ALBERT

Description: Landscape analyses of mutational patterns have shown that virtually all myelodysplastic syndromes (MDS) harbor somatic mutations in 〉80% of cases. These molecular alterations provide useful clonality markers with a potential for early diagnosis of MDS when only cytopenia without marked dysplasia is observed. These markers have been proposed as future prognostic tools to guide therapeutic strategies (Bejar et al., 2011; Itzykson et al, 2013; Mufti et al 2013). Mutational analysis is finally a good way to track disease complexity by deciphering oligoclonality in MDS and better understand clonal evolution. Alterations in the TP53 gene are the most common cause of tumor escape from apoptosis. The aim of this study was to identify TP53 mutations in consecutive samples of lower-risk MDS (IPSS ≤1) with del(5q)obtained at follow-up or progression after sequential classical treatments. Next-generation sequencing (NGS) was used to backtrack the mutant clone(s) identified in late samples. The study was performed both by conventional Sanger sequencing and NGS on a GS Junior Instrument (Roche Applied Science, Mannheim, Germany). For each sample, eight exons (4-11) were amplified from 320 ng of DNA with preconfigured primer plates provided within the IRON II study network. PCR reactions were performed using the FastStart High Fidelity PCR System kit (Roche Applied Science). After double purification with Agencourt AMPure XP beads (Beckman Coulter, Miami, FL), exon-specific amplicon pools were generated and quantified using the Quant-iT™ Broad-Range PicoGreen DNA Assay Kit (Invitrogen, Carlsbad, CA). Emulsion PCR was performed with GS Junior emPCR Reagents (Lib-A) (Roche Applied Science) using 5 x 106 beads at a copy per bead ratio of 0.6. Finally, a fraction of 5-7% enriched beads was loaded on GS Junior Titanium sequencing PicoTiterPlate kit (Roche Applied Science). Data were analyzed for sequence alignment and variant detection using the GS Junior Sequencer and GS Amplicon Variant Analyzer softwares, versions 2.7 and 2.9 (Roche Applied Science). The results were further processed using the Sequence Pilot software version 4.0.1 (JSI Medical Systems, Kippenheim, Germany). The sensitivity of variant detection was set to a lower limit of 〉1% for bidirectional reads. This threshold was chosen according to a recent study investigating the assay's lower limit of detection (Grossmann et al., 2013), thus underlining the strength of NGS to identify subclones at a low frequency, not detectable by conventional Sanger analysis. A total of 89 DNA samples were extracted from the cytogenetics pellets of a cohort of 40 MDS with del(5q). TP53 mutation analysis was performed on 40 initial and 49 follow-up or progression samples including serial samples for 23 subjects. The depth of coverage was at least 500X and up to 8,444X per amplicon. Of those samples obtained and analysed at time of last follow-up or progression, 14 (61%) had TP53 mutations, mostly in the DNA-binding domain. Performing backtracking on previously collected serial samples, TP53 mutations were retrieved by NGS in 43% of initial samples (n=6), which is different from what was previously described by Jädersten et al (2011). A complete scenario of clonal evolution was retrieved in 11 cases, evidenced by TP53 mutations and/or cytogenetics. These were always consecutive to treatment with lenalidomide, yet 6 of the 12 cases without clonal evolution were also consecutive lenalidomide. Figure 1 provides the example of a complete follow-up including nine time points. More correlation with treatment will be provided. Although lenalidomide remains the treatment of choice for MDS with del(5q), resistant subclones may survive and culminate even following therapy initiation. This theory was recently suggested by Landau et al. in CLL (2013) and our test results support this. Early detection of emerging subclones could lead to initiation of alternative treatment, and we thus propose that a monitoring of TP53 alleles is performed annually after the onset of therapy for MDS using NGS. Figure 1. Figure 1. Disclosures: Kohlmann: MLL Munich Leukemia Laboratory: Employment. Moreau:CELGENE: Honoraria, Speakers Bureau; JANSSEN: Honoraria, Speakers Bureau.

Description: Introduction: Despite therapeutic advances in recent years, disease relapse is still observed in up to 50-60% of the patients (pts) receiving allogeneic transplantation for high risk AML and MDS. In an initial Phase II trial of 30 pts treated with prophylactic low-dose AZA and escalated doses of DLI to prevent relapse, we reported that such prophylactic treatment can be safely administered and compared favorably to patients receiving no post-transplant maintenance. We here update 16 pts from our center, included in that protocol, as well as a larger cohort of additional patients treated with combined epigenetic and cellular therapy and the resultant effect on their event-free survival and their overall survival. Patients and methods: Fifty-nine pts (median age 59 yrs (range, 37-70); 30 M/29 F), comprising 40 pts with AML and 19 pts with MDS, were treated. Among the AML pts (ELN classification FAV n=2, INT n=17, ADV n=21), high risk criteria were as follows: 15 had complex karyotypes, 7 Flt3-ITD, 1 MECOM (EVI1) rearr., 3 monosomies, 2 t(9;11), and 1 t(11;19)); 9 were in CR≥2, 4 were refractory, and 13 had 2ary AML to MDS/chemotherapy/or MPS. Among the MDS pts, high risk criteria included 6 pts with complex caryotypes, 2 monosomies, 1 MECOM (EVI1) rearr., and 4 had 2ary MDS. IPSS-R median was 5.5 (3 - 7.5). MDS pre-transplant status included 7 CR1, 1 CR2, 5 PR, 1 relapse, 4 upfront, and 1 refractory. The therapeutic protocol administered to the initial 16 pts consisted of AZA, starting between d56 and d100 post-transplant, at a dose of 32 mg/m²/d SC, for 5 consecutive days, every 28 days, for up to a total of 12 cycles followed by DLI commencing after 3 cycles of AZA and 4 weeks following discontinuation of immunosuppressive prophylaxis. Two additional DLI were scheduled every 8 weeks following the 1st DLI. The doses of DLI 1, 2 and 3 were, respectively, 5x106, 1x107, and 5x107 CD3+ cells/kg for matched related donor (MRD), and 1x106, 5x106, and 1x107 CD3+ cells/kg for unrelated donor (UD). In the extended patient cohort, presented here, we slightly modified the schedule: DLI could be given earlier (after one or two cycles of AZA) and haploidentical pts could receive AZA/DLI as well, with DLI at the escalated doses of 1x105, 5x105, and 1x106 CD3+ cells/kg. Immunosuppression included cyclosporine A (CsA) in case of MRD, CsA and mycophenolate mofetil (MMF) in case of UD or haplo. MMF was progressively reduced during the first 2 months. CsA was tapered starting at day 60-100 post-transplant. Patients could start AZA while they were still receiving CsA. The conditioning regimens consisted of MAC for 5 pts, RIC for 46 pts and sequential for 8 pts. Donors were MRD, MUD, UD 9/10, and haplo for 20, 30, 1 and 8 pts respectively. Results: The median number of cycles AZA was 7 (range 1-12), 17 pts received 12 cycles of AZA, while 42 pts (71%) received at least one DLI. The median number of DLI was 1 (range 0-4), 15 pts received ≥ 3 DLI. The median time for the first post-transplant AZA injection was 83 days (range 56-145 d) and the median time post-transplant for those pts who received a first DLI was 148 days (range 78-245 d). The median pt-follow-up was 17 months (range 2-83). Eight pts (13%) relapsed (7 AML and 1 MDS). The cumulative incidence of relapse and NRM at 1 year was 12% and 11.5% respectively. Fifteen pts (25%) died. Causes of death included relapse in 6 pts, infection in 7 pts, myocardial infarction in 1 pt, and GvHD in 1 pt. Overall survival and event free survival for the entire group at 2 years was 71% (95% CI 54-82%) and 67% (95% CI 50-80%) respectively. The cumulative incidence of acute GvHD grade 1-4 and chronic GvHD were 32% (95% CI 16-49%) and 39% (95% CI 20-58%). Among the 8 pts who developed grade 3 acute GvHD, 4 occurred in pts who had received DLI. One pt died from grade 4 digestive GvHD post-AZA alone. Conclusion: We conclude that, despite their very high risk disease, prophylactic/preemptive low-dose AZA and DLI can be readily and safely administered with an acceptable incidence of subsequent GvHD to the AML and MDS pts described here. Significantly, in the poor-prognosis pts under study, the incidence of relapse is lower than expected. Furthermore, considering the immune escape mechanisms prophylactic or pre-emptive either AZA or DLI might be associated to additive non-cross reactive interventions, such as checkpoint inhibitors, in order to further decrease disease relapse and increase overall survival. Disclosures Peterlin: Jazz Pharma: Consultancy; Astellas: Consultancy; Daiichi-Sankyo: Consultancy; AbbVie Inc: Consultancy. Orvain:Novartis: Honoraria; Incyte: Honoraria. Chevallier:Jazz Pharmaceuticals: Honoraria; Daiichi Sankyo: Honoraria; Incyte: Consultancy, Honoraria.

