ALBERT

Description: Donor-recipient incompatibility for human leukocyte antigen (HLA) ligands of killer cell immunoglobulin-like receptors (KIRs) in haploidentical hematopoietic stem cell transplantation (HSCT), has been associated with a selective graft versus leukemia (GvL) effect mediated by donor-derived alloreactive natural killer (NK) cells expressing KIRs whose ligands are missing in the recipient. In this study, we show that NK cells arising from hematopoietic stem cell progenitors after transplantation into haploidentical recipients, acquire a receptor repertoire that is compatible with patient-specific tolerance due to engagement of patient HLA ligands by inhibitory NK receptors. Using four-color immunofluorescence with monoclonal antibodies (mAbs) specific for the receptors CD94/NKG2A, KIR2DL1/2DS1, KIR2DL2/2DL3/2DS2 and KIR3DL1, we have analyzed NK receptor reconstitution kinetics in eleven adult patients affected by acute myeloid (n=9) or lymphoblastic (n=2) leukemia, who underwent HSCT from a KIR ligand matched (n=5) or mismatched (n=6) haploidentical family donor, using high doses (median 12.5x106/kg) of purified CD34+ progenitors. Nine patients achieved long-term (〉150 days) complete remission of disease, independently from disease status at time of transplantation, and, importantly, from the presence (n=5) or absence (n=4) of donor NK alloreactivity. Within the first two months after transplantation, the vast majority (96% at 30 days, 86% at 60 days; SD 2% and 11%, respectively) of NK cells arising in the patients expressed the inhibitory receptor CD94/NKG2A, whose ligand HLA-E is ubiquitously expressed by cells positive for classical HLA class I molecules including leukemic blasts. As shown by mAb inhibition studies, lysis of patient-derived phytohemagglutinin-activated T cell blasts by these early arising NK cells was specifically inhibited by engagement of CD94/NKG2A. KIR expression was restored with variable kinetics in the later post-transplantation phase (3–9 months). Interestingly, however, during this period, NK cells devoid of CD94/NKG2A were found to express at least one KIR specific for an HLA ligand present in the patient, suggesting functional silencing of NK cells arising in the later phases after transplantation by acquisition of specific KIRs. Taken together, these data challenge current broad view on putative antileukemic effect of alloreactive NK cells reconstituting from haploidentical donor CD34+ cells and suggest that optimal exploitation of NK alloreactivity for GvL requires the presence of NK cells matured in the context of the donor’s rather than the recipient’s HLA repertoire. Ultimately, these findings provide a rationale for emerging clinical evidence in favor of efficacy of NK-based immunotherapy with mature donor NK cells.

Description: Background Binding of E-selectin (E-sel) to sialyl Lex, the E-sel ligand, on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Higher expression of E-sel ligand is associated with relapse and poor survival. Uproleselan (GMI-1271), a novel E-selectin antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity such as mucositis with improved survival in vivo. Preclinical data support combination of uproleselan with chemotherapy improves response without additional toxicity. A phase 1/2 study (NCT02306291) of uproleselan added to chemotherapy (mitoxantrone, etoposide, cytarabine, MEC) in R/R AML showed promising outcomes at the recommended phase 2 dose (RP2D), including a CR/CRi rate of 41% and median OS of 8.8 m (95% CI 5.7-11.4). 11/16 (69%) evaluable patients were MRD negative (DeAngelo et al ASH 2018). Patients with sufficient expression of the appropriate E-selectin ligand (the target of the E-selectin inhibitor) exhibited higher CR/CRi rate and longer survival. Median OS for Leukemic blasts/E-sel ligand ≥10% vs leukemic blasts/E-sel ligand

Description: BACKGROUND: The biological basis for the adverse prognosis of chr1q gain/amplification (1q+) present in ~30% of patients with multiple myeloma (MM) remains ill-defined. The transcription factor (TF) Pre-B-cell leukaemia homeobox 1 (PBX1), encoded on chr1q, acts as master regulator of early hematopoiesis and as an oncogene in leukemia and other malignancies. Herein, we hypothesized that PBX1 orchestrates proliferative regulatory networks that underpin the poor prognosis associated with 1q+ in MM. METHODS: We employed qPCR for mRNA quantification, western blotting and immunohistochemistry for protein analysis, lentiviral shRNA-mediated knock-down, Hoechst/Annexin V staining and flow-cytometry for apoptosis and cell cycle analysis, ChIPseq for cistrome and RNAseq after knock-down for transcriptome analysis. Additional data were obtained from MMRF/CoMMpass, Blueprint Consortium and Arkansas datasets. Computational analysis of clinical and "-omics" data was performed using standard bioinformatic work-flows; pathway enrichment analysis using EnrichR and GSEA. RESULTS: Combined genomic (WGS/WES) and transcriptomic (RNAseq) analysis of the CoMMpass dataset identified a subgroup of 1q+ MM patients (60%) characterized by aberrant PBX1 overexpression and amplification (PBX1amp); survival analysis revealed significantly worse outcome of this subgroup compared to 1q+ non-PBX1amp (p

