ALBERT

Description: Introduction: Allogeneic hematopoietic stem cell transplantation (Allo-HCT) is the only curative treatment for myelodysplastic syndrome (MDS). The portion of patients referred for transplant and the proportion who are subsequently transplanted is unknown. Aim: Tostudy the frequency of allo-HCT in pts with MDS and identify factors associated with transplant referral and barriers to transplant. Methods: Pts were included if they were under the age of 75 and seen at our center by a leukemia physician between 2008-2015 and within 6 months of MDS diagnosis. Pts were eligible for allo-HCT if they did not have major organ dysfunction, i.e. left ventricular ejection fraction 2mg/dL, FEV1

Description: Introduction: We have previously reported that clinically relevant, dramatic reductions occur in intestinal bacterial diversity during allogeneic hematopoietic stem cell transplant (allo-HSCT). These are likely attributable to antibiotic exposure, nutritional alterations, and intestinal mucosa injury from high-dose chemotherapy. Patients undergoing autologous hematopoietic stem cell transplantation (AHCT) also receive antibiotics and experience nutritional alterations due to mucositis and other gastrointestinal toxicities. We hypothesized that the pattern of dysbiosis seen in AHCT patients would reflect the changes in allo-HSCT patients. Here, we present a novel analysis of microbiota diversity in AHCT patients from two independent institutions. Methods: We retrospectively identified a cohort of 365 patients (median age 60 years) who underwent AHCT for treatment of hematologic malignancy between May 2009 to February 2018 at two large-volume transplant centers in the US. The population was diverse in terms of histology, conditioning regimens and remission status prior to transplant, with 179 (49%) patients diagnosed with multiple myeloma, 153 (42%) patients diagnosed with lymphoma, and 33 (9%) patients with other diseases. Stool samples from the selected patients were collected approximately weekly during inpatient hospitalization. Sequencing of the V4-V5 region of the bacterial 16S rRNA genes from all samples was performed on the Illumina platform at a central site. Microbial diversity was measured by the Simpson reciprocal a-diversity index (S). We defined the pre-AHCT period as days -10 to 0, and computed median values for patients with multiple samples within that period. We additionally defined monodomination of the microbiota as a single operational taxonomic unit comprising 〉30% of bacterial abundance. For comparison, we sequenced samples from 17 healthy volunteers and used a public dataset of sequences from 313 healthy volunteers from the NIH Human Microbiome Project (HMP). Median pre-transplant microbial diversity in the healthy patient and AHCT groups was compared by a pairwise Wilcox test to a retrospective cohort of allo-HSCT patients. Results: We evaluated 857 samples from 365 adult patients undergoing AHCT, with 316 patients from Memorial Sloan Kettering Cancer Center (MSKCC) and 49 patients from Duke University Medical Center (DUMC). Median pre-transplant diversity in AHCT patients from both centers was significantly lower than in normal controls (Fig 1A) (HMP vs MSKCC AHCT, S=12.05 vs. 9.19, p75% by day +14. Conclusion: Microbial diversity is reduced prior to transplant in both AHCT and allo-HSCT patients. Loss of diversity after AHCT occurs across centers and the degree of injury is comparable to the dysbiosis in allo-HSCT patients. Preliminary analysis suggests that lower diversity may correlate with worse progression-free survival (PFS) in myeloma patients in our diverse AHCT cohort. Given the known associations of alterations in microbiota composition with toxicities and overall survival in allo-HSCT patients, further evaluation of microbiota injury and its associations with toxicities, PFS, and overall survival (OS) in AHCT patients is warranted. Figure 1: A: The median Simpson reciprocal a-diversity index (S) of pre-transplant (days -10 to 0) samples of AHCT and allo-HSCT patients from two centers, as well as two cohorts of healthy volunteers, was plotted and a pairwise Wilcox test was performed, with p-values as indicated. B: (S) was plotted against time relative to allo-HSCT (on L) and AHCT (on R), for samples collected from day -10 to day +30. Larger values indicate greater diversity. C: Microbiota composition and changes in bacterial monodominance after transplant (days -14 to +28); the most common genus post-transplant is Streptococcus. Figure 1. Figure 1. Disclosures Peled: Seres Therapeutics: Research Funding. Sauter:Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; Novartis: Consultancy; Precision Biosciences: Consultancy; Kite: Consultancy. Shah:Amgen: Research Funding; Janssen: Research Funding. Perales:Novartis: Other: Personal fees; Incyte: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees and Clinical trial support; Merck: Other: Personal fees; Takeda: Other: Personal fees; Abbvie: Other: Personal fees. Jenq:Ziopharm Oncology: Consultancy; Seres Therapeutics, Inc.: Membership on an entity's Board of Directors or advisory committees; MicrobiomeDx: Consultancy; Seres Therapeutics, Inc.: Patents & Royalties.

Description: Keywords Allogeneic transplantation; endothelial damage; biomarkers. Background Endothelial damage is associated with severe complications and increased risk of death after allogeneic hematopoietic cell transplantation (AlloHCT). The recently developed Endothelial Activation and Stress Index (EASIX) is a prognostic tool that uses clinical lab values and has been shown to predict non-relapse mortality (NRM) and overall survival (OS) at onset of acute graft versus host disease (aGVHD) in reduced intensity (RIC) alloHCT (Luft, Lancet Haematol 2017). We hypothesized that EASIX may be valuable for more broadly predicting aGVHD, NRM and OS after AlloHCT, beyond time of onset of aGVHD. Design We evaluated 152 adult patients who received an unmodified RIC AlloHCT from a related or unrelated donor with uniform GVHD prophylaxis of sirolimus/tacrolimus and low-dose MTX for treatment of lymphoid malignancies, between April 2008 and May 2017. The EASIX formula (LDH*Creatinine/platelet counts) was calculated at multiple timepoints (pre-HCT, day 30, day 100, onset TMA and aGVHD). For all EASIX assessments post-HCT, a landmark analysis was conducted at the given timepoint A log transformation using base 2 (log2) was applied to all EASIX variables to reduce skew. A one-unit increase in log2 EASIX is associated with a doubling (one-fold increase) of EASIX on the original scale. Kaplan-Meier, cumulative incidence, and cox modeling (cause specific for NRM and aGVHD) were used to evaluate EASIX as it relates to outcomes of interest. Relapse and death or relapse were considered competing risks for NRM and aGVHD respectively. Results The median age at transplant was 54 years (range 23-78), 70% were males, a majority had non-Hodgkin lymphoma (68%), and most had sensitive disease at time of HCT (CR=56%; PR=33%). All patients, except two, received peripheral blood stem cells. Sixty-three patients had an HLA-identical related donor, while the remaining 89 had an unrelated donor transplant (HLA-matched in 75 patients, and HLA-mismatched in 14 patients). HCT-CI was 0 in 49 patients, 1-2 in 41 and ≥ 3 in 62 patients. With a median follow-up in surviving patients of 5.4 years (range, 0.8-10), the 1 and 3 years OS rate was 84.2% (95% CI, 77.3-89.1) and 67.9% (95% CI, 59.6-74.8), respectively. The NRM rate at 1 and 3 years was 7.9% (95% CI, 4.3-12.9) and 16.4% (95% CI, 10.9-22.8), respectively. The 1-year cumulative incidences of grades 1-4, 2-4 and 3-4 aGVHD were 56.6% (95% CI, 48.3-64.1), 42.1% (95% CI, 34.2-49.8) and 7.9% (95% CI, 4.3-12.9), respectively. Post-HCT thrombotic microangiopathy was only observed in 13 patients, representing too few events for EASIX analysis. As expected, HCT-CI was significantly associated with both OS and NRM. Pre-HCT EASIX was significantly associated with increased NRM (HR=1.60 [95% CI, 1.15-2.23], p=0.005) and aGVHD grade 1-4 and 2-4 (HR=1.33 [95% CI, 1.08-1.64], p=0.006 and HR=1.39 [95% CI, 1.10-1.75], p=0.005; respectively), but not OS or grade 3-4 aGVHD (Table 1). EASIX at day 30 and day 100 was significantly associated with both OS and NRM (Figures 1-4). Furthermore, confirming the results of Luft, EASIX calculated at onset of any grade aGVHD was significantly associated with OS (HR=1.34 [1.10-1.63], p=0.004) and NRM (HR=1.47 1.11-1.94], p=0.007). Finally, there was no correlation between HCT-CI and EASIX score. Conclusions We conclude that the EASIX formula, calculated at various timepoints pre and post AlloHCT, is significantly associated with NRM and OS. Pre-HCT EASIX also predicts risk of aGVHD, confirming prior results, EASIX at onset of acute GVHD is a predictor of NRM and OS in adult recipients RIC AlloHCT. EASIX provides an independent and easily accessible tool to predict important AlloHCT outcomes that can be used in addition to HCT-CI to better risk stratify patients. Disclosures Sauter: Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; Novartis: Consultancy; Precision Biosciences: Consultancy; Kite: Consultancy. Perales:Incyte: Membership on an entity's Board of Directors or advisory committees, Other: Personal fees and Clinical trial support; Merck: Other: Personal fees; Takeda: Other: Personal fees; Abbvie: Other: Personal fees; Novartis: Other: Personal fees.

Description: Introduction Chronic graft-versus-host disease (cGVHD) affects up to 50% of the long-term survivors of allogeneic hematopoietic stem cell transplantation (HCT), and is the leading cause of mortality in patients who survive to two years post-transplant. Unlike acute GVHD (aGVHD), the primary pathology in cGVHD is fibrotic, affecting the skin, and lacrimal and salivary glands, and shares many features with the autoimmune conditions Sjogrens syndrome and systemic sclerosis. Certain gastrointestinal microbiota compositions have been associated with these autoimmune conditions, and we thus hypothesized that the configuration of microbial communities would also be associated with cGVHD, and may then serve as predictive biomarkers or offer mechanistic insights into cGVHD pathogenesis. Methods We identified a cohort of 55 patients with cGVHD as confirmed by a formal clinical consensus process applying NIH criteria, transplanted at MSKCC between January 2013 and August 2017. 47% of patients underwent transplantation for acute leukemia, with the remainder for non-hodgkin lymphoma (25%), myelodysplastic syndrome (13%), chronic leukemia (6%), myeloma and myeloproliferative disorder (each 2%). The majority received unmodified peripheral blood stem cell grafts (60%) with the remainder receiving CD34- selected grafts (20%), and marrow or cord blood grafts (20%). 55% of the cohort developed acute GVHD prior to day 100. 532 stool samples were available from 55 cGVHD cases, and were compared with 1462 samples from 165 control patients (matched for graft-source from the MSK allo-HCT Fecal Biobank). The median day of cGVHD onset in the cases was d194. The patient characteristics in the cases and controls were equivalent, including the rate of aGVHD prior to day 100 (55% vs 46%; p = 0.27). In addition, we compared the cGVHD cases with a separate cohort of patients with grade 3-4 aGVHD who were selected from the database on the basis of aGVHD diagnosis and a failure to develop cGVHD (n = 71 patients, contributing 835 samples), and an additional control group (matched for graft-source, n = 213 patients, 1786 samples) who did not develop any GVHD. All stool samples underwent 16S-targeted sequencing (V4-V5 region) on the Illumina platform. Results No differences in a-diversity as a function of time peri-HCT were observed, nor did we observe clustering of community characteristics in tSNE-space, or differences using the linear discriminant effect size (LEfSE) pipeline when we specifically examined samples collected pre-transplant, peri-engraftment, or peri-d100. Targeted analysis of genera reported to be enriched in intestinal communities of patients with autoimmune diseases however, revealed higher relative abundance in Prevotella prior to BMT in patients who went on to develop chronic GVHD (cGVHD case vs source-matched control p 〈 0.0001; cGVHD case vs cGVHD case vs no-GVHD control p

Description: Background Acute graft-versus-host disease (aGVHD) is common after double-unit cord blood transplantation (CBT) with an incidence of grade II-IV aGVHD as high as 55% by day 180 in patients transplanted without ATG. aGVHD is associated with increased morbidity and transplant-related mortality (TRM). Mycophenolate mofetil (MMF) combined with a calcineurin-inhibitor is commonly used to prevent GVHD after CBT. However, unlike the 1 gram (gm) every 8 hours dosing that is now standard in adult donor allografts, MMF dosing in CBT has traditionally been every 12 hours. Our center has increased MMF dose from 1 gm every 12 (q12) to 1 gm every 8 (q8) hours in an effort to reduce severe aGVHD after double-unit CBT. However, the efficacy of this intervention is not established and a theoretical concern is that intensified MMF dosing could result in an increased risk of delayed engraftment or graft failure. Methods We evaluated 171 double-unit CBT recipients (median age 39 years, range 0.9-71) transplanted with either myeloablative (MA, n = 133) or non-myeloablative (NMA, n = 38) conditioning for high-risk hematologic malignancies between 10/2005 and 4/2013. CB units were 4-6/6 HLA-A, -B antigen, -DRB1 allele matched to the recipient (16 6/6, 171 5/6, 155 4/6). All patients received GVHD prophylaxis with intravenous calcineurin-inhibitor (predominantly CSA) and MMF from day -3 without ATG. Prior to 9/2009, 80 patients (47%) received MMF 1 gm IV q12 (and those 12 years and ≥50 kg (or 15 mg/kg/dose if 〉12 years but

