scholarly journals Selectivity of T Cell Engager AMV564 Against Different Leukemic Blast Populations and Potential Application for Patient Selection

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 25-26
Author(s):  
Aurelien Sarde ◽  
Sterling Eckard ◽  
Li Mei ◽  
Curtis Ruegg ◽  
Patrick Chun ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Phase 1 ◽  
Myeloid Cells ◽  
Daily Injection ◽  
Target Cells ◽  
Private Company ◽  
Phase 1 Study ◽  
The Difference

Introduction AMV564 is a bivalent T cell engager that targets CD33 on leukemic blasts and myeloid-derived suppressor cells (MDSC). In a phase 1 study in relapsed/refractory AML patients, AMV564 administered by continuous intravenous infusion for 14 consecutive days over a 28 day cycle was well-tolerated and demonstrated anti-leukemic activity including bone marrow blast reductions in 17 of 35 efficacy evaluable patients (Westervelt P et al. Blood. 2019;134:834). In a phase 1 study in solid tumor patients, AMV564 administered by subcutaneous route via a daily injection was well tolerated with evidence of clinical activity (Starodub A et al. J Clin Oncol. 2020;38:3101) and a preliminary half-life of 58 hours, supporting transition to a more patient-friendly daily injection for future clinical studies in selected AML patients. The bivalent structure of AMV564 promotes more potent binding to clustered CD33, such as that found in lipid raft regions or active signaling configurations. CD33 is an active signaling molecule on immature and immune suppressive myeloid cells such as MDSC (Chen CL et al. J Clin Invest. 2013;123:4595-611) with no apparent role on differentiated myeloid cells, but less is known about the configuration of CD33 on leukemic blasts. While CD33 is broadly expressed by leukemic blasts, the degree and homogeneity of expression can vary. The binding of AMV564 to leukemic blasts and primary human myeloid cells and impact on T cell mediated cytotoxicity was thus further explored, and novel assays for evaluation of patient samples were developed. Methods AML cell lines, primary human cells, and patient samples were analyzed using flow cytometry with appropriate marker panels including AMV564, which was directly labeled (phycoerythrin) or detected with labeled anti-AMV564 antibodies. T cell cytotoxicity assays were conducted using primary human T cells and leukemic blasts or other target cells (3:1 ratio) for 48 or 72 hours. Results Results from flow cytometry assays of cell binding by AMV564 were similar whether using phycoerythrin-labeled AMV564 or a labeled anti-AMV564 antibody. AMV564 showed consistent binding characteristics for many leukemic blast lines (largely of M2 FAB subtype); however, substantial differences in binding were detected between the KG1 myeloid cell line (M2 FAB subtype) and the KG1a cell line (M0 FAB subtype) that represents a morphologically and functionally less mature state than the parental KG1. At saturating concentrations (10 nM), there was >10-fold less binding of AMV564 to KG1a vs KG1, whereas a reagent CD33 antibody (WM53) had a similar binding profile for each cell line (Figure 1). The difference in AMV564 binding between these two cell lines is reflected in the cytotoxic potency of AMV564, with a 17.6-fold difference in EC50 (0.42 pM for KG1 vs 7.39 pM for KG1a, Figure 2). AMV564 can engage CD8 and CD4 T cells to drive target-dependent killing and the difference in potency against KG1 vs KG1a was observed using both CD8 and CD4 T cells. Similarly, whereas purified naïve CD8 T cells killed KG1 effectively with AMV564, there was almost no cytotoxicity against KG1a. T cell proliferation was proportional to cytotoxicity in these assays, with much larger increases in proliferating cells apparent with KG1 target cells. There was little or no detectable AMV564 binding or killing of autologous monocytes or neutrophils. The AMV564 binding assay is compatible with primary human samples and analysis of residual samples from patients enrolled in the phase 1 AML study is underway to assess the degree of CD33 clustering on leukemic blasts and associations with response. Conclusions AMV564 demonstrated a high degree of selectivity across the myeloid lineage in a novel binding assay using labeled drug, and there was little or no evidence of cytotoxicity against differentiated myeloid cells such as neutrophils and monocytes. Furthermore, significant differences in potency across AML blasts were observed, which could be further impacted by the available T cells. While AMV564 has demonstrated anti-leukemic activity across an unselected relapsed/refractory AML population, this novel assay could be used to select patients in whom blasts are expressing CD33 in a predominantly clustered configuration, and thus identify patients most likely to experience deeper and more durable responses with AMV564 monotherapy. Disclosures Sarde: Amphivena Therapeutics: Current Employment, Current equity holder in private company. Eckard:Amphivena Therapeutics: Current Employment, Current equity holder in private company. Mei:Amphivena Therapeutics: Current Employment, Current equity holder in private company. Ruegg:Amphivena Therapeutics: Current Employment, Current equity holder in private company. Chun:Amphivena Therapeutics: Current Employment, Current equity holder in private company. Smith:Amphivena Therapeutics: Current Employment, Current equity holder in private company.

627 The DLL3-targeted half-life extended bispecific T cell engager (HLE BiTE®) immune-oncology therapy AMG 757 has potent antitumor activity in neuroendocrine cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Mouse Models ◽  
T Cell Activation ◽  
Phase 1 ◽  
Phase 1 Study ◽  
Human T Cells

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.

scholarly journals 475 GEN-011–101 (the TiTAN-1 trial): phase 1 study to evaluate the safety, proliferation and persistence of GEN-011, an autologous neoantigen-targeted peripheral T cell therapy in solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A504-A504
Author(s):  
Thomas Davis ◽  
Arthur DeCillis ◽  
Richard Hernandez ◽  
Jessica Price ◽  
Craig Carey ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
T Cells ◽  
T Cell ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Phase 1 ◽  
Small Cell ◽  
Small Cell Lung ◽  
Phase 1 Study ◽  
T Cell Therapy

BackgroundGEN-011 is a personalized neoantigen-targeted peripheral blood T cell therapy (NPT) developed for the treatment of adult patients (pts) with solid tumors. The proprietary ATLAS™ (Antigen Lead Acquisition System) will be used to identify true immunogenic neoantigens from each patient‘s tumor mutanome that are recognized by their own CD4+ and/or CD8+ T cells. ATLAS will also identify Inhibigens™, antigen targets of T cells that promote tumor growth.1 Autologous peripheral T cells will be specifically stimulated by up to 30 ATLAS-identified neoantigens, avoiding Inhibigens, to generate an adoptive T cell product. Preliminary data show yields of billions of highly active T cells with 96% neoantigen targeting across 89% of ATLAS selected neoantigens.MethodsTITAN-1 is a multicenter Phase 1 study of GEN-011 NPTs in patients with refractory melanoma, non-small cell lung cancer (NSCLC), squamous cell carcinoma of the head and neck (SCCHN), urothelial carcinoma (UC), renal cell carcinoma (RCC), small cell lung cancer (SCLC), cutaneous squamous cell carcinoma (CSCC), and anal squamous cell carcinoma (ASCC). Patients may enter into one of 2 cohorts of 6 DLT-evaluable patients, either a multiple lower dose (MLD) regimen of GEN-011 as an IV infusion at 4-week intervals, up to 5 doses maximum without lymphodepletion, or a single high dose (SHD) regimen of GEN-011 after flu/cy lymphodepletion. Each dose of GEN-011 will be followed by a course of interleukin-2 (IL-2). Patients will be followed for safety, immunogenicity, and anti-tumor activity over approximately a 5-month treatment period. A long-term follow-up will continue through 2 years after the initial dose of GEN-011.Trial Registration clinicaltrials.gov identifier: NCT04596033ReferencesLam H, et al. An empirical antigen selection method identifies neoantigens that either elicit broad anti-tumor response or drive tumor growth. Cancer Discovery 2021 March; 11(3):696–713.Ethics ApprovalThis study was approved by Western Institutional Review Board, approval number 1-1078861-1

scholarly journals Lenalidomide Enhances CAR-T Cell Activity Against Solid Tumor Cells

2020 ◽  
Vol 29 ◽  
pp. 096368972092082 ◽  
Author(s):  
Zhixiong Wang ◽  
Guomin Zhou ◽  
Na Risu ◽  
Jiayu Fu ◽  
Yan Zou ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cytokine Secretion ◽  
Target Cells ◽  
Functional Assay ◽  
Cell Functions ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Chimeric antigen receptor (CAR) T-cell immunotherapy still faces many challenges in the treatment of solid tumors, one of which is T-cell dysfunction or exhaustion. Immunomodulator lenalidomide may improve CAR T-cell function. In this study, the effects of lenalidomide on CAR T-cell functions (cytotoxicity, cytokine secretion, and cell proliferation) were investigated. Two different CAR T cells (CD133-specific CAR and HER2-specific CAR) were prepared, and the corresponding target cells including human glioma cell line U251 CD133-OE that overexpress CD133 and human breast cancer cell line MDA-MB-453 were used for functional assay. We found that lenalidomide promoted the killing of U251 CD133-OE by CD133-CAR T cells, the cytokine secretion, and the proliferation of CD133-CAR T cells. Lenalidomide also enhanced the cytotoxicity against MDA-MB-453 and the cytokine secretion of HER2-CAR T cells but did not affect their proliferation significantly. Furthermore, lenalidomide may regulate the function of CAR T cells by inducing the degradation of transcription factors Ikaros and Aiolos.

scholarly journals Nef enhances HIV-1 replication and infectivity independently of SERINC3 and SERINC5 in CEM T cells

2020 ◽  
Author(s):  
Peter W. Ramirez ◽  
Aaron A. Angerstein ◽  
Marissa Suarez ◽  
Thomas Vollbrecht ◽  
Jared Wallace ◽  
...  
Keyword(s):  
Growth Rate ◽  
T Cells ◽  
T Cell ◽  
Viral Replication ◽  
Cell Line ◽  
Host Protein ◽  
Target Cells ◽  
Viral Fusion ◽  
Viral Growth ◽  
Hiv 1

AbstractThe lentiviral nef gene encodes several discrete activities aimed at co-opting or antagonizing cellular proteins and pathways to defeat host defenses and maintain persistent infection. Primary functions of Nef include downregulation of CD4 and MHC class-I from the cell surface, disruption or mimicry of T-cell receptor signaling, and enhancement of viral infectivity by counteraction of the host antiretroviral proteins SERINC3 and SERINC5. In the absence of Nef, SERINC3 and SERINC5 incorporate into virions and inhibit viral fusion with target cells, decreasing infectivity. However, whether Nef’s counteraction of SERINC3 and SERINC5 is the cause of its positive influence on viral growth-rate in CD4-positive T cells is unclear. Here, we utilized CRISPR/Cas9 to knockout SERINC3 and SERINC5 in a leukemic CD4-positive T cell line (CEM) that displays robust nef-related infectivity and growth-rate phenotypes. As previously reported, viral replication was severely attenuated in CEM cells infected with HIV-1 lacking Nef (HIV-1ΔNef). This attenuated growth-rate phenotype was observed regardless of whether or not the coding regions of the serinc3 and serinc5 genes were intact. Moreover, knockout of serinc3 and serinc5 failed to restore the infectivity of HIV-1ΔNef virions produced from infected CEM cells in single-cycle replication experiments using CD4-positive HeLa cells as targets. Taken together, our results corroborate a recent study using another T-lymphoid cell line (MOLT-3) and suggest that Nef modulates a still unidentified host protein(s) to enhance viral growth rate and infectivity in CD4-positive T cells.ImportanceHIV-1 Nef is a major pathogenicity factor in vivo. A well-described activity of Nef is the enhancement of virion-infectivity and viral propagation in vitro. The infectivity-effect has been attributed to Nef’s ability to prevent the cellular, antiretroviral proteins SERINC3 and SERINC5 from incorporating into viral particles. While the activity of the SERINCs as inhibitors of retroviral infectivity has been well-documented, the role these proteins play in controlling HIV-1 replication is less clear. We report here that genetic disruption of SERINC3 and SERINC5 rescues neither viral replication-rate nor the infectivity of cell-free virions produced from CD4-positive T cells of the CEM lymphoblastoid line infected with viruses lacking Nef. This indicates that failure to modulate SERINC3 and SERINC5 is not the cause of the virologic attenuation of nef-negative HIV-1 observed using this system.

scholarly journals Results from Lummicar-1: A Phase 1 Study of Fully Human B-Cell Maturation Antigen-Specific CAR T Cells (CT053) in Chinese Subjects with Relapsed and/or Refractory Multiple Myeloma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 49-50
Author(s):  
Wenming Chen ◽  
Chengcheng Fu ◽  
Zhen Cai ◽  
Zonghai Li ◽  
Huijuan Wang ◽  
...  
Keyword(s):  
T Cells ◽  
Phase 1 ◽  
Private Company ◽  
Phase 1 Study ◽  
Car T Cells ◽  
Car T ◽  
Post Infusion ◽  
Efficacy Assessment ◽  
Grade 3 ◽  
Experienced Grade

Background: CT053 are autologous T cells genetically modified with a second-generation chimeric antigen receptor (CAR) incorporating a fully human B-cell maturation antigen (BCMA)-specific single-chain fragment variant (25C2) with high binding affinity. Twenty-four subjects were previously treated in investigator-initiated (IIT) studies with 87.5% overall response rate (ORR), 79.2% complete response (CR) and a median duration of response of 21.8 months without inducing immunogenicity [Blood (2019) 134 (Supplement_1): 4435]. We report herein the first disclosed results from the ongoing phase 1 study (LUMMICAR-1) in China (NCT03975907). Methods: The phase 1 study included subjects with relapsed/refractory multiple myeloma (RRMM) who had received ≥3 prior therapy regimens including a proteasome inhibitor and an immunomodulatory drug, and had measurable disease per 2016 International Myeloma Working Group (IMWG) criteria. All subjects received conditioning treatment of cyclophosphamide (300 mg/m2/day ×3 days) and fludarabine (25 mg/m2/ day × 3 days). After conditioning, subjects received a single infusion of CT053 at the 1.0-1.5×108 CAR+ T-cell dose. Primary objectives for phase 1 were to evaluate the safety and tolerability of CT053 and to identify the recommended phase 2 dose. Adverse events (AEs) were graded using CTCAE, v5.0; cytokine release syndrome (CRS) and neurotoxicity were graded according to ASTCT CRS consensus grading system (Lee DW et al, 2019). Response was assessed per 2016 IMWG criteria. Results: As of July 20, 2020, a total of 14 subjects have been enrolled in the study. All 14 subjects have been apheresed and received CT053 infusion, including 3 subjects who received 1.0×108 CAR+ T cells and 3 subjects who received 1.5×108 CAR+ T cells at dose escalation, followed by 8 subjects who received 1.5×108 CAR+ T cells at dose expansion. The 14 batches of CT053 were manufactured in a median of 8 days (range 7-10). Treated subjects had a median age of 54 years (range 34-62) and had received a median of 6 (range 3-7) prior lines of therapy. Of the 14 subjects, 10 (71.4%) received autologous stem cell transplantation, 2 (14.2%) had extramedullary disease at baseline, and 5 (35.7%) had high-risk cytogenetics. No subject received bridging therapy. At data cutoff, 12 subjects had at least 4 weeks of safety and efficacy assessment with median follow-up of 5 months (range, 1-11). No dose-limiting toxicities were detected. The most common ≥ grade 3 AE was hematological toxicity. Of the 12 subjects with at least 4 weeks follow-up, all experienced ≥ grade 3 neutropenia (100%), 91.7% of subjects had ≥ grade 3 thrombocytopenia, and most recovered to ≤ grade 2 within 2 weeks. No grade 3 or higher CRS or neurotoxicity was observed. Eleven of 12 subjects (91.7%) experienced grade 1 or 2 CRS, including 3 subjects who experienced grade 2 CRS and 8 subjects who experienced grade 1 CRS. CRS events occurred at a median of 6 days (range 2-12) post-infusion with a median duration of 7 days, following a generally predicable onset pattern. Eight subjects received tocilizumab treatment, of whom one subject with grade 2 CRS received both tocilizumab and steroid. At the data cutoff, among 12 subjects with at least 4 weeks of efficacy assessment, a 100% ORR was observed, with 4 stringent complete responses (sCR), 1 CR, 3 very good partial responses and 4 partial responses. All 5 subjects with CR/sCR were minimal residual disease (MRD)-negative at the 10 5 sensitivity level. Responses were independent of baseline BCMA expression in bone marrow. CT053 transgene levels showed expansion and persistence in peripheral blood, with peak expansion at 7-14 days after dosing in all subjects, with peak copies 45,469 (range 11,825-258,574). Serum C-reactive protein and cytokine levels (i.e., IL-6, IFNγ, IL-8, IL-10) increased post-infusion within 7 days and correlated with the onset of CRS symptoms. No immunogenicity was detected. Conclusion: These results demonstrate that CT053 at a target dose of 1.0-1.5×108 CAR+ T cells delivers early and deep responses, including MRD negativity in all complete responders, with an acceptable safety profile in subjects with heavily pretreated RRMM. The results from this LUMMICAR-1 study are consistent with the previous IIT phase 1 studies and the ongoing North American LUMMICAR-2 study and support the launch of pivotal LUMMICAR-1 study in China. Updated results will be presented at this conference. Disclosures Li: CARsgen Therapeutics Co. LtD: Current Employment, Current equity holder in private company. Wang:CARsgen Therapeutics Corp.: Current Employment. Xiao:CARsgen Therapeutics Corp.: Current Employment. Wang:CARsgen Therapeutics Co. LtD: Current Employment, Current equity holder in private company. Ma:CARsgen Therapeutics Corp.: Current Employment.

scholarly journals Virus-Specific CD4+ T Cells Eliminate Borna Disease Virus from the Brain via Induction of Cytotoxic CD8+T Cells

1998 ◽  
Vol 72 (5) ◽  
pp. 4387-4395 ◽  
Author(s):  
Kerstin Nöske ◽  
Thomas Bilzer ◽  
Oliver Planz ◽  
Lothar Stitz
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Disease Virus ◽  
Target Cells ◽  
Borna Disease Virus ◽  
Infected Control ◽  
Low Level ◽  
The Brain ◽  
Borna Disease

ABSTRACT Persistent Borna disease virus infection of the brain can be prevented by treatment of naive rats with a virus-specific CD4+ T-cell line prior to infection. In rats receiving this treatment, only a transient low-level encephalitis was seen compared to an increasingly inflammatory reaction in untreated infected control rats. Virus replication was found in the brain for several days after infection before the virus was cleared from the central nervous system. The loss of infectivity from the brain was confirmed by negative results by reverse transcription-PCR with primers for mRNA, by in situ hybridization for both genomic and mRNA, and by immunohistology. Most importantly, in vitro assays revealed that the T-cell line used for transfusion had no cytotoxic capacity. The kinetics of virus clearance were paralleled by the appearance of CD8+ T cells and the expression of perforin in the brain. Testing of lymphocytes isolated from the brains of CD4+T-cell-treated rats after challenge revealed high cytotoxic activity due to the presence of CD8+ cytotoxic T cells at time points when brain lymphocytes from infected control rats induced low-level cytolysis of target cells. Neutralizing antiviral antibodies and gamma interferon were shown not to be involved in the elimination of virus from the brain.

scholarly journals A Phase 1 Study of ACTR087 in Combination with Rituximab, in Subjects with Relapsed or Refractory CD20-Positive B-Cell Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 244-244
Author(s):  
Javier Munoz ◽  
Samantha Jaglowski ◽  
Matthew S. McKinney ◽  
Iris Isufi ◽  
Patrick J. Stiff ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antitumor Activity ◽  
Dose Escalation ◽  
Research Funding ◽  
Phase 1 ◽  
Human Study ◽  
Advisory Board ◽  
Phase 1 Study ◽  
Dose Levels

Background: The Antibody-Coupled T-cell Receptor (ACTR) platform is an autologous engineered T-cell therapy that combines the cell-killing ability of T cells and the tumor-targeting ability of co-administered antibodies to exert potent antitumor immune responses. ACTR087 comprises the extracellular domain of CD16 linked to a CD3ζ-signaling domain and a 4-1BB co-stimulatory domain. Here we present the clinical experience from Study ATTCK-20-2 (NCT02776813), a multicenter, phase 1 study of ACTR087 in combination with rituximab in subjects with relapsed or refractory (R/R) CD20+ NHL. Methods: The main objectives of this first-in-human study were to evaluate the safety and antitumor activity of ACTR087+rituximab. Other objectives included evaluating ACTR T-cell persistence and other correlative biomarkers. Subjects must have had CD20+ NHL that was R/R after prior treatments, which must have included anti-CD20 antibody-containing chemotherapy. Subjects received lymphodepleting chemotherapy (cyclophosphamide and fludarabine) for 3 days, followed by rituximab and a single dose of ACTR087. Additional doses of rituximab were administered q3w until disease progression, unacceptable toxicity, or Investigator decision. The study included a dose escalation phase (increasing doses of ACTR087) and an expansion phase (ACTR087 at the preliminary recommended phase 2 dose [RP2D]); all subjects received rituximab at a fixed dose of 375 mg/m2 q3w. Results: Two dose levels (DL) of ACTR087 were evaluated during dose escalation (n=17). The MTD was exceeded at DL2, with severe cases of cytokine release syndrome (CRS) and neurotoxicity. Statistical analysis of the relationship between non-hematologic toxicity and ACTR+ T-cell doses was retrospectively performed (two-parameter Bayesian logistic regression model) to estimate an RP2D of 35×106 ACTR+ T cells. Nine subjects enrolled in an expansion cohort and received ACTR087 at this RP2D in combination with rituximab. Among all subjects treated (n=26), the majority (69%) were diagnosed with DLBCL. Subjects had received a median of 3 (range 1-9) prior lines of therapy, with 77% having received ≥3 prior lines. ACTR087 showed dose-dependent expansion with peak levels generally observed 7 to 14 days post administration. In subjects with ongoing clinical response (CR), ACTR remained detectable through the last timepoint evaluated. Across all cohorts, Grade ≥3 TEAEs reported in >3 subjects regardless of causality were limited to hematologic events. Potential T cell-mediated toxicities were observed, including 4 serious cases of CRS (Gr 4 in 2 subjects, both with fatal sepsis) and 2 serious cases of neurotoxicity (1 Gr 5, 1 Gr 4 in a subject with fatal septic shock). Elevated baseline inflammatory markers (eg, ferritin, CRP) were observed in patients who developed Gr ≥3 CRS and neurotoxicity post ACTR087. Of note, severe CRS presented without fever and events occurred >7 days post ACTR087. Clinical activity was reported with an ORR of 50% in all dose levels tested, including durable complete responses, with one subject in CR for 869+ days (Table 1). Conclusions: ACTR087+rituximab demonstrated antitumor activity, with observed safety events that are expected with other autologous T-cell products. The time to onset and clinical presentation of severe CRS and neurotoxicity events in this study informed the safety monitoring and adverse reaction management guidance across clinical studies of ACTR T-cell products. Data from this first-in-human study of ACTR087+rituximab confirm the proof of concept and will be used to guide further development for the ACTR platform. Updated clinical data, as well as expanded biomarker correlations to efficacy and safety, will be presented. Disclosures Munoz: Pharmacyclics /Janssen: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy; Fosunkite: Speakers Bureau; AstraZeneca: Speakers Bureau; Kyowa: Consultancy, Honoraria, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene/Juno: Consultancy, Research Funding; Genentech: Consultancy, Research Funding, Speakers Bureau; Kite/Gilead: Consultancy, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy; Alexion: Consultancy; Portola: Research Funding; Incyte: Research Funding; Bayer: Consultancy, Speakers Bureau; Merck: Consultancy. Jaglowski:Kite: Consultancy, Other: advisory board, Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding; Unum Therapeutics Inc.: Research Funding; Juno: Consultancy, Other: advisory board. Isufi:Celgene: Consultancy; Novartis: Consultancy; Astra Zeneca: Consultancy. Stiff:Gamida-Cell: Research Funding; Incyte: Research Funding; Cellectar: Research Funding; Unum: Research Funding; Gilead/Kite Pharma: Consultancy, Honoraria, Research Funding; Amgen: Research Funding. Sachs:Unum Therapeutics Inc.: Employment. Ranger:Unum Therapeutics Inc.: Employment. Harris:Unum Therapeutics Inc.: Employment. Payumo:Unum Therapeutics Inc.: Employment. Akard:Bristol-Myers Squibb: Speakers Bureau; Gilead: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Celgene: Speakers Bureau.

A phase 1 study of an off-the shelf, multi-neoantigen vector (ADXS-503) in subjects with metastatic non-small cell lung cancer (NSCLC) progressing on pembrolizumab as last therapy.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2616-2616
Author(s):  
Missak Haigentz ◽  
Suresh S. Ramalingam ◽  
Gregory James Gerstner ◽  
Balazs Halmos ◽  
Neil Morganstein ◽  
...  
Keyword(s):  
Lung Cancer ◽  
T Cells ◽  
T Cell ◽  
Disease Control ◽  
Disease Progression ◽  
Dose Escalation ◽  
Phase 1 ◽  
T Cell Responses ◽  
Phase 1 Study ◽  
Cell Responses

2616 Background: ADXS-503 (A503) is an off-the-shelf, attenuated Listeria monocytogenes (Lm)-based immunotherapy bioengineered to elicit potent T cell responses against 22 tumor antigens commonly found in NSCLC (i.e., 11 hotspot mutations and 11 tumor-associated antigens, TAAs). Pembrolizumab (Pembro) is a programmed death receptor-1 (PD-1)- blocking antibody approved for the treatment of advanced lung cancer. A503 and Pembro have complementary mechanisms of immune activation and reversal of immune tolerance. Methods: A phase 1 study of A503 ± Pembro has been conducted in patients (pts) with metastatic squamous or non-squamous NSCLC. In dose-escalation part B, A503 was added-on to Pembro within 12 weeks of the first scan showing disease progression per RECIST criteria v1.1. Both, A503 (1 x108 CFU) and Pembro (200 mg) were infused by IV every 3 weeks until disease progression or limiting toxicity. The dose-escalation cohort has established safety, tolerability and immunogenicity of the combination therapy and it has been further expanded to evaluate efficacy (Goldman JW et.al., SITC 2020). Results: Nine pts have been treated and evaluated in Part B. Pembro + A503 combo has been well tolerated and without immune related AEs. Of the nine evaluable pts, one has achieved partial response (PR) and 3 stable disease (SD), yielding an overall response rate (ORR) of 11% and disease control rate (DCR) of 44%. Two patients have had clinical benefit for over 12 months (i.e., one PR and one SD) and both of them had been on Pembro therapy for 2 years before enrollment. The two other pts with SD have sustained it for almost 6 months thus far. Seven pts have been evaluated for immunogenicity. In all pts there was a transient release of pro-inflammatory cytokines and proliferation of cytotoxic- and memory-CD8+ T cells. Seven evaluable pts had antigen-specific T cells within 1-2 weeks after starting therapy and 4/7 showed antigen spreading. Conclusions: ADXS-503 as an add-on therapy to Pembro at disease progression has been well tolerated and it has induced antigen specific-T cell responses and durable disease control in 44% of pts. Part B cohort is currently enrolling additional pts to further explore the potential reversal of Pembro resistance with ADXS-503. Clinical trial information: NCT03847519.

392 Phase 1 study of CI-8993 anti-VISTA antibody in patients with advanced solid tumor malignancies

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A417-A417
Author(s):  
Elizabeth Martinez ◽  
Jason Faris ◽  
Reinhard Von Roemeling ◽  
Steven Angelides ◽  
Melissa Johnson
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Solid Tumor ◽  
Phase 1 ◽  
Cell Mediated Immunity ◽  
Quiescent State ◽  
Antibody Treatment ◽  
Phase 1 Study

BackgroundVISTA (V-domain Ig suppressor of T cell activation) is a key negative immune checkpoint regulator, locking T cells in a quiescent state, unlike PD1 and CTLA4, which are expressed on activated T cells. Preclinically, VISTA monoclonal antibody treatment increased the number of tumor-specific T cells in the periphery, and enhanced the infiltration, proliferation and effector function of tumor-reactive T cells within the tumor microenvironment (TME). VISTA blockade alters the suppressive feature of the TME by decreasing the presence of monocytic myeloid-derived suppressor cells and increasing the presence of activated dendritic cells (DCs) within the TME leading to enhanced T cell mediated immunity. VISTA monoclonal antibody administration as a monotherapy has been shown to suppress the growth of both transplantable and inducible melanoma in preclinical models. CI-8993 is a first-in-class, fully human immunoglobulin (Ig) G1κ monoclonal antibody (mAb) against the VISTA ligand. Prior human clinical evaluation of CI-8993 demonstrated target-related clinical findings and pharmacodynamic activity at 0.15 mg/kg.MethodsThis phase 1 study is being conducted in the USA (NCT04475523) and is designed as a 3+3 dose escalation study beginning at 0.15 mg/kg. Patients with solid tumor malignancy (non-lymphoma) that is metastatic or unresectable and considered relapsed and/or refractory to prior therapy will be included, excluding prior CAR-T therapy or allogenic transplant. Patients will be treated with an initial step-dose of CI-8993 by IV infusion, followed by every 2 weeks of a full dose, until disease progression or toxicity. Efficacy, pharmacokinetics, pharmacodynamic and safety endpoints will be monitored and reported.ResultsN/AConclusionsN/AEthics ApprovalThe study was approved by Dartmouth-Hitchcock, Norris Cotton Cancer Center Ethics Board, approval number IRB00012031The study was approved Sarah Cannon Caner Research Institute, approval number IORG0000689

scholarly journals Preliminary Clinical Results from a Phase 1 Study of ACTR707 in Combination with Rituximab in Subjects with Relapsed or Refractory CD20+ non-Hodgkin Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1587-1587
Author(s):  
Ian W. Flinn ◽  
Jason R. Westin ◽  
Jonathon B. Cohen ◽  
Luke P. Akard ◽  
Samantha Jaglowski ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Dose Escalation ◽  
Research Funding ◽  
Phase 1 ◽  
Advisory Board ◽  
Phase 1 Study ◽  
Advisory Committees ◽  
Clinical Responses

Background: The Antibody-Coupled T-cell Receptor (ACTR) platform is an autologous engineered T-cell therapy that combines the cell-killing ability of T cells and the tumor-targeting ability of co-administered antibodies to exert potent antitumor immune responses. ACTR707 comprises the extracellular domain of CD16 linked to a CD3ζ signaling domain and a CD28 co-stimulatory domain. ACTR707 is in clinical development in combination with rituximab (NCT03189836) or trastuzumab (NCT03680560). Here we present clinical findings from the dose escalation phase of Study ATTCK-20-03, an ongoing, multicenter, phase 1 study of ACTR707+rituximab in subjects with relapsed or refractory (R/R) CD20+ NHL. Methods: The primary objectives of this first-in-human study are to evaluate the safety of the combination of ACTR707 and rituximab and to determine a recommended phase 2 dose (RP2D). Other objectives include evaluating antitumor activity and ACTR T-cell persistence. Subjects must have CD20+ NHL that is R/R after prior treatments, which must include anti-CD20 antibody-containing chemotherapy. Subjects receive lymphodepleting chemotherapy (cyclophosphamide and fludarabine) for 3 days, followed by rituximab and a single dose of ACTR707. Additional doses of rituximab are administered q3w until disease progression, unacceptable toxicity, or Investigator decision. The study includes a dose escalation phase (increasing doses of ACTR707 with fixed dose of rituximab at 375 mg/m2 q3w) and an expansion phase at the RP2D. Results: Six subjects received ACTR707 at Dose Level 1 (DL1; 23-38×106 ACTR+ T cells), 3 subjects at DL2 (30-50×106 ACTR+ T cells), and 5 subjects at DL3 (45-55×106 ACTR+ T cells). The majority of the subjects were diagnosed with DLBCL (93%) and had refractory disease (71%), defined as progressive disease as the best response to any prior treatment or relapse <1 year post autologous stem cell transplant. In DL1 through DL3, as of 27 May 2019, there were no dose-limiting toxicities, AEs of cytokine release syndrome (CRS), serious or severe neurologic AEs, or AEs leading to deaths on treatment. TEAEs reported in >2 subjects, regardless of causality or grade, included neutropenia, thrombocytopenia, anemia, febrile neutropenia, pyrexia, cough, constipation, diarrhea, nausea, and vomiting. SAEs considered possibly related to ACTR707 were febrile neutropenia (n=2) and cytopenia (n=1). ACTR707 expansion generally reached peak levels within 1 to 2 weeks after administration. All subjects with complete response (CR) up to 1 year had detectable ACTR at the last timepoint evaluated. Higher ACTR707 CD8:CD4 T-cell ratios were associated with clinical responses. Clinical activity was reported across DL1 through DL3, with an overall response rate of 64% including durable complete responses (CRs), with one subject in CR for 387+ days (Table 1). Conclusions: Data available from DL1 through DL3 of ACTR707+rituximab suggest that clinical responses can be achieved without severe T cell-mediated toxicities (eg, CRS and neurotoxicity) that have been reported with other autologous T-cell products. Dose escalation continues at a target dose of 80×106 ACTR+ T cells; enrollment in DL4 (n=6) was recently completed. Updated data, including identified correlates of clinical outcomes, will be presented for DL1 through DL4. Disclosures Flinn: TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; AbbVie, Seattle Genetics, TG Therapeutics, Verastem: Consultancy; TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; Acerta Pharma, Agios, Calithera Biosciences, Celgene, Constellation Pharmaceuticals, Genentech, Gilead Sciences, Incyte, Infinity Pharmaceuticals, Janssen, Karyopharm Therapeutics, Kite Pharma, Novartis, Pharmacyclics, Portola Pharmaceuticals: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding. Westin:Genentech: Other: Advisory Board, Research Funding; Janssen: Other: Advisory Board, Research Funding; Kite: Other: Advisory Board, Research Funding; Unum: Research Funding; Curis: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; MorphoSys: Other: Advisory Board; 47 Inc: Research Funding; Celgene: Other: Advisory Board, Research Funding; Novartis: Other: Advisory Board, Research Funding. Cohen:Genentech, Inc.: Consultancy, Research Funding; Takeda Pharmaceuticals North America, Inc.: Research Funding; Gilead/Kite: Consultancy; LAM Therapeutics: Research Funding; UNUM: Research Funding; Hutchison: Research Funding; Astra Zeneca: Research Funding; Lymphoma Research Foundation: Research Funding; ASH: Research Funding; Bristol-Meyers Squibb Company: Research Funding; Seattle Genetics, Inc.: Consultancy, Research Funding; Janssen Pharmaceuticals: Consultancy. Akard:Celgene: Speakers Bureau; Novartis: Speakers Bureau; Takeda: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau; Gilead: Speakers Bureau. Jaglowski:Juno: Consultancy, Other: advisory board; Kite: Consultancy, Other: advisory board, Research Funding; Unum Therapeutics Inc.: Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding. Sachs:Unum Therapeutics Inc.: Employment. Ranger:Unum Therapeutics Inc.: Employment. Harris:Unum Therapeutics Inc.: Employment. Payumo:Unum Therapeutics Inc.: Employment. Bachanova:Celgene: Research Funding; Gamida Cell: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; GT Biopharma: Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding; Novartis: Research Funding.

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