorable genotype.

Randomized Study of Intensified Anthracycline Doses for Induction and Recombinant Interleukin-2 for Maintenance in Patients With Acute Myeloid Leukemia Age 50 to 70 Years: Results of the ALFA-9801 Study

PURPOSE In patients with acute myeloid leukemia (AML), induction chemotherapy is based on standard doses of anthracyclines and cytarabine. High doses of cytarabine have been reported as being too toxic for patients older than age 50 years, but few studies have evaluated intensified doses of anthracyclines. PATIENTS AND METHODS In this randomized Acute Leukemia French Association 9801 (ALFA-9801) study, high doses of daunorubicin (DNR; 80 mg/m(2)/d x 3 days) or idarubicin (IDA4; 12 mg/m(2)/d x 4 days) were compared with standard doses of idarubicin (IDA3; 12 mg/m(2)/d x 3 days) for remission induction in patients age 50 to 70 years, with an event-free survival (EFS) end point. After two consolidation courses based on intermediate doses of cytarabine, patients in continuous remission were randomly assigned to receive or not receive maintenance therapy with recombinant interleukin-2 (rIL-2; 5 x 10(6) U/m(2) x 5 days each month) for a total duration of 12 months. A total of 468 patients entered the study (median age, 60 years). Results Overall complete remission rate was 77% with significant differences among the three randomization arms (83%, 78%, and 70% in the IDA3, IDA4, and DNR arms, respectively; P = .04). However, no significant differences were observed in relapse incidence, EFS, or overall survival among the three arms. In the 161 patients randomly assigned for maintenance therapy, no difference in outcome was observed between the rIL-2 and the no further treatment arms. CONCLUSION Neither intensification of anthracycline doses nor maintenance with rIL-2 showed a significant impact on AML course, at least as scheduled in this trial.

The Role of Cytogenetic Abnormalities in Acute Myeloid Leukemia with NPM1 mutations and No FLT3 Internal Tandem Duplication.

Abstract 1594Poster Board I-620 BackgroundNucleophosmin (NPM1) gene mutations are observed in almost one-third of adult acute myeloid leukemia (AML). If the favorable genotype defined by the presence of NPM1 mutations without fms-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) is known to be associated with favorable outcome in patients with cytogenetically normal (CN) acute myeloid leukemia (AML), impact of these molecular abnormalities are still debated in those with cytogenetically abnormal (CA) AML. Patients and MethodsWe analyzed the role of these factors in newly diagnosed AML patients homogeneously treated in the Acute Leukemia French Association (ALFA) trials between 1990 and 2006 (ALFA 9000, 9801, 9802). Among 1529 patients (15-70 years of age), 554 patients were screened for NPM1 mutation, FLT3-ITD and have informative karyotype. Mutations screening were centrally performed according to previously described procedures. Karyotype was considered as normal if at least 20 normal marrow metaphases were present without any abnormal marrow metaphases. Favorable core binding factor (CBF) AML (74 patients) were excluded from this analysis. ResultsAmong the 480 remaining patients, 137 (29%; median age 48 years, range 17-68) were NPM1 mutated, 22 of them (16%) having CA-AML. We found no difference between NPM1 mutated CN-AML patients (n=115) and NPM1 mutated non-CBF CA-AML patients (n=22) in term of complete remission rate (88% vs 83%; P= .49), overall survival (OS) (39% vs 38 % at 5 years, P= .85), event-free survival (EFS) (33% vs 25% at 5 years, P= .39). However, in the context of the favorable genotype, EFS was significantly longer in the 79 CN- than in the 16 CA-AML patients (41% vs 19% at 5 years ; P= .04) with a trend to better OS (51% vs 31% at 5 years ; P= .12). No significant differences were observed in patients with NPM1 mutated AML but FLT3-ITD (5-year EFS, 12% vs 40%; 5-year OS, 20% vs 60%; P= .47 and .27, respectively), even if the numbers of patients were here very low (35 CN- vs 5 CA-AML). More importantly, the favorable genotype was predictive of a longer EFS and OS in the 267 patients with CN-AML (5-year EFS, 41% vs 19%; 5-year OS, 51% vs 30%; P= .0001 and .001, respectively), while no differences were observed in the 213 patients with non-CBF CA-AML (5-year EFS, 19% vs 16%; 5-year OS, 31% vs 27%; P= .38 and .36, respectively). ConclusionAs shown, patients with the favorable genotype but CA-AML had an outcome relatively similar to those with a non favorable genotype and either CA- or CN-AML. The favorable outcome associated with NPM1 mutation in the absence of FLT3-ITD might thus depend on the presence of a normal karyotype. We thus think that larger studies or overviews are needed to definitely answer this question. DisclosuresDombret:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Wilms tumor 1 gene mutations are associated with a higher risk of recurrence in young adults with acute myeloid leukemia

Wilms tumor 1 (WT1) is a transcription factor that is overexpressed in most acute myeloid leukemias (AMLs). Recently, 2 groups reported that WT1 mutations occur in approximately 10% of normal karyotype AMLs and are an independent predictor of poor outcome in this subgroup of patients with AML. The authors studied a cohort of 268 young adults (ages 15-50 years) with AML who were treated on the Acute Leukemia French Association 9802 trial. WT1 exon 7 and 9 mutations were screened retrospectively by polymerase chain reaction and direct sequencing. The patients also were assessed for the presence of the fms-related tyrosine kinase 3 internal tandem duplication (FLT3-ITD), FLT3-D835/I836, nucleophosmin 1 (NPM1), and CCAAT/enhancer binding protein alpha (CEBPA) mutations. WT1 mutations were identified in 14 patients (5%) and were associated with a younger age (P = .02) and an FLT3-ITD (P = .03). No mutation was detected in patients who had favorable cytogenetics. Patients who had WT1 mutations had a shorter overall survival at 4 years (22% vs 56%; P = .01) and a higher risk of recurrence at 4 years (82% vs 46%; P = .0008) compared with patients who had wild-type WT1. Within the subgroup of patients who had normal karyotype AML (n = 106), WT1 mutation was identified as an independent adverse prognostic factor for the risk of recurrence. The current results indicted that WT1 mutations represent an adverse prognostic factor in young adults with AML. Prospective trials should confirm the clinical relevance of WT1 mutations in relation to other prognostic factors in patients with AML.

The favorable impact of CEBPA mutations in patients with acute myeloid leukemia is only observed in the absence of associated cytogenetic abnormalities and FLT3 internal duplication

AbstractMutations of the CCAAT/enhancer binding protein alpha (CEBPA) gene have been associated with a favorable outcome in patients with acute myeloid leukemia (AML), but mainly in those with a normal karyotype. Here, we analyzed the impact of associated cytogenetic abnormalities or bad-prognosis fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) in 53 patients with CEBPA+ de novo AML treated in the Acute Leukemia French Association trials. We found that only those with a normal karyotype and no FLT3-ITD displayed the expected favorable outcome. In this context, relapse-free, disease-free, and overall survival were significantly longer than in corresponding patients without the CEBPA mutation (P = .035, .016, and .047, respectively). This was not observed in the context of an abnormal karyotype or associated FLT3-ITD. Furthermore, after adjustment on age, trial, and mutation type, these features were independently predictive of shorter overall survival in the subset of patients with CEBPA+ AML (multivariate hazard ratio = 2.7; 95% confidence interval, 1.08-6.7; and 2.9; 95% confidence interval, 1.01-8.2; with P = .034 and .05, for abnormal karyotype and FLT3-ITD, respectively).

Which AML Subsets Benefit from Leukemic Cell Priming during Chemotherapy? Long-Term Analysis of the ALFA-9802 GM-CSF Study

Sensitization of leukemic cells with G- or GM-CSF may enhance the cytotoxicity of chemotherapy in younger adults with newly diagnosed acute myeloid leukemia (AML). In this multicenter randomized trial conducted by the Acute Leukemia French Association (ALFA), 259 patients (median age, 38 years; range: 15–50) were randomized at baseline to receive a timed-sequential induction (DNR 80mg/m2/d d1-3, AraC 500mg/m2/d d1-3 and 500mg/m2/12h d8-10, Mitox 12mg/m2/d d8-9) either without (135 patients) or with GM-CSF (124 patients) administered i.v. at 5μg/kg/d from day 1 to day 10. Patients reaching remission (eventually after salvage therapy) and not eligible for allogeneic stem cell transplantation were then randomized to compare the timed-sequential ALFA-9000 consolidation (Mitox 12mg/m2/d d1-3, VP16 200mg/m2/d d8-10, AraC 500mg/m2/d d1-3, 8-10) to the CALGB postremission chemotherapy, which includes 4 cycles of high-dose AraC (3g/m2/12h d1,3,5) followed by 4 additional DNR/AraC courses. Patients initially randomized in the GM-CSF arm received GM-CSF concurrently with chemotherapy during all cycles of consolidation therapy. First published results were encouraging showing that priming of leukemic cells with GMCSF is a means of enhancing the efficacy of chemotherapy in younger adults with AML (Thomas et al., Leukemia 2007). The effects of GM-CSF on EFS and according to distinct biological subgroups are reported herein with a longer follow-up.A significantly higher CR rate was observed after induction chemotherapy in patients primed with GM-CSF (88% for patients receiving GM-CSF versus 78% for those not receiving GM-CSF; p = 0.04). With a median follow-up of 5.4 years, the EFS rate was confirmed to be better in the GM-CSF group (43% vs 34%; p = 0.04). However, the difference between the two arms remained not statistically different in terms of OS. GM-CSF did not improve the outcome in the subgroups with favorable cytogenetics constituted by CBF leukemias (61% at 5 years in the GM-CSF group vs 62% in the non GM-CSF group; p = 0.9). Research in defining prognostic factors has moved from classical cytogenetic to an examination of molecular markers. Molecular markers are particularly important for patients with AML and a normal karyotype, identifying within this group two genotypes, NPM1+ FLT3-ITD− and CEBPA+ FLT3-ITD−, with a relatively favorable outcome which were classified here as intermediate-1. In the present study cohort, these intermediate-1 genotypes were associated with a risk profile comparable with that of CBF AML (5-year EFS at 67%). Comportment after priming with GM-CSF was also comparable showing no difference in terms of long-term EFS compared to absence of priming. Although results were not statistically significant, patients with intermediate-risk cytogenetics other than intermediate-1, referred here as intermediate-2, and patients with unfavorable cytogenetics benefited from GM-CSF therapy (5-year EFS, 24% vs 18%, p = 0.2). The benefit of GM-CSF was in part related to a higher proportion rate of CR after the initial course of induction chemotherapy (89% vs 67%, p = 0.04) for unfavorable cytogenetics and a trend for a lower relapse rate (38% vs 52%) in intermediate-2 patients. It appeared that the difference in terms of EFS probability in this population resulted from GM-CSF-mediated activation of subpopulations of leukemic cells that were initially the more proliferative. Actually, the effect of GM-CSF became significant when considering only patients with higher initial WBC count (> 10 × 109/l) (5-year EFS, 32% vs 5%, p = 0.003), while there was no difference in patients with lower initial WBC count (< 10 × 109/l). Among frequent mutations observed in AML, FLT3-ITD provides a proliferative advantage to a population in which normal maturation is blocked. Similarly, MLL fusion proteins also confer a remarkable growth/survival advantage. When combining these two abnormalities for comparison of the effect of GM-CSF priming, the difference in terms of EFS was highly significant (5-year EFS, 39% with GM-CSF vs 8% without GM-CSF in the population of patients FLT3-ITD or MLL positive, p = 0.005). The results of priming in the ALFA-9802 trial confirm that chemotherapy and sensitization of leukemic cells and their progenitors by GM-CSF is a plausible strategy for improving the outcome of younger patients with newly diagnosed AML particularly for those with intermediate-2 or unfavorable cytogenetics displaying higher proliferative features.