ALBERT

Description: Introduction: As showed in a recent study of our group, considering bone marrow (BM) blasts from nonerythroid cellularity (NECs) improves the prognostic evaluation of MDS (Arenillas et al, J Clin Oncol 2016). By enumerating blasts from NECs, 12% of MDS patients diagnosed within WHO categories with less than 5% BM blasts were reclassified into higher-risk categories and showed a poorer overall survival than did those who remained in the initial categories. Refractory anemia with ring sideroblasts (RARS) and refractory cytopenia with multilineage dysplasia and ring sideroblasts (RCMD-RS) have shown an special good outcome in different studies. As MDS with ring sideroblasts (MDS-RS) usually present a high percentage of BM erythroblasts, considering BM blasts from NECs could imply a risk overestimation of this subset of patients. Aim: we evaluated the relevance of considering BM blasts from NECs or from total nucleated cells (TNCs) on classification and prognostication of the group of patients diagnosed with MDS-RS. Methods: We retrospectively analyzed 3,924 de novo MDS diagnosed according to WHO 2001 and 2008 classifications from the MDS Spanish registry. 1,045 patients presented less than 5% BM blasts from TNCs and equal or greater than 15% BM ring sideroblasts, fulfilling current definition for RARS (WHO 2001 and 2008) and RCMD-RS (WHO 2001). Moreover 1,233 patients with equal or greater than 5% BM ring sideroblasts and less than 5% BM blasts were analyzed in order to explore the future definition of WHO 2016, that considered as MDS-RS those patients with 5%-

Description: Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell (HSC) malignancies characterized by ineffective hematopoiesis. Genetic alterations do not fully explain the molecular pathogenesis of the disease, indicating that other types of lesions, such as transcriptional aberrations, may play a role in its development. Moreover, MDS prevalence is almost exclusive to older patients, suggesting that elderly-related alterations may predispose to the development of this clinical entity. Thus, study of the transcriptional lesions occurring in the aging-MDS axis could shed some light of the molecular bases of the disease. To characterize the transcriptional profile of HSCs in aging and MDS, we isolated CD34+, CD38-, CD90+, CD45RA- cells from 11 untreated MDS patients with unilineage and multilineage dysplasia (median of 75 y/o), as well as from 16 young and 8 elderly healthy donors (median of 21 and 70 y/o, respectively), and their expression profile was analyzed using MARS-seq. Unsupervised principal component analysis demonstrated that the three groups of HSCs clustered separately, indicating that different expression profiles characterize healthy young and elderly, and MDS-associated HSCs. To better understand the gene expression deregulation of HSCs, we analyzed the transcriptional dynamisms along the aging-MDS axis, detecting groups of genes following different patterns of expression. Some gene clusters showed exclusive alteration either in aging or in the progression from elderly HSCs to MDS-HSCs, other groups of genes presented a continuous alteration along the axis, and some displayed opposite regulation in aging and in the transition to MDS (Figure 1). Genes showing specific downregulation in aging were involved in DNA damage sensing and repair, and in cell cycle regulation, whereas genes overexpressed in this process were enriched in apoptosis regulators and in cancer-associated genes, including AML-related factors. These findings indicate that transcriptional changes in aging may predispose for MDS and AML, and potentially other malignancies. Interestingly, we detected a group of genes in which the age-mediated upregulation of gene expression was reversed to that of young HSCs in MDS, indicating a "rejuvenation" profile of malignant HSCs. These genes were involved in response to inflammation, to different types of stress conditions such as hypoxia or radiation, and to cytokines. Elderly HSCs may upregulate such genes in response to the known inflammatory microenvironment of elderly bone marrow. Intriguingly, the decrease in expression detected in MDS suggests that malignant HSCs lose the ability of reacting to such stimuli, possibly favoring their survival in a hostile microenvironment. Finally, the analyses performed allowed for the identification of genes showing MDS-specific deregulation. Genes specifically overexpressed in MDS compared to normal (both young and elderly) HSCs, we enriched in transcriptional and epigenetic regulators, and among them, we detected the presence of DDIT3/CHOP, a member of the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors. To determine its potential effects on hematopoietic deregulation, DDIT3 was exogenously overexpressed in healthy HSCs. Notably, its upregulation produced an erythroid bias in an ex-vivo differentiation system, with an increase in the percentage of erythroblasts and a decrease in granulocytes and monocytes compared to HSCs transduced with the empty vector. Transcriptomic analysis of transduced HSCs not subjected to differentiation demonstrated how DDIT3 overexpression produced an erythroid-prone state of HSCs, suggesting it may act as a pioneer factor in MDS-HSCs. Furthermore, gene set enrichment analysis showed that DDIT3 overexpression produced an MDS-like transcriptional profile, suggesting this factor may be key in the acquisition of the disease. Altogether, our results demonstrate that HSCs undergo transcriptional changes in the aging-MDS axis that may alter their intrinsic functions as well as their response to the microenvironment, ultimately contributing to the acquisition of the disease. In particular, our data show that DDIT3 may be a potential driver of MDS transformation. Disclosures Paiva: Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, Novartis, Roche, and Sanofi; unrestricted grants from Celgene, EngMab, Sanofi, and Takeda; and consultancy for Celgene, Janssen, and Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau. Díez-Campelo:Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Abstract 5026 Myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic stem cell with low life expectancy due to several blood cytopenias and high risk of acute myeloid leukemia transformation (AML). Classically, evolution to AML, infection, and hemorrhage are reported as the main causes of death. However, there are few reports analyzing other causes of death in MDS patients, particularly the prevalence of non-MDS-related causes in large series from single-centers. We present here the analysis of causes of death of 200 patients (median age 75yr, range 16–96, 59% male) diagnosed of MDS in our institution between 2000 and 2010. Patients were diagnosed and classified according to the FAB criteria, WHO 2008 classification, IPSS (International Prognostic Scoring System) and SPI (Spanish Prognostic Index). Overall survival (OS) and survival of different MDS subtypes were analyzed. Two prognostic subgroups were defined: low-risk subgroup, composed by patients with low or intermediate-1 IPSS and low SPI; and high-risk subgroup, that included patients with intermediate-2 and high IPSS and intermediate and high SPI. Infection, hemorrhage, disease progression and transformation to AML were considered MDS-related deaths. All other causes of death were classified as non-MDS-related. Median follow-up of the series was 1.8 years (range: 0–11 years). MDS subtypes distribution was as follows: RA, RARS and 5q– 19%; RCMD and RCMD-RS 32%; RAEB-1 and RAEB-2 27%; hypoplastic and unclassified MDS 8%; and CMML 13%. One hundred twenty-nine patients (64.5%) belonged to the low-risk subgroup, whereas 65 patients (32.5%) to the high-risk subgroup. Only 6 patients (3%) could not be classified. Median OS of the whole series was 2 years, being of 3.7 years in the low-risk subgroup and of 0.9 years in the high-risk subgroup (P

Description: Abstract 702 Despite that low and intermediate-1 (int-1) IPSS groups are commonly considered as low risk diseases with a median overall survival exceeding 60 months, some of these patients will evolve as higher risk myelodysplastic syndrome (MDS). Recently several new prognosis indexes (PI) have been proposed: The new IPSSr, WPSSr, MD Anderson for lower risk patients (MDA) Index, and the Spanish Group of MDS (GESMD) proposal that considers as high risk those patients with int-1 IPSS and at least one of the following: platelets

Description: Background Chronic myelomonocytic leukemia (CMML) is an ultrarare stem cell disorder defined by the presence of monocytosis (≥1.0 G/l, ≥10%). Depending on white blood cell (WBC) count, CMML can be divided into a myelodysplastic (MD) (WBC ≤13 G/l) and a myeloproliferative (MP) variant (WBC 〉13 G/l). Although hypomethylating agents (HMA) have been shown to prolong overall survival (OS) in MDS patients (pts) in prospective, randomized phase III trials, only 6-14 MD-CMML pts were included, and MP-CMML pts were excluded [Silverman 2002; Kantarjian 2006; Fenaux 2009]. EMA approval of azacitidine (AZA) in CMML is thus based on limited experience and restricted to MD-CMML with 10-29% bone marrow blasts (BMB), whereas decitabine (DAC) is not approved for treatment (trt) of CMML in the EU. Smaller analyses and single-arm trials of HMA in CMML exist [Wijermans 2008; Ades 2013; Pleyer 2014; Zeidan 2017; Duchmann 2018; Santini 2018; Coston 2019; Diamantopoulos 2019], but it is still unclear whether HMA provide a benefit in CMML (subgroups) compared with other trts. Aim Evaluate the impact of HMA and hydroxyurea (HU) trt on OS and time to next trt (TTNT). Methods Data were collected from 7 European study groups and 2 US MDS Centers of Excellence; database lock 27.05.19; Assign Data Management and Biostatistics GmbH performed statistical analyses with SAS® 9.3. Of 1657 CMML pts, only those who received trt (n=950), with documented WBC and BMB at 1st line, were included in these analyses (n=845, cohort 1). Pts were stratified according to the EMA approved AZA indication, and inclusion/exclusion criteria of the GFM-DAC-CMML trial assessing DAC +/- HU vs HU (NCT02214407) (diagnosis of CMML, no prior trt [except supportive care, erythropoietin or ≤6 weeks HU], WBC ≥13 G/l and ≥2 of the following: BMB ≥5%, clonal cytogenetic abnormality [other than -Y], hemoglobin 16 G/l, platelet count 2 excluded) (n=486; cohort 2). Results In cohort 1, pts receiving HMA 1st line (n=375) had longer OS (19.8 vs 16.3 months [mo], P=0.0102) and TTNT (13.2 vs 6.7 mo, P=0.0001) than pts treated with non-HMA 1st line (n=470). Survival benefit was longer when comparing pts who received HMA (any time) (AZA [n=442], DAC [n=37], both [n=27]) with those that never received HMA (never HMA; n=339) (23.0 vs 13.0 mo, P

Description: Cytogenetic abnormalities are found in around half of MDS patients (pts) and have both clinical impact and may be subtype-defining, e.g. in 5q-syndrome. Interstitial deletion of the long arm of chr.5 [del(5q)] is the most common aberration (almost 20% of cases with abnormal cytogenetics). Del(5q) is heterogeneous, occurring as a sole abnormality or in combination, with the deleted region often truncated within or extended and/or beyond the CDR boundaries. Isolated del(5q) is frequently shorter and confers a more favorable prognosis with regard to survival and lenalidomide (LEN) responsiveness, while del(5q) in the context of a complex karyotype (CK) imparts a poor prognosis. In addition to chromosomal lesions, somatic mutations can contribute to the pathogenesis of MDS, including del(5q). We theorized that recognition of molecular defects in MDS with del(5q) may clarify the pathogenic mechanisms behind this lesion and help explain the clinical heterogeneity. We analyzed 225 pts with myeloid neoplasia and del(5q) using WES (n= 107 samples) and targeted multiplexed PCR (top 60 most frequently mutated genes) (n =133 samples); serial analysis was performed in 15 pts studied at ≥2 time points, 11 during LEN therapy and 4 upon relapse/progression. A total of 116 samples had a CK with other lesions such as -7/del(7q) found in 31% cases, and 18% had -17/del(17p). WES (average depth 〉60x) was followed by a bioanalytic pipeline, detecting ≥1 mutated gene in 71% of cases. Candidate somatic alterations were found in 357 genes and selected for further analysis. When focused on hemizygous mutations within the retained 5q allele, CSNK1A1 mutations were the most common, found in 4 pts, while other genes were only sporadically affected. Among heterozygous mutations on the non-deleted portion of del(5q) and other chromosomes (Chr), we found several novel mutations, in addition to TP53 (n=26), DNMT3A (n=8), PRPF8 (n =8), RUNX1 (n=5), TET2 (n=5), and ASXL1 (n=4), among others. Furthermore, LOH/haploinsuffciency of genes on 7q (e.g., LUC7L2, CUX1, EZH2 and MLL3) appears to be a common defect seen in pts with non-isolated del(5q), suggesting synergistic functional defects. When functionally grouping gene mutations, DNA methylation family (8 cases) and transcription factor mutations (29 cases) were associated with advanced disease (AD) and a CK. Heterozygous mutations in TP53 (34%) or deletions involving the TP53 locus (23%) resulted in total of 42% of cases carrying either TP53 LOH or mutation. TP53 lesions were more common in pts with AD vs. low risk. (21 vs. 5 p =.0008). In contrast, TP53 mutations are found in 8-10% of cases of MDS. A total of 34 pts were treated with LEN and subgrouped into responders (n=17) vs. refractory (n=9) with an overall response rate of 65%. When mutational profiles were compared, the presence of TP53 mutations did not preclude responsiveness to LEN. CK was present in 12% of responders vs. 67% of refractory pts. The most frequent Chr abnormalities were -7/7q (0% vs. 67% in responders vs. refractory) and 17p-(6% vs. 67% in responders vs. refractory) suggestive of their role in LEN resistance. In addition to cross sectional analysis, our WES study using paired Germline/tumor samples followed by deep sequencing facilitated analyses of clonal architecture by examining clonal dynamics over time. Assessment of del(5q) clone size by allelic imbalance combined with clonal burden by VAF allowed us to reconstruct the clonal hierarchy: in 73% of cases, del(5q) appeared to be the initial defect followed by subsequent mutations (e.g., TP53, DNMT3A, IDH2). In contrast, in 24% of cases, TP53, RUNX1, JARID2, were the primary defect followed by a subclonal del(5q) events. Serial samples collected before and after therapy demonstrated that responses were associated with decreased clonal burden for del(5q) but persistence of certain mutations. In refractory cases, persistent subclonal lesions and the appearance of new lesions were associated with progression. For example, pts with TP53, LAMB4, EPHA6 progressed and acquired additional lesions such as CSMD2 or KCND2, and did not see the disappearance of TP53 alterations upon treatment. In conclusion, no unifying somatic defect was found in pts with del(5q) regardless if the deletion event was primary or subclonal. Most commonly associated lesions were not present on the retained 5q alleles but rather other chr yet modified clinical behavior, including responsiveness to LEN. Disclosures Bejar: Celgene: Consultancy, Honoraria; Alexion: Other: ad hoc advisory board; Genoptix Medical Laboratory: Consultancy, Honoraria, Patents & Royalties: MDS prognostic gene signature. Sekeres:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; TetraLogic: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

Description: Introduction: Proportion of bone marrow (BM) blasts is a major prognostic factor for outcome in patients with myelodysplastic syndromes (MDS) and is included in the most applied prognostic scoring systems: IPSS and IPSS-R. IPSS-R stratifies patients in five risk categories: very low (VL), low (L), intermediate (I), high (H) and very high (VH). Some concerns exist about the real prognostic significance of intermediate risk group, as these patients showed around 30 months of median overall survival (OS) in different studies. The Spanish Group of myelodysplastic syndromes considers as high-risk patients those with an expected median OS inferior to 30 months. As showed in a recent study of our group, considering BM blasts from nonerythroid cellularity improves the prognostic evaluation of MDS (Arenillas et al, J Clin Oncol 2016) when applying IPSS and WHO classification. Aims: 1) To assess OS and leukemia-free survival (LFS) prediction by IPSS-R by counting BM blast percentage from nonerythroid cells (NECs). 2) To evaluate whether considering BM blasts from NECs rather than from total nucleated cells (TNCs) improves the prognostic assessment of patients classified into the intermediate risk group. 3) To establish which of these methods present the best prediction capacity for survival and leukemic transformation. Methods: We retrospectively analyzed 3,924 denovo MDS diagnosed according to WHO 2008 from the MDS spanish registry. Percentage of BM blasts from NECs was calculated as follows: [%BM blasts from TNCs/(100 - %BM erythroblasts) x 100]. Survival curves were constructed by using the Kaplan-Meier (K-M) method and compared using the log-rank test. C-index was implemented to assess the method with the best predictive value for survival and leukemic transformation. Results: Median age at diagnosis was 75y (16-101y) and 59% were males. Estimated median follow-up, as calculated by reverse K-M method, was 46.5 months (95% CI, 43.9-49) and median OS was 56.97 months. We assessed OS predicted by IPSS-R by considering BM blasts from TNCs and from NECs (recoded IPSS-R) Fig 1A and 1B. As depicted, five groups with significant differences in OS were observed by using both methods. Interestingly, median OS of intermediate risk group patients changed from 32.3 to 40.4 months by considering blasts from NECs instead of TNCs, whereas patients classified in high and very high risk categories showed almost the same survival even though the higher-risk categories were increased in 25.7%. Of 3,285 patients, 164 (5%) classified in the lower-risk IPSS-R categories (VL, L, I) were reclassified into higher-risk categories (H, VH) when BM blasts were enumerated from NECs. OS and LFS of these upgraded patients was significantly shorter to those observed in patients who remained in the initial categories (median OS, 28.2 vs 71.7 months, P

Description: Introduction The therapy of myelodysplastic syndromes (MDS) has undergone a dramatic change in the last years with the inclusion of the demethylating agents but data regarding their impact on the “real life” setting are still scarce. Moreover the time to therapy from diagnosis, that has been evaluated in acute myeloid leukemia has not formally been evaluated in the MDS. The aim of our study was to evaluate the use of the different therapies and the time to therapy in an unselected Spanish population within the ERASME study. Here we present data from a pre-specified interim analysis of MDS patients who fall into higher-risk categories (Group-2: int-2/high) included in the ERASME study. Materials and methods The ERASME study (CEL-SMD-2012-01) is an observational, post-authorization, prospective, multicenter study that will include a total of 600 patients with MDS and Chronic myelomonocytic leukemia (CMML) according to the World Health Organization 2008 classification and that follow them for at least three years (or until death). The primary objective of this study is to describe disease progression in routine clinical practice, based on the initial therapeutic strategy, in patients with newly diagnosed MDS and CMML. The patients are classified in three groups: 1) low/Int-1 IPSS, 2) int-2/high and 3) CMML. Initial patient management strategy is classified in three groups: Observation (OB) & support (SP) (including blood and platelet transfusions and growth factors), active therapy (AT) (including chemotherapy, azacitidine, lenalidomide, etc) and allogenic hematopoietic cell transplant (HCT) (including those patients receiving other therapies before transplant). Initial data from the pre-specified interim analysis are presented. Results A total of 87 at int-2/high risk out of 254 MDS patients, 45% women with a median age of 73 years (range 39-87) were recruited between January 2013-June 2014. Of all patients, 57% had int-2 risk and 43% had high risk MDS. Median follow-up was 5.5 months (range 0-14.9). The most common MDS types were refractory anemia excess of blast type 1 and 2 (15% and 67%, respectively) and refractory cytopenia with multilineage dysplasia (16%). Cytogenetic abnormalities were present in 70% of patients (11% complex and 33% very complex Karyotype). Median bone marrow blast count was 12% (range 0-27). Hemoglobin, platelet, and neutrophil count was: 9.5 g/dL (range 6.7-13.3), 65x103/µL (9.7-439), and 1x109/L (range 0-24), respectively. In this patient population, the first therapeutic decision taken by the investigating physician was: AT in 49 (56%), HCT in 18 (21%) and OB&SP in 20 (23%) patients, each one. The main reason for treatment selection were risk-disease disease (94%), age (82%), symptomatology (66%) and comorbidities (55%). Patients in AT received azacitidine (n=44, 90%), chemotherapy plus azacitidine (n=4, 8%) and immunomodulatory therapy (n=1, 2%). Of those patients considered for HCT (n=18), 2 (11%) received transplant without prior therapy, and 16 (89%) received prior therapy with: azacitidine (n=10, 56%) chemotherapy (n=3, 17%), or both in (n=3, 17%). At last follow-up, 8 out of 18 HCT patients had undergone transplant within a median of 9.1 months (range 3.2-11) from diagnosis; 3 patients died before transplant, and 7 are still waiting for transplant. At last follow-up, a total of 26 (30%) have died: 11/6/9 patients for AT/HCT/OB&SP respectively (22%, 33%, 45%) (Log Rank, p= 0.1823). The overall survival was not reached (NR)/11.6/7.89 months (95% CI: 9.86-NR), (95% CI: 5.59-NR) and (95% CI: 2.17-NR), for each group, respectively. The median time from diagnosis to death in each group was 4.2, 4.8 and 2.2 months, respectively. The median time between diagnosis and therapy for AT/HCT/OB&SP was 0.77/0.24/5.3 months (range 0.09-2.75), (range 0.03-2.79), (range 2.2-6.0), for each group, respectively. Conclusions Higher-risk MDS patients were treated on an individualized therapy strategy after diagnostic evaluation and prognosis assessment. Our prospective study confirms that azacitidine has become the most common therapy for higher-risk MDS patients, including most of HCT candidates. Disclosures Off Label Use: Vidaza, erythropoietin -stimulating agents, Revlimid. Valcarcel:Celgene: Honoraria, Speakers Bureau. Sanchez:Celgene: Consultancy, Speakers Bureau. Rafel:Celgene: Employment.

Description: Introduction Risk assessment is essential for guiding therapy in patients with myelodysplastic syndromes (MDS). Currently, the most widely used prognostic scoring models are the International Prognostic Scoring System (IPSS) and the revised IPSS (IPSS-R). The prognostic relevance of the percentage of erythroid precursors (EP) in bone marrow (BM) and its relationship with other biological characteristics has been poorly studied, although it has been proposed that a very low percentage of EP in BM may represent a cohort of patients with potentially adverse outcome. Our main aim was to analyze the biological and clinical features of MDS patients according to the percentage of EP in BM at diagnosis and evaluate its prognostic value on survival. Patients and Methods Data from 4,791 de novo MDS patients from the MDS Spanish Registry with available cytogenetics were collected. All patients included were diagnosed based on the 2008 WHO criteria and risk stratification was performed following the IPSS-R. Patients were distributed, according to the percentage of EP in BM, into three groups: less than 15% (EP49%). Proportions were compared by the Chi-square test. Survival curves were constructed by Kaplan-Meier method and differences between curves were evaluated by log rank tests. Multivariable analysis of survival was performed using Cox's proportional hazards regression model. P-values

Description: Background Specific scoring systems developed for patients (pts) with lower-risk myelodysplastic syndromes (LR-MDS) (Garc'a-Manero G et al. Leukemia 2008; Falantes J et al. Clin Lymphoma Myeloma Leuk 2013) are able to identify a significant fraction of pts with a poorer (median OS, 13 months) than expected outcome (Greenberg P et al. Blood 1997). Retrospective data of azacitidine (AZA) in LR-MDS showed hematological improvement and survival when compared to non-responder pts (Lyons R et al. J Clin Oncol 2009; Musto P et al. Cancer 2010). However, the impact of AZA treatment in the group of LR-MDS with poor prognosis by a LR-specific score (LR-S) is uncertain. Aim To evaluate the impact of AZA treatment in LR-MDS pts with more adverse LR-S by multivariable time-dependent analysis. Patients Eighty-eight LR-MDS pts (IPSS Low/Int-1 or