Academic literature on the topic '66.045.1; 662.99'

Room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of hydrated lanthanoid(III) trichlorides with 2,2′-bipyridine (‘bpy’) and 1,10-phenanthroline (‘phen’), crystallized from water, methanol or ethanol solutions, containing mononuclear arrays with 1 : 2 Ln/bpy or phen stoichiometry. LaCl3/phen/H2O(1 : 3 : 9), [(phen)2La(OH2)5]Cl3.phen.4H2O, although of overall 1 : 3 LaCl3/phen stoichiometry, has a lattice phen; it is orthorhombic, Pnna, a 19·947(7), b 16·457(5), c 12·213(2) Å, Z = 4; conventional R on |F| was 0·030 for No 2567 ‘observed’ (I >3σ(I)) diffractometer reflections. LaCl3/phen/H2O/MeOH (1 : 2 : 6 : 1), [(phen)2La(OH2)5]Cl3.H2O.MeOH, is triclinic, P 1, a 19·060(3), b 9·252(3), c 8·994(3) Å, α 69·33(3), β 86·81(2), γ 89·66(2)°, Z = 2, R 0·037 for No 5452. LaCl3/bpy/H2O (1 : 2 : 6), [(bpy)2La(OH2)4Cl]Cl2.2H2O, is monoclinic, P 21/c, a 19·389(3), b 9·071(1), c 16·873(2) Å, β 114·10(1)°, Z = 4, R 0·029 for No 4699. All three of these complexes have a nine-coordinate [(N,N′-bidentate)2La(unidentate)5] coordination environment with quasi-2 symmetry; that of the remaining compounds following is eight-coordinate [(N,N′-bidentate)2Ln(unidentate)4]. LuCl3/phen/H2O (1 : 2 : 6), [(phen)2Lu(OH2)4]Cl3.2H2O, is monoclinic, C 2/c, a 11·045(7), b 17·660(6), c 14·474(9) Å, β 92·82(5)°, Z = 4, R 0·042 for No 1695, the Lu lying on a crystallographic 2 -axis. Crystals of LnCl3/phen/H2O(1 : 2 : 4), [(phen)2Ln(OH2)3Cl]Cl2.H2O (Ln = Dy, Er, Y), are triclinic, P 1, a≈ 12·6, b ≈ 10·5, c ≈ 10·4 Å, α ≈ 93·3, β ≈ 109·3, γ ≈ 96·8°, Z = 2, R 0·030, 0·040, 0·052 for No 4221, 5100, 2690 respectively. PrCl3/bpy/H2O/EtOH (1 : 2 : 1 : 0·5), [(bpy)2Pr(OH2)Cl3].½EtOH, is triclinic, P 1, a 13·331(3), b 10·734(2), c 9·758(2) Å, α 63·67(2), β 78·99(2), γ 71·24(2)°, Z = 2, R 0·033 for No 4596, while [(bpy)2Pr(OH2)2Cl2]Cl is monoclinic, C 2/c, a 15·921(15), b 11·314(8), c 14·114(8) Å, β 116·70(6)°, Z = 4, R 0·041 for No 2269. ErCl3/bpy/H2O(1 : 2 : 2 (also)), [(bpy)2Er(OH2)2Cl2]Cl, is cubic, I 23, a 26·032(4) Å, Z = 24, R 0·066 for No 1644. Crystals of LnCl3/phen/H2O/MeOH (1 : 2 : 1 : 1), [(phen)2Ln(OH2)Cl3].MeOH (Ln = La, Pr, Nd, Eu), are monoclinic, P 21/a, a ≈ 13·2, b ≈ 10·7, c ≈ 18·5 Å, β ≈ 102·1°, Z = 4, R 0·054, 0·032, 0·040, 0·054 for No 2872, 4792, 3179, 2847 respectively. LnCl3/bpy/H2O/EtOH (1 : 2 : 1 : 1), [(bpy)2Ln(OH2)Cl3].EtOH (Ln = Nd, Eu), are triclinic, P 1, a ≈ 11·3, b ≈ 10·9, c ≈ 10·4 Å, α ≈ 75·5, β ≈ 89·8, γ ≈ 78·0°, Z = 2, R 0·044, 0·056 for No 4979, 3596 respectively. LaCl3/bpy/EtOH (1 : 2 : 0·5) is binuclear [(bpy)2Cl2La(µ-Cl)2LaCl2(bpy)2].EtOH, monoclinic, P 21/c, a 9·6878(2), b 17·5696(3), c 16·1341(2) Å, β 123·10(1)°, Z = 2, R 0·033 for No 4256. A totally unsolvated array is found for YbCl3/bpy (1 : 2), [(bpy)2YbCl3], monoclinic, P 21/c, a 15·065(8), b 8·598(4), c 16·92(1) Å, β 112·46(5)°, Z = 4, R 0·032 for No 3548, in which, alone, the metal atom is seven-coordinate.

Objective. To describe the yield of smear-microscopy and radiological findings by male and female patients with symptoms of tuberculosis in Abuja, Nigeria.Methods. Patients ≥15 years old with cough for >3 weeks submitted 3 sputum samples for smear microscopy. One specimen was cultured using MGIT-960. All patients had lung X-rays and screened for HIV.Results. were more likely to be smear-positive than females (262/774 [34%] and 137/547 [25%],P<.01), but similar proportions of males and females were culture-positive (437/691 [63%] and 294/495 [59%],P=.09). 317/626 (50.6%) males and 249/419 (59.4%) females were HIV-positive (P<.005). Among culture-positives patients, HIV-infected males were less likely to have positive smears than HIV-negative males (49.2% versus 66%,P=.001). Among females, smear positivity did not vary with HIV (46.4% for HIV-positive and 52.9% for HIV-negative,P=.38). Of 274 culture-confirmed TB cases, 226 (82.5%) had cavities, and 271 (99%) had ≥1 lung areas affected. HIV-positive males were more likely to have lung cavities than HIV-positive females (85% versus 69%,P<.04) and to have ≥3 lung areas affected (P=.03).Conclusion. Differences in the yield of smear-microscopy, culture and X-rays on presentation are due to several factors including HIV coinfection and gender.

The most severe manifestation of the new coronavirus infection COVID-19 in children is the multisystem inflammatory syndrome in children (MIS-C). A systematic review of foreign publications as of July 25, 2020 contains an analysis of the disease course in 662 children with this syndrome and is used for comparison with the data obtained. Objective of the research: to characterize clinical manifestation, results of laboratory and instrumental studies, therapy, outcomes and consequences of the COVID-19- associated MIS-C, based on the observation of patients hospitalized to Morozov Children's City Clinical Hospital and Children’s clinical hospital of infectious diseases № 6 from May 1 to September 15, 2020. Materials and methods: the pilot study included 32 children aged 9 months – 15 years with COVID-19-associated MIS-C, verified based on WHO criteria (2020), including symptoms of Kawasaki disease (KD), arterial hypotension/shock, laboratory and instrumental signs of heart damage, signs of coagulopathy, gastrointestinal symptoms, increased inflammation markers, COVID-19 markers. Results: the median age of patients was 6 years, boys predominated among the patients (66%), all patients had antibodies to SARS-CoV-2 (31 children of the IgG class); MIS-C manifested itself as a combination of KD symptom complex (75% of patients) with arterial hypotension/shock (28%), neurological (50%), respiratory (41%), gastrointestinal (59%) symptoms; macrophage activation syndrome (MAS) was verified in 16% of patients. Therapy included intravenous immunoglobulin (75%), systemic glucocorticosteroids (88%), anticoagulants (91%), vasoactive/vasopressor support (31%). In 38% of cases treatment was performed in intensive care unit; one child died. According to echocardiography, 16% of patients had coronariitis, ectasia, and coronary arteries aneurysms. Conclusion: COVID-19-associated MIS-C is characterized by a severe course, cross-features with KD, shock syndrome with KD, MAS which requires intensive therapy and can cause acquired pathology of the cardiovascular system in children.

Abstract Context Patients with mutations in thyroid hormone transporter MCT8 have developmental delay and chronic thyrotoxicosis associated with being underweight and having cardiovascular dysfunction. Objective Our previous trial showed improvement of key clinical and biochemical features during 1-year treatment with the T3 analogue Triac, but long-term follow-up data are needed. Methods In this real-life retrospective cohort study, we investigated the efficacy of Triac in MCT8-deficient patients in 33 sites. The primary endpoint was change in serum T3 concentrations from baseline to last available measurement. Secondary endpoints were changes in other thyroid parameters, anthropometric parameters, heart rate, and biochemical markers of thyroid hormone action. Results From October 15, 2014 to January 1, 2021, 67 patients (median baseline age 4.6 years; range, 0.5-66) were treated up to 6 years (median 2.2 years; range, 0.2-6.2). Mean T3 concentrations decreased from 4.58 (SD 1.11) to 1.66 (0.69) nmol/L (mean decrease 2.92 nmol/L; 95% CI, 2.61-3.23; P &lt; 0.0001; target 1.4-2.5 nmol/L). Body-weight-for-age exceeded that of untreated historical controls (mean difference 0.72 SD; 95% CI, 0.36-1.09; P = 0.0002). Heart-rate-for-age decreased (mean difference 0.64 SD; 95% CI, 0.29-0.98; P = 0.0005). SHBG concentrations decreased from 245 (99) to 209 (92) nmol/L (mean decrease 36 nmol/L; 95% CI, 16-57; P = 0.0008). Mean creatinine concentrations increased from 32 (11) to 39 (13) µmol/L (mean increase 7 µmol/L; 95% CI, 6-9; P &lt; 0.0001). Mean creatine kinase concentrations did not significantly change. No drug-related severe adverse events were reported. Conclusions Key features were sustainably alleviated in patients with MCT8 deficiency across all ages, highlighting the real-life potential of Triac for MCT8 deficiency.

Abstract Background: The role of bone marrow response in patients with immune thrombocytopenia (ITP) has gained paramount importance since the last 10 years, with the demonstrations that marrow megakaryocytes (MGK) are unable to properly compensate platelets peripheral destruction. TPO receptor agonists (TPOa), namely romiplostim (ROMI) and eltrombopag (EPAG), by stimulating megakaryopoiesis are able to induce a response in 74% to 94% of cases in clinical trials. However, real world use of these drugs has shown frequent changes in individual dose requirement, the possibility of treatment discontinuation, and their effectiveness outside registered indications; moreover, nothing is known about predictors of response. Aim: To evaluate clinical and morphologic predictors of response in a real world cohort of ITP patients treated with TPOa. Methods: ITP patients treated with EPAG and ROMI from September 2009 to May 2018 at seven Italian Centers were evaluated. Clinical and hematologic parameters including treatment response and marrow characteristics were retrospectively collected. Results: Table 1 shows baseline clinical and morphologic characteristics for the 86 cases enrolled, altogether and divided according to the TPOa used: patients were mainly middle-aged females presenting with severe thrombocytopenia; anti-PLT autoantibodies were positive in 32.6% of cases, and 58.1% of cases presented with bleeding, 22% of grade III-IV. All cases had received 1st line treatment with steroids and 43% at list a 2nd line among those listed in Tab1. Pre-TPOa marrow evalutation showed hypocellularity in 30.2% of cases, reticulinic fibrosis in 33.7%, a polyclonal lymphoid infiltrate in 43% (mostly mixed or T-cell), and reduced MGK in 4.7% of patients. Some dysplastic features were present in about 50% of cases, either dysmegakaryopoiesis (46.5%) or dyserythropoiesis (25.6%). Median time from diagnosis to TPOa was 2.4 years (0.1-28.8). Patients were treated for a median of 1.4 years (0.3-10.8), and ORR at 3 months and 9 months were 75.6% (CR 44.2 and PR 31.4%) and 65.1% (CR 36 and PR 29.1%), respectively. Response rates to EPAG and ROMI were comparable. Regarding predictors of response, bone marrow hypocellularity (40 NR vs 21% ORR, p=0.05) and megakaryocytopenia (33 vs 6%, p=0.06) were significantly more frequent among NRs. Other factors associated with poor response were dyserythropoiesis (58 vs 26%, p=0.04) and erythroid hyperplasia (18 vs 8%, p=0.03), and presence of a T cell infiltrate (66 vs 18.9%, p=0.03). Finally, NRs cases showed significantly lower neutrophil counts at baseline (1.9 vs 2.3x103/mmc in ORR, p=0.01), and had been more frequently exposed to cyclosporine or azathioprine (50 vs 18% in ORR, p=0.01). Fifty-five patients are still on treatment, whereas 31 (20 EPAG/11 ROMI) discontinued because of NR or relapse (17), adverse events or intolerance (2); of note, 12 patients with ORR discontinued the drug because of sustained CR, and 7 of them are still in remission. 14/65(21.5%) responding cases (10 EPAG/4 ROMI) lost the response after a median of 6.2 months (1.8-60) and were variably managed (3 splenectomized, 1 switched from ROMI to EPAG, 1 received danazol, 5 were re-treated with EPAG, and the remaining were managed with steroids and supportive treatment). Median RFS was 2.3 years (0.1-10), longer in patients without megakaryocytopenia (9.9+0.5 vs 4.1+0.6, p=0.06), dyserythropoiesis (mean 9.1+0.5 vs 4.9+0.7, p=0.2), and reticular fibrosis (9.6+0.5 vs 5.5+0.6, p=0.08). During EPAG treatment 7 grade adverse events occurred: 2 grade IV (1 stroke with PLT counts of about 30x103/mmc, and 1 NSTEMI 1 month after EPAG discontinuation for sustained CR), 1 grade III pneumonia, and 4 grade I/II transaminase elevation. No events occurred under ROMI. Conclusions: TPOa use in the real world setting confirms their reported efficacy, the option to switch and/or re-treat with either EPAG or ROMI, and the possibility to discontinue the drugs. The presence of hypocellularity and megakaryocytopenia, along with dysplastic features and of a lymphoid T cell infiltrate are associated with a reduced response to TPOa and a shorter RFS. Pre-treatment bone marrow evaluation may give hints to unravel the physiopathologic mechanisms underlying TPOa refractoriness. Disclosures Rossi: MUNDIPHARMA: Honoraria; JANNSEN: Other; AMGEN: Other: ADVISORY BOARD; PFIZER: Other: ADVISORY BOARD; BMS: Honoraria; NOVARTIS: Honoraria; ROCHE: Other: Advisory Board; ABBVIE: Other: ADVISORY BOARD; TEVA: Other: ADVISORY BOARD; CELGENE: Other: ADVISORY BOARD; JAZZ: Other: ADVISORY BOARD; SANOFI: Other: ADVISORY BOARD; GILEAD: Other: ADVISORY BOARD; SANDOZ: Honoraria.

Abstract Pts with hematologic malignancies (HM) are at high risk of developing SS and sepsis-related mortality. The diagnosis of sepsis requires suspicion of infection accompanied by at least two signs of systemic inflammation. The SIRS criteria were devised to improve the early bedside detection of sepsis and provide objective inclusion criteria for clinical research. Cut-point values based on consensus opinion are: HR >90, Temp > 100.4 or <96.8, RR>20, and WBC >12k or <4k. SIRS is defined by the presence of ≥2 abnormalities. Although widely used, SIRS criteria have not been studied in pts with HM because factors such as immunosuppression and other disease characteristics result in clinical and laboratory changes which are thought to potentially invalidate the SIRS criteria. Since HM pts have been excluded from pivotal sepsis trials, clinicians must extrapolate data from other populations to make diagnostic and treatment decisions for HM patients with SS. The purpose of this study was to evaluate the SIRS criteria as predictors of development of SS in pts with HM. Methods: The association between the SIRS and SS was evaluated in hospitalized adult pts (age 18–83) with HM in a prospective single-center, nested case-control study. The primary outcome was SS, defined as an infection resulting in cardiovascular or respiratory failure. Vital signs were performed every eight hours. Of the 547 pts who consented for the study, 54 developed SS (9.9% CI 7.7–12.7%). Using incidence density sampling, 211 controls were selected by matching on length of stay at time of SS. Evidence-based cut-points were then derived for the individual SIRS variables by examining risk estimates based on variable percentiles. Results: At hospital admission, HR, RR, BP, WBC, ANC, age, diagnosis, and transplant status were similar between the groups. In univariable analysis (24° prior to SS), significance of the four individual SIRS variables were: HR (p=.001), RR (p<.001), Temp (p<.001) and WBC (p=.218). Sensitivity, specificity and LR(+) for SIRS scores (1–4) are reported in the Table. In multivariable logistic regression, HR (OR 2.0, CI 1.0–4.1 p=.047), RR (OR 8.3, CI 2.8–24.4 p<.001) and Temp (OR 3.8, CI 1.8–8.0 p=.001) remained significant (ROC area=0.75). Age, diagnosis and transplant status did not modify these risks. WBC and hypothermia did not contribute to the model. Empirically derived cut-points for HR, Temp and RR were: HR (≥109, OR 5.5 2.64–11.5 p <.001), Temp (≥100.2°F, OR 2.71, CI 1.2–6.2, P<.001), (RR> 20, OR 8.3, CI 2.8–24.4 p<.001), ROC area= 0.79 (24° prior to SS). Conclusions: This study is the first to evaluate and define the test characteristics of the SIRS criteria in hospitalized pts with HM. The rationale for excluding HM patients from SS clinical trials based on diagnostic concerns should be revisited when planning future SS studies. Fever, tachycardia and tachypnea seem most predictive in this population. These results suggest that cut-points for significant SIRS variables can be redefined to improve the specificity of the SIRS score. Additional markers for the early detection of SS may further improve upon SIRS in HM pts. SIRS Score Sensitivity % (95 CI) Specificity LR(+) 1 98 (97–99) 12 (8–18) 1.1 2 76 (71–81) 60 (54–66) 1.9 3 39 (33–45) 91 (88–94) 4.3 4 7 (4–11) 99 (99–100) 15.6

Abstract The last four decades have seen significant increase in the incidence of non-Hodgkin’s lymphoma (NHL) as a possible result of increasing environmental carcinogens exposure. Based on the increasing evidence for the association between carcinogens exposure related cancer risk and xenobiotic gene polymorphisms. We have undertaken a case control study on xenobiotic gene polymorphisms in Saudi individuals with a diagnosis of diffuse large B-cell lymphoma (DLBCL). Polymorphisms in five genes (CYP1A1, GSTT1, GSTP1, GSTM1 and NQO1) were characterized in 187 individuals with DLBCL and 513 normal controls using polymerase chain reaction (PCR) based method. We chose the Saudi population as our study population because of its high consanguinity and its relative genetic homogeneity. The CYP1A1*2C, GSTT1 null and GSTP1 TT genotype were all found to be significant predictors of DLBCL risk (odds ratio 6.62, 11.94 and 3.42 respectively). None of the other alleles tested for proved to be significant indicators of DLBCL risk. These results suggest that the risk of DLBCL may indeed be associated with xenobiotics - metabolism and thus with environmental exposures. Table 1 Distribution of polymorphisms in healthy population and lymphoma patients. Polymorphism Genotype Control group Lymphoma patients p OR CYP1A1 −/− 384(76.5%) 104(78.8%) *2A −/2A 105(20.9%) 24(18.18%) 0.543 0.844 2A/2A 13(2.6%) 3(2.27%) 1.000 0.852 2A allele 13% 11.36% 0.659 0.839 CYP1A1 −/− 443(88.2%) 121(91.66%) *2B −/2B 50(10%) 10(7.58%) 0.505 0.732 2B/2B 9(1.8%) 1(0.76%) 0.697 0.407 2B allele 6.8% 4.55% 0.424 0.646 CYP1A1 −/− 497(99%) 125(94.7%) *2C −/2C 5(1%) 4(3.03%) 0.090 3.181 2C/2C 0 3(2.27%) 0.008 ND 2C allele 0.5% 3.8% 0.011 6.627 NQO1 C609T CC 295 (58.5%) 94 (62.7%) CT 177 (35.1%) 37 (24.7%) 0.051 0.656 TT 32 (6.4%) 19 (8.7%) 0.059 1.863 CT+TT 209 (41.5%) 56 (37.3%) 0.395 0.841 GSTP1 2293 CC 389 (76.3%) 113 (77.9%) CT 113 (22.2%) 24 (16.6%) 0.240 0.731 TT 8 (1.5%) 8 (5.5%) 0.017 3.422 CT+TT 121 (23.7%) 32 (22%) 0.739 0.910 GSTP1 A1578G AA 170 (33.5%) 56 (35%) AG 271 (53.5%) 96 (60%) 0.772 1.075 GG 66 (13%) 8 (5%) 0.013 0.368 AG+GG 337 (66.5%) 104 (65%) 0.774 0.937 GSTT1 P 385 (75%) 36 (20.1%) D 128 (25%) 143 (79.9%) <0.001 11.948 GSTM1 P 233 (45.4%) 91 (50%) D 280 (54.6%) 91 (50%) 0.300 0.832 Table 2 Distribution of combined GSTT1 and GSTM1 polymorphisms in case and control group. Genotype Control Case p OR Null: Complete deletion of GSTT1 and GSTM1 allele Present 423 (82.8%) 109 (60.9%) Double Null 88 (17.2%) 70 (39.1%) <0.001 3.087

Abstract Background: In AL amyloidosis, circulating free light chains (FLC) are not only a clonal marker, but they are the causal agent of the disease. The recently validated criteria of hematologic response are based solely on the measurement of FLC. Patients with a difference between involved and uninvolved FLC (dFLC) <50 mg/L do not have measurable disease and cannot be assessed for response. Hence, they are commonly excluded from clinical trials. Nevertheless, these subjects represent a significant proportion of the patients suffering from AL amyloidosis, and given the lower burden of the toxic amyloidogenic precursor we hypothesize that they have distinctive clinical features. Patients and methods: The study population is composed of 984 consecutive, newly diagnosed patients with AL amyloidosis evaluated between 2004 and 2013 at the Pavia Amyloidosis Center and prospectively followed for response and survival. We compared the 187 subjects (19%) who had a baseline dFLC <50 mg/L (low-dFLC group) with the remaining 797 patients (evaluable-dFLC group). Results: Patients' characteristics are reported in the table. Heart involvement was less common in the low-dFLC group, and cardiac and renal dysfunction was more advanced in the evaluable-dFLC group, whereas renal involvement was more frequent and severe in the low-dFLC group. The Mayo clinic staging system based on NT-proBNP and cardiac troponin was able to discriminate three groups with significantly different outcomes in both groups (P<0.001). Overall survival was significantly better in the low-dFLC group (median 90 vs. 48 months, P<0.001). Within each Mayo stage patients with low-dFLC had a longer survival (at 3 years, 88% vs. 78%, P=0.03 in stage I, 69% vs. 45%, P=0.001 in stage II, 36% vs. 22%, P=0.02 in stage III). Complete response was associated with a significant survival advantage in the low-dFLC group (median 122 months vs. 92 months, P=0.02). Conclusions: Nineteen percent of newly diagnosed patients with AL amyloidosis have very low dFLC burden. They represent a subgroup with a distinct and better outcome compared to other patients. Nevertheless, complete response can still significantly improve survival. Patients with low baseline dFLC can be included in clinical trials with appropriate stratification and are evaluable for complete response. Table 1. Patients' characteristics. Variable Low dFLC group 187 patients N (%) - median (range) Evaluable dFLC group 797 patients N (%) - median (range) P Age, years 66 (40-85) 65 (30-87) 0.124 Male sex 99 (52) 444 (55) 0.272 Organ involvement Heart Kidney Liver >2 organs 88 (47) 142 (76) 26 (13) 99 (53) 662 (83) 511 (64) 112 (14) 566 (71) <0.001 0.001 0.532 <0.001 Mayo Stage 1 2 3 69 (37) 91 (49) 27 (14) 109 (12) 338 (42) 350 (44) <0.001 0.071 <0.001 NYHA class 3 36 (19) 331 (40) <0.001 NT-proBNP >8500 ng/L 12 (6) 212 (27) 0.0001 Renal Stage 1 2 3 62 (33) 85 (45) 40 (21) 384 (48) 320 (40) 93 (11) 0.001 0.107 0.001 Alkaline phosphatase, U/L 144 (82-215) 159 (99-239) 0.077 Involved ligh-chain type κλ 37 (20) 150 (80) 190 (24) 607 (76) 0.02 0.13 Bone marrow plasma cells, % 8 (5-12) 12 (8-20) 0.001 Melphalan-dexamethasone (MDex) Cyclophosphamide-bortezomib-Dex Bortezomib-MDexOthers 67 (35) 41 (22) 19 (10) 60 (33) 289 (36) 207 (26) 102 (12) 199 (26) 0.491 0.145 0.194 0.030 Disclosures Merlini: Millennium-Takeda: Honoraria; Janssen-Cilag: Honoraria; Pfizer: Honoraria; Prothena: Honoraria.

Abstract Background: IMDs including mucopolysaccharidosis type IH (MPS1/Hurler Syndrome), metachromatic leukodystrophy (MLD), globoid cell leukodystrophy (GLD) and cerebral adrenoleukodystrophy (cALD) are progressive, fatal diseases affecting the central nervous system which are treatable through allogeneic hematopoietic stem cell transplantation (HSCT). CB, in the absence of a matched donor, is the preferred source of stem cells as it is rapidly available and allows greater flexibility in allele matching. As a result of low cell doses, CB transplants in IMD are associated with prolonged periods of neutropenia and reported graft failure rates in up to ~20% (Lum et al 2017 Bone Marrow Transplant 52:846-53; Mallhi et al 2017 BBMT 23:119-25). MGTA-456 is a first-in-class cell therapy produced from a single CB unit using an aryl hydrocarbon receptor antagonist in a 15-day expansion culture of CD34+ cells. In previous phase 1/2 studies, 24 adult and 3 pediatric patients with hematologic malignancies treated with myeloablative conditioning (MAC) and MGTA-456 demonstrated a median 324-fold expansion of CD34+ cells, all patients engrafted, and the time to neutrophil recovery was significantly reduced by a median of 9 days compared to historical controls (Wagner et al 2016 Cell Stem Cell 18:144-55; Wagner et al 2017 Blood 130 supp:662 abstr). Furthermore, higher CD34+ dose has been correlated with improved engraftment and outcomes in IMD transplant patients (Prasad et al 2008 Blood 112:2979-89). Based on these promising data, we postulate the increased CD34+ dose provided by MGTA-456 would reduce the length of neutropenia and risk of graft failure in IMD patients. Patients and Methods: A Phase 2, open-label trial (NCT03406962) initiated in Feb 2018 is enrolling up to ~12 patients <16 yo with a diagnosis of MPS1, cALD, MLD, and GLD lacking a non-carrier matched related donor. Eligible CB units were matched at ≥ 6 of 8 HLA loci (A, B, C and DRB1) using allele-based typing. The reduced toxicity MAC regimen consists of anti-thymocyte globulin (days -9 to -6) followed by fludarabine (40 mg/m2 days -5 to -2) and busulfan (total exposure 21,000 to 22,000 μM/min/L-1 days -5 to -2). Immunoprophylaxis consists of cyclosporin and methylprednisolone. Results: Four patients have been treated thus far (Table 1). The MGTA-456 process provided a marked expansion of CD34+ cells (median 482-fold, Figure 1) with a median infused CD34+ cell dose of 84 x 106 cells/kg and median total nucleated cell (TNC) dose from the expanded fraction of 19.6 x 107 (Table 1). TNC dosing was capped at 27.0 x 107 cells/kg per protocol. The only infusion-related reaction noted was grade 3 nausea in 1 patient. Two patients had no days of neutropenia and 2 patients had 1 and 4 days respectively (mean 1.25 days) in contrast to a mean of 7.8 days for a historical cohort of 27 IMD patients undergoing CB transplantation at the same institution with identical conditioning (Figure 2). Myeloid chimerism (CD33+/66+) achieved ≥98% donor by day +14 in all patients. For the 3 patients with data at time of reporting, days to discharge after transplant were 17, 12 and 18. No patients experienced acute or chronic GVHD. One patient developed autoimmune cytopenia (not related to MGTA-456) which is a known complication reported in 20-56% of IMD patients undergoing HSCT that resulted in death at day +143 (Page et al 2008 BBMT 14:1108-17; Khalil et al 2014 Sci World J 581657). Long-term disease specific outcome measures including enzymatic activity are being collected and will be reported over time. Conclusions: Preliminary results of transplantation in IMD patients with MGTA-456, containing highly expanded CD34+ cell doses, demonstrated early and robust engraftment in all patients with marked reduction in days of neutropenia (to 0-4 days or mean 1.25 days) in comparison to a historical cohort. MGTA-456 was well tolerated with one infusion-related event of grade 3 nausea. These data, in combination with the previous 27 hematologic malignancy patients treated, suggest that MGTA-456 substantially enhances the engraftment potential of CB. Based on these promising data, MGTA-456 has potential to improve transplant-related outcomes in patients undergoing HSCT and increasing the availability of well-matched CB units that may have been previously excluded due to inadequate CD34+ dose. Disclosures Orchard: Magenta Therapeutics: Research Funding. Raffel:Magenta Therapeutics: Employment, Equity Ownership. Condon:Magenta Therapeutics: Employment, Equity Ownership. Monaghan:Magenta Therapeutics: Employment, Equity Ownership. Vernet:Magenta Therapeutics: Employment. Sheirr:Magenta Therapeutics: Employment, Equity Ownership. Braun:Magenta Therapeutics: Research Funding. Shanley:Magenta Therapeutics: Research Funding. Lund:Magenta Therapeutics: Research Funding. Boitano:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Cooke:Magenta Therapeutics: Employment, Equity Ownership, Patents & Royalties. Davis:Magenta Therapeutics: Employment, Equity Ownership. Wagner:Novartis: Research Funding; Magenta Therapeutics: Consultancy, Research Funding.

Abstract Introduction The association of NPM1mut and FLT3-ITD in de novo acute myeloid leukemia (AML) with intermediate-risk cytogenetics has different prognostic impact depending on the FLT3 allelic burden. Previous studies published by our cooperative group showed that patients with de novo AML of intermediate-risk cytogenetics with NPM1mut and FLT3-ITD low ratio (<0.5, FLT3low) at diagnosis presented an overall survival and relapse rate similar to those with NPM1mut and FLT3wt. Therefore, in the CETLAM-2012 protocol, patients with FLT3low NPM1mut AML are not considered for allogenic hematopoietic stem cell transplant (allo-HSCT) in first complete remission (CR1). Recent studies suggest that the co-occurrence of DNMT3A mutation in FLT3-ITD NPM1mut AML patients confers a worse prognosis regardless of FLT3-ITD ratio. We analysed our data to determine whether these findings were confirmed in our cohort, specifically in the low FLT3-ITD ratio patients, since this could have therapeutic implications. Methods and patients A total of 163 patients with de novo AML, intermediate-risk cytogenetics and NPM1mut were analysed (median age 53 years (18-72); male:female 72:91 (0.79)). Eighty patients (49%) harboured an FLT3-ITD, with a high allelic ratio in 42 of 76 patients with available ITD/wt ratio (55%). They were included in the AML-2003 (n=49) and AML-2012 (n=114) CETLAM protocols. Proportion of patients undergoing alloHSCT in CR1 is detailed in table 1. Bone marrow samples from diagnosis were studied for DNMT3A mutations as previously described. The definition of complete remission (CR), overall survival (OS), leukemia-free survival (LFS) and risk of relapse (RR) followed recommended ELN criteria. The Kaplan-Meier method was used to estimate the distribution of LFS and OS, for RR cumulative incidence was used. Results Out of the 163 patients with AML of intermediate risk cytogenetics and NPM1mut, 78 presented DNMT3A mutations (48%). Of these, 62 (79%) presented mutations in codon R882 or corresponded to DNA insertions/deletions while 16 (21%) harboured missense mutations. Presence of DNMT3A mutation did not associate with FLT3-ITD (ITD/85 DNMT3Awt vs ITD/78 DNMT3Amut, p=0.394). In the entire cohort, 5-year OS, LFS and RR were 58±4.5%, 59±4.6% and 27±13.9%. FLT3-ITD ratio confirmed its prognostic impact when analysing FLT3wt (n=83) vs FLT3low (n=34) vs FLT3high (n=42) patients (5-year OS of 68±6% vs 62±8.7% vs 37±8.6%; p=0.002; and 5-year RR of 18±9.4% vs 27±16.1% vs 41±23.2%; p=0.023). On the contrary, DNMT3Amut did not exert any effect on overall outcome (5-yr OS DNMT3Awt vs DNMT3Amut 61±6.2% vs 55±6.2%; p=0.234) When DNTM3A mutational status was considered, the impact of FLT3-ITD on outcome was mitigated in wild-type DNMT3A population. Thus, we found that DNMT3Awt patients presented no statistical differences in OS according to FLT3 mutational status or ratio: FLT3wt (n=46) vs FLT3-ITD (n=39) was 67±8.5% vs 57±8.2%; p=0.122, whereas FLT3wt (n=46) vs FLT3low (n=18) vs. FLT3high (n=19) was 67±8.5% vs. 66±11.5% vs 46±11.8%; p=0.088 (image 1A).This was also seen in relation to LFS and RR according to FLT3 ratio: 5-yr LFS of FLT3wt vs FLT3low vs FLT3high was 72±7.9% vs 61±12.6% vs 51±13.4%; p=0.244 and 5-year RR of the same groups: 19±8.8% vs 26±12.5% vs 27±21.9%; p=0.724 (image 2A). In the DNMT3Amut group, patients with FLT3-ITD (n=41) presented shorter OS than those with FLT3wt (n=37) with an OS of 37±10.7% vs 69±7.8%; p=0.028. When FLT3 ratio was considered, FLT3wt (n=37) vs FLT3low (n=16) vs FLT3high (n=23) showed an OS of 69±7.8% vs. 58±13.2% vs 27±13.1%; p=0.038 (image 1B). Similar results were seen in LFS according to FLT3 ratio (FLT3wt (n=29) vs FLT3low (n=16) vs FLT3high (n=20) 71±8.6% vs 53±12.9% vs 18±13.8%; p=0.012). Finally, we observed significant differences in the 5-year RR when considering DNMT3Amut patients in relation to FLT3 ratio (FLT3wt vs FLT3low vs FLT3high 18±10.6% vs 27±20% vs 54±28.8%; p=0.021)(image 2B). Conclusions In this study, patients with NPM1mut and FLT3-ITDlow presented a similar outcome to patients with NPM1mut and FLT3wt regardless of DNMT3A mutational status. These results support the modification of alloHCST policy in CR1 in CETLAM-2012, which do not consider alloHSCT for patients with FLT3low. On the other hand, concurrence of DNMT3A mutation may have an added negative effect in patients with NPM1mut and FLT3-ITDhigh, which should be further confirmed in larger studies. Disclosures No relevant conflicts of interest to declare.