Description: Introduction: Allogeneic stem cell transplantations (allo-SCT) using alternative donors are increasingly used in patients lacking suitable matched sibling or unrelated donor. Recently, the use of post-transplant cyclophosphamide (CY) has allowed to re-consider first-generation relatives (brother, sister, father, mother, son or daughter) as haplo-identical donors for allo-SCT. Indeed, the incidence of severe acute GVHD is lowered by post-transplant administration of CY, due to the early destruction of putative alloreactive T cells. Still, some patients may not have a suitable relative donor for various reasons such as older age of the parents, no siblings nor children, no cord blood available, or because use of a graft from a first-generation haplo-identical relatives is contra-indicated. The probability of having a haplo-identical donor among siblings is 50% while it is almost 100% when considering both biological parents and offspring. When considering as a potential donor the child of a matched or haplo-identical sibling, the probabilities for the donor to be haplo-identical with the recipient remain 50% and 25%, respectively. Thus, second-generation relative donor (i.e. nephew or niece) may be finally considered as a source of stem cell graft. Methods: Here we report the case of a 61-year old man who received a T-replete haplo-identical allo-SCT with high-dose post-transplant CY from his second-generation relative nephew. In 2010, the patient was diagnosed with ALK- CD30+ anaplastic T-cell lymphoma and received 8 cycles of CHOD allowing to obtain morphologic and metabolic partial response. The patient received an allo-SCT from a sibling matched donor (brother) on November 2010 after an FB2A2 reduced-intensity conditioning regimen but secondary graft failure was rapidly documented in spite of donor lymphocyte infusions. Relapse occurred in September 2014 and brentuximab vedotin was administered each 21 days for seven cycles allowing to obtain a complete morphologic and metabolic response. It was decided to perform a second allograft using a different donor. The patient was childless and no unrelated donor or cord blood units were available. It was thus chosen to ask for donor the son of the matched brother, who was haplo-identical and had no antibodies directed against the patient's HLA specificities. This nephew had a O- blood group and negative CMV serology while the recipient was O+ and CMV+. Results: The second allograft was performed on April 2nd 2015 using the Baltimore (Luznik, BBMT 2008) conditioning regimen with 2 days of post-transplant CY. A megadose of peripheral blood stem cell was administered (14.16x106 CD34+ cells/Kg) at day 0. Neutrophils and platelets recovery (〉50 Giga/L) were achieved as early as days +18 and +33, respectively, with full donor whole blood chimerism (99.8%) at day +30, persisting on day +60 and +100 (both whole blood 99.9%, CD3+ T cells: 99.9%).Grade 2 acute cutaneous GVHD occurred at day +21. The evolution was favorable after initiating corticosteroids at 2 mg/kg/day with tapering thereafter. Not surprisingly, CMV reactivation was documented at day+22, controlled by ganciclovir treatment. Immune reconstitution evaluated at days +30, +60 and +100 showed normal monocyte counts while B lymphocytes were undetectable. NK cells increased from 42/mm3 at day+30 to 453/mm3 at day +60 and 665/mm3 at day +100. Interestingly, after profound lymphopenia within the first 100 days post-transplant, CD8+ T large granular lymphocytes expansion was documented at day + 110. At four months post-transplant, the patient is alive in persistent metabolic remission with no active acute or chronic GVHD nor active infection. His outcomes will be updated for the meeting. Conclusion: T-replete haplo-identical allo-SCT with high-dose post-transplant CY using a second-generation relative donor was feasible allowing for full engraftment and moderate acute GVHD in our patient. This result expands the possibility to find a donor for a selected patient, meanwhile paving the way for using unrelated haplo-identical donor, which could be of interest when considering solid transplantation. Indeed, combining solid organ transplantation and allo-SCT from the same haplo-identical donor may open the door to withdraw immunosuppression in this particular setting, because stable tolerance may be induced, as it has been already reported for kidney transplant (Kawai, NEJM 2013). Disclosures Moreau: Celgene: Honoraria, Other: Adboard; Amgen: Other: Adboard; Takeda: Other: Adboard; Janssen: Other: Adboard; Novartis: Other: Adboard.

