578 Tumor selective immune responses of STA551, a novel anti-CD137 agonist antibody activated by extracellular ATP

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A612-A612
Author(s):  
Yoshinori Narita ◽  
Mika Kamata-Sakurai

BackgroundAgonistic antibodies targeting CD137 in clinic have failed due to severe hepatotoxicity, leading to the development of bispecific approaches that must rely on high tumor-associated antigen expression to crosslink CD137. Here we report on STA551, a novel anti-CD137 agonist antibody which binds to CD137 only in the presence of ATP. Extracellular ATP concentration is well-known to be elevated in tumor tissue while remaining tightly regulated in non-tumor tissue, suggesting that STA551 can activate immune cells only in tumor tissue and not elsewhere. Thus, STA551 has great potential to overcome the limitations of conventional CD137-targeted antibodies.MethodsWe evaluated in vitro STA551’s effect on IFN-γ production from human CD8+ T cells. We also evaluated in vivo STA551’s effect on tumor growth, RNAseq-based immune-related gene expression, immunohistochemistry, and T cell activation in tumor and non-tumor tissues in human CD137 knock-in mice treated with mouse surrogate STA551 (Sta-MB) or urelumab (Ure-MB) in combination with anti-PD-L1 antibody.ResultsIn a human T cell assay, STA551 induced IFN-γ only in the presence of ATP. In contrast, urelumab induced IFN-γ regardless of ATP concentration. In mice with Colon 38 tumors, Sta-MB inhibited tumor growth at least as strongly as Ure-MB, but whereas Ure-MB elicited systemic immune responses in draining lymph node, spleen, and liver, Sta-MB appeared to evade such responses. To confirm immune responses in tumors, we evaluated immune-related gene expression and found changes after treatment with Sta-MB or Ure-MB. These results suggest that STA551 works only in tumor tissue. Furthermore, Sta-MB with anti-PD-L1 antibody synergistically inhibited tumor growth and dramatically changed immune-related gene expression, CD8+ T cell infiltration, and PD-L1 expression without systemic immune responses. Also, it was well-tolerated in cynomolgus monkey in a repeated-dose toxicity study*.ConclusionsSTA551 is a novel anti-CD137 agonist antibody that exerts agonistic activity selectively in tumors without on-target toxicity in non-tumor tissues, regardless of tumor-associated antigen expression. These results strongly support the clinical testing of STA551 for the treatment of solid tumors. STA551 is currently being tested in a phase 1 clinical study.Ethics ApprovalAll animal studies were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC).

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3563-3563
Author(s):  
Ji-Young Lim ◽  
Mi-Sun Choi ◽  
Eun Young Choi ◽  
Hyