ALBERT

Description: INTRODUCTION Anemia is the most frequent cytopenia in lower-risk MDS. Erythropoietic-stimulating agents (ESAs) are commonly used in these patients. The use of ÒclassicalÓ parameters (EPO and ferritin levels) and the revised IPSS (IPSS-R) has been proposed1 (SantiniÕs score) to predict response to ESAs and overall survival (OS) among patients with lower risk MDS by IPSS and a favorable Nordic group score2. OBJECTIVES The main objective of the study was to evaluate overall response rate (ORR) to ESAs and OS according to the proposed SantiniÕs score in an independent and large cohort of anemic lower risk MDS patients receiving treatment with ESAs. METHODS Data from 530 anemic patients with low/int1 risk IPSS de novo MDS (according to FAB and WHO criteria) and sufficient follow-up data available were recorded in Spresas3 (SPanish Registry of Erythropoietic Stimulating Agents Study from GESMD). Two hundred and twenty six patients (42.6% of the patients) were selected according to specific criteria regarding the published SantiniÕs score1: Hb level 350 ng/mL(=1) and IPSS-R very low=0, low=1, intermediate=2 and high=3) yielded a score ranging from 0 to 5. ESAs response rate and overall survival were analysed according to these score. Response to treatment was evaluated according to IWG 2006 response criteria and a multivariate logistic regression analysis was used to identify independent predictors of erythroid response (ER). OS were defined as the time between diagnosis and the corresponding event or last follow up (Feb 2015) and were analyzed using univariable and multivariable Cox proportional hazards regression methods. RESULTS Median age was 77 years (interquartile range [IQR] 25%-75%: 71-83 y), median Hb level at start of treatment was 10 g/dL (IQR25-75: 9-10), median EPO level was 90 (IQR25-75: 27,25-108) and median ferritin level was 338,5 (IQR25-75: 146,5-568,75). Among 139 patients with this data available, 85 patients (61,1%) were RBC transfusion dependent before ESAs treatment. Median time from diagnosis to ESAs treatment was 82 (IQR25-75: 27-353) days. According to the IPSS, 68.6% (N=155) and 31.4% (N=71) were in low and Int-1 risk groups, respectively. Regarding IPSS-R, 23% (N=52), 66.8% (N=151), 9.7% (N=22) and 0.4% (N=1) were in very low, low, intermediate and high risk, respectively. ORR to ESA treatment was 71.2% (N=161), with a median duration of response of 2.06 years. Prognosis factors of ER showed a trend toward to a higher ER among patients in the lower IPSS-R (P〉0.05), low IPSS (p=0.039) and lower EPO levels (p

Description: Abstract 3142 Background: Recent studies indicate that the use of highly effective rituximab (R)-containing primary therapy in Diffuse Large B-cell Lymphoma (DLBCL) makes it more difficult to salvage patients who are refractory or who relapse. To date, peripheral-blood autologous stem-cell transplantation (PBASCT) is the reference treatment for these patients, but the impact of previous exposure to R on the ulterior results of ASCT is still unknown. Patients and methods: We have retrospectively analysed 252 patients (pts) with DLBCL or grade 3B follicular lymphoma with relapsed or refractory disease after at least one rituximab-containing regimen (“R+” group) who received PBASCT in 17 GELTAMO centers, in comparison to a control group of 127 patients who received APBSCT as salvage therapy without previous exposure to rituximab (“R-” group). Patients with refractory disease at transplant were excluded from the analysis. Results: No significant differences between R+ and R- groups were found with respect to age-adjusted IPI at transplant, disease status at salvage therapy and at transplant, nor number or prior chemotherapy regimens. More patients in the R+ group were ≥60 years (30% vs 19%, p=.02). Complete response (CR) (69% v 70%) and overall response (84% v 83%) rates to PBASCT were similar in R+ and R- groups. In multivariate analysis, factors with significant influence on CR rates were: age-adjusted IPI at diagnosis (

Description: Background: Clinical, morphological and genetic characteristics of chronic myelomonocytic leukemia (CMML) are heterogeneous and vary from a myelodysplastic predominant profile to a myeloproliferative one. CMML has a highly variable course, with a median overall survival (OS) of 20 months and 15-30% of progression to acute myeloid leukemia (AML). Cytogenetic abnormalities are present in only 20-40% of cases. CMML-specific cytogenetic risk classification stratifies karyotypes into three groups: low risk (normal karyotype and isolated loss of Y chromosome, -Y), poor risk (trisomy 8, monosomy 7, 7q deletion and complex karyotype) and intermediate risk (all other chromosomal abnormalities). According to this model, 65-85% of patients fall into the low risk cytogenetic category. The aim of this study was to characterize type, frequency and prognostic impact of cytogenetic alterations detected by SNP arrays (SNP-A) in a series of 128 patients with CMML and low risk cytogenetic features or no metaphases. Methods: A retrospective study was performed on 128 patients with CMML. Cases with normal karyotype (n=120), isolated -Y (n=4) and no metaphases (n=4) were selected. Median age at diagnosis was 73 years (range 39-98), there was a 2.4:1 male predominance and 22.4% (28/125) of cases progressed to AML. Median follow up of patients was 26 months (range 1-115). Morphological WHO subtypes were CMML-1 in 104 (81%) cases and CMML-2 in 24 (19%). According to the FAB criteria 82 (64%) cases were included in the myelodysplastic variant (CMML-MD) and 46 (36%) in the myeloproliferative one (CMML-MP). High density SNP-A (Cytoscan HD, Affymetrix) were performed using DNA extracted from bone marrow (n=124) or peripheral blood (n=4) samples at diagnosis. The statistical analysis was performed with SPSS. Kaplan-Meier method was used for OS and progression-free survival (PFS) analysis and log-rank test was used for comparisons between groups. Results: SNP-A revealed novel chromosomal alterations (copy number alterations, CNA, and loss of heterozygosity, LOH) in 66% (85/128) of cases. Among the abnormal cases (CNA plus LOH), 1 alteration was detected in 65% (55/85) of cases, 2 in 20% (17/85) and ≥3 in 15% (13/85). The median size of the affected genome for CNA and LOH was 759 Kb (range 0-142Mb). CNA were detected in 38% (48/128) of cases, most of them being gains and losses smaller than 10Mb. Only 7 CNA were larger than 10Mb, four of them corresponded to patients with isolated -Y and three were novel alterations that had not been detected by conventional G-banding cytogenetics. Most affected regions (detected in 5 cases) were gains in chromosomes 3q, 8p and 21q as well as losses in chromosomes 10q and 12p. LOH were detected in 39% (50/128) of patients. Interstitial LOH larger than 〉25Mb were detected in 30% (39/128) of cases. Recurrent interstitial LOH were detected in: 4q24-4q35 region (12 cases), involving TET2 gene, which is mutated in 40-50% of CMML; and in chromosome 11 (9 cases), 7 of which included 11q13.3-11q25 region, involving CBLgene, mutated in 5-20% of CMML. Although the number of total alterations (1, 2 or ≥3) do not have a survival impact, we found a significant correlation between the size of the affected genome (≥30 Mb, including CNA and LOH) and a poorer OS (OS at 3 years 26% vs. 46%, P=0.039). Regarding type of alterations, cases with interstitial LOH had lower OS than cases without LOH (OS at 3 years 19% vs. 45%, P=0.049). Cases with high risk alterations as defined by CMML-specific cytogenetic risk classification (losses in 7q, gains in 8q and ≥3 CNA) had lower PFS than patients with other aberrations (PFS at 1 year 76% vs. 93%, P=0.036), although statistical significance was not reached for OS (OS at 3 years, 27% vs.49%, P=0.096). Conclusions: SNP-A in CMML patients with low risk cytogenetic features or no metaphases has led to the detection of chromosomal alterations in 66% of cases. Using this technique the prognosis can be better defined, and we can detect a group of patients with worse outcome who could be considered for more intensive treatment. Acknowledgments: Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Spain (PI 11/02519; PI 11/02010); RTICC, FEDER (RD12/0036/0044; RD12/0036/0014); 2014 SGR225 (GRE) Generalitat de Catalunya; Fundació Internacional Josep Carreras, Obra Social “La Caixa” and Celgene Spain; NHRI-EX103-10003NI, Taiwan. Footnote: Francesc Solé and Lurdes Zamora contributed equally Disclosures Xicoy: Celgene: Honoraria. Sole:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: INTRODUCTION: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard treatment for patients with relapsed or refractory aggressive B-cell lymphoma, and is frequently used as part of first-line therapy in patients with peripheral T-cell lymphoma (PTCL). However, long-term remission rates with this strategy are inferior to 50%, so novel approaches are required. We have designed a prospective multicenter phase II study to evaluate the safety and efficacy of bendamustine as part of conditioning regimen in patients with aggressive lymphomas undergoing ASCT. METHODS: Inclusion criteria were: histologic diagnosis of i) relapsed or refractory diffuse large B-cell lymphoma (DLBCL) or grade 3B follicular lymphoma (FL) in partial response (PR) or complete remission (CR) after salvage therapy, or ii) transformed DLBCL or peripheral T-cell lymphoma (PTCL) in first or subsequent PR or CR. Conditioning regimen consisted of bendamustine (200 mg/m2, days -7 and -6), etoposide (200 mg/m2, days -5 to -2), cytarabine (400 mg/m2, days -5 to -2), and melphalan (140 mg/m2, day -1) (BendaEAM regimen). Primary endpoint was progression-free survival (PFS) at 3 years. Secondary endpoints were toxicity, response to transplant at 3 months, and overall survival (OS). This trial was registered at EMEA (EUDRACT number 2010-020926-17). RESULTS: Sixty patients (median age 54 years, range 27-70) from 22 Spanish hospitals were included since May 2011 to November 2012. Histologies were: 40 DLBCL, 3 grade 3B FL, 13 transformed DLBCL, and 7 PTCL. 82% of patients have received ³2 lines of treatment prior to ASCT. 37 patients (62%) were in CR at the time of transplant and 23 (38%) in PR. A median number of 4.05 x 106/Kg (range: 1.69-19.80) CD34+ cells were reinfused. All patients (except one who died early) engrafted after a median of 11 (range: 9 to 72) and 14 (range: 4 to 53) days, respectively, to achieve 〉0.5 x109/L neutrophils and 〉20 x109/L platelets. 39 serious adverse events (SAEs) were reported before day +100, including 14 infectious episodes, 2 of them resulting in respiratory failure and death (3.3% of transplant related mortality). Another major SAE was renal toxicity developed by 5 patients (8.3%) after bendamustine administration, reversible in all cases (3 of these patients had developed mild renal failure during previous salvage therapy). Non-relapse mortality after day +100 was 3.3% (1 patient died because of Wernicke's encephalopathy, and 1 patient from infectious complications). Concerning response to transplant, 44 patients (73.3%) achieved CR, 7 (11.7%) PR, and 6 patients (10%) did not respond. Univariate analysis showed that patients who received more than 2 lines of treatment prior to transplant (1 line: 100% of CR post-transplant; 2 lines: 71%; 〉2 lines: 50%; p=0.013), and those who were in PR at transplant (48% vs 89%, p0.1). At the time of analysis, 13 patients (22%) had disease progression and 8 patients (13%) have died (4 from lymphoma, and 4 from other causes). With a median follow-up of 18.9 (9.5 to 32.3) months, the estimated 2-year PFS and OS were 73% and 88%, respectively. CONCLUSIONS: The BendaEAM conditioning regimen is feasible and active in patients with aggressive lymphomas. Toxicity profile is similar to that commonly observed in the ASCT setting, but renal toxicity can occur and should be carefully monitored, especially in patients with prior history of renal failure. Longer follow-up is needed to assess the long-term toxicity and the efficacy of this regimen, although patients who are not in CR before transplant seem to have poorer outcomes. Disclosures No relevant conflicts of interest to declare.

Description: Introduction: We have evaluated the clinical outcome and the prognostic variables in patients with large B-cell non-Hodgkin’s lymphoma (DLBCL) who relapse after autologous stem cell transplantation (ASCT). Methods. One hundred and two patients autografted for DLBCL [58 males (60%) and 44 (40%) females, median age of 49 (18–70) years] reported to the GEL/TAMO Cooperative Group between July 1993 and July 2007 who relapsed at a median time of 9 (range, 2–90) months after ASCT were included in this retrospective multicenter study. Inclusion criteria were to achieve at least a partial response (PR) after transplant and to receive treatment after relapse. After transplant 81 patients (79.4%) had achieved complete remission (CR), 11 (10.8%) uncertain CR, and 10 (9.8%) were partial responders. At relapse or progression, 65 patients (67%) had advanced clinical stage, 28.4% presented with B symptoms, 20 patients (15%) had age older than 60 and 13.8% with a bulky disease. Forty-seven percent of the patients had an age-adjusted IPI 2 or 3 and 52 (53.6%) and 25 (41%) had an elevated LDH or a high beta 2 microglobulin respectively. Regarding treatment at relapse or progression, forty-seven patients (46%) received rituximab, either alone (n=7) or in combination with chemotherapy (n=40), 44 received chemotherapy, 6 involved-field radiotherapy and the remaining 5 patients received a palliative treatment. Finally, 20 patients received a consolidation therapy with a second stem cell transplantation, (9 a second ASCT, and 11 an allogeneic transplant). Results. Overall response (OR) rate was 54% (38.2% CR). Among the 47 patients who received rituximab-based protocols, the OR rate was 70.2% (48.9% CR). With a median follow-up after relapse/progression of 39.3 months (2.6 to 121.8) for surviving patients, the median overall survival (OS) from ASCT failure was 288 days with a median time to progression of 120 days. The actuarial 5-year OS and event-free survival (EFS) for the entire population of relapsed patients were 30.7% and 0%, respectively. Adverse prognostic factors significantly influencing OS and EFS in multivariate analyses were: haemoglobin level

Description: Objectives: To evaluate the efficacy and toxicity of a response-adapted therapy with rituximab/bendamustine/mitoxantrone/dexamethasone (RBMD), followed by rituximab (R) maintenance therapy in patients with relapsed or refractory follicular lymphoma (R/R FL) to first-line treatment with R-chemotherapy (R-ChemoT). Material and methods: Multicenter phase II trial including 60 patients with R/R FL, after a first R-ChemoT line. Induction therapy: R 375 mg/m2 IV, day 1; bendamustine 90 mg/m2 IV, days 1 and 2; mitoxantrone 6 mg/m2 IV, day 1; dexamethasone 20 mg/day, PO, days 1 to 5. Cycles of 28 days. Evaluation of response after third cycle. If stable (SD) or progression disease (PD): patient withdrawn from the study. If complete response (CR) or unconfirmed complete response (CRu): administration of fourth cycle. If partial response (PR): administration up to 6 cycles. If CR, CRu, or PR after induction: patient received maintenance therapy with R (375 mg/m2/day every 12 weeks for 2 years). Results: N=60 patients: 50% female, age 63 (32-76) years. Ann Arbor stage III-IV 70% (42/60). FLIPI intermediate-high risk: 50% (30/60). Refractory to R-ChemoT: 18% (11/60). Received RCHOP as first line therapy: 77% (43/60). R maintenance after first line therapy: 43% (26/60). Number of administered RBMD cycles: 4 (1-6). Efectiveness: CR/CRu after 3 cycles (CR-3), 27 patients. Response after induction therapy (4-6 cycles): Overall response (OR), 88.5% (53/60); CR, 58.5% (35/60); CRu, 12% (7/60); PR, 18% (11/60); SD, 1.5% (1/60); PD, 10% (6/60). Median follow-up: 24.41 mo. (15.58-30.15). Progression free survival, median not reached (NR) (28.28-NR). Overall survival, median NR (NR-NR). OR after RBMD in patients who received R maintenance after first line therapy, 96% (25/26; CR + CRu, 65%). OR in patients who did not receive R maintenance after first line therapy, 94% (32/34; CR + CRu, 82%). Safety: Grade 3/4 hematologic toxicity: neutropenia, 60% (n=36; 34 patients received G-CSF); anemia, 2% (n=1); thrombopenia, 4% (n=2). Grade 3/4 infections: 8% (n=4); febrile neutropenia 8%, (n=4). Exitus, 2/60 (PD, cycle 1; influenza A, cycle 5). Grade 3/4 non-hematologic toxicity: infusion reaction, 4% (n=2). No skin reactions. Patient withdrawals before R maintenance therapy: no inclusion criteria (NIC), 2/60; protocol delay of over 4 weeks, 7/60. Forty-four patients began R maintenance therapy (CR-3, 24/44). During R maintenance therapy: PD, 8/44 (18%; 5/8 in CR-3 patients); SD, 1/44 (2.5%); NIC, 3/44 (7%, all CR); protocol delay, 1/44 (2.5%); toxicity, 1/44 (2.5%, myelodysplastic syndrome). Response to R maintenance therapy: OR, 68% (30/44); CR, 61% (27/44; in CR-3 patients, 65%, 17/26); CRu, 4.5% (2/44); PR, 2.5% (1/44). Conclusions: RBMD is an effective and safe alternative for patients with R/R FL who have received first line treatment with R-ChemoT and R maintenance therapy. This response-adapted treatment strategy achieved results similar to the scheme with 6 cycles and may allow reduction of the intensity and duration of induction therapy and minimize toxicity. No skin reactions were reported, possibly due to the inclusion of dexamethasone in the treatment scheme. Disclosures No relevant conflicts of interest to declare.

Description: Background: Survival of DLBCL patients with high IPI treated with RCHOP immunochemotherapy is poor. In this population, the combination of RCHOP with new drugs is an attractive approach, along with performing an evaluation with PET/CT after 2 to 4 cycles to change the therapy if an early complete response is not achieved. Methods : We performed a clinical trial comparing 6 cycles of RCHOP vs 6 cycles of BRCAP, a modified RCHOP regimen changing vincristine by bortezomib 1.3 mg/m2 sc days 1, 8, and 15 of a 21-day cycle. Pre-phase therapy was permitted for patients who could not wait the results of the screening procedures to start therapy due to the aggressiveness of the disease. (ClinicalTrials.gov Identifier: NCT01848132). Patients younger than 71 yrs diagnosed with DLBCL and an age-adjusted IPI (aaIPI) 2-3 or aaIPI 1 with increased beta2microglobulin were eligible. The primary endpoint was the proportion of patients who survives free of event at 2 years. Centralized anatomopathology review was performed in all cases; samples were classified as germinal center B-cell-like (GCB) vs non-GCB subtypes by immunohistochemistry according to the Hans algorithm. PET/CTs were performed baseline, after 2, 4 and 6 cycles (PET2, PET4, and PET6), and were reviewed at real time by at least 3 experts of a central panel. Response at the end of therapy was analyzed following the visual method with the Deauville scale, and response after PET2 and PET4 was evaluated using the semiquantitative method. Persistent disease at PET4 was considered as failure of therapy and these patients were removed from trial treatment. EFS was calculated from diagnosis until event defined as death from any cause, relapse, progression or need of salvage therapy (defined as PET4 or PET6 positive). Overall survival (OS) was calculated from diagnosis until death for any cause. We present here a preliminary analysis of results. Results: One hundred and twenty-one patients were included; data on 113 are presented (diagnosis not confirmed in 6, data missing in 2). Median age was 57.1 yrs (range 23-70), 57 (50.4%) were males. Characteristics at diagnosis were: non-GCB subtype 32/87 (36.8%), immunohistochemical co-expression of myc/bcl2 56/82 (77.8%), stage III-IV 107 (94.7%), ≥2 extranodal locations 55/76 (72.5%), ECOG 2-3 36 (32.1%), increased LDH 88 (77.9%), increased beta 2 microglobulin 73 (64.6%), aaIPI 3: 32 (28.3%). No differences were found between treatment arms. Fifty-five patients were treated in the experimental arm (EA) and 58 in the control arm (CA). Twenty-eight (28.3%) out of 99 patients required of pre-phase treatment. The mean relative dose intensity for bortezomib was 88.3%. Data about the most frequent toxicity are shown in table 1. Twenty-nine (30.2%) out of 96 patients who have finished 4 cycles had a positive PET4 according to central review and were withdrawn to receive salvage therapy. Complete remission (CR) at the end of therapy (PET4-/PET6-) was observed in 44 (45.8%) patients. After a median follow-up of 9 months, estimated 12-mo EFS was 36.6%, and 12-mo OS was 82.9% in the whole series. Data of the subgroup analysis according the immunohistochemistry subtypes by Hans algorithm are show in table 2. Conclusions: In the present preliminary analysis, no significant differences were found between RCHOP and BRCAP in terms of CR and EFS in this very high-risk population of young DLBCL patients. However, in the subgroup analysis of patients with non-GCB disease, we found a significantly better CR rate in patients treated with BRCAP. A longer follow-up is needed to evaluate the real impact of this therapy on survival. Disclosures González-Barca: Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria. Martín:Sevier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees. Sancho:Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion, Inc: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. López-Jiménez:Abbvie: Membership on an entity's Board of Directors or advisory committees; Velgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; MundiPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. López-Guillermo:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; MundiPharma: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Ramírez:Bristol-Myers-Squibb: Honoraria; Novartis: Honoraria; Roche: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees. Conde:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Amgen: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees.

Description: Abstract 1639 Objectives To evaluate the efficacy and safety of rituximab-bendamustine-mitoxantrone-dexamethasone (R-BMD) in patients with relapsed or refractory follicular lymphoma, (R/R FL) to first-line therapy with R-chemotherapy (R-ChemoT), followed by maintenance with R. Methods Phase II trial including 61 patients with R/R LF, after a 1st R-ChemoT line. Induction treatment: Rituximab 375 mg/m2 iv, day 1; bendamustine 90 mg/m2 iv, days 1 and 2; mitoxantrone 6 mg/m2/day iv, day 1; oral dexamethasone 20 mg / day, days 1 to 5. Cycles of 28 days. Evaluation of response after 3rd cycle. If stable disease or progression: withdrawal from the study. If complete response (CR) or complete response unconfirmed (CRu): administration of a 4th cycle. If partial response (PR): administration up to 6 cycles. If CR, CRu or PR at the end of induction: patients receive maintenance with R 375 mg/m2/day every 12 weeks for 2 years. Primary objective: Complete responses (CR + CRu). Results are presented as valid % and median [range]. Results Results from 46 patients who completed induction period. 52.2% women, age 63 [32–76] years. Ann Arbor stage III / IV 75.6% (31/41) and III / IV-B 22.6% (7/31). FLIPI: intermediate risk 28.9% (11/38); high-risk 23.7% (9/38). Number of administered cycles: 4 [1–6]. Overall response 93.5% (43/46); CR: see Table 1. Progression Free Survival –median (CI95%)-: 14.5 (11.6-NA) months. The most relevant grade 3/4 toxicity: neutropenia 52% (n = 24; 17 patients received G-CSF) and thrombocytopenia 4.3% (n = 2). Infections grade 3/4: 6.5% (n = 3). One patient died due to CMV reactivation. No skin reactions were reported. There are maintenance available data from 15 patients: 3 patients sustained CR at the end of this period, and 2 patients progressed. Conclusions R-BMD is a treatment schedule effective and a safe alternative for patients with R/R FL, after a 1st line with R-ChemoT. No skin reactions were reported, possibly due to the inclusion of dexamethasone in the treatment scheme. Additional follow up is required to achieve more conclusive findings. Disclosures: No relevant conflicts of interest to declare.

Description: Approximately 30-40% of patients with myelodysplastic syndromes (MDS) develop acute myeloid leukemia (AML). Several recurrent mutations have been identified in MDS using next-generation sequencing (NGS) technology and recent studies have greatly illuminated the molecular landscape of this disorder. However, the molecular events driving MDS progression to AML remain poorly understood. In order to investigate the genetic basis of leukemic transformation in MDS during disease progression, we evaluated the frequency and chronology of the acquisition of mutations using a targeted NGS myeloid gene panel on serial (paired) samples from 41 MDS patients before (pre-progression) and after disease progression (post-progression) to a more advanced subtype (n=7) or to AML (n=34). The mutational profile was characterized using a TruSeq Custom Amplicon panel (Illumina) targeting the hotspots of 31 recurrently (〉1%) mutated genes in myeloid malignancies. Samples were run on an Illumina MiSeq and variants were annotated and filtered using Illumina VariantStudio v2.1.36, and interpreted according to the ACMG recommendations. The proportion of sequencing reads reporting a given mutation (variant allele frequency, VAF) was used to estimate the fraction of tumor cells carrying that mutation, and to determine whether mutations are clonal (in all tumor cells) or subclonal (in a fraction of tumor cells). A total of 100 and 123 mutations across 23 genes were identified in pre- and post-progression samples, respectively. The number of mutations was generally higher in the post-progression samples: the number of cases with one or two mutations was 24 in pre-progression samples and 16 in post-progression samples, while the number of cases with three or four mutations was 12 in pre-progression samples and 18 in post-progression samples. Several cases showed ≥5 mutations. The most frequently mutated genes (in 〉15% of samples) were ASXL1, TET2, SRSF2, U2AF1, RUNX1 and TP53; ASXL1 was the top ranking mutated gene with a frequency of 44% in pre-progression samples and 46% in post-progression samples. SF3B1, the most frequently mutated gene in MDS, was mutated in only two cases in our cohort. This finding is consistent with the strong association of SF3B1 mutation with the low-risk MDS subtype RARS, and its status as a good prognostic marker. Our patient cohort is highly selected, comprised only of patients whose disease has progressed and our data thus indicate that ASXL1 mutations are strongly associated with MDS cases that show disease progression and conversely that SF3B1 mutations are rarely associated with MDS disease progression. Mutations of genes involved in splicing (U2AF1, SRSF2), chromatin modification (EZH2, ASXL1) and DNA methylation (TET2, IDH1/2) were present in the pre-progression samples for almost all cases with mutations of these genes; these mutations often occur in founding clones (VAF 〉40%) and may play a role in disease initiation. Mutations of genes involved in transcriptional regulation (RUNX1, ETV6, PHF6) and signal transduction (NRAS, KRAS) were found in many cases in the post-progression sample only, suggesting that these are often late events that may co-operate with early events to drive disease progression. Interestingly, co-occurrence of NRAS and ASXL1 mutations was a frequent event in post-progression samples (n=5) in our cohort. It has been reported that NRas mutation and Asxl1 loss co-operate to drive myeloid proliferation and myeloid leukemia in mice, and our data support this observation. The average VAF of some mutations changed markedly during disease progression, with NRAS showing the largest VAF fold increase among genes mutated in 〉5 cases. The majority of subclones containing mutations in RUNX1 or ASXL1 expanded with disease progression. EZH2 mutations were mainly in the founding clone, while TP53 mutations were mainly in a subclone. For six cases we sequenced an additional serial sample, thus giving more precise information on the mutational profile evolution during disease progression. This is the first study to investigate the mutation status of a large group of MDS patients showing disease progression by the study of serial samples using a NGS myeloid gene panel. This study informs the timing of mutation acquisition during disease initiation and progression in MDS and closely related conditions, illuminating the genetic basis of leukemic transformation in these disorders. Disclosures No relevant conflicts of interest to declare.

Description: INTRODUCTION Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal myeloid stem cell disorders highly prevalent in elderly populations. MDS are characterized by inefficient hematopoiesis, peripheral blood (PB) cytopenias, and increased risk of transformation to acute myeloid leukemia (AML; 20–30%). Around 50% of MDS patients carry at least one karyotoypic aberration, the most common being 5q-, -7/7q-, +8, 20q-, and isochromosome 17(q10) [i(17q)]. Isochromosome 17(q10) according to cytogenetic risk stratification is of intermediate prognostic significance when is observed as a single abnormality. As i(17q) has be postulated to be associated to recurrent mutational patterns we investigated the TP53 and SETBP1 mutational status in 31 untreated MDS patients harboring i(17q). METHODS Genomic DNA was isolated from fixed cells from bone marrow samples using QIAamp DNA mini-kit Qiagen. TP53 exons 5–9 and SETBP1 exon 3 were amplified using PCR. Amplification products were all purified and sequenced in an automated sequencer. Additionally, we studied the methylation status of TP53 in 21 of the 31 patients. Sequence analyses were performed with PyroQ-CpG analysis software. RESULTS SETBP1 mutational spectrum was characterized by the presence of non-synonmous point mutations, mainly located in residues 868-871 in 13 out of the 31 analyzed patients (41.9 %). In seven of the 13 positive cases, the mutations corresponded to heterozygous D868N, in 5 cases associated with an isolated i(17q) and with 1 additional abnormality in the remaining samples. Three of the 13 SETBP1 mutations were heterozygous G870S associated to i(17q) as a single abnormality. Another three patients had single heterozygous mutations S869G, and I871T along with an i(17q) as a single abnormality or D868Y in the context of a complex karyotype. Regarding TP53 mutations six of the 31 had non-synonymous point mutations. Two patients had mutations in exon 7, three had mutations in exons 5, 6, and 8, and one patient had an intronic mutation at the splicing recognition site. A statistically significant correlation was found between TP53 mutation and a complex karyotype (P=0.001), and between SETBP1 mutation and isolated i(17q) (P=0.001). Univariate analysis for overall survival (OS) found a statistically significant difference between non-mutated and TP53-mutated patients (14.1 months vs. 2.9 months, respectively; P=0.001), and between SETBP1-mutated and TP53-mutated patients (14.5 months vs. 2.9 months, respectively; P=0.002). Only one patient, with isolated i(17q), was found to have an aberrant TP53 methylation status. CONCLUSIONS MDS patients with i(17q) as a sole abnormality presented a higher incidence of SETBP1 mutations, whereas a higher incidence of TP53 mutations, were found in the presence of complex karyotypes. These data allowed us to conclude that a better informed and more accurate prognosis can be achieved in MDS patients with isolated i(17q) or i(17q) plus one additional abnormality, by studying the mutational status of SETBP1 as a first approach. ACKNOWLEDGEMENTS: This work has been partially supported by grants from Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Spain (PI 11/02010); by Red Temática de Investigación Cooperativa en Cáncer (RTICC, FEDER) (RD07/0020/2004; RD12/0036/0044); 2014 SGR225 (GRE) Generalitat de Catalunya; Fundació Internacional Josep Carreras; Obra Social “la Caixa”; Sociedad Española de Hematología y Hemoterapia (SEHH) and Celgene Spain. Disclosures Sole: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.