scholarly journals A Phase II Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial to Evaluate the Efficacy of Cmvpepvax for Preventing CMV Reactivation/Disease after Matched Related/Unrelated Donor Hematopoietic Cell Transplant

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2887-2887
Author(s):  
Ryotaro Nakamura ◽  
Corinna La Rosa ◽  
Dongyun Yang ◽  
Joshua A. Hill ◽  
Armin Rashidi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Primary Endpoint ◽  
Research Funding ◽  
Immune Reconstitution ◽  
Unrelated Donor ◽  
Advisory Committees ◽  
Double Blind ◽  
Cmv Reactivation

Abstract Cytomegalovirus (CMV) infection remains a major cause of morbidity/mortality after allogeneic hematopoietic cell transplantation (HCT). Preemptive antiviral therapy is associated with drug-induced toxicities, and prophylactic therapy with letermovir is associated with late reactivations and delayed antiviral immune reconstitution. Therefore, substituting antivirals with a vaccine that harnesses the native immune response to CMV may improve outcomes for HCT recipients. Our group has developed a peptide vaccine, CMVPepvax, composed of an HLA-A*0201 restricted pp65 495-503 CD8 T cell epitope, covalently linked to a universal tetanus T helper epitope and co-administered with PF-03512676 adjuvant. CMV PepVax was safe and immunogenic in a healthy volunteer study (La Rosa et al. PMID: 22402037;) and a phase Ib HCT recipient trial (Nakamura, et al. PMID: 26853648) with the latter demonstrating a promising sign of efficacy in reducing CMV viremia. In this double blind, placebo-controlled, randomized phase 2 trial (NCT02396134), HCT recipients were enrolled at four USA transplant centers. Eligible patients were CMV seropositive, HLA A*0201-positive, 18-75 years, receiving HCT from a matched related/unrelated donor. T-cell depleting agents (i.e. ATG) or recipients of ex-vivo T-cell-depleted grafts were excluded. Prophylactic antiviral therapy was not allowed. Patients were enrolled prior to day 0 of HCT and reassessed on day +28 for eligibility and randomization to the vaccine (VA) or placebo arm (PA), stratified by donor CMV serostatus. PepVax was administered subcutaneously on days +28 and +56 post-HCT. The primary endpoint of the trial was CMV viremia ≥1250 IU/m or CMV disease through 100 days post-HCT. A total of 96 patients were planned to be randomized at 1:1 ratio, providing 90% power to detect a reduction of viremia from 40% to 15%. CMVpp65-specific immune reconstitution was monitored by measuring levels of CD8 T cells binding to MHC class I pp65 495-503 and HIVgag 77-85 (as control) multimers (Immudex Dextramers), as well as CD28 and CD45 memory markers (BD Biosciences). The intensity of the fluorescent labels was measured using a Gallios flow cytometer with Kaluza software (Beckman Coulter). Enrollment started in June 2015 but was stopped in November 2017 when a planned interim analysis suggested futility for the primary efficacy endpoint. By that time, 76 subjects had been consented, of whom 61 met the day 28 eligibility criteria and were randomized to the VA (n=32) or PA (n=29). The unblinded data were released when the planned one-year follow up was completed for these 61 subjects. The two groups were overall balanced in their demographics and HCT characteristics. There was no difference in the primary endpoint of CMV reactivation/disease between VA (25.1%) and PA (13.8%, p=0.15). The incidence of preemptive therapy was similar between the two arms. PepVax was well tolerated with no increase in adverse events. Transplant outcomes were also similar between the two groups with regards to 1-year overall survival, relapse-free survival, non-relapse mortality, relapse, and acute GVHD. In subjects in VA who reached the primary endpoint (n=8), CMV viremia occurred at a median of 20 days (interquartile range: 15-23 days; range, 0-48) after the first vaccine, suggesting that there was insufficient time for the vaccine-induced T cell expansion. Significantly higher levels of long lasting pp65-specific T cells with effector memory phenotype were measured in non viremic participants in the VA compared to those in the PA; this effect was driven by differences observed late after vaccination (p = 0.004 by GEE analysis; Figure, panel A). In patients who controlled viremia, robust expansion of functional pp65-specific CD8 T cells was observed following PepVax injections (Figure, panels B-C). Our results confirm safety and immunogenicity of PepVax in CMV seropositive HCT recipients. However, the trial failed to demonstrate a clinical efficacy of PepVax in reducing CMV viremia/disease despite favorable CD8 T cell responses. Early CMV reactivation/disease detected before receipt of the second vaccine may have reduced the ability of PepVax to elicit a protective T cell response. Transfer of vaccine-induced immunity through donor CMV immunization combined with recipient booster immunization may overcome this issue and lead to faster immune reconstitution post-HCT. Figure 1 Figure 1. Disclosures Hill: Amplyx: Consultancy; OptumHealth: Consultancy; CRISPR therapeutics: Consultancy; Gilead: Consultancy, Research Funding; Allogene therapeutics: Consultancy; Octapharma: Consultancy; Allovir: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; CLS Behring: Consultancy; Karius: Research Funding. Al Malki: Hansa Biopharma: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; Neximmune: Consultancy; Rigel Pharma: Consultancy; CareDx: Consultancy. Pullarkat: Amgen, Dova, and Novartis: Consultancy, Honoraria; AbbVie, Amgen, Genentech, Jazz Pharmaceuticals, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees. Aribi: Seagen: Consultancy. Devine: Tmunity: Current Employment, Research Funding; Magenta Therapeutics: Current Employment, Research Funding; Sanofi: Consultancy, Research Funding; Johnsonand Johnson: Consultancy, Research Funding; Orca Bio: Consultancy, Research Funding; Be the Match: Current Employment; Vor Bio: Research Funding; Kiadis: Consultancy, Research Funding. Verneris: Novartis: Other: advisory board; jazz: Other: advisory board; Fate Therapeutics: Consultancy. Miller: Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding; GT Biopharma: Consultancy, Patents & Royalties, Research Funding; Vycellix: Consultancy; ONK Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Magenta: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Wugen: Membership on an entity's Board of Directors or advisory committees. Forman: Allogene: Consultancy; Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company; Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company. Diamond: Pfizer Inc: Other; Helocyte Inc: Membership on an entity's Board of Directors or advisory committees, Other, Patents & Royalties.

scholarly journals Automated Manufacture of Matched Donor-Derived Allogeneic CD19 CAR T-Cells for Relapsed/Refractory B-ALL Following Allogeneic Stem Cell Transplantation: Toxicity, Efficacy and the Important Role of Lymphodepletion

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 776-776
Author(s):  
Claire Roddie ◽  
Maeve A O'Reilly ◽  
Maria A V Marzolini ◽  
Leigh Wood ◽  
Juliana Dias Alves Pinto ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Peak Car ◽  
Matched Donor

Introduction: 2nd generation CD19 CAR T cells show unprecedented efficacy in B-ALL, but several challenges remain: (1) scaling manufacture to meet patient need and (2) feasibility of generating products from lymphopenic patients post allogeneic stem cell transplant (allo-SCT). To overcome these issues we propose: (1) use of the CliniMACS Prodigy (Miltenyi Biotec), a semi-automated cGMP platform that simplifies CAR T cell manufacture and (2) the use of matched donor T cells to overcome the challenge posed by patient lymphopenia, albeit this may come with a heightened risk of graft versus host disease (GvHD). CARD (NCT02893189) is a Phase I study of matched donor derived CD19 CAR T cells generated on the CliniMACS Prodigy in 14 adult patients with relapsed/refractory (r/r) B ALL following allo-SCT. We additionally explore the requirement for lymphodepletion (LD) in the allogeneic CAR T cell setting and report on the incidence of GvHD with this therapy. Methods: Manufacturing: CARD utilises non-mobilised matched donor leucapheresate to manufacture 2nd generation CD19CAR T cells using a closed CliniMACS® Prodigy/ TransACTTM process. Study design: Eligible subjects are aged 16-70y with r/r B ALL following allo SCT. Study endpoints include feasibility of CD19CAR T cell manufacture from allo-SCT donors on the CliniMACS Prodigy and assessments of engraftment and safety including GvHD. To assess the requirement for LD prior to CD19CAR T cells in lymphopenic post-allo-SCT patients, the study is split into Cohort 1 (no LD) and Cohort 2 (fludarabine (30 mg/m2 x3) and cyclophosphamide (300mg/m2 x3)). To mitigate for the potential GvHD risk, cell dosing on study mirrors conventional donor lymphocyte infusion (DLI) schedules and is based on total CD3+ (not CAR T) cell numbers: Dose 1=1x106/kg CD3+ T cells; Dose 2= 3x106/kg CD3+ T cells; Dose 3= 1x107/kg CD3+ T cells. Results: As of 26 July 2019, 17 matched allo SCT donors were leukapheresed and 16 products were successfully manufactured and QP released. Patient demographics are as follows: (1) median patient age was 43y (range 19-64y); (2) 4/17 had prior blinatumomab and 5/17 prior inotuzumab ozogamicin; (3) 7/17 had myeloablative allo SCT and 10/17 reduced intensity allo SCT of which 6/17 were sibling donors and 12/17 were matched unrelated donors. No patients with haploidentical transplant were enrolled. To date, 12/16 patients have received at least 1 dose of CD19CAR T cells: 7/16 on Cohort 1 and 5/16 on Cohort 2 (2/16 are pending infusion on Cohort 2 and 2/16 died of fungal infection prior to infusion). Median follow-up for all 12 patients is 22.9 months (IQR 2.9-25.9; range 0.7 - 25.9). At the time of CAR T cell infusion, 7/12 patients were in morphological relapse with >5% leukemic blasts. Despite this, CD19CAR T cells were administered safely: only 2/12 patients experienced Grade 3 CRS (UPenn criteria), both in Cohort 1, which fully resolved with Tocilizumab and corticosteroids. No patients experienced ≥Grade 3 neurotoxicity and importantly, no patients experienced clinically significant GvHD. In Cohort 1 (7 patients), median peak CAR expansion by flow was 87 CD19CAR/uL blood whereas in Cohort 2 (5 patients to date), median peak CAR expansion was 1309 CD19CAR/uL blood. This difference is likely to reflect the use of LD in Cohort 2. CAR T cell persistence by qPCR in Cohort 1 is short, with demonstrable CAR in only 2/7 treated patients at Month 2. Data for Cohort 2 is immature, but this will also be reported at the meeting in addition to potential mechanisms underlying the short persistence observed in Cohort 1. Of the 10 response evaluable patients (2/12 pending marrow assessment), 9/10 (90%) achieved flow/molecular MRD negative CR at 6 weeks. 2/9 responders experienced CD19 negative relapse (one at M3, one at M5) and 3/9 responders experienced CD19+ relapse (one at M3, one at M9, one at M12). 4/10 (40%) response evaluable patients remain on study and continue in flow/molecular MRD negative remission at a median follow up of 11.9 months (range 2.9-25.9). Conclusions: Donor-derived matched allogeneic CD19 CAR T cells are straightforward to manufacture using the CliniMACS Prodigy and deliver excellent early remission rates, with 90% MRD negative CR observed at Week 6 in the absence of severe CAR associated toxicity or GvHD. Peak CAR expansion appears to be compromised by the absence of LD and this may lead to a higher relapse rate. Updated results from Cohorts 1 and 2 will be presented. Disclosures Roddie: Novartis: Consultancy; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. O'Reilly:Kite Gilead: Honoraria. Farzaneh:Autolus Ltd: Equity Ownership, Research Funding. Qasim:Autolus: Equity Ownership; Orchard Therapeutics: Equity Ownership; UCLB: Other: revenue share eligibility; Servier: Research Funding; Bellicum: Research Funding; CellMedica: Research Funding. Linch:Autolus: Membership on an entity's Board of Directors or advisory committees. Pule:Autolus: Membership on an entity's Board of Directors or advisory committees. Peggs:Gilead: Consultancy, Speakers Bureau; Autolus: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Identification of Two CAR T-Cell Populations Associated with Complete Response or Progressive Disease in Adult Lymphoma Patients Treated with Axi-Cel

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 779-779 ◽  
Author(s):  
Zinaida Good ◽  
Jay Y. Spiegel ◽  
Bita Sahaf ◽  
Meena B. Malipatlolla ◽  
Matthew J. Frank ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Board ◽  
Advisory Committees ◽  
Car T Cells ◽  
Scientific Advisory Board ◽  
Car T ◽  
Scientific Advisory

Axicabtagene ciloleucel (Axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for the treatment of relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL). Long-term analysis of the ZUMA-1 phase 1-2 clinical trial showed that ~40% of Axi-cel patients remained progression-free at 2 years (Locke et al., Lancet Oncology 2019). Those patients who achieved a complete response (CR) at 6 months generally remained progression-free long-term. The biological basis for achieving a durable CR in patients receiving Axi-cel remains poorly understood. Here, we sought to identify CAR T-cell intrinsic features associated with CR at 6 months in DLBCL patients receiving commercial Axi-cel at our institution. Using mass cytometry, we assessed expression of 33 surface or intracellular proteins relevant to T-cell function on blood collected before CAR T cell infusion, on day 7 (peak expansion), and on day 21 (late expansion) post-infusion. To identify cell features that distinguish patients with durable CR (n = 11) from those who developed progressive disease (PD, n = 14) by 6 months following Axi-cel infusion, we performed differential abundance analysis of multiparametric protein expression on CAR T cells. This unsupervised analysis identified populations on day 7 associated with persistent CR or PD at 6 months. Using 10-fold cross-validation, we next fitted a least absolute shrinkage and selection operator (lasso) model that identified two clusters of CD4+ CAR T cells on day 7 as potentially predictive of clinical outcome. The first cluster identified by our model was associated with CR at 6 months and had high expression of CD45RO, CD57, PD1, and T-bet transcription factor. Analysis of protein co-expression in this cluster enabled us to define a simple gating scheme based on high expression of CD57 and T-bet, which captured a population of CD4+ CAR T cells on day 7 with greater expansion in patients experiencing a durable CR (mean±s.e.m. CR: 26.13%±2.59%, PD: 10.99%±2.53%, P = 0.0014). In contrast, the second cluster was associated with PD at 6 months and had high expression of CD25, TIGIT, and Helios transcription factor with no CD57. A CD57-negative Helios-positive gate captured a population of CD4+ CAR T cells was enriched on day 7 in patients who experienced progression (CR: 9.75%±2.70%, PD: 20.93%±3.70%, P = 0.016). Co-expression of CD4, CD25, and Helios on these CAR T cells highlights their similarity to regulatory T cells, which could provide a basis for their detrimental effects. In this exploratory analysis of 25 patients treated with Axi-cel, we identified two populations of CD4+ CAR T cells on day 7 that were highly associated with clinical outcome at 6 months. Ongoing analyses are underway to fully characterize this dataset, to explore the biological activity of the populations identified, and to assess the presence of other populations that may be associated with CAR-T expansion or neurotoxicity. This work demonstrates how multidimensional correlative studies can enhance our understanding of CAR T-cell biology and uncover populations associated with clinical outcome in CAR T cell therapies. This work was supported by the Parker Institute for Cancer Immunotherapy. Figure Disclosures Muffly: Pfizer: Consultancy; Adaptive: Research Funding; KITE: Consultancy. Miklos:Celgene: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Kite-Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; AlloGene: Membership on an entity's Board of Directors or advisory committees; Precision Bioscience: Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotech: Membership on an entity's Board of Directors or advisory committees; Becton Dickinson: Research Funding; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees. Mackall:Vor: Other: Scientific Advisory Board; Roche: Other: Scientific Advisory Board; Adaptimmune LLC: Other: Scientific Advisory Board; Glaxo-Smith-Kline: Other: Scientific Advisory Board; Allogene: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Apricity Health: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Unum Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Obsidian: Research Funding; Lyell: Consultancy, Equity Ownership, Other: Founder, Research Funding; Nektar: Other: Scientific Advisory Board; PACT: Other: Scientific Advisory Board; Bryologyx: Other: Scientific Advisory Board.

scholarly journals Human CD83 Targeted Chimeric Antigen Receptor T Cell for the Prevention of Graft Versus Host Disease and Treatment of Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 196-196
Author(s):  
Bishwas Shrestha ◽  
Kelly Walton ◽  
Jordan Reff ◽  
Elizabeth M. Sagatys ◽  
Nhan Tu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Graft Versus Host ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Fund Research

Distinct from pharmacologic immunosuppression, we designed a programmed cytolytic effector T cell that prevents graft versus host disease (GVHD). CD83 is expressed on allo-activated conventional T cells (Tconv) and pro-inflammatory dendritic cells (DCs), which are implicated in GVHD pathogenesis. Therefore we developed a novel human CD83 targeted chimeric antigen receptor (CAR) T cell for GVHD prophylaxis. Here we demonstrate that human CD83 CAR T cells eradicate cell mediators of GVHD, significantly increase the ratio of regulatory T cells (Treg) to allo-activated Tconv, and provide lasting protection from xenogeneic GVHD. Further, we show human, acute myeloid leukemia (AML) expresses CD83 and can be targeted by CD83 CAR T cells. A 2nd generation CD83 CAR was generated with CD3ζ and 41BB costimulatory domain that was retrovirally transduced in human T cells to generate CD83 CAR T cells. The CD83 CAR construct exhibited a high degree of transduction efficiency of about 60%. The CD83 CAR T cells demonstrated robust IFN-γ and IL-2 production, killing, and proliferation when cultured with CD83+ target cells. To test whether human CD83 CAR T cells reduce alloreactivity in vitro, we investigated their suppressive function in allogeneic mixed leukocyte reactions (alloMLR). CD83 CAR T cells were added to 5-day alloMLRs consisting of autologous T cells and allogeneic monocyte-derived DCs at ratios ranging from 3:1 to 1:10. The CD83 CAR T cells potently reduced alloreactive T cell proliferation compared to mock transduced and CD19 CAR T cells. We identified that CD83 is differentially expressed on alloreactive Tconv, compared to Tregs. Moreover, the CD83 CAR T cell efficiently depletes CD83+ Tconv and proinflammatory DCs with 48 hours of engagement. To test the efficacy of human CD83 CAR T cells in vivo, we used an established xenogeneic GVHD model, where mice were inoculated with human PBMCs (25x106) and autologous CD83 CAR (1-10x106) or mock transduced T cells. The CD83 CAR T cells were well tolerated by the mice, and significantly improved survival compared to mock transduced T cells (Figure 1A). Mice treated with CD83 CAR T cells exhibited negligible GVHD target organ damage at day +21 (Figure 1B). Mice inoculated with CD83 CAR T cells demonstrated significantly fewer CD1c+, CD83+ DCs (1.7x106 v 6.2x105, P=0.002), CD4+, CD83+ T cells (4.8x103 v 5.8x102, P=0.005), and pathogenic Th1 cells (3.1x105 v 1.1x102, P=0.005) at day +21, compared to mice treated with mock transduced T cells. Moreover, the ratio of Treg to alloreactive Tconv (CD25+ non-Treg) was significantly increased among mice treated with CD83 CAR T cells (78 v 346, P=0.02), compared to mice injected with mock transduced T cells. Further, CD83 appears to be a promising candidate to target myeloid malignancies. We observed CD83 expression on malignant myeloid K562, Thp-1, U937, and MOLM-13 cells. Moreover, the CD83 CAR T cells effectively killed AML cell lines. Many AML antigens are expressed on progenitor stem cells. Thus, we evaluated for stem cell killing in human colony forming unit (CFU) assays, which demonstrated negligible on-target, off-tumor toxicity. Therefore, the human CD83 CAR T cell is an innovative cell-based approach to prevent GVHD, while providing direct anti-tumor activity against myeloid malignancies. Figure Disclosures Blazar: Kamon Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Five Prime Therapeutics Inc: Co-Founder, Membership on an entity's Board of Directors or advisory committees; BlueRock Therapeutics: Membership on an entity's Board of Directors or advisory committees; Abbvie Inc: Research Funding; Leukemia and Lymphoma Society: Research Funding; Childrens' Cancer Research Fund: Research Funding; KidsFirst Fund: Research Funding; Tmunity: Other: Co-Founder; Alpine Immune Sciences, Inc.: Research Funding; RXi Pharmaceuticals: Research Funding; Fate Therapeutics, Inc.: Research Funding; Magenta Therapeutics and BlueRock Therapeuetics: Membership on an entity's Board of Directors or advisory committees; Regeneron Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Davila:Atara: Research Funding; Celgene: Research Funding; Precision Biosciences: Consultancy; Bellicum: Consultancy; GlaxoSmithKline: Consultancy; Adaptive: Consultancy; Anixa: Consultancy; Novartis: Research Funding.

scholarly journals Pre-Existing T Cell Subsets Determine Anti-PD1 Blockade Response in Richter's Transformation

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 42-43
Author(s):  
Prajish Iyer ◽  
Lu Yang ◽  
Zhi-Zhang Yang ◽  
Charla R. Secreto ◽  
Sutapa Sinha ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Board Of Directors ◽  
Peripheral Blood ◽  
Research Funding ◽  
Gene Signature ◽  
T Cell Subsets ◽  
Rna Seq ◽  
Advisory Committees

Despite recent developments in the therapy of chronic lymphocytic leukemia (CLL), Richter's transformation (RT), an aggressive lymphoma, remains a clinical challenge. Immune checkpoint inhibitor (ICI) therapy has shown promise in selective lymphoma types, however, only 30-40% RT patients respond to anti-PD1 pembrolizumab; while the underlying CLL failed to respond and 10% CLL patients progress rapidly within 2 months of treatment. Studies indicate pre-existing T cells in tumor biopsies are associated with a greater anti-PD1 response, hence we hypothesized that pre-existing T cell subset characteristics and regulation in anti-PD1 responders differed from those who progressed in CLL. We used mass cytometry (CyTOF) to analyze T cell subsets isolated from peripheral blood mononuclear cells (PBMCs) from 19 patients with who received pembrolizumab as a single agent. PBMCs were obtained baseline(pre-therapy) and within 3 months of therapy initiation. Among this cohort, 3 patients had complete or partial response (responders), 2 patients had rapid disease progression (progressors) (Fig. A), and 14 had stable disease (non-responders) within the first 3 months of therapy. CyTOF analysis revealed that Treg subsets in responders as compared with progressors or non-responders (MFI -55 vs.30, p=0.001) at both baseline and post-therapy were increased (Fig. B). This quantitative analysis indicated an existing difference in Tregs and distinct molecular dynamic changes in response to pembrolizumab between responders and progressors. To delineate the T cell characteristics in progressors and responders, we performed single-cell RNA-seq (SC-RNA-seq; 10X Genomics platform) using T (CD3+) cells enriched from PBMCs derived from three patients (1 responder: RS2; 2 progressors: CLL14, CLL17) before and after treatment. A total of ~10000 cells were captured and an average of 1215 genes was detected per cell. Using a clustering approach (Seurat V3.1.5), we identified 7 T cell clusters based on transcriptional signature (Fig.C). Responders had a larger fraction of Tregs (Cluster 5) as compared with progressors (p=0.03, Fig. D), and these Tregs showed an IFN-related gene signature (Fig. E). To determine any changes in the cellular circuitry in Tregs between responders and progressors, we used FOXP3, CD25, and CD127 as markers for Tregs in our SC-RNA-seq data. We saw a greater expression of FOXP3, CD25, CD127, in RS2 in comparison to CLL17 and CLL14. Gene set enrichment analysis (GSEA) revealed the upregulation of genes involved in lymphocyte activation and FOXP3-regulated Treg development-related pathways in the responder's Tregs (Fig.F). Together, the greater expression of genes involved in Treg activation may reduce the suppressive functions of Tregs, which led to the response to anti-PD1 treatment seen in RS2 consistent with Tregs in melanoma. To delineate any state changes in T cells between progressors and responder, we performed trajectory analysis using Monocle (R package tool) and identified enrichment of MYC/TNF/IFNG gene signature in state 1 and an effector T signature in state 3 For RS2 after treatment (p=0.003), indicating pembrolizumab induced proliferative and functional T cell signatures in the responder only. Further, our single-cell results were supported by the T cell receptor (TCR beta) repertoire analysis (Adaptive Biotechnology). As an inverse measure of TCR diversity, productive TCR clonality in CLL14 and CLL17 samples was 0.638 and 0.408 at baseline, respectively. Fifty percent of all peripheral blood T cells were represented by one large TCR clone in CLL14(progressor) suggesting tumor related T-cell clone expansion. In contrast, RS2(responder) contained a profile of diverse T cell clones with a clonality of 0.027 (Fig. H). Pembrolizumab therapy did not change the clonality of the three patients during the treatment course (data not shown). In summary, we identified enriched Treg signatures delineating responders from progressors on pembrolizumab treatment, paradoxical to the current understanding of T cell subsets in solid tumors. However, these data are consistent with the recent observation that the presence of Tregs suggests a better prognosis in Hodgkin lymphoma, Follicular lymphoma, and other hematological malignancies. Figure 1 Disclosures Kay: Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma: Research Funding; Sunesis: Research Funding; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding; MEI Pharma: Research Funding. Ansell:AI Therapeutics: Research Funding; Takeda: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Bristol Myers Squibb: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; ADC Therapeutics: Research Funding. Ding:Astra Zeneca: Research Funding; Abbvie: Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; DTRM: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding. OffLabel Disclosure: pembrolizumab

An Update On The Clinical Activity Of Resimmune, a Targeted Therapy Directed To CD3 Receptor, In Patients With Cutaneous T Cell Lymphomas--CTCL

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4381-4381 ◽  
Author(s):  
Arthur E. Frankel ◽  
Jung H Woo ◽  
Jeremy P Mauldin ◽  
Francine M. Foss ◽  
Madeleine Duvic ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Pichia Pastoris ◽  
Cell Line ◽  
Board Of Directors ◽  
Research Funding ◽  
Response Rate ◽  
The United States ◽  
Advisory Committees ◽  
Systemic Therapies

Abstract Cutaneous T cell lymphoma—CTCL is a malignancy of skin-tropic T cells. CTCL cells have ubiquitous overexpression of CD3. Although uncommon, CTCL has been estimated to affect 1,500 patients per year in the United States. There are multiple approved systemic therapies for CTCL, but responses are brief lasting months. Allogeneic stem cell transplantation may provide long-term remissions, but is suitable for only rare CTCL patients. Overall, CTCL has a long clinical course with relentless progression over months to years with estimated median survival of 3-5 years for stage IB-IIB patients. The CD3 targeted agent, Resimmune, was synthesized and prepared for clinical use. It consists of the catalytic and translocation domains of diphtheria toxin fused to two anti-human CD3 Fv fragments. DNA encoding Resimmune protein was integrated into the Pichia pastoris genome, and recombinant protein was produced in Pichia pastoris via the secretory route (Woo, Protein Expr Purif 25, 270, 2002). Protein was purified by anion exchange and size exclusion chromatography. The CD3+ Jurkat cell line incubated with Resimmune yielded an IC50 for protein synthesis inhibition of 0.017pM. The CD3- Vero cell line incubated with Resimmune showed an IC50 >10pM. Mice, rats, and monkeys given total doses of >200mg/kg over four days showed only transient transaminasemia without histopathologic tissue injury or clinical signs or symptoms (Woo, Cancer Immunol Immunother 57, 1225, 2008). In a mouse model with human CD3e transfected lymphocytes, four logs of antigen positive cells were reproducibly depleted from nodes and spleen with 100mg/kg total dose of Resimmune (Thompson, Protein Eng 14, 1035, 2001). Based on these findings, a phase 1 study was initiated and this report serves to update the results of a single cycle of Resimmune given at 2.5-11.25mg/kg 15 min IV infusion twice daily for 8 doses to 18 CTCL patients. There were 10 females and 8 males with ages 20-81 years. Two patients were naïve to systemic therapies, and all others had failed 1-4 prior treatments including interferon, bexarotene, gemcitabine, vorinostat, chlorambucil, etoposide, pralatrexate, doxil, romidepsin, methotrexate, CHOP, and brentuximab vedotin. None of the Resimmune treated CTCL patients had dose-limiting toxicities. Side effects were mild-moderate and transient with fevers, chills, nausea, transaminasemia, hypoalbuminemia, lymphopenia, reactivation of EBV and CMV, and hypophosphatemia. Toxicities responded to antipyretics, anti-emetics, albumin infusions, rituximab treatment and valgancyclovir. Among measured patients, there was a 3 log decline in normal, circulating T cells by day 5 that recovered by day 14. Because of vascular leak syndrome toxicities in non-CTCL patients, the MTD was defined as 7.5mg/kg x 8 doses. Cmax ranged from 1.9-40.7ng/mL and half-life from 5-66min. Pretreatment anti-DT titers were 0.9-251mg/mL and day 30 post-therapy increased to 5-4059 mg/mL. 17 CTCL patients were evaluable for response. There were six responses for a response rate of 35%. There were four CRs (24% CR rate). Three of the CRs are over 4-years duration. Patients with IB or IIB disease and mSWAT<50 had an overall response rate of 86% and CR rate of 56%. The long time required to convert from a PR to a CR in the absence of any additional therapy beyond the four treatment days suggest an additional anti-tumor mechanism beyond immunotoxin-induced killing such as immunomodulation. Accrual of patients with mSWAT scores of 50 or less is ongoing. Disclosures: Woo: Angimmune: Patents & Royalties, Research Funding. Foss:celgene: Honoraria, Research Funding; millenium: Honoraria, Membership on an entity’s Board of Directors or advisory committees; eisai: Membership on an entity’s Board of Directors or advisory committees; spectrum: Research Funding; merck: Research Funding; seattle genetics: Research Funding. Neville:Angimmune: Employment, Equity Ownership, Patents & Royalties.

scholarly journals CD4+ T Cell Fate in Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4494-4494
Author(s):  
Rachel Elizabeth Cooke ◽  
Jessica Chung ◽  
Sarah Gabriel ◽  
Hang Quach ◽  
Simon J. Harrison ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Research Funding ◽  
Flow Cytometric Analysis ◽  
Advisory Committees ◽  
Mitochondrial Mass ◽  
Flow Cytometric

Abstract The average incidence of multiple myeloma (MM) is in the 7th decade that coincides with the development of immunosenescence and thymic atrophy, meaning that lymphocyte recovery after lymphopenia-inducing therapies (most notably autologous stem cell transplant, ASCT) is largely reliant on homeostatic proliferation of peripheral T cells rather than replenishing the T cell pool with new thymic emigrants. We have previously shown that there is a significant reduction in circulating naïve T cells with a reciprocal expansion of antigen-experienced cells from newly diagnosed MM (NDMM) to relapsed/refractory disease (RRMM). This results in a reduced TCR repertoire and the accumulation of senescence-associated secretory phenotype cytotoxic T cells, which maintain the ability to produce IFNγ but lose proliferative potential. A reduction in CD4:8 ratio is also a characteristic finding in MM with disease progression, which can be explained by high IL-15 levels in lymphopenic states that preferentially drive expansion of CD8+ memory T cells. We wanted to further evaluate what changes were occurring in the CD4+ T cell population with disease progression in MM. We analyzed paired peripheral blood (PB) samples from patients with NDMM and RRMM, and compared with age-matched normal donors (ND). In the NDMM cohort, we examined T cells from PB samples at baseline, after 4 cycles of lenalidomide and dexamethasone (len/dex), and after ASCT; and in the RRMM cohort samples from baseline and after 6 cycles of len/dex. We firstly confirmed in flow cytometric analysis of T cells at serial intervals in NDMM patients that the reduction in circulating naïve T cells and in CD4:8 ratio occurs post ASCT and does not recover by time of last follow-up. We next utilised RNA-seq to analyse differences in CD4+ T cells from NDMM, RRMM and ND. CD4+ T cells from RRMM showed downregulation of cytosolic ribosomal activity but maintenance of mitochondrial ribosomal activity and significant upregulation of pathways involved with calcium signalling. To this end, we evaluated mitochondrial biogenesis and metabolic pathways involved with mitochondrial respiration. Flow cytometric analysis of mitochondrial mass showed a marked increase in RRMM compared with ND, in keeping with a shift towards memory phenotype. Key rate-limiting enzymes in fatty acid β-oxidation (CPT1-A, ACAA2 and ACADVL) were all significantly increased in RRMM compared with ND. To analyse whether these cells were metabolically active, we also measured mitochondrial membrane potential and reactive oxygen species (ROS), gating on cells with high mitochondrial mass. Mitochondrial membrane potential was significantly increased in RRMM compared with ND, although ROS was reduced. The significance of this is not clear, as ROS are not only implicated in cell senescence and activation-induced cell death, but are also positively involved in tyrosine kinase and PI3K-signalling pathways. PD-1 has been shown to play a role in transitioning activated CD4+ T cells from glycolysis to FAO metabolism, and elevating ROS in activated CD8+ T cells. We analysed PD-1 expression on T cells in RRMM and at treatment intervals in NDMM (as described earlier). The proportion of CD4+ and CD8+ T cells expressing PD-1 was increased 4-6 months post-ASCT and remained elevated in CD4+ T cells 9-12 months post-ASCT, but normalised to baseline levels in CD8+ T cells. Increased PD-1 expressing CD4+ T cells was also evident in RRMM patient samples. This may suggest that in the lymphopenic state, PD-1 expression enhances longevity in a subset of CD4+ T cells by promoting reliance on mitochondrial respiration; however, their ability to undergo homeostatic proliferation is impaired. In CD8+ T cells, high PD-1 expression may lead to cell death via ROS accumulation, and these cells do not persist. ASCT remains a backbone of myeloma treatment in medically fit patients. However, this leads to significant permanent defects in the T cell repertoire, which may have unintended adverse outcomes. Additionally, T cells post-ASCT may not be metabolically adequate for the production of CAR-T cells, nor respond to checkpoint blockade therapies. Disclosures Quach: Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Sanofi Genzyme: Research Funding; Janssen Cilag: Consultancy. Harrison:Janssen-Cilag: Other: Scientific advisory board. Prince:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Phase 1/2 Study of Nexi-001 Donor-Derived Multi-Antigen Specific CD8+ T Cells for the Treatment of Relapsed Acute Myeloid Leukemia (AML) after Allogeneic Hematopoietic Transplantation

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4819-4819
Author(s):  
Monzr M. Al Malki ◽  
Sumithira Vasu ◽  
Dipenkumar Modi ◽  
Miguel-Angel Perales ◽  
Lucy Y Ghoda ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Phase 1 ◽  
Clinical Activity ◽  
Advisory Committees ◽  
Over Time

Abstract Patients who relapse after allogeneic HCT have a poor prognosis and few effective treatment options. Responses to salvage therapy with donor lymphocyte infusions (DLI) are driven by a graft versus leukemia (GvL) effect. However, relapses and moderate to severe graft versus host disease (GVHD) are common. Therapies that increase the GvL effect without inducing GVHD are needed. The NEXI-001 study is a prospective, multicenter, open-label phase 1/2 trial designed to characterize the safety, immunogenic, and antitumor activity of the NEXI-001 antigen specific T-cell product. This product is a donor-derived non-genetically engineered therapy that consists of populations of CD8+ T cells that recognize HLA 02.01-restricted peptides from the WT1, PRAME, and Cyclin A1 antigens. These T cells consist of populations with key memory phenotypes, including stem-like memory, central memory, and effector memory cells, with a low proportion (&lt;5%) of potentially allogeneic-reactive T-naïve cells. Patients enrolled into the first cohort of the dose escalation phase received a single infusion of 50 million (M) to 100M cells of the NEXI-001 product. Bridging anti-AML treatment was permitted during the manufacture of the cellular product with a wash-out period of at least 14 days prior to lymphodepletion (LD) chemotherapy (intravenous fludarabine 30 mg/m 2 and cyclophosphamide 300 mg/m 2) that was administered on Days -5, -4, and -3 prior to the infusion of the NEXI-001 product up to 72 hours later (Day1). Lymphocyte recovery to baseline levels occurred as early as three days after the NEXI-001 product infusion with robust CD4 and CD8 T cell reconstitution after LD chemotherapy. NEXI-001 antigen specific T cells were detectable in peripheral blood (PB) by multimer staining and were found to proliferate over time and to traffic to bone marrow. The phenotype composition of detectable antigen specific T cells at both sites was that of the infused product. T-cell receptor (TCR) sequencing assays revealed T cell clones in the NEXI-001 product that were not detected in PB of patients tested at baseline. These unique clones subsequently expanded in PB and bone marrow (BM) and persisted over time. Neutrophil recovery, decreased transfusion burden of platelets and red blood cells, and increased donor chimerism were observed. Decreases in myeloblasts and reduction in the size of an extramedullary myeloid sarcoma were suggestive of clinical activity. One patient, a 23-year- old with MRD+ disease at baseline, received two doses of 200M NEXI-001 cells separated by approximately 2 months. Following the first infusion, antigen specific CD8+ T cells increased gradually in PB to 9% of the total CD3+ T cell population just prior to the second infusion and were found to have trafficked to bone marrow. By Day 2 following the second infusion, which was not preceded by LD chemotherapy, the antigen specific CD8+ T cells again increased to 9% of the total CD3+ T cell population in PB and remained at ≥5% until the end of study visit a month later. The absolute lymphocyte count increased by 50% highlighting continued expansion of the NEXI-001 T cells. These cells also maintained significant Tscm populations. Treatment related adverse events, including infusion reactions, GVHD, CRS, and neurotoxicity (ICANS), have not developed in these patients who have received 50M to 200M T cells of the NEXI-001 product either as single or repeat infusions. In conclusion, these results show that infusion of the NEXI-001 product is safe and capable of generating a cell-mediated immune response with early signs of clinical activity. A second infusion is associated with increasing the level of antigen specific CD8+ T cells and their persistence in PB and BM. TCR sequencing and RNA Seq transcriptional profiling of the CD8+ T cells are planned, and these data will be available for presentation during the ASH conference. At least two cycles of 200M NEXI-001 cells weekly x 3 weeks of a 4-week cycle is planned for the next dose-escalation cohort. Early data suggest that the NEXI-001 product has the potential to enhance a GvL effect with minimal GVHD-associated toxicities. Disclosures Al Malki: Jazz Pharmaceuticals, Inc.: Consultancy; Neximmune: Consultancy; Hansa Biopharma: Consultancy; CareDx: Consultancy; Rigel Pharma: Consultancy. Vasu: Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Kiadis, Inc.: Research Funding; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees. Modi: MorphoSys: Membership on an entity's Board of Directors or advisory committees; Seagen: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding. Perales: Sellas Life Sciences: Honoraria; Novartis: Honoraria, Other; Omeros: Honoraria; Merck: Honoraria; Takeda: Honoraria; Karyopharm: Honoraria; Incyte: Honoraria, Other; Equilium: Honoraria; MorphoSys: Honoraria; Kite/Gilead: Honoraria, Other; Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Medigene: Honoraria; NexImmune: Honoraria; Cidara: Honoraria; Nektar Therapeutics: Honoraria, Other; Servier: Honoraria; Miltenyi Biotec: Honoraria, Other. Edavana: Neximmune, Inc: Current Employment. Lu: Neximmune, Inc: Current Employment. Kim: Neximmune, Inc: Current Employment. Suarez: Neximmune, Inc: Current Employment. Oelke: Neximmune, Inc: Current Employment. Bednarik: Neximmune, Inc: Current Employment. Knight: Neximmune, Inc: Current Employment. Varela: Kite: Speakers Bureau; Nexlmmune: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Targeting BTN2A1 By a Unique Activating Mab Improves Vγ9Vδ2 T Cell Cytotoxicity Against Primary Acute Lymphoblastic Blasts

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2302-2302
Author(s):  
Anne-Charlotte Le Floch ◽  
Caroline Imbert ◽  
Aude De Gassart ◽  
Florence Orlanducci ◽  
Aude Le Roy ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Leukemic Cells ◽  
Target Cells ◽  
Advisory Committees ◽  
Vγ9vδ2 T Cells ◽  
Privately Held

Abstract Introduction Vγ9Vδ2 T cells are new promising cytotoxic effectors in hematological malignancies. In acute myeloid leukemia and in non-Hodgkin lymphomas, Vγ9Vδ2 T cells-based immunotherapy has shown encouraging results both in preclinical models and in early phase clinical trials. Acute lymphoblastic leukemia (ALL) includes very heterogeneous clinico-biological entities, for which recent immunotherapy approaches are currently being developed. Nevertheless, global prognosis of ALL patients still be poor with a 5 years-overall survival of less than 40% and therefore, treatments need to be improved. Very few data are currently available on susceptibility of ALL blasts to Vγ9Vδ2 T cell cytotoxic activity. Vγ9Vδ2 T cells are activated by phosphoantigens bound to BTN3A1 on target cells. BTN3A molecules are targeted at clinical level, with the ICT01 agonist monoclonal antibody (mAb), that is currently tested in a multicentric phase ½ study (EVICTION study). Biology of Vγ9Vδ2 T cells has recently undergone a new paradigm with the identification of BTN2A1 as the direct ligand for Vγ9 chain of γδ TCR. BTN2A1 is mandatory for Vγ9Vδ2 T cell activation but its precise role in modulating functions of Vγ9Vδ2 T cells remains unknown. Here, we show that allogenic and autologous Vγ9Vδ2 T cells exert cytolytic functions against ALL cell lines and primary ALL blasts, and we report that Vγ9Vδ2 T cell cytotoxic activity is enhanced after treatment with a unique agonist mAb targeting BTN2A1. Material and methods 5 ALL cell lines (697, RS4;11, NALM-6, HPB-ALL, SUP-T1) and PBMC from 11 adults ALL patients at diagnosis (B-ALL, T-ALL and Ph+ ALL) were tested in functional assays. We evaluated apoptosis of ALL cell lines and of primary ALL blasts after coculture with allogenic Vγ9Vδ2 T cells. ALL samples were also tested for their expansion capacities and a degranulation assay was performed at D14. We assessed in parallel relative quantification of the level expression of BTN2A1 (ICT0302 and 7.48 epitopes), and BTN3A (20.1 and 108.5 epitopes) on surface of ALL blasts. DAUDI-BTN2AKO+2A1 and HEK293-BTN2AKO+2A1 cells were used in binding assays, and modulation of TCR binding was assessed using recombinant tetramerized Vγ9Vδ2 TCR. Results We showed that Vγ9Vδ2 T cells exert spontaneous cytotoxicity against ALL cell lines and primary ALL blasts with a heterogeneous susceptibility depending on the target. We demonstrated that anti-BTN2A1 ICT0302 agonist mAb significantly enhanced Vγ9Vδ2 T cells mediated apoptosis in comparison to control condition, even for the less spontaneously susceptible cells. We confirmed these observations with degranulation of autologous Vγ9Vδ2 T cells expanded from 5 ALL patients at diagnosis that was increased after treatment with anti-BTN2A1 ICT0302 agonist mAb. BTN3A and BTN2A1 were detected on surface of ALL blasts, and BTN3A 108.5 was the most expressed epitope. Interestingly, we observed that anti-BTN2A1 ICT0302 strongly increased binding of a recombinant Vγ9Vδ2 TCR to target cells using with HEK293 and DAUDI cells. Discussion Our results highlighted that Vγ9Vδ2 T cells exert cytolytic functions against ALL cells, both in allogenic and autologous setting and demonstrated that BTN2A1 targeting with our unique agonist mAb could potentiate effector activities of Vγ9Vδ2 T cells against ALL blasts. These results indicate that the sensitization of leukemic cells can be induced by activation BTN3A as well as BTN2A1 mAbs. These data bring novel understanding on the biology of BTN2A1 on leukemic cells and our ability to enhance both binding and function. These findings could be of great interest for the design of innovative Vγ9Vδ2 T cells-based immunotherapy strategies for treating ALL that could be extended to other cancer types. Disclosures De Gassart: ImCheck Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Cano: ImCheck Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company. Olive: Emergence Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Alderaan Biotechnology: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; ImCheck Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Anti-BTN2A1 ICT0302 is a murine agonist monoclonal antibody targeting BTN2A1 whose aim is to increase Vgamma9Vdelta2 T cells functions.

scholarly journals The Tumor Microenvironment of Nodular Lymphocyte Predominant Hodgkin Lymphoma Is a Unique Immunobiological Entity Distinct from Classical Hodgkin Lymphoma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4123-4123
Author(s):  
Jay Gunawardana ◽  
Karolina Bednarska ◽  
Soi C Law ◽  
Justina Lee ◽  
Muhammed Bilal Sabdia ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Hodgkin Lymphoma ◽  
Research Funding ◽  
Host Immunity ◽  
Immune Checkpoints ◽  
Classical Hodgkin Lymphoma ◽  
Advisory Committees ◽  
Immune Effector

Abstract There is proven pre-clinical and clinical efficacy of mono or combinatorial immune strategies to boost host anti-lymphoma immunity, with classical Hodgkin Lymphoma (cHL) seen as the 'poster child'. Approaches include blockade of immune-checkpoints on exhausted tumor-specific T-cells (via mAb blockade of PD-1, TIM3, LAG3, TIGIT or their ligands), activation of T-cells via mAbs agonistic to CD137, and finally modulation of FOXP3, CTLA-4 and/or LAG3 regulatory T-cells (Tregs) or immunosuppressive tumor-associated macrophages (TAMs). In contrast, studies characterizing the circulating and intra-tumoral microenvironment (TME) of the distinct but rare CD20+ Hodgkin Lymphoma entity (5-8% of HL), Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL), are minimal. Furthermore, to our knowledge no functional profiling studies comparing the host immunity of NLPHL with cHL has been performed. We compared host immunity in 29 NLPHL patients, 30 cHL patients and 10 healthy individuals, with a focus on pertinent and clinically actionable immune parameters. Paraffin-embedded tissue and paired (pre- and post-therapy) peripheral blood mononuclear cells samples were interrogated by digital multiplex hybridization (Nanostring Cancer Immune Profiling Panel) and flow cytometry. Although cytotoxic T-cell gene counts (CD8a, CD8b) were similar, compared to cHL there were higher levels of the immune effector activation marker CD137 (gene counts 439 vs. 287; P<0.01). Consistent with this, CD4 and the Treg markers LAG3, FOXP3 and CTLA-4 were lower in NLPHL (2-4 fold lower, all P<0.05), with no difference in T-helper cell activation markers CD40L and CD30L seen between tumors. TAMs and dendritic cell markers MARCO, CD36, CD68, CD163, COLEC12 and CD11b were all lower in NLPHL than cHL (all P<0.05). In line with the known 'rossette' formed around LP cells by PD-1+ T-lymphocytes, we observed strikingly elevated PD-1 and the other T-cell checkpoints TIM3 and TIGIT in NLPHL (all 2-3 fold, P<0.001). However, in line with the known gene amplification of PD-L1 on HRS cells and its presence on TAMs, gene counts of this checkpoint ligand were 2-fold higher in cHL (P<0.001). Flow cytometry profiling of immune subsets in peripheral blood showed findings consistent with findings in the TME. Specifically, there was elevation of multiple exhaustion markers within CD4, CD8, and NK immune effector cells, with a striking proportion of highly anergic dual-LAG3/PD-1 positive CD8+ T-cells. Also there was elevation of immune-suppressive monocyte/macrophages in cHL relative to NLPHL. Relative to healthy lymph nodes, there was prominent up-regulation of a range of T-cell associated exhaustion markers in both NLPHL and cHL, indicating dysregulated priming of effector immune responses and host immune homeostasis. Comparison between NLPHL and cHL illustrated that NLPHL had a myriad of features that marked its intratumoral TME as a unique immunobiological entity typified by elevated immune checkpoint markers and T-cells with a highly anergic phenotype. Put together, these findings indicate that distinct immune evasion mechanisms are operative within the TME of NLPHL, including markedly higher levels of multiple immune-checkpoints relative to cHL. In contrast, Treg subsets and immune-suppressive monocyte/macrophages were relatively lower than that seen in cHL. T-cells frequently had dual immune-checkpoint expression. The findings from this study provides a compelling pre-clinical rationale for targeting PD-1 or combinatory checkpoint inhibition in NLPHL and sets the basis for future 'chemo-free' rituximab + checkpoint inhibitor clinical trials. Disclosures Tobin: Amgen: Other: Educational Travel; Celgene: Research Funding. Birch:Medadvance: Equity Ownership. Keane:Takeda: Other: Educational Meeting; BMS: Research Funding; Roche: Other: Education Support, Speakers Bureau; Celgene: Consultancy, Research Funding; Merck: Consultancy. Gandhi:BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Takeda: Honoraria; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals Development and Evaluation of a Human Single Chain Variable Fragment (scFv) Derived Bcma Targeted CAR T Cell Vector Leads to a High Objective Response Rate in Patients with Advanced MM

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 742-742 ◽  
Author(s):  
Eric L Smith ◽  
Sham Mailankody ◽  
Arnab Ghosh ◽  
Reed Masakayan ◽  
Mette Staehr ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Employment Equity ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Patients with relapsed/refractory MM (RRMM) rarely obtain durable remissions with available therapies. Clinical use of BCMA targeted CAR T cell therapy was first reported in 12/2015 for RRMM, and based on small numbers, preliminary results appear promising. Given that host immune anti-murine CAR responses have limited the efficacy of repeat dosing (Turtle C. Sci Trans Med 2016), our goal was to develop a human BCMA targeted CAR T cell vector for clinical translation. We screened a human B cell derived scFv phage display library containing 6x1010 scFvs with BCMA expressing NIH 3T3 cells, and validated results on human MM cell lines. 57 unique and diverse BCMA specific scFvs were identified containing light and heavy chain CDR's each covering 6 subfamilies, with HCDR3 length ranges from 5-18 amino acids. 17 scFvs met stringent specificity criteria, and a diverse set was cloned into CAR vectors with either a CD28 or a 4-1BB co-stimulatory domain. Donor T cells transduced with BCMA targeted CAR vectors that conveyed particularly desirable properties over multiple in vitro assays, including: cytotoxicity on human MM cell lines at low E:T ratios (&gt;90% lysis, 1:1, 16h), robust proliferation after repeat antigen stimulation (up to 700 fold, stimulation q3-4d for 14d), and active cytokine profiling, were selected for in vivo studies using a marrow predominant human MM cell line model in NSG mice. A single IV injection of CAR T cells, either early (4d) or late (21d) after MM engraftment was evaluated. In both cases survival was increased when treated with BCMA targeted CAR T cells vs CD19 targeted CAR T cells (median OS at 60d NR vs 35d p&lt;0.05). Tumor and CAR T cells were imaged in vivo by taking advantage of luciferase constructs with different substrates. Results show rapid tumor clearance, peak (&gt;10,000 fold) CAR T expansion at day 6, followed by contraction of CAR T cells after MM clearance, confirming the efficacy of the anti-BCMA scFv/4-1BB containing construct. Co-culture with primary cells from a range of normal tissues did not activate CAR T cells as noted by a lack of IFN release. Co-culture of 293 cells expressing this scFv with those expressing a library of other TNFRSF or Ig receptor members demonstrated specific binding to BCMA. GLP toxicity studies in mice showed no unexpected adverse events. We generated a retroviral construct for clinical use including a truncated epithelial growth factor receptor (EGFRt) elimination gene: EGFRt/hBCMA-41BBz. Clinical investigation of this construct is underway in a dose escalation, single institution trial. Enrollment is completed on 2/4 planned dose levels (DL). On DL1 pts received cyclophosphamide conditioning (3g/m2 x1) and 72x106 mean CAR+ T cells. On DL2 pts received lower dose cyclophosphamide/fludarabine (300/30 mg/m2 x3) and 137x106 mean CAR+ T cells. All pts screened for BCMA expression by IHC were eligible. High risk cytogenetics were present in 4/6 pts. Median prior lines of therapy was 7; all pts had IMiD, PI, high dose melphalan, and CD38 directed therapies. With a data cut off of 7/20/17, 6 pts are evaluable for safety. There were no DLT's. At DL1, grade 1 CRS, not requiring intervention, occurred in 1/3 pts. At DL2, grade 1/2 CRS occurred in 2/3 pts; both received IL6R directed Tocilizumab (Toci) with near immediate resolution. In these 2 pts time to onset of fever was a mean 2d, Tmax was 39.4-41.1 C, peak CRP was 25-27mg/dl, peak IL6 level pre and post Toci were 558-632 and 3375-9071 pg/ml, respectively. Additional serum cytokines increased &gt;10 fold from baseline in both pts include: IFNg, GM CSF, Fractalkine, IL5, IL8, and IP10. Increases in ferritin were limited, and there were no cases of hypofibrinogenemia. There were no grade 3-5 CRS and no neurotoxicities or cerebral edema. No pts received steroids or Cetuximab. Median time to count recovery after neutropenia was 10d (range 6-15d). Objective responses by IMWG criteria after a single dose of CAR T cells were observed across both DLs. At DL1, of 3 pts, responses were 1 VGPR, 1 SD, and 1 pt treated with baseline Mspike 0.46, thus not evaluable by IMWG criteria, had &gt;50% reduction in Mspike, and normalization of K/L ratio. At DL2, 2/2 pts had objective responses with 1 PR and 1 VGPR (baseline 95% marrow involvement); 1 pt is too early to evaluate. As we are employing a human CAR, the study was designed to allow for an optional second dose in pts that do not reach CR. We have treated 2 pts with a second dose, and longer follow up data is pending. Figure 1 Figure 1. Disclosures Smith: Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: BCMA targeted CAR T cells, Research Funding. Almo: Cue Biopharma: Other: Founder, head of SABequity holder; Institute for Protein Innovation: Consultancy; AKIN GUMP STRAUSS HAUER & FELD LLP: Consultancy. Wang: Eureka Therapeutics Inc.: Employment, Equity Ownership. Xu: Eureka Therapeutics, Inc: Employment, Equity Ownership. Park: Amgen: Consultancy. Curran: Juno Therapeutics: Research Funding; Novartis: Consultancy. Dogan: Celgene: Consultancy; Peer Review Institute: Consultancy; Roche Pharmaceuticals: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Liu: Eureka Therpeutics Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Brentjens: Juno Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

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