Description: Abstract 3080 As compared to single-unit CBT, DCBT may improve engraftment and protect against relapse. Therefore, we have adopted DCBT for both children and adults with acute leukemia, myelodysplasia (MDS), and myeloproliferative diseases (MPD). However, determinants of disease-free survival (DFS) have yet to be fully established. Furthermore, whether DFS after DCBT is comparable in patients of European and non-European ancestry is of special interest. Therefore, we analyzed the DFS of 75 DCBT recipients with acute leukemia in morphologic remission or aplasia (n = 69), and MDS/MPD with ≤ 5% blasts (n = 6) transplanted from 10/2005-4/2011. Nearly all patients had high-risk disease. Children 0–15 years (n = 23) had the following characteristics: median age 9 years (range 0.9–15); median weight 37 kg (range 7–72); 30% European; and 26% CMV sero-positive. Diagnoses were 43% AML (or biphenotypic), 52% ALL, and 4% MDS/MPD, and all received high-dose conditioning. The children received grafts with a median infused TNC × 107/kg of 3.3 (larger unit) and 2.6 (smaller unit), and 2% of units were 6/6 HLA-A, -B antigen, -DRB1 allele matched, 63% 5/6, and 35% 4/6. Adults ≥ 16 years (n = 52) had the following characteristics: median age 41 years (range 16–69); median weight 69 kg (range 47–105); 48% European; 69% CMV sero-positive; and diagnoses were 63% AML (or biphenotypic), 27% ALL, and 10% MDS/MPD. Fifty percent received high-dose and 50% reduced intensity conditioning. Their units had a median infused TNC/kg of 2.7 and 1.9, and 3% were 6/6 HLA-matched, 47% 5/6, and 50% 4/6. All patients (pediatric and adult) received calcineurin-inhibitor/ mycophenolate mofetil immunosuppression, and none received anti-thymocyte globulin. Sustained donor neutrophil engraftment was seen in 91% of children and 94% of adults at medians of 20 and 26 days, respectively. The incidence of grade II-IV acute GVHD by day 180 was 44% in children and 58% in adults. Day 100 transplant-related mortality (TRM) was 9% in children and 19% in adults. The 2-year relapse incidence was 9% in children and 6% in adults. With a median follow-up of survivors of 26 months (range 4–70), 2-year Kaplan-Meier estimate of DFS was 78% in children and 64% in adults (Figure). Differences in survival by age did not reach significance. Univariate analysis of variables potentially influencing 2-year DFS (with log rank estimates of significance) in all patients is shown in the Table. There were no differences in 2-year DFS according to ancestry, remission status, and conditioning intensity. There was also no difference in 2-year DFS according to engrafting unit-recipient HLA-match (4-6/6 or 10 allele), or engrafting unit infused TNC dose/kg. However, patients who were CMV seronegative had a higher 2-year DFS (85% vs 55%, p = 0.018). Multivariate analysis revealed recipient CMV serostatus was a predictor of DFS independent of patient age, and its effect was mediated by an influence on TRM. We have previously shown that DCBT extends transplant access to minority patients. We now demonstrate that DCBT can achieve high and comparable DFS in both European and non-European pediatric and adult patients with acute leukemia and MDS/MPD. While these are very encouraging results further investigation in racial/ethnic sub-groups is needed. Nonetheless, our findings support DCBT as an immediate alternative therapy for high-risk acute leukemia in patients without suitable unrelated volunteer donors, especially given the very low incidence of relapse. Disclosures: No relevant conflicts of interest to declare.

Description: Key Points ST2 is independently associated with aGVHD after day 28 in cord blood transplantation recipients. High ST2 levels predict for increased TRM in cord blood transplantation recipients.

Description: Tumor lysis remains a significant cause of morbidity and mortality in patients with highly proliferative hematologic malignancies. Traditionally, intravenous hydration and oral allopurinol have been the mainstays of therapy. However in some patients, hyperuricemia and renal failure still occur. The resultant renal failure precludes the administration of full doses of chemotherapy and results in a poor treatment outcome. Recently we participated in a large phase III randomized trial comparing rasburicase with standard allopurinol therapy. Rasburicase is a recombinant urate oxidase that effectively reduces serum uric acid due to conversion of uric acid into allantoin, a readily excretable and soluble substance. The results of that study are reported in a separate abstract. However while the study was open, we treated 12 extremely high risk, newly diagnosed hematologic malignancy patients who were ineligible for the study with commercially available rasburicase off study. The reasons for study ineligibility were ECOG Performance Status 4 and/or expected survival of less than one month. Other baseline characteristics: Diagnosis: Burkitts ALL: 3, AML: 7, CML-BP: 1, T-ALL: 1; Age: 64 (27–85), Sex: 6M/6F; WBC: 58,000/mm3 (1.6- 245,000); LDH: 2201 U/l (1068- 〉2500); # of preexisting comorbid medical conditions: 4 (0–7); chemotherapy: hyper-CVAD: 4, standard ara-c based rx: 5, high dose ara-C based rx: 3. Nine patients received one dose of rasburicase (0.2 mg/kg IV), 3 patients required a second dose. The median uric acid levels were: pretreatment : 9.2 mg/dl (2.8–28.6), at 24 hours:

Description: Abstract 5049 Introduction: New blood vessel formation (angiogenesis) is a multistep process that involves extracellular matrix remodeling, endothelial cell migration and proliferation, capillary differentiation and anastomosis formation. Angiogenesis has a key role in tumor growth and spread. Vascular endothelial growth factor (VEGF) is a positive regulatory cytokine and has a key, rate-limiting dose in promoting tumor angiogenesis. Abnormal VEGF expression has been described in acute leukemias as well as lymphomas. The available data in chronic myeloproliferative neoplasms (MPN) suggests that microvascular density (MVD) and VEGF expression are involved in angiogenesis process. Aim: The aim of this study was to evaluate MVD, VEGF expression and its correlation with clinical parameters. Material and Methods: The study was performed according to the regulation of the Ethics comitee. We included 41 patients with newly diagnosed MPN and 6 controls [28 PV, 23 PMF, 6 secondary eryhtrocytosis] from 2006 through 2009. G-band karyotype, FISH analysis (chromosomes 5, 7, 8 and 20) and JAK2V617F mutation were done according to standard techniques. Two experienced pathologists assessed morphology on hematoxylin-eosin stained slides, bone marrow fibrosis on Gomori silver slides and fibrosis was determined according to Thiele criteria (Thiele et al 2005). Bone marrow MVD was visualized in paraffin tissue sections using CD34 immunohistochemical staining and classified using a score system 0–4. Immunoexpression of VEGF was done in bone marrow core biopsies. A VEGF score was based on VEGF-positive megakaryocytes vs VEGF-immunohistochemistry staining. Statistical analysis was done using Chi-square test. Results: Most of PV patients had a low MVD (grade 0+1) (73%), whereas the majority of PMF patients had high MVD (grade 2+4) (76 %). MVD score was higher in PMF than PV (median grade 3 vs 1, respectively p=0.8). There were no differences in MVD score (both PV and PMF) according to JAK2V617F mutation status (respectively p=0.79 and p=0.8). Interestingly, PV and PMF patients with high MVD presented high platelet count (315 vs 694 × 109/L in PV, 664 vs 985 ×109/L in PMF); and a high incidence of thrombosis (18.1 vs 50% in PV p=0.9; and 0 vs 26.3% in PMF). VEGF score was higher in PV than PMF (median score 3 vs 2 p=0.22). Thus, PV and PMF patients with low MVD presented a higher rate of abnormal karyotype than high MVD patients (18% vs 0 in PV; 33 vs 10,5% in PMF p=0.0002). We combined data and analyzed together PV and PMF patients who presented low MVD and high MVD. High MVD patients (n=23) were older than low MVD group (68 vs 59 p=0.77), had low hemoglobin value (12.5 vs 18.5g/dL p=0.10), presented high platelet count (738 vs 351 × 109/L) and had a high incidence of thrombosis (30.4 vs 15.3% p=0.98) but there was no difference in VEGF score (median score 3 p=0.39). There was a correlation of high MVD and advanced fibrosis in (r=0.54 Pearson test). Low and high MVD patients had similar JAK2V617F rate mutation (61.5 vs 60.8%, p=0.4) and low MVD patients presented a slightly higher incidence of abnormal cytogenetic findings (31 vs 6.6%). There was no correlation with MVD and VEGF score (r=0.34), age (r=0.17), platelet count (r=0.27). There were no differences in VEGF score according to JAK2V617F mutation status. There was a correlation between VEGF score (grade 2+3) and the occurrence of massive splenomegaly in PV patients (r=0.52 Pearson test). PV patients who presented advanced fibrosis had a high platelet compared to mild fibrosis (567 vs 1031× × 109/L). There were no changes in platetet count regarding to fibrosis degree in PMF. Discussion and Conclusions: According to our results we found increase of platetet count and thrombosis in patients with high MVD. VEGF score did not relate to MVD findings neither thrombosis. The occurrence of high MVD correlated with high platelet count and thrombosis, suggest that MVD mechanisms may determine clonal changes and influence platelet differentiation and survival. Probably other biological interactions such as abnormal signaling network in bone marrow may play a role in determining MVD changes in MPN. This question remains to be further validated and investigated in other studies. Our current data show that stromal abnormalities were correlated with thrombosis and raise the question of the evolutive changes in the hematopoietic stem cell leading to abnormal changes in bone marrow during the course of the disease. Disclosures: No relevant conflicts of interest to declare.

Description: Background FLT3, PIM1, PIM2 and CXCR4 are proteins implicated in the signal transduction of the regulation of proliferation, differentiation and survival of hematopoietic stem cells, at different levels. The impairing of these three processes, regulated by these molecules, constitutes the main hallmark of Acute Myeloid Leukemia (AML). The objectives of this work were to evaluate the expression level of the genes that codify such proteins in patients with AML; as well as correlate this level of expression with biological variables at diagnosis and survival. Methods peripheral blood or bone marrow samples from 31 healthy subject (HS) and 92 AML patients at diagnosis between 2004 and 2012 were studied. The median follow up was 14 months (69% of patients had died). We quantified the expression of FLT3, PIM1 and 2, and CXCR4 by real time PCR, employing primer pairs designed in our laboratory to amplify all known protein-coding transcripts; highlighting the presence of a 30.4% FLT3 ITD, 5.4% of other FLT3 mutations and 26% of NMP1 mutations. Results were then analyzed with the statistical package IBM“ SPSS” Statistics, v20 (IBM“, Nueva York). Results FLT3 was overexpressed in AML patients (FLT3 expression: controls 0.99 vs patients 36.97; p