Description: Introduction: Recently, theuse of high-dose post-transplant cyclophosphamide (PTCY) has contributed to reconsider T-replete haplo-identical allo-SCT because of the lower incidence of severe graft-versus-host disease (GVHD) observed in patients. However, the influence of PTCY on early outcomes has been poorly studied so far, especially in comparison to the standard use of anti-thymoglobulin (ATG) as GVHD prophylaxis. Patients and Methods: This retrospective study was conducted at the University Hospital of Nantes with the aim to compare the incidence of early outcomes (engraftment, neutrophils and platelets recovery, viral infections (HHV-6, CMV, EBV, BKv, ADV), acute GVHD, relapse or deaths and day+100 non-relapse mortality (NRM)) between patients receiving either PTCY (n=30) or ATG (n=46) as part of GVHD prophylaxis for a RIC allo-SCT. In the PTCY group, RIC was the Baltimore regimen (Luznic, BBMT 2008) in 17 patients while 9 patients received clofarabine instead of fludarabine because of a myeloid malignancy and 4 patients a sequential approach. In this group, 6 and 24 patients received 1 or 2 days of PTCY, respectively, while donors were matched (sibling n=2, unrelated n=5) in 7 cases and haplo-identical in 23, respectively. All patients received cyclosporine + MMF with PTCY as GVHD prophylaxis. In the ATG group (2 days of ATG for siblings and 10/10, 3 days for 9/10), 13, 11 and 22 patients received respectively a FB2, FB3 or CloB2 RIC regimen (Chevallier, Haematologica, 2014). Donors were siblings in 18, matched unrelated in 23 and mismatched unrelated (9/10) in 5. GVHD prophylaxis was cyclosporine alone in case of sibling donors and cyclosporine +MMF for all other cases. The characteristics of both groups (PTCY vs ATG) were similar in terms of gender (male: 63% vs 54%), type of disease (myeloid: 67% vs 63%) and disease status at transplant (complete remission: 43% vs 67%). PTCY patients were significantly younger (median age: 55.5 vs 63 years, p=0.01) and had been previously allografted in a significantly higher proportion (40% vs 4%, p=0.003). Patients were transplanted between March 2012 and April 2015 and were considered up to day+100 post-transplant. All patients received peripheral blood stem cells as stem cell source except one patient in the PTCY group who received bone marrow. Results: All patients engrafted except one in the ATG group. The median time of neutrophils recovery was similar between both groups (PTCY 18 days vs ATG 19 days, p=0.9). Conversely, median time of platelets recovery was significant higher for the PTCY group (27 vs 13 days, p

Description: Introduction: A number of approaches have been explored to prevent relapse in AML setting, including immune-strategies such as dendritic cells (DC) vaccination. There is no report so far of the use of autologous apoptotic leukemic cells as a source of tumor antigen for DC vaccine. Methods: The main objective of this prospective monocentric Phase I/II study was to explore the feasibility to produce autologous leukemic apoptotic corpse-pulsed DC for elderly AML patients in first or second complete remission (CR) and to report the toxicity of such a vaccine. Inclusion criteria were AML (except promyelocytic) patients older than 59 years with a good performans status (ECOG =50% of leukemic blasts in bone marrow (BM) or peripheral blood, and with no contra-indications to apheresis. Vaccines were produced by Nantes UTCG according to good manufacturing practices for cell and gene based therapies in order to comply to the French AFSSAPS (currently ANSM) agency guidelines. Patients had to be pre-included (refractory or not) at diagnosis or at time of first relapse in order to collect sufficient leukemic cells (〉2.4 108) prior to chemotherapy after 1 or 2 days of collection. After blasts collection, the choice of chemotherapy regimen was at the discretion of the investigator. Few courses of chemotherapy were allowed before vaccine production but not after. Patients were definitively included only in case of CR to allow collecting autologous non-leukemic peripheral monocytes by apheresis to generate the DC vaccine. Patients were programmed to receive up to 5 doses of vaccine (days +1 +7 +14 +21 and +35 +2) which consisted of 10 millions pulsed DC, including 9 millions administered subcutaneously (1 mL) and 1 million administered intradermally (0.1mL). Minimal residual disease (MRD) was studied after vaccines using flow cytometry. Results: Between November 2009 and March 2015, 23 patients were pre-included but 2 patients were excluded for analyses because blast collection was finally not performed. Thus, overall, 21 elderly AML patients (male n=14; median age: 74 years (range: 65-84), secondary AML n=8) were considered either at time of diagnosis or at time of first relapse. The median % of BM blasts was 63% (range: 20-92), including 3 and 4 cases with less than 40% and between 40-49%, respectively (protocol deviation). Although it was not the case for one patient with 〉50% of BM blasts, all patients between 40-49% of BM blasts reached the threshold of 2.4x108blasts required for the study. Two patients out of 3 with less than 40% BM blasts had insufficient blast collection to pursue the protocol. After blast collection, the majority of patients (n=19) received non-intensive chemotherapy. 5/21 (24%) cases achieved CR, a rate that was expected for this very old population. All of CR patients could proceed to apheresis after 2 (n=4) or 4 (n=1) courses of non-intensive consolidation. Production of the 5 vaccines was possible for all of them and first infusion was made at a median of 25 days (range: 20-28) from the apheresis. However, a median of 27 vaccines (range: 8-85) could have been theoretically produced in CR patients, suggesting the possibility to realize a longer maintenance therapy to prevent relapse in the future. All patients received as expected the 5 vaccines and no adverse events were documented. Durations of response from CR were: +8.5, +8, +4.5, +4, +12 months and from first vaccine: +5.5, +4.5, +1.8, +1.8, and +9 months. Two patients had relapsed before day+55. At this time, the 3 other patients were documented with negative MRD. In July 2016, 2 patients are still alive, 1 at +30 months from CR in relapse and 1 at +13 months in CR. The 3 other cases died of relapse at +15.5, +8 and +5.5 months from CR. The median OS from pre-inclusion was significantly higher for vaccinated CR patients (13 months (9-41) vs 4.75 months (1-24), p=0.009). Conclusion: Our strategy seems promising for elderly AML patients achieving CR in terms of relapse prevention. Vaccine production is reproducible and compliant for clinical use. Larger Phase 2 studies are required to confirm our results in younger and older AML population. The trial is registered at Clinicaltrials.gov NCT01146262. This study was supported by a grant from the French National Cancer Institute. Disclosures Moreau: Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Janssen: Honoraria, Speakers Bureau; Novartis: Honoraria; Takeda: Honoraria; Amgen: Honoraria.

Description: Introduction: Prognosis markers available at diagnosis are needed to discriminate high-risk (HR) from low-risk (LR) mantle cell lymphoma (MCL) patients (Delfau-Larue et al. Blood 2005; Balasubramanian et al. ASH 2014 abstract 78). In the present work, we report a whole-genome copy number analysis performed with a new technical approach. Samples from ninety-six young MCL patients treated in the phase III LyMa trial (Le Gouill et al. ASH 2014) have been investigated. Methods: Samples were selected according to material availability and patient's outcome. The cohort included 9 HR patients with primary refractory disease or relapse within one year post-diagnosis and 87 patients still in response one year after diagnosis, including 64 LR patients who were still in complete remission more than 30 months after diagnosis. Lymph node biopsies collected at diagnosis, formalin-fixed and paraffin-embedded were used to extract DNA, even when highly degraded. Both whole-genome copy number profiling and the most frequent somatic mutations of TP53 were analyzed with 50 ng of genomic DNA using the OncoScan® FFPE Assay, a new robust and validated single nucleotide polymorphism (SNP) array (Foster et al. BMC Med Genomics 2015). This assay uses the Molecular Inversion Probe technology (MIP) optimized for highly degraded FFPE samples. The ~200000 probes allowed for the detection of genome-wide copy number alterations (CNAs) with a higher concentration in cancer-related genes. The frequency and prognosis impact of CNAs were evaluated. Results and discussion: Overall, 68 recurrently altered regions were observed in 98% of patients. Deletions were more frequent than amplifications, at 9 vs 3 by patient respectively. Recurrent CNAs included losses at 1p21 (43%), 11q22 (ATM) (40%), 13q14 (24%), 9q22-31 (CDKN2A/CDKN2B) (25%), 13q33-34 (RB1) (21%), 8p11 (18%), 17p13 (TP53) (17%) and gains at 3q26-27 (35%), 3q21 (27%), 10q11 (13%) 15q11 (13%), 11q13 (CCND1) (12%), 13q31 (mir-17-92) (11%), 7p22 (CARD11) (10%), 10p12 (BMI1) (9%), 8q24 (MYC) (8%) and 12q13 (CDK4) (7%). TP53 mutations were detected in 5 patients including two with 17p13 deletion and showed a trend to be more frequent in the HR group vs LR (22% vs 3%; p=0.07). Deletions of TP53 (44% vs 14%; p=0.04), CDKN2A (67% vs 29%; p=0.054) and 8p11 (89% vs 24%; p=0.0002) were more frequent in the HR. The CDK4 (33% vs 6%; p=0.03) and mir-17-92 (44% vs 9%; p=0.01) loci were more frequently amplified in HR patients. Amplification of the miR-17-92 locus could explain why miR-17-92 overexpression, a PI3K/AKT pathway regulator, was associated with a worse prognosis in MCL (Roisman et al. Genes Chromosomes Cancer 2016). In contrast, amplification of the CARD11 locus was associated with LR (16% vs 0%; p=0.03). Conclusion: This study confirms the poor prognostic impact of TP53 alterations and reveals new CNAs associated with HR MCL such as 8p11 deletion and mir-17-92 locus amplification. Conversely CARD11 amplification appears to be associated with LR and absent from HR patients. These findings provide important clues for future theranostic-driven therapies in MCL. Disclosures Hermine: Alexion: Research Funding; Novartis: Research Funding; Celgene: Research Funding; AB science: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding, Speakers Bureau.

Description: Introduction: Peripheral lymphocytosis encountered after myeloablative (MAC) or reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) is an ill-defined feature. Most reports in the literature deal with large granular lymphocytes (LGL) expansions and only seldom of B-cell increases (Bellucci, Blood, 2002). With an incidence of 3 to 18%, LGL proliferations occur generally late after allo-SCT with a median onset of 9 to 16 months. Such expansions can be polyclonal, oligoclonal or monoclonal, arising from either CD3+ T-cells or CD3- NK cells or both. LGL expansion has been frequently linked to CMV reactivation, indolent clinical course and a usually favorable outcome. Most available data were mainly described in the setting of allo-SCT using bone marrow (BM) or peripheral blood (PBSC) as stem cell source. Here, we report data regarding the incidence and features of lymphocyte expansions after unrelated cord blood (UCB) transplantation. Patients and Methods: Ninety-nine UCB allo-SCT performed in adults between October 2005 and October 2014 were considered for the purpose of this study. Most patients received double CB units (n=94) and a RIC regimen (n=89), for various hematological diseases. Whenever detected, we collected the date of onset and termination of peripheral blood lymphocyte expansions (4x109/L) among the 86 UCB-SCT patients alive at 3 months post-transplant. LGL expansion was defined as sustained LGL above 0.5x109/L and/or 〉40% of LGL in peripheral blood (Zambello, Haematologica, 1998). Concomitant immunophenotypic results, allowed to discriminate expansions of cytotoxic T-cells (CD3+CD8+CD56+), NK-cells (CD3-CD16+/CD56+) and B-cells (CD19+). LGL expansion data were also analyzed with respect to viral reactivation episodes, acute or chronic graft vs host disease, relapse and survival. Results: Lymphocytosis was observed in 21 cases (24%; 10 females and 11 males; median age: 58 y., range: 32-69). Most patients had a myeloid-lineage disease (67%) and were in complete remission at time of UCB-SCT (76%). The median onset of lymphocyte expansion after UCB-SCT was 12.6 months (range, 1.4-49). The median initial lymphocyte count was 4.76x109/L at time of expansion diagnosis. The median duration of expansion was 12 months (range: 1-52). Twenty patients could be further analyzed phenotypically, showing 8 CD8+ T, 1 NK and 1 T-NK LGL expansions. Interestingly, 7 cases of polyclonal B-lymphocytes expansions were also documented while 3 patients presented both T CD8+ and B expansions. Of note, B-cell expansions were CD5+. For 6 patients with T-cell expansion, concomitant DNA from CD3+ sorted cells is available to test clonality. Lymphocyte expansion were from donor origin for 12/14 tested patients. Acute and chronic GVHD developed respectively in 31% and 68% of lymphocytosis patients, and in 57 and 45% of the 65 patients without lymphocyte expansion (P=NS). Comparing these two groups for viral reactivations, the rates were 86% and 76% for HHV-6 (P=NS) and 23% and 39% for EBV (P=NS) respectively. CMV reactivation was significantly more frequent in the group of lymphocytosis patients (76% vs. 29%, P=0.0001). Interestingly, CMV reactivation was significantly higher in the 10 patients of the T or NK group compared to the 7 patients with B cell expansion (100% vs 57%, P=0.05). At time of analysis, 1 patient had relapsed and 4 had died, the causes of death being disease in 1 case and transplant-related mortality in 3. These events were significantly lower than in the group of patients without lymphocytosis (p=0.003 for relapses and p=0.04 for death). Two-year disease-free survival (Fig A) and overall survival (Fig B) were significantly different at respectively 85% vs. 55% (p=0.01) and 85% vs. 63%. (p=0.03). Conclusion: Lymphocyte expansion, at 24%, is not a rare event in adults receiving UCB allo-SCT. These expansions involve equally the T or B-lineages. The latter are often CD5+ suggesting a proliferation of innate B1 cells from the UCB. Lymphocyte expansions are significantly associated with previous reactivation of CMV, but not HHV-6 or EBV. Because these cells were of donor origin, it can be postulated that they represent primo-activation upon encounter with CMV. Finally, both types of lymphocyte expansions are associated with a significant favorable outcome, suggesting a possibly bystander anti-GVL effect. Figure 1. Figure 1. Disclosures Moreau: Celgene, Janssen, Takeda, Novartis, Amgen: Membership on an entity's Board of Directors or advisory committees.

Description: Introduction: Allogenic stem cell transplantation (Allo-SCT) remains currently the only curative treatment for primary myelofibrosis (PMF) or myelofibrosis secondary (SMF) to essential thrombocythemia (ET)/polycythemia vera (PV). Indication of allo-SCT refers to high-risk patients defined by various scores such as Lille score, IPSS, DIPSS or more recently DIPSS+. However, JAK2, CALR, MPL or triple negative mutation profiles have recently been shown to impact on the outcome of PMF patients and thus may challenge the indication of allo-SCT in the future. CALRmut patients seem to have the best survival conversely to triple-negative patients, while JAK2mut and MPLmut status can be considered as an intermediate molecular signature (Tefferi, Leukemia 2014). The outcome of MF patients with a validated allo-SCT indication who do not proceed to transplant is generally unknown although relatively long survival can be documented, especially since the availability of JAK inhibitors such as ruxolitinib. Also, data regarding impact of mutational status on outcome after allo-SCT remain scarce. Patients and Methods: This single-center retrospective study considered MF patients with a validated indication of allo-SCT between 2000 and 2013. The main objective was to compare the overall survival (OS) between patients who ultimately received allo-SCT or not. Secondary objectives were to analyze the impact of mutational molecular status on OS and the use of ruxolitinib in patients not allografted. Results: An indication of allo-SCT was validated in 67 patients (males: 64%; PMF: 59%; SMF post-ET 25%, SMF post-PV 16%). At the time of indication of ASCT, the median age was 59 years (range: 41-69); DIPSS+ score was: int-2 in 40%, high risk in 60%. Mutational status, available for 86% of patients, was as follows: JAK2V617F (n=37), CALRmut (n=12); MPLmut (n=3), triple-negative (n=6). Thirty-three patients proceeded to allo-SCT (reduced intensity conditioning: 82%) while 34 did not for lack of donor (31%), comorbidity (28%), progressive disease (14%), stable disease on conventional therapy (18%), refusal (9%). The two groups (allo/non-allo SCT) were comparable for gender, year of indication of allo-SCT, type of MF, number of prior lines of treatment before allo-SCT, DIPSS+ categorization, mutational status and median follow-up. Patients who did not proceed to allo-SCT were significantly older (61 vs 57 years, p65%) (median OS: NR vs 18 months, HR: 0.18, 95%CI:0.03 -1.11, p=0.065). Interestingly, the survival of patients who did not proceed to allo-SCT was increased by the use of ruxolitinib (median OS: NR vs 20 months, HR: 2.3, 95%CI: 0.08-0.6, p=0.003). Conclusion: Allo-SCT remains a valid strategy for high-risk MF patients with unfavorable karyotype, high DIPSS+ score and secondary MF while impact of mutational status and JAK2V617F burden have to be confirmed in larger studies. MF patients who cannot proceed to transplant likely benefit from JAK2 inhibitor prescription. Disclosures Milpied: Celgene: Honoraria, Research Funding. Moreau:Celgene, Janssen, Takeda, Novartis, Amgen: Membership on an entity's Board of Directors or advisory committees.

Description: A prospective study was performed over one year at Nantes University Hospital in France, in order to investigate whether suspected myelodysplastic syndromes (MDS) could be detected on a complete blood count (CBC), the most rapid laboratory investigation. Indeed, the recently developed XN-10® (Sysmex, Kobe, Japan), provides novel CBC parameters witch could be useful to discriminate such patients from normal samples or from cytopenia of other etiology. Seventy-nine patients were enrolled in the study, for whom a diagnosis of MDS was concluded based on CBC, bone marrow smears examination and karyotype. All patients were free of treatment, including transfusions, at inclusion. They were 40 men and 39 women with a median age of 77,9 years (range 36,4-92,4). CBC were performed on a Sysmex analyzer XN-10®, including investigation of reticulocytes and fluorimetric analysis of platelets. For comparison with normal values, results from 776 healthy samples, for which CBC were performed on the same analyzer and generated no flag, were used. All had parameters within the normal range according to age. The classical parameters of hemoglobin level, Mean Corpuscular Volume (MCV), reticulocytes, platelets and neutrophil counts were recorded. In addition, the extra-parameters, immature reticulocytes fraction (IRF%), platelets by fluorescence (PLT-F) and immature platelets fraction (IPF%), were taken into account. The neutrophils median position on the three axes as well as their dispersion (Neut-WX) were also measured by the analyser. The primary end-point was to discriminate between MDS and healthy patients and the secondary end-point was to distinguish MDS with excess blasts, MDS with multilineage dysplasia and MDS with single lineage dysplasia within the MDS group and by comparison with controls. According to the WHO 2016 classification, 27 patients in the cohort had MDS with excess blasts, 26 MDS with multilineage dysplasia (among whom 7 had ring sideroblasts [RS], group 2), 16 MDS-RS and single lineage dysplasia, 7 MDS with single lineage dysplasia and 3 MDS with isolated del(5q). Forty-four patients had a normal karyotype and 28 displayed anomalies classically reported in MDS, including 5 complex karyotypes. Among the latter, 4 were associated with MDS with excess blasts. Both classical and extra parameters indeed showed significant differences between the subgroups tested. Among the whole group of MDS patients, a number of parameters of all lineages were statistically different from the healthy cohort. The median level of hemoglobin was 9,8 g/dL (range 4,7-14,9), (p