Description: T-cells are critical mediators of immune defense against pathogens and cancer. Adoptive T cell immunotherapy and T-cell engineering have promising clinical applications but T cell survival and exhaustion are current limitations. Central memory cells (TCM CD62L+ CCR7+) and their precursors, stem central memory T-cells (TSCM) possess the stem-like properties needed to reconstitute and prolong an effective immune response long-term. These cells have been shown to significantly improve therapeutic efficacy of adoptive T-cell therapy. The challenge remains to harvest good quality TCM-cells for these immunotherapy approaches. The bone marrow (BM) is the major reservoir of CD8+ TCM and their precursors. We have previously shown that E-selectin is expressed in the BM vasculature and drives activation and differentiation of hematopoietic stem cells during G-CSF induced mobilization to the blood. We find therapeutic blockade of E-selectin promotes HSC self-renewal and reconstitution in vivo. We now examine the impact of E-selectin blockade on CD8+ T cell mobilization from the bone marrow to the blood and hypothesize that E-selectin blockade may also dampen the activation/differentiation of this subset. First we administered a standard G-CSF regime (filgastim 250ug/kg/day for 3 days) to mice and then dosed some cohorts with GMI-1271 (40mg/kg BID) from 12 to 72 hours within this 3 day period. Administration of G-CSF alone results in a near complete disappearance of bone marrow resident CD8+ TCM cells, and their apparent migration (increase in numbers) to the blood, while CD8+ subsets in the lymph nodes and spleen were barely affected by G-CSF. Furthermore among T-cell subsets, CD8+ but not CD4+ TCM were specifically mobilized into the blood when GMI-1271 was co-administered for the last 12 to 24 hours of G-CSF. These findings are consistent with reports demonstrating the bone marrow to be a major reservoir for CD8+ but not CD4+ central memory T-cells. Administration of GMI-1271 caused a marked enhancement in mobilization into the blood of CD8+ TCM/SCM (CD62Lhi, CCR7+) cells over treatment with G-CSF alone (p

Description: Introduction: The pan-selectin antagonist rivipansel (GMI-1070) reduced intravascular arrest of red/white blood cell aggregates and improved blood flow and survival in a mouse model of sickle cell disease vaso-occlusive crisis (SCD VOC). In a Phase 1 study of GMI-1070 infusion in SCD adults at steady state (not in VOC), GMI-1070 decreased markers of cellular activation including neutrophil integrins, platelet/neutrophil aggregates, soluble adhesion molecule concentration; and markers of hemostatic activation. Furthermore, in a randomized Phase 2 study of SCD patients, treatment of VOC with GMI-1070 improved clinical outcomes such as time to resolution of crisis, time to discharge, and IV opioid use. Herein we report on the effect of GMI-1070 on biomarkers of cellular and hemostatic cascade activation from this Phase 2 trial. Methods: Patients in VOC enrolled in a prospective, randomized multi-center double-blind Phase 2 trial, ages 12-60 with HbSS or HbSB0thalassemia were treated with GMI-1070 q12h or placebo, in addition to standard treatment per institutional practice, until resolution of VOC. Clinical outcomes and pharmacokinetics have been previously reported (ASH 2013 Abstracts 775, 776, and 2206). Biomarker blood samples were drawn prior to study drug, and on a sparse sampling basis at times starting 30 minutes after initial dose and continuing until 36 hours after the last dose. Analytes measured included: soluble adhesion molecules E-selectin (sEsel), P-selectin, L-selectin, intercellular adhesion molecules 1 and 3, vascular cell adhesion molecule-1; and tissue factor and thrombin-antithrombin complexes by ELISA. At some sites, surface expression of monocyte b2 integrins MAC-1 & LFA-1 and platelet-monocyte aggregates were also measured by flow cytometry. Comparisons were made between the GMI-1070 and placebo groups, and serial expression levels were compared over time. Subgroup analyses were performed by hydroxyurea (HU) use, age group, baseline WBC, and responders' based on clinical outcomes. A mixed effect model was used to test the LS means difference at each time point and ANCOVA model was used to analyze the nadir, peak, and last dose values. Results: ELISA and flow cytometry samples were collected from 70 and 15 subjects, respectively. Soluble E-selectin levels were reduced for the group on GMI-1070 compared to placebo throughout hospitalization, and the differences were statistically significant at some time-points (Figure 1). Baseline sEsel levels were similar; but the peak, nadir, and level at last dose were all lower in the GMI-1070 group (Figure 2). Exploratory subgroup analysis by HU use, age group, response as measured by visual analog scale or opiate use, frequency of VOC in the past, and baseline white blood cell count revealed consistently lower sEsel levels in the GMI-1070 group. Many, but not all, of these differences reached statistical significance. Conclusion: GMI-1070 use during VOC resulted in consistent and significant reductions of sEsel, overall and in sub-groups as compared to placebo. These findings are consistent with the hypothesized effect of GMI-1070 on endothelial activation and/or apoptosis, mediated by inhibition of E-selectin, although an effect on sEsel clearance cannot be excluded. A Phase 3 study is planned to evaluate efficacy and safety of GMI-1070 as treatment for VOC. Soluble E-selectin concentrations may be useful as a biomarker of pharmacodynamic effect. Figure 1: sE-sel was reduced in the GMI-1070 group at all timepoints tested. Comparison to placebo for change from baseline over time is shown. *p

Description: T-cell depletion of allogeneic hematopoietic stem cell graft (HSCT) represents the most powerful approach to prevent graft-versus-host disease (GvHD), thus allowing to overcome HLA barriers in patients with high risk malignancies, lacking a conventional donor. We hypothesized that early add-back of suicide-gene transduced donor lymphocytes (TK cells) to leukemic patients undergoing haploidentical HSCT (haplo-HSCT) could provide early immune-reconstitution and selective control of GvHD. In a phase II clinical trial (protocol MMTK007), 17 of 29 enrolled pts, (median age 52), received add-backs of 10^7/kg TK cells 42 days after haplo-HSCT. TK cells engraftment, observed in 14 patients, was necessary and sufficient for a rapid and effective immunereconstitution (IR), with a median of 144 (101–336) CD3+, 59 (28–149) CD4+ and 86 (52–279) CD8+ cells/mcl at day 100 after HSCT. Accordingly, engraftment of TK cells was tightly correlated with clinical outcome: while 3/3 pts who failed TK cells engraftment died of infections, only 1/14 TK engrafted patients died from infections (last event at day +166). As shown in Table I, the immune repertoire of treated patients improved significantly at 6 months post transplant and normalized completely in 12 months. High numbers of T cell precursors specific for CMV and EBV were detected at immune reconstitution (median of 86 and 69 gIFN specific spots/10^5 PBMC respectively) and predicted subsequent freedom from viral reactivation (p=0.002). Six pts developed acute (GvHD), (grade I to IV) that was always completely abrogated by the suicide system. Overall survival of TK cells treated patients is 50% at three years. These results indicate that TK-DLI abolish late mortality after CD34+ haplo-SCT in adults. A phase III multicentric study will start in 2007 to validate prospectively the advantage of TK-DLI in haplo-SCT.

Description: Hematopoietic stem cells (HSC) reside in specific peri-vascular niches in the bone marrow (BM). We have shown interactions with the inflammatory vascular adhesion molecule E-(endothelial)-selectin awakens HSC (Nat Med 2012). We now report that BM vascular cell-surface E-selectin expression is strongly upregulated during HSC mobilization regimens raising the question of a role for endothelial E-selectin in HSC transplant outcome. G-CSF was administered to cohorts of E gene-deleted or wildtype C57BL/6 mice together with E-selectin antagonist Uproleselan (Upro, GMI-1271). We found absence (Sele-/- mice) or therapeutic blockade (Upro) of E-selectin alone in steady-state hosts did not alter levels of circulating peripheral blood (PB) HSC. In contrast absence or therapeutic blockade of E-selectin strongly synergized with mobilizing regimens such as G-CSF or cyclophosphamide+G-CSF by boosting long-term engraftment and reconstitution potential of mobilized blood. The effect was pronounced boosting reconstitution potential over G-CSF-alone-mobilized blood 24-fold (

Description: The influence of human T-cell leukemia/lymphoma virus type II (HTLV-II) in individuals also infected with HIV-1 is poorly understood. To evaluate the reciprocal influence of HTLV-II and HIV-1 infection, primary peripheral blood mononuclear cell (PBMC) cultures from coinfected individuals were established in the presence of interleukin 2 (IL-2). In these cultures, the kinetics of HTLV-II replication always preceded those of HIV-1. Noteworthy, the kinetics of HIV-1 production were inversely correlated to the HTLV-II proviral load in vivo and its replication ex vivo. These observations suggested a potential interaction between the 2 retroviruses. In this regard, the levels of IL-2, IL-6, and tumor necrosis factor- (TNF-) were measured in the same coinfected PBMC cultures. Endogenous IL-2 was not produced, whereas IL-6 and TNF- were secreted at levels compatible with their known ability to up-regulate HIV-1 expression. The HIV-suppressive CC-chemokines RANTES, macrophage inflammatory protein-1 (MIP-1), and MIP-1β were also determined in IL-2–stimulated PBMC cultures. Of interest, their kinetics and concentrations were inversely related to those of HIV-1 replication. Experiments were performed in which CD8+ T cells or PBMCs from HTLV-II monoinfected individuals were cocultivated with CD4+ T cells from HIV-1 monoinfected individuals separated by a semipermeable membrane in the presence or absence of antichemokine neutralizing antibodies. The results indicate that HTLV-II can interfere with the replicative potential of HIV-1 by up-regulating viral suppressive CC-chemokines and, in particular, MIP-1. This study is the first report indicating that HTLV-II can influence HIV replication, at least in vitro, via up-regulation of HIV-suppressive chemokines.

Description: Abstract 1632 GMI-1070 is a pan-selectin inhibitor that targets E-, P-, and L-selectins and has shown activity in multiple animal models of disease. Sickle cell disease (SCD) is characterized by periodic vaso-occlusive (VOC) episodes in which cell adhesion and aggregation play a crucial role. GMI-1070 has previously been shown to restore blood flow and improve survival in a mouse model of VOC, and safety and PK have been evaluated in normal, healthy volunteers in phase 1. Here we report clinical, safety, and PK results from the first study of GMI-1070 in individuals with SCD. Methods: An open-label phase 1/2 study was performed, enrolling adults with SCD at steady state. GMI-1070 was administered in two IV doses given on the same day: 20 mg/kg in the first dose, followed 10 hours later by 10 mg/kg. Patients were evaluated for safety on days 0, 1, 2, 7 and 28, including adverse events (AEs), routine clinical labs, and clinical exam. Plasma and urine concentrations of GMI-1070 were measured on days 0, 1, and 2, and PK parameters calculated and compared with those from healthy volunteers. Results: Fifteen adults were enrolled at three centers; 13 with HbSS, 2 with HbSB0thal. All were African-American, 9 were male, mean age was 32 years (range 18–50), mean weight was 64.7 kg; 4 were on hydroxyurea. In the past year, 6 had experienced VOC requiring medical care; 2 had ACS; 2 required transfusions; and 1 had an episode of priapism. Five were hospitalized in the past year; 12 were hospitalized in the past 5 years. All subjects received both doses of study drug; all but one were followed for 28 days. The PK in adults with SCD was in good agreement with that in the controls. The elimination half-life of GMI-1070 averaged 7.73 ± 2.45 hours (Figure). Renal clearance averaged 18.0 ± 7.93 mL/min and accounted for essentially all elimination. Physical exam parameters after dosing were unchanged, and all infusions were well tolerated. Four subjects reported headache within 24 hours of dosing, all of which were mild or moderate and resolved within 24 hours. Two subjects experienced VOC not requiring hospitalization, at 2 and 4 weeks after dosing. One subject had worsening anemia requiring transfusion 5 days after dosing. Other adverse events typical of SCD were reported without apparent association with study drug; none were serious adverse events. Routine labs demonstrated no changes from baseline (Hb, reticulocytes, platelets, electrolytes, glucose, ALT, LDH, BUN, Cr, bilirubin, urinalysis) with the exception of white blood cell counts (WBC) and absolute neutrophil counts (ANC). At 24 hours, mean WBC change from baseline was 1.9K/mm3, or 20% (p=0.076, using parametric test with mixed model); mean ANC change was 2.7, or 67% (p=0.019); all returned to baseline by 7 days. One individual had marked leukocytosis 24 hours after dosing (from 10.4 to 28K/mm3), returning to baseline by day 7; no other effects were observed in this subject. Mean C-reactive protein (CRP) increased at 24 and 48 hours, returning to baseline by day 7. Two subjects had marked increases in CRP: one exhibited leukocytosis with dosing and the other had a high baseline WBC count. There was otherwise no apparent correlation between PK, WBC/ANC, hydroxyurea use, or adverse events. In conclusion, GMI-1070, a pan-selectin inhibitor, when administered to adults with SCD at steady state, has a similar safety and PK profile to that in healthy volunteers. However, SCD patients had moderate WBC and ANC increases at 24–48 hours after dosing, which return to baseline without other observed symptomatic adverse events. This study supports further evaluation of GMI-1070 for the treatment of vaso-occlusive crisis. Disclosures: Styles: GlycoMimetics: Consultancy, clinical trial sponsorship. Wun:GlycoMimetics: Consultancy, clinical trial sponsorship. De Castro:GlycoMimetics: clinical trial sponsorship. Telen:GlycoMimetics: Consultancy, clinical trial sponsorship. Kramer:GlycoMimetics: Consultancy. Flanner:GlycoMimetics: Employment, Equity Ownership. Magnani:GlycoMimetics: Employment, Equity Ownership. Thackray:GlycoMimetics: Employment, Equity Ownership. Off Label Use: This drug (GMI-1070) has not been approved for any clinical indication.