Abstract: Randomized comparison of two treatment strategies in frontline therapy of acute promyelocytic leukemia ( APL ): all‐trans retinoic acid ( ATRA ) and double induction intensified by high‐dose cytosine arabinoside ( HD ara‐C) (German AMLCG ) and therapy with ATRA and anthracyclines (Spanish PETHEMA , LPA 99). Patients and results Eighty of 87 adult patients with genetically confirmed APL of all risk groups were eligible. The outcome of both arms was similar: AMLCG vs PETHEMA : hematological complete remission 87% vs 83%, early death 13% vs 17% ( P  = .76), overall survival, event‐free survival, leukemia‐free survival, cumulative incidence of relapse at 6 years 75% vs 78% ( P  = .92); 75% vs 68% ( P  = .29); 86% vs 81% ( P  = .28); and 0% vs 12% ( P  = .04, no relapse vs four relapses), respectively. The median time to achieve molecular remission ( RT ‐ PCR negativity of PML ‐ RARA ) was 60 days in both arms ( P  = .12). The AMLCG regimen was associated with a longer duration of neutropenia ( P  = .02) and a higher rate of WHO grade ≥3 infections. Conclusions The small number of patients limits the reliability of conclusions. With these restrictions, the outcomes of both approaches were similar and show the limitations of ATRA and chemotherapy. The HD ara‐C–containing regimen was associated with a lower relapse rate in high‐risk APL .

Abstract: Introduction: Insulin-like growth factor binding proteins (IGFBP) are carriers of insulin-like growth factors (IGFs). They prolong their half-life and modulate their availability and activity. The IGF-signaling system has been shown to have an important role in various solid cancers and hematologic malignancies. High levels of IGFBP2 and IGFBP7 have been associated with chemoresistance, relapse and inferior survival in different leukemias. Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML), which has been reported to have increased expression of IGFBP2. However, there is no data on its impact on prognosis. In addition, no data exist on IGFBP7 in APL. The aim of this study was to elucidate the influence on prognosis of both candidate genes in APL patients. Methods: Expression levels of IGFBP2 und IGFBP7 were retrospectively analysed in bone marrow (BM) samples at the time of initial diagnosis from 69 APL patients (42 female, 27 male) after informed consent. Median age of patients was 46 years (range 19 to 82 years). All patients were diagnosed and treated in the German AML Cooperative Group (AMLCG) studies. Treatment consisted of simultaneous ATRA and double induction chemotherapy including high dose ara-C, one cycle of consolidation chemotherapy and 3 years monthly maintenance chemotherapy. In patients older than 60 years, the second induction cycle was at the discretion of the treating physician. Three patients (4%) received an induction of ATRA and an anthracycline without ara-C. BM samples of 22 healthy volunteers served as a control group. Multiplex reverse transcriptase quantitative real-time PCR (qRT-PCR) was performed on a LightCycler® 480 (Roche, Mannheim, Germany) PCR system. Glucose-6-phosphat isomerase was used as a housekeeping gene. For quantification of relative expression values a modified delta-delta CT calculation model according to Pfaffl was used after determination of PCR efficiencies. cDNA from the cell line K562 served as a calibrator in each run. All reactions were performed in triplicates. IGFBP2 expression groups were defined as follows: Patients with IGFBP2 expression below or equal the 25th percentile (IGFBP2low) were compared to patients with higher IGFBP2 expression (IGFBP2high). Overall survival (OS), relapse free survival (RFS) and the cumulative incidence of relapse (CIR) were calculated using the Kaplan-Meier method and a log-rank test was used to compare differences between the groups (p 〈 0.05). Results: Expression levels of IGFBP2 did not differ between APL patients and healthy controls. However, there was a significantly higher relapse rate in APL patients with low IGFBP2 expression (CIR: 25% in the IGFBP2low group vs. 5% in the IGFBP2high group; p=0.04). Accordingly, RFS of patients in the IGFBP2low group was also inferior (41% vs. 81% in the IGFBP2high group; p=0.0002; Fig. 1). The OS of patients who had responded to induction therapy was also influenced by IGFBP2 expression (OS of responders: 61% for IGFBP2low vs. 83% for IGFBP2high; p=0.02). However, there was no significant difference in the analysis of OS of all patients including patients who suffered early death. In contrast to these findings, IGFBP7 was expressed significantly lower in APL patients compared to healthy controls (p 〈 0.0001) but there was no association with outcome of APL patients. Conclusion: Of the two analysed IGFBP family members only IGFBP2 showed impact on the prognosis of APL patients. Remarkably, IGFBP2 was not overexpressed compared to healthy controls in our patient cohort. The reason might be that whole BM samples of healthy controls were used instead of subpopulations. Still, among the APL patients cohort its expression showed a strong influence on prognosis especially on relapse rate and RFS. To find low expression as a negative prognostic marker is surprising as for leukemias only high expression has been reported as a negative factor. However, IGFBP2 has been proposed to suppress tumor development through binding IGFs and preventing IGF-receptor driven tumorigenesis. This is supported by the fact that the IGFBP2 promotor is hypermethylated in various types of cancer. In summary, we identified low IGFBP2 expression as a novel prognostic marker for APL. Further investigations are warranted to clarify its possible role in leukemia. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract: Introduction: With many treatment options for chronic myeloid leukemia (CML), endpoints like health-related quality of life (HRQoL) move into focus and might be essential for deciding on treatment strategies. We sought to evaluate HRQoL in CML patients who had been registered in four consecutive studies of the German CML study group. Methods: The EORTC QLQ-C30 questionnaire was used to assess HRQoL of CML patients. Functional scales and global health status were calculated in accordance with Aaronson (1993) and Fayers (2001). With scales ranging from 0 to 100, 8 points are regarded as a minimally important difference (Efficace et al., 2013). Baseline data of responders (R) and non-responders (NR) were compared. Associations between two variables were assessed by the Fisher or Mann-Whitney tests, as appropriate. The global health status and the functioning scores were compared between groups with the van Elteren test, if the groups were stratified for another variable. Furthermore, results of the global health status and the functioning scores in our sample were standardized in accordance with the age (18-29, 30-39, 40-49, 50-59, 60-69, ≥70 years) and sex distribution of the 2448 participants of the German HRQoL outcome study reported by Hinz et al. 2014. The outcome of our sample was then compared with the outcome of these 2448 patients representing QoL of the German population in general. Comparison was performed using a t test. Results: A questionnaire was sent to 1634 patients. During January to April 2011, 858 questionnaires (53%) were sent back. Compared to NR, R were older (median age: 55 vs. 58, p=0.0426); years since diagnosis (median 6.5 vs. 7.4) and the percentage that had been transplanted were lower (24%vs.18%). No differences were observed regarding sex, Euro score, or time after allogeneic hematopoietic stem cell transplantation (HSCT). When answering the questionnaire, 517 (60%) patients received imatinib 400mg (IM400) and 102 (12%) were off therapy after HSCT. Less than 10% of patients received imatinib 800mg, imatinib+AraC or interferon alpha, nilotinib, or dasatinib. Time since diagnosis was ≤3 years in 156 (18%), 〉 3 and ≤7 years in 309 (36%), and 〉 7 years in 393 (46%) of the patients. Women (352, 41%) perceived a significant reduction in global health status (mean: 62.7, p 〈 0.001), role (65.4, p=0.0016), emotional (60.3, p=0.0002), and physical functioning (74.9, p 〈 0.0001) when compared to males (68.9, 71.5, 67.6, and 82.7, respectively). In the latter two cases, this perception met the definition of a clinical relevance. Results on significance did not change with adjustment for age. Compared to the German population, the 858 CML patients had significantly lower scores for global health status (mean: 67.9, p 〈 0.0001), role (70.8, p 〈 0.0001), social (69.2, p 〈 0.0001), emotional (64.6, p 〈 0.0001), physical (81.0, p 〈 0.0001) and cognitive functioning (77.3, p 〈 0.0001). Only for global health status, the difference was below 8. To evaluate HRQoL in patients with long standing disease, 100 patients with diagnosis 〉 7 years off therapy after HSCT and 203 patients receiving IM400 were analyzed. Adjusted for age group and sex, CML patients receiving IM400 for more than 7 years had lower scores for global health status (mean: 63.8, p 〈 0.0001 ), role (66.7, p 〈 0.0001), social (68.8, p 〈 0.0001), emotional (64.0, p 〈 0.0001), physical (75.2, p 〈 0.0001) and cognitive functioning (68.0, p 〈 0.0001) than the German control population. With respect to all six HRQoL scores, significantly lower scores than from the German population were also observed for the CML patients being seven years without treatment after HSCT: global health status (mean: 69.2, p 〈 0.0001 ), role (68.6, p 〈 0.0001), social (67.5, p 〈 0.0001), emotional (68.1, p 〈 0.0001), physical (83.1, p 〈 0.0001) and cognitive functioning (71.2, p=0.0053). Conclusions: In this cross-sectional study, women showed an impaired global health status, role, emotional, and physical functioning compared to males. Considering all 858 CML patients, the HRQoL was significantly impaired in all scales when compared to the German population. The same results were observed for the subgroups of patients either receiving IM400 for at least 7 years or being off therapy 7 years after HSCT. Reduced HRQoL remains an issue for all patients after long-term TKI treatment or after HSCT. These data may serve as a basis to evaluate HRQoL in stopping studies in CML. Disclosures Saussele: BMS: Honoraria, Other: Travel grant, Research Funding; Novartis Pharma: Honoraria, Other: Travel grant, Research Funding; ARIAD: Honoraria; Pfizer: Honoraria, Other: Travel grant. Kremers:Novartis: Honoraria; Bristol Myers Squibb: Other: Travel costs, supporting educational meeting; Novartis: Other: supporting educational meeting. Hochhaus:Bristol-Myers Squibb: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding. Müller:BMS: Honoraria, Other: Consulting or Advisory Role, Research Funding; Novartis: Honoraria, Other: CONSULTING OR ADVISORY ROLE, Research Funding; ARIAD Pharmaceuticals Inc.: Honoraria, Other: Consulting & Advisory Role, Research Funding. Hehlmann:Novartis Pharma: Research Funding; BMS: Consultancy. Pfirrmann:BMS: Consultancy, Honoraria; Novartis Pharma: Consultancy, Honoraria.

Abstract: Systemic mastocytosis with an associated hematologic neoplasm (SM-AHN) is the most common subtype of advanced SM (advSM), diagnosed in up to 80% of patients. The AHN is most frequently diagnosed as a myeloid neoplasm, e.g., SM-MDS/MPNu or SM-CMML. Acquired mutations in KIT (usually KIT D816, KIT D816mut) are detectable in 〉 90% of patients. The basis for the SM-AHN phenotype is usually the multi-lineage involvement, e.g. monocytes, eosinophils and other non-mast cell lineages, of KIT mutations. Core binding factor (CBF) positive AML (CBFpos AML) represents a distinct subtype and is identified in 5-8% of all AMLs. KIT mutations, most frequently KITD816mut, are detectable in up to 45% of CBFpos AML patients and are associated with an adverse prognosis. There is, however, only little information on KIT D816mut/CBFneg AML. We therefore evaluated a) clinical and molecular characteristics, b) response to treatment and, c) survival and prognostic factors in 40 KIT D816mut/CBFneg patients with histologically proven SM and associated AML (SM-AML), collected at 4 centers of the European Competence Network on Mastocytosis (ECNM). Molecular analyses (n=32) revealed at least one additional somatic mutation (median, n=3) apart from KIT D816, most frequently SRSF2 (n=12, 38%), RUNX1 (n=11, 34%), TET2 (n=11, 34%), ASXL1 (n=10, 31%), or NPM1 (n=7, 22%). At least one mutation in SRSF2, ASXL1 or, RUNX1 (S/A/Rpos) was identified in 21/32 (66%) patients. At diagnosis of SM-AML 21/40 (52%) patients had an aberrant karyotype. Secondary AML evolved in 29/40 (73%) patients from SM ± associated myeloid neoplasm and longitudinal molecular analyses revealed acquisition of new somatic mutations (TP53, n=2; NPM1, n=1; RUNX1, n=1, ASXL1, n=1; BCOR, n=1; IDH1/2, n=1) and/or karyotype evolution in 15/16 (94%) patients at the time of SM-AML. Thirty-one of 40 (78%) patients were treated with intensive chemotherapy (ICT) with a complete response (CR) rate of 40%. Allogeneic stem cell transplantation (SCT) was performed in 12/40 (30%) patients with durable CR in 6/12 (50%) patients. S/A/Rpos and/or the presence of a poor-risk karyotype were adverse predictive markers for response to treatment. To further investigate whether KITD816mut/CBFneg AMLdefines a distinct AML subtype associated with SM, two independent AML databases (AMLdatabases) were retrospectively screened and 69 KIT D816mut/CBFneg AML patients identified. The comparison between KIT D816mut/CBFneg SM-AML from ECNM (n=40) centers with KIT D816mut/CBFneg AMLdatabases(n=69) revealed remarkable similarities: a) a high KIT D816 variant allele frequency (VAF) (median 34% vs. 29%), b) with the exception of SRSF2 (38 vs. 18%), a highly similar mutation landscape, rather comparable to that of advSM (Jawhar et al., Blood 2017) than to that of de novo AML, c) in contrast to de novo AML, a low frequency of FLT3 mutations (3 vs. 7%), and d) a high frequency of an aberrant karyotype (52 vs. 42%). The median overall survival (OS) of 40 KIT D816mut/CBFneg SM-AML and 17 evaluable KIT D816mut/CBFneg AMLdatabases was 5.4 (95% confidence interval, CI [1.7-9.1]) and 26.4 (95% CI [0-61.0] ) (P=0.015) months, respectively (Figure 1). However, if only the patients with ICT ± allogeneic SCT were compared, median OS between the two groupswas not different (16.7 vs. 26.4 months, P=0.4). In multivariate analyses, S/A/Rpos and a poor-risk karyotype remained the only independent poor-risk factors with regard to OS. These results were independent of treatment modalities. We conclude that KIT D816mut/CBFneg AML is a new poor-risk subtype associated with SM (SM-AML). The remarkable clinical, genetic and prognostic similarities between SM-AML and AMLdatabases suggest that a significant proportion of the AMLdatabases patients may in fact have SM-AML. We therefore strongly recommend to determine serum tryptase and KIT D816 mutation status in all AML patients, and to perform bone marrow histology in KIT D816mut patients. These simple diagnostic measures would allow reclassification to SM-AML and inclusion of KIT inhibitors in established treatment modalities of AML. Disclosures Meggendorfer: MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Döhner:Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Celator: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Astellas: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Jazz: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Pfizer: Research Funding; Pfizer: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding. Sperr:Novartis: Honoraria; Pfizer: Honoraria; Daiichi Sankyo: Honoraria. Valent:Incyte: Honoraria; Pfizer: Honoraria; Novartis: Honoraria. Reiter:Incyte: Consultancy, Honoraria.

Abstract: Biallelic mutations of the CCAAT/enhancer binding protein α (CEBPA) gene define a distinct genetic entity of acute myeloid leukemia (AML) with favorable prognosis. The presence of GATA2 and CSF3R mutations that are specifically associated with this subgroup but not mutated in all samples suggests a genetic heterogeneity of biCEBPA-mutated AML. We characterized the mutational landscape of CEBPA-mutated cytogenetically normal AML by targeted amplicon resequencing. We analyzed 48 biallelically mutated CEBPA (biCEBPA), 32 monoallelically mutated CEBPA (moCEBPA), and 287 wild-type CEBPA (wtCEBPA) patient samples from German AML Cooperative Group studies or registry. Targeted sequencing of 42 genes revealed that moCEBPA patients had significantly more additional mutations and additional mutated genes than biCEBPA patients. Within the group of biCEBPA patients, we identified 2 genetic subgroups defined by the presence or absence of mutations in chromatin/DNA modifiers (C), cohesin complex (C), and splicing (S) genes: biCEBPACCSpos (25/48 [52%]) and biCEBPACCSneg (23/48 [48%] ). Equivalent subgroups were identified in 51 biCEBPA patients from the Cancer Genome Project. Patients in the biCEBPACCSpos group were significantly older and had poorer overall survival and lower complete remission rates following intensive chemotherapy regimens compared with patients in the biCEBPACCSneg group. Patients with available remission samples from the biCEBPACCSpos group cleared the biCEBPA mutations, but most had persisting CCS mutations in complete remission, suggesting the presence of a preleukemic clone. In conclusion, CCS mutations define a distinct biological subgroup of biCEBPA AML that might refine prognostic classification of AML. This trial was registered at www.clinicaltrials.gov as #NCT00266136 and NCT01382147.