Description: Introduction Next generation sequencing (NGS) has allowed to improve knowledge about the genomic landscape of hematological malignancies. Somatic mutations (SM) are valuable new biomarkers but the utility of incorporating routine sequencing to guide diagnosis and therapeutic decisions remains challenging. We report here an observational multicentric study aimed at assessing the impact of SM testing by NGS in a real-life setting on the diagnosis and treatment of chronic myeloid malignancies (CMM). Patients and Method All patients who benefited from molecular assessment, between 10/2014 and 03/2019 in our University Hospital were included. All provided informed consent for data collection. All NGS requests were validated during a regional multidisciplinary concertation meeting. A custom targeted panel of 34 genes (145kbp i.e. ASXL1,BCOR, BCORL1, CBL, CSF3R, DNMT3A, ETV6, EZH2, GATA2, IDH1, IDH2, JAK2, KDM6A, KIT, KRAS, MPL, NPM1, NRAS, PIGA, PTEN, PTPN11, RAD21, RUNX1, SETBP1, SF3B1, SMC1A, SMC3, SRSF2, STAG2, TET2, TNFAIP3, TP53, U2AF1, ZRSR2) was applied on DNA extracted from peripheral blood or bone marrow samples. DNA libraries, built with the Haloplex® target enrichment protocol (Agilent Technologies, Santa Clara, CA), were paired-end sequenced (150bp reads) with a MiSeq® Instrument (Illumina, San Diego, CA). Data analysis used an in-house pipeline including three variant callings (GATK HaplotypeCaller, VarScan and SAMTools). In a first group (A), NGS indication was to search for clonal hematopoiesis (CH), defined by the presence of at least one SM, in order to confirm or rule out a diagnosis of Idiopathic Cytopenia of Undetermined Significance (ICUS), Clonal Cytopenia of Undetermined Significance (CCUS), myelodysplastic syndrome (MDS), mixed myelodysplastic/myeloproliferative neoplasm (MDS/MPN), aplastic anemia (AA)/hypoplastic myelodysplasia (hMDS) or myeloproliferative neoplasm (MPN), based on recommendations of the WHO classification. In a second group (B), the theranostic impact of SM was studied. Prognostic SMs according to Bejar (2011) were used for MDS and MDS/MPN excluding chronic myelomonocytic leukemia that were analyzed with Itzykson score (2013) and/or CPSS-Mol score (Elena 2016). Prognostic SMs according to Vannucchi (2013) were used for myelofibrosis. Results The median age of the cohort was 60 years old (range: 10-87) with a median follow up of 1.1 years from molecular assessment to last follow-up. Within group A (94 patients), the most frequent blood count anomalies were cytopenia (68%), thrombocytosis (16%), and monocytosis (13%). The karyotype was normal in 77% and failed in 5% of the cases. Non-specific abnormalities (i.e. loss of chr Y, del 20q), were found in 8% of the cases. Before molecular assessment, the diagnoses proposed were ICUS (n=37), suspicion of MDS/MPN (n=16), AA/hMDS (n=16), or MPN (n=25). CH was detected in 31 patients comforting the diagnosis of CMM for 33% of group A (8 CCUS, 3 MDS, 7 MDS/MPN, 6 medullary hypoplasia, 7 MPN) patients. Considering the patients for whom no CH was detected (n=63), the initial suspected diagnosis of CMM was ruled out in 47 patients (i.e. 50% of group A). For the 16 remaining (i.e. 17% of group A), no firm diagnosis could be retained. Within group B (95 patients), NGS identified prognosis SM in 33% of the patients, i.e. poor prognosis SM in 24, including 8/40 MDS, 10/29 MDS/MPN and 6/17 myelofibrosis and good prognosis SM(SF3B1) in 7 of them, respectively 6/40 MDS and 1/29 MDS/MPN. Prognostic SMs had a therapeutic impact in 18/95 pts (19%). Indeed 13 patients with poor prognosis SM had a therapeutic change including 12 allogeneic stem-cell transplantation and 1 hypomethylating agent. Conversely, 5 patients with a good prognosis SM or absence of poor prognosis SM had a de-escalation of treatment intensity. Conclusion The use of NGS in daily practice had a clinical impact in both diagnostic and therapeutic decisions provided that the prescription is made in a critically explored context and not as a systematic test. In this "real life" cohort, the presence or absence of SM was a useful complement for integrated diagnoses in 83% of the patients, allowing to confirm (33%), or exclude (50%) a suspected condition. Moreover, in this cohort 34% of the patients had a SM with a reported prognostic impact and the treatment was modified in 19% of the cases. Yet, it remains necessary to integrate these results with other diagnostic criteria. Disclosures Peterlin: AbbVie Inc: Consultancy; Jazz Pharma: Consultancy; Astellas: Consultancy; Daiichi-Sankyo: Consultancy. Moreau:Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Le Gouill:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Roche-Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support. Chevallier:Daiichi Sankyo: Honoraria; Incyte: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria.