Abstract: Abstract 333 Background: Standard chemotherapy for elderly AML patients results in a median overall survival of only about one year. Case reports and early phase I/II data have shown that the kinase inhibitor Sorafenib might show clinical benefit for Flt3-ITD-positive AML patients (Metzelder S Blood 2009; 113:6567) and that its addition to standard chemotherapy is feasible (Ravandi F JCO 2010; 28:1856). Sorafenib is a potent Raf, c-Kit and FLT3 inhibitor that may also affect AML blasts and bone marrow (BM) stroma cells via VEGFR and PDGFR-β inhibition. Therefore, we performed a multicenter, randomized, placebo-controlled, double-blind phase II trial in elderly ( & gt;60 y) AML patients analyzing the effect of Sorafenib in addition to standard chemotherapy and as a maintenance therapy for up to one year. Methods: 197 AML patients in 16 centers received up to two cycles of standard 7+3 induction chemotherapy plus two cycles of consolidation therapy with intermediate dose (6 × 1g/sqm) AraC. Before start of treatment, they were randomly assigned to receive either placebo or Sorafenib (400 mg bid between the cycles and after chemotherapy for up to one year after start of induction). The primary aim was to compare the event-free survival (EFS) of the two treatment groups. Secondary end points were to compare EFS and overall survival (OS) of predefined subgroups according to NPM and FLT3 mutation status and toxicity of treatment. Results: Among the 197 evaluable patients, 102 pts received Sorafenib and 95 pts placebo. EFS and OS were not significantly different between the two treatment groups (placebo vs. Sorafenib: EFS: Median: 7 vs. 5 months, hazard Ratio (HR): 1.261(p=0.13); OS: Median: 15 vs. 13 months, HR 1.025 (p=0.89)). CR or blast clearance without complete blood count recovery was observed in 49 (48%) and 9 (8.8%) Sorafenib patients and 57 (60%) and 4 (4.2%) placebo pts, respectively. Exploratory subgroup analyses did not reveal any significant difference between the treatment groups but showed a tendency towards decreased EFS in the Sorafenib arm for NPM1-wild type AML cases. Flt3-ITD mutations were found in 28 out of 197 patients (14.2%), in line with the reported incidence in the target population. No differences in EFS or OS were to be noted in this small patient population. Also, CR rate was not improved by the study drug in this subgroup of patients. Sorafenib was relatively well tolerated. The most frequent adverse events (AE) ≥grade 3 were febrile neutropenia, pneumonia in neutropenia, sepsis, diarrhea, skin rash, mucositis, hypertension (77 vs 74, 54 vs 35, 15 vs 15, 17 vs 6, 14 vs 7, 9 vs 6, 8 vs 5 events in the Sorafenib vs the placebo group). A hand-foot-skin reaction (≥grade 3) was noted in 5 vs 0 events in Sorafenib vs control pts. There was a trend of slower regeneration of leukocytes and thrombocytes within the Sorafenib arm compared to the control arm after the first and second induction course but not after consolidation cycles. Conclusion: Although the combination regimen appeared to be feasible and tolerable in elderly AML pts, Sorafenib treatment did not improve EFS or OS in this unselected elderly AML patient population. Further studies should focus on selected AML target populations for Sorafenib, especially FLT3-ITD+ AML patients. Disclosures: Off Label Use: Sorafenib (multikinase inhibitor) is given in combination with standard chemotherapy in elderly AML patients. (See title of the abstract!).

Abstract: Data on benefit and toxicity by treatment intensification for AML are now available and allow rediscussing current dosing. Methods In a multicenter trial involving patients between 16 and 86 years of age, patients below 60 years received uniform double induction by the 1st course with standard dose araC/ daunorubicin (60mg/m²x3)/ thioguanine followed by the 2nd course with high-dose araC (3g/m²x6)/ mitoxantrone (10mg/m²x3), or randomly two high-dose courses. As age adaption patients of 60y or older received the 2nd course only in case of persistent blasts, and high-dose araC at 1 instead of 3g/m². Post remission treatment was consolidation and maintenance or randomly autologous stem cell transplantation in younger patients. Results 3369 patients entered the trial with 1843 patients 60y or older. A multivariate analysis identified age as continuous variable, favorable cytogenetics/ molecular genetics, unfavorable cytogenetics, white blood cell count and lactate dehydrogenase as categorical variables to be risk factors predicting complete remission, overall survival as well as relapse free survival. To separate the age effect from the treatment effect, two subgroups of similar age and baseline characteristics but different treatment were compared. Thus, the 239 patients aged 57-59 and the 336 patients aged 60-62 years shared not only similar age but also similar baseline characteristics, while their treatment by protocol and age adaption differed substantially. The difference as expressed by the cumulative araC dosis amounted to a factor of 3.6, which however did not translate into a different overall survival (equally 28%) or relapse rate (equally 70%) at 5 years. In contrast to different treatment, different age had a strong effect on outcome. Thus, the survival in patients aged 16-46y was 65% at 5 years versus 40% in those of 47-59y receiving the same treatment (p 〈 0.001). A corresponding age related difference was also found between the patients of 60-66y and those of 67-86y (p 〈 0.001) receiving the same age adapted treatment. As shown by others in patients of 18-60y doubling an intermediate cumulative dose of araC produced excessive toxicity without therapeutic benefit (Löwenberg B et al. NEJM 2011; 364: 1027-36), while high dose daunorubicin (90mg/m²) instead of standard dose (45mg/m²) improved the remission rate and survival in younger patients (Fernandez H et al. NEJM 2009; 361: 1249-59) and older patients of 60-65y (Löwenberg B et al. NEJM 2009; 361: 1235-48). No comparable data are available about daunorubicin 60mg/m² the standard in present study. Conclusion Age and disease biology rather than chemotherapy intensity are the main determinants of outcome in AML. Once a certain intensity and antileukemic effect has been achieved, a further escalation does not seem to overcome the age factor in AML. Present data require rediscussing current chemotherapy dosing and treatment alternatives. Disclosures: No relevant conflicts of interest to declare.

Abstract: Abstract 2773 Introduction: For patients with high-risk myelodysplastic syndromes an epigenetic therapy with hypomethylating agents is considered standard of care. Intensive chemotherapy can be offered to a subset of patients; however, data about the long-term outcome of MDS patients receiving intensive chemotherapy are scarce. Methods: For this evaluation, 104 adult patients with IPSS intermediate-2 or high-risk MDS with at least 10% bone marrow blasts of all age groups treated within the AMLCG1999 trial were included. Patients were randomized upfront to receive 1. double induction therapy with either standard-dose containing TAD - versus high-dose containing HAM–HAM, 2. TAD consolidation therapy followed by either a monthly maintenance therapy for 3 years after achievement of CR or an autologous stem cell transplantation (patients aged ≥ 60 years were all assigned to maintenance therapy), and 3. blast priming with filgastrim starting on day -1 of chemotherapy in selected centers. Results: Fifty-four patients had IPSS Score intermediate-2 and 50 patients were IPSS high risk. Median bone marrow blast count at diagnosis was 15%. The median age was 63.5 years (range: 27–76 years), 39 patients (37.5 %) were female. Median lactate dehydrogenase (LDH) serum level was 296 U/l, median leukocyte count at diagnosis was 5,950 per μl. The cytogenetic risk groups were as follows: favorable 3, intermediate 57, unfavourable 37, missing 7. Among 38 patients with normal karyotype, NPM1/FLT3 mutational status was available for 22 with 5 patients having the combination NPM1 mutated/FLT3 wildtype. Comparison with 2051 patients with de novo AML within the same trial revealed the following significant differences: patients with MDS were older, had a higher male to female ratio, a lower LDH serum level at diagnosis, a lower leukocyte count at diagnosis and were more likely to have adverse cytogenetic risk. Compared to 636 patients with secondary AML after MDS, cytotoxic therapy or irradiation, the cohort of patients with MDS did not display any significant differences except the sex distribution. Patients with MDS displayed a CR rate of 48% (50/104 patients), which was significantly lower than de novo AML patients (67%) and not different to secondary AML patients (47%). Median overall survival in MDS patients was 320 (95% CI: 236 to 505) days with a 2-year and 5-year survival of 33.4% (95% CI: 23.6% to 43.2%) and 22.7% (95% CI: 13.5% to 31.9%), respective, which was significantly (p=0.03) lower than in patients with de novo AML (median 484, 95% CI 435 to 541 days) and comparable to patients with secondary AML (median 282, 95% CI 224 to 311 days, p=0.13). Median relapse-free survival in responding MDS patients was 536 (95% CI: 264 to 1299) days with no significant differences of RFS compared to de novo or secondary AML patients. In multivariate analyses, the diagnosis of MDS remained an independent prognostic factor for CR probability but had no independent influence on survival compared with de novo AML patients. Nine patients proceeded to allogeneic stem cell transplantation in first complete remission of whom six remain in first complete remission between 1354 and 1911 days after achievement of CR. In addition, 16 patients remained in CR for more than one year without allogeneic transplantation. Discussion: Taken together, outcome of patients with intermediate-2 or high-risk MDS after intensive chemotherapy is comparable to the outcome of patients with secondary AML. Adjustment for known risk factors such as age, cytogenetic risk and LDH revealed that inferior outcome of MDS patients compared to patients with de novo AML is attributable to the higher incidence of adverse risk factors. CR-rates appear to be higher compared to hypomethylating therapy and a fraction of MDS patients experiences long-term survival by intensive chemotherapy. Allogeneic transplantation can improve long-term survival for patients achieving remission. Disclosures: Krug: MedA Pharma: Honoraria; Novartis: Honoraria; Alexion: Honoraria; Boehringer Ingelheim: Research Funding; Sunesis: Honoraria. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Abstract: Abstract 425 The introduction of all-trans-retinoic acid (ATRA) in front line therapy of acute promyelocytic leukemia (APL) has improved the outcome of all age groups. In the elderly patients (pts), multi-morbidity and higher vulnerability to chemotherapy-related toxicity are the main problems reducing the chance of cure. This has led to recommendations to reduce the intensity of therapy in elderly APL pts. We report on the long-term outcome of pts with newly diagnosed APL registered in two prospective studies of the German AML Cooperative Group (AMLCG) from December 1994 until June 2011. The therapy consisted of ATRA and anthracycline/ara-C-based induction and consolidation therapy (TAD/HAM–TAD) followed by maintenance therapy as reported previously in younger APL pts (Lengfelder et al. Leukemia 2009;23:2248–2258). In pts ≥60 years (y), the administration of the second induction cycle (HAM with an age adapted cumulative ara-C dose of 6g/sqm) was at the discretion of the treating physician. After December 2005, the pts were included in the ongoing APL protocol and randomized between the AMLCG strategy and the protocols of the Spanish PETHEMA. Among 295 adult pts with newly diagnosed APL, 83 pts (28%) were ≥60y of age. Seventeen elderly pts (20%) were not enrolled in the study, due to death before start of therapy, contraindications against chemotherapy or concomitant other malignancy. Eleven pts randomized in the PETHEMA arm were excluded from the present analysis to cover homogeneity of therapy. In 53 of 55 pts treated according to the AMLCG protocol, results are available. Median age was 67 y (range 60 to 83); 58% were male, 42% female; 68% had low/intermediate and 32% high risk according to Sanz score. Morphology was FAB M3 in 62%, M3v in 38%. Cytogenetics showed t(15;17) alone in 52%, and combination with other abnormalities in 48% of pts. The bcr1/bcr2 transcript of PML/RARA was found in 41% and the bcr3 transcript in 59% of pts. Forty-four pts (83%) achieved complete remission (CR). Early death (ED) occurred in 9 pts (17%). Median time to ED was 12 days (range 2 to 19) after start of therapy. Causes of ED were bleeding, multi-organ failure and sepsis. Manifest APL differentiation syndrome occurred in 25% of pts and WHO grade '3 bleeding, fever/infection or cardiac failure in 8%, 43% and 17% of pts, respectively. After consolidation therapy, 96% of pts were in molecular remission. After a median follow up of 5.3 y (1 day to 12.8 y), the 6-year overall (OS), event free (EFS) and relapse free survival (RFS) and the cumulative incidence of relapse (CIR) were 45%, 41%, 50% and 26%, respectively. The outcome was further analyzed according to risk group, number of induction cycles, and age ≥60y to 69y and ≥70y. Pts with pretreatment white blood cell (WBC) count 〈 10 × 109/L (low/intermediate risk; n=36) had a significantly superior outcome compared to pts with high WBC counts (high risk; n=17) resulting in a CR rate of 92% vs. 65% and ED rate of 8% vs. 35%, respectively (p=0.02). The 6-year OS, EFS, RFS and CIR of the low/intermediate risk pts was 56%, 53%, 60% and 14%, respectively, compared to 25%, 15%, 23% and 58% in high risk pts (p=0.006, p=0.0004; p=0.008; p 〈 0.01). All 12 pts, who had received two induction cycles achieved CR, and no relapse occurred so far resulting in a significantly superior outcome compared to patients, who had received only one induction cycle (OS: p=0.007; EFS: p=0.0002; RFS: p=0.01). In the pts '70y (n=17), 71% entered CR and 29% died from ED. Separated according to low and high WBC counts, the CR rate of this group was 83% vs. 40% and the ED rate 17% vs. 60% (p=0.07), respectively, resulting in an inferior OS (p=0.08) of the pts with high WBC count. Conclusions: Among our elderly pts, we found a high proportion of pts with high risk profile and a high rate of exclusion from the study due to death before the start of therapy or poor condition. In patients included in our study, high WBC count and advanced age are associated with a high risk of ED. The inferior outcome in pts, who received only one induction cycle, suggests that intensification of chemotherapy should be considered in elderly APL pts, if possible. The incorporation of arsenic trioxide might be an alternative, which could be investigated in future trials. Disclosures: No relevant conflicts of interest to declare.

Abstract: Abstract 1974 Most available data on the relative value of allogeneic stem cell transplantation (allo-SCT) for acute myeloid leukemia (AML) in first complete remission (CR1) in the past, were generated from donor versus no-donor comparisons, focusing on documented tissue-typed patients and their siblings. The inclusion of patients who are not HLA-typed, for instance all those without siblings, causes bias of unknown magnitude. Additionally, concerns about the equivalence of related and unrelated donors should no longer be a problem in contemporary evaluation of allo-SCT. Using data of the prospective AMLCG 1999 trial, we performed a matched-pair analysis, to evaluate outcome in patients with AML according to post-remission allo-SCT or conventional postremission chemotherapy (PRT). 165 patients pairs in CR1 were identified, who matched for the following criteria: AML type (de novo AML, s-AML, t-AML, high-risk MDS); cytogenetic risk group [unfavorable (UNF-CG), intermediate (INT-CG), and favorable with the exclusion of t(15;17)]; age (± 5 years); and time in CR1 to account for the time to transplant in allo-SCT patients. If possible, patients were also matched for sex and assigned induction treatment (TAD-HAM versus HAM-HAM). 34 patient pairs had an UNF-CG, 122 pairs INT-CG, and 9 pairs had favorable cytogenetics. Median patients age at diagnosis was 45 years (range: 16–59). In the allo-SCT cohort, 105 patients had a related donor (matched related donor [MRD] 104, haploidentical 1) and 60 a matched unrelated donor (MUD). Median follow-up of surviving patients after first diagnosis of CR1 was 7.5 years. Projected 7-year relapse-free survival (RFS) was 56% in the allo-SCT group and 39% in the control group (p 〈 .0001, log-rank test). Overall survival (OS) was 58% and 45% (p=.143), respectively. RFS was significantly improved by allo-SCT in patients with UNF-CG (23% vs. 12% at 7 years; p=.005) or INT-CG (58% vs. 37%; p=.001). OS was 31% in allo-SCT patients with UNF-CG versus 18% in matched controls (p=.052) and 64% in INT-CG patients with allo-SCT versus 54% in matched controls (p=.403). Dividing the 330 patients into age groups by decades, revealed an age dependent, increasing risk of relapse for patients receiving conventional post-remission therapy, with cumulative relapse incidences of 51% ( 〈 31 years), 47% (31–40 years), 60% (41–50%) and 87% (51–60 years) at 7 years, whereas allo-SCT patients had similar relapse incidences of 32%, 34%, 25% and 34% respectively. The higher relapse incidence in control patients 〉 50 years of age, resulted in a significantly better OS of allo-SCT patients with 27% versus 58% (p=.022) in this age group. In the subset of patients with INT-CG, allo-SCT patients with non-normal karyotype had both a significant better OS and RFS after 7 years compared to control patients, whereas patients with normal karyotype had similar RFS and OS regardless of NPM1 and FLT3 mutational status. Of note, 48 of 99 patients with AML relapse in the control cohort, received an allo-SCT (18 from a MRD, 30 from a MUD) beyond CR1 (9 with UNF-CG, 38 with INT-CG, 1 with favorable CG). Median OS of 48 matched patients receiving an allo-SCT in CR1 was 54%, while it was 39% in paired patients with allo-SCT beyond CR1 (p=.289). We conclude that allo-SCT is the most potent post-remission therapy for AML with UNF-CG and INT-CG. Its impact on OS is difficult to assess, as about a third of patients initially treated with conventional PRT, underwent allo-SCT beyond CR1. In contrast to results from donor versus no-donor comparisons, our data highly suggest a benefit of allo-SCT in CR1, particularly for elderly patients, and in line with such comparisons, for patients with intermediate-II (according to the European LeukemiaNet [ELN] recommendation) or unfavorable ELN cytogenetic risk. Ultimately, the gold standard for the evaluation of allo-SCT in patients with INT-CG in CR1 is a randomized controlled trial, which is now feasible with unrelated donors becoming w idely available and is conducted by the German Cooperative Transplant Study Group (ETAL-1 study). Disclosures: No relevant conflicts of interest to declare.

Abstract: Cytogenetically normal acute myeloid leukemia (CN-AML) is the largest and most heterogeneous cytogenetic AML subgroup. For the practicing clinician it is difficult to know how to use the prognostic information of the growing number of clinical and molecular markers. Our purpose was to develop a widely applicable prognostic model by combining well-established pre-treatment patient and molecular characteristics. Patients and methods Two prognostic indices for CN-AML, one with regard to overall survival (PINAOS) and the other regarding relapse-free survival (PINARFS) were derived based on a cohort of 669 CN-AML patients treated within the AML Cooperative Group 99 (AMLCG99) study. Results Based on age (median: 60 years [range: 17-85 years]), performance status, white blood count, and presence or absence of NPM1 mutation, biallelic CEBPA mutation, and FLT3-ITD, patients were classified into three risk groups according to PINAOS and PINARFS: 29% of all and 32% of responding patients had low risk (5-year OS 72%; 5-year RFS 55%), 56% and 39% intermediate risk (5-year OS 28%; 5-year RFS 27%), and 15% and 29% high risk disease (5-year OS 3%; 5-year RFS 8%) (Figure 1). PINAOS and PINARFS further subdivided the European LeukemiaNet (ELN) favorable-genetic group as well as the ELN intermediate-I-genetic group. Both, PINAOS and PINARFS were confirmed in a large, independent, and comparable CN-AML cohort of 529 patients from the Cancer and Leukemia Group B (CALGB/Alliance) trials (Figure 2). Conclusions We have developed and validated the first prognostic indices specifically designed for CN-AML patients of all ages combining well-established molecular and clinical variables easily applicable in routine clinical care. The integration of both clinical and molecular markers could provide a basis for individualized patient care by risk-adapted therapy of CN-AML. Disclosures: No relevant conflicts of interest to declare.

Abstract: Despite recent advances, treatment of elderly patients with AML remains a challenge because of adverse disease biology, comorbidities and therapy related toxicities. The balance between effectivity and toxicity of treatment strategies play a key role. Since comparative studies are lacking, a prospective randomized trial was designed among German AML study groups with different treatment strategies to compare outcome. Patients ≥60 years with all AML subtypes except M3 were randomized up-front to a common standard arm (CSA) (10%) and to study specific arms (90%) of the AMLCG or the OSHO. The CSA consisted of one or two inductions of araC 100 mg/m2/d continuous IV (CI) d 1-7 d and daunorubicin (dauno) 60 mg/m2/d IV d 3, 4, 5 and two courses of araC 1 g/m2/d BID IV d 1, 3 and 5 as consolidation (Mayer RJ et al, NEJM 1994). The AMLCG study arm randomized TAD (araC 100 mg/m2/d CI d1-2 followed by BID d 3-8, dauno 60 mg/m2/d IV d 3-5 and 6-thioguanine 100 mg/m2/d po BID d 3-9) and HAM [araC 1 mg/m2/d IV BID d 1-3 and mitoxantrone (mito) 10 mg/m2/d IV d 3-5] versus two courses of HAM with any 2nd course only given if blasts persisted ± G-CSF. Two courses of TAD were given as consolidation followed by maintenance chemotherapy over three years. The OSHO study arm included araC 1 g/m²/d BID IV d 1 + 3 + 5 + 7 and mito 10 mg/m2/d IV d 1 - 3 for one or two induction courses and ara-C 500 mg/m² BID 1h IV d 1 + 3 + 5 in combination with mito10 mg/m2/d IV d 1 + 2 as consolidation. Pegfilgrastim 6 mg s.c. was applied on day 10 of induction and on d 8 of consolidation. The study was approved by the IRB and registered at clinicaltrials.gov (NCT01497002 and NCT00266136). Written informed consent was obtained from all patients prior to randomization. Between April 1st, 2005 and May 26th, 2015 1286 patients were assigned randomly to the CSA (n=132) or to the study groups arm (n=1154). After excluding 139 patients (10.8%), 1147 patients were eligible for analysis, 1120 with follow-up for overall survival (OS) and 1079 for complete remission (CR) analysis. Baseline characteristics of all eligible patients showed median ages of 68 (60-82) years for the CSA and 69 (60-87) and 70 (60-85) years in the study arms A and B, respectively (p=0.05). Proportions of patients with secondary AML differed significantly between study arms (A: 42%, B: 30%, CSA: 36%; p=0.003). The CSA had less flt3 wildtype/npm1 wildtype patients (31%) vs. arm A (51% p=0.040) and arm B (58%, p=0.0455). No differences were observed with respect to cytogenetic risk groups, white blood cell counts, LDH, and npm1 mutant/ flt3-wildtype or mutant. The primary endpoint event free survival (EFS) did not differ between the CSA and study group strategies. Three-year EFS was 12.4% (95% CI: 6.7 - 19.9%) in the CSA, 15.6% (95% CI: 13.1 - 18.3%) in group A and 11.4% (95% CI, 7.4% to 16.4%) in group B (n.s.;Fig.1). With a median follow-up of 67 months, OS did not differ significantly between CSA and study group regimens. The 3-year survival probability was 22.3% (95% CI: 14.7-30.9%) in the CSA, 24.7% (95% CI: 21.6-27.9%) in group A and 22.4% (95% CI, 16.7% - 18.3%) in group B (Fig.2). CR status after 90 days of therapy was evaluated as secondary endpoint. The proportion of patients in CR in the CSA [51% (95% CI: 42-61%)] was comparable to the 50% (95% CI: 47-54%) and 48% (95% CI: 41-55%) of the study group arms (p=n.s.). Persistent leukemia was seen in 16% (95% CI: 10-24%) in the CSA vs 17% (95% CI: 14-19%) and 12% (95% CI: 8-17%) in groups A and B, respectively (both p= n.s.). A total of 226 patients died within 90 days of treatment, 24% (95% CI: 17-33%) in CSA, 19% in group A (95% CI: 16-22%) and 27% (95% CI: 21-33%) in group B; CSA vs A p=0.1859, CSA vs B p=0.5902). Death without AML was 3% in CSA, 2% in group A and 3% in group B, death with AML was 9% in CSA, 6% in group A and 5% in group B and death from indeterminate cause was 12% in CSA, 11% in group A and 20% in group B. Three-year relapse free survival (RFS) was 21.3% (95% CI: 12.2 - 31.0) in the CSA, 28.9% (95% CI: 24.9 -33.0%) in group A and 24.0% (95% CI: 16.8 - 31.9) in group B (both p=n.s.; Fig.3). In multivariate analysis independent variables for EFS and OS were age, type of disease, cytogenetic group and WBC count, but not the allocation to one of the treatment arms. Age and cytogenetic group were determinants for RFS. Conclusion A strictly prospective comparison of different treatment strategies in patients with AML did not show clinically relevant outcome differences when compared to a common standard arm. Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Niederwieser: Novartis Oncology Europe: Research Funding, Speakers Bureau; Amgen: Speakers Bureau. Hoffmann:Novartis Oncology Europe: Research Funding. Al-Ali:Celgene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Hegenbart:Pfizer: Other: Travel grant; Janssen: Honoraria, Other: Travel grant. Sayer:Riemser Pharma: Consultancy. Hochhaus:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding. Fischer:Novartis: Consultancy, Honoraria. Dreger:Novartis: Consultancy; Janssen: Consultancy; Gilead: Consultancy; Gilead: Speakers Bureau; Roche: Consultancy; Novartis: Speakers Bureau. Hiddemann:Roche: Membership on an entity's Board of Directors or advisory committees; Genentech: Other: Grants; Roche: Other: Grants.

Abstract: As a global approach to acute myeloid leukemia the AMLCG started a clinical trial in 1999 with the intention to clarify the influence of baseline characteristics as well as treatment variables on patients’ outcome. The heterogeneity of this disease in mind, all randomization was done stratified for potential risk factors. Furthermore, all randomization was restricted to the single time point up-front of any treatment. Thus, an unbiased intention-to-treat analysis could be provided. Between June 1999 and January 2012, 3370 consecutive patients 16 - 86 (median 61) years of age entered the trial at 57 participating centers. The general up-front randomization comprised (A) repeated G-CSF priming versus no G-CSF, (B) double induction by TAD (thioguanine-araC-daunorubicin) all at standard dose plus HAM (high-dose araC- standard dose mitoxantrone) versus HAM plus HAM, (C) postremission TAD and maintenance versus TAD and autologous stem cell transplantation. For age adaption patients of 60 years and older received reduced intensity double induction (B) and maintenance instead of autologous transplantation (C). The complete remission rate was 57% (65% 〈 60 and 51% 60+ years, p= 〈 .0001). With a median observation time of 7.1 years the overall survival at 5 years is 26% (40% 〈 60 years and 14% 60+ years, p 〈 .0001) and the rate of patients in complete remission at 5 years is 29% (41% 〈 60 years and 15% 60+ years, p 〈 .0001). There were no significant differences in the CR rates, the 5 years survival and continuous complete remission rates according to randomizations for treatment variables. In contrast, the CR rates and the therapeutic endpoints projected to 5 years were found significantly influenced by risk factors as identified within both age groups and including favorable cytogenetics/ molecular genetics (Döhner H et al. Blood 115: 453-74; 2010), adverse genetics, AML secondary to cytotoxic treatment or to previous myelodysplastic syndrome, LDH in serum, and in particular increasing age itself. In patients between 16 and 59 years of age receiving equal intensity treatment those below versus above the median age of 48 years showed a CR rate of 69% versus 57% (p 〈 .0001), a 5 years survival of 48% versus 33% (p 〈 .0001), and a 5 years proportion in CR of 46% versus 35% (p 〈 .0001). In patients between 60 and 86 years who received reduced intensity treatment the median age was 67 years, and those below versus above this median showed 51% versus 47% CR (p=.1), 5 years survival of 19% versus 9% (p 〈 .001) and 19% versus 12% 5 years proportion in CR (p=.01). Thus, up-front randomization proved to provide unbiased informations about the impact of various risk factors and treatment variables. While age was found to dominate other risk groups (Büchner T et al. J Clin Oncol: 27: 61-69; 2009), a difference in treatment intensity by factor 3.7 had no influence of outcome in a sample of equal baseline characteristics (Büchner T et al. Blood 122: 1447; 2013). As an alternative to antileukemic cytotoxicity, allogeneic stem cell transplantation in first remission was found to prolong even the overall survival in a matched pair analysis again done prospectively within present AMLCG99 trial (Stelljes M et al. J Clin Oncol 32: 288-96; 2013). Up-front randomization and a common standard arm also qualified as a model to compare treatment strategies between different studies (Büchner T et al. Leukemia Research 26: 1073-75; 2002, J Clin Oncol 30:3604-10; 2012). In older patients a web-based prediction of complete remission and early death could be established based upon the AMLCG99 trial (Krug U et al. Lancet 376: 2000-08; 2010). In summary, present long-term results from up-front randomization strongly support a strict prospective strategy for cooperative clinical research on acute myeloid leukemia. Disclosures No relevant conflicts of interest to declare.

Abstract: Abstract 1509 Introduction: Both, patients' age and genetic groups are important predictors of outcome in AML while their influence remains poorly quantified and compared. Methods: In the AMLCG (Acute Myeloid Leukemia Cooperative Group) 1999 trial 1470 patients (pts) were 16–59y and 1747 pts were 60–85y of age. 95% of pts could be classified according to genetic risk groups as standardized on behalf of the ELN (Blood 2010;115:453-74). Their treatment was randomized between TAD-HAM versus HAM-HAM induction (TAD, standard dose thioguanine, cytarabine, daunorubicin 60mg/m2 × 3; HAM, high-dose cytarabine 3g/m2 × 6, mitoxantrone 10mg/m2 × 3), TAD consolidation and monthly maintenance vs TAD and autologous SCT, any chemotherapy + vs – G-CSF priming. All assignment was done upfront. Pts of 〈 60y received routine double induction and full dose HAM while pts of 60+y preferentially received only 1 course induction and HAM at 1g instead of 3g cytarabine/m2 × 6. Results: With little difference according to randomizations, pts 〈 60y and 60+y achieved a complete remission (CR) rate of 65% and 51% (p 〈 .001), a 5y overall survival (OS) of 41% and 14% (p 〈 .001), and a 5y ongoing remission duration (RD) of 47% and 21% (p 〈 .001). We particularly focussed on pts around 60y of age and compared the 231 pts of 57–59y with the 315 pts of 60–62y. Corresponding to their similar age the two groups showed similar baseline characteristics. In contrast and due to the cutoff point for age adaption at 60y they differed considerably in treatment. Expressed by the cumulative dosage of cytarabine in induction and early consolidation, the difference between the two groups was by factor 3.9. This difference, however, did not translate into a different outcome being 60% vs 57% CR (p=0.59), 28% vs 25% 5y OS (p=0.40) and 32% vs 29% RD at 5y (p=0.46). Through focussing on patients around 60y a relevant influence of chemotherapy intensity and age adaption could thus be excluded. A multivariable analysis in the complete patients between 16 and 85y of age identified genetic groups and age (as a continuous variable) to be the only risk factors predicting CR, OS as well as RD whereas other risk factors such as secondary AML, WBC, and LDH were predictive only for subsets of endpoints. Among all treatment variables only HAM-HAM induction was associated with a slightly superior RD (p= 0.0715). Grouping by age resulted in 4 age categories (16–46y:n=683, 47–59y: n=787, 60–66y: n=815, and 67+y: n=932) with significantly different OS as well as RD. Subdividing by genetic groups (favorable: n=593, intermediate I: n=1169, intermediate II: n=526, adverse: n=780) distinguished 3 significantly different categories (favorable, intermediate, adverse), a pattern observed in all age groups. Conclusion: In a defined representative population of pts with AML the longterm outcome was mainly determined by age and genetic groups but not by treatment intensity or variables, nor by other prognostic factors. Both, age and genetic groups should thus contribute to a reliable prediction of outcome in AML. Disclosures: No relevant conflicts of interest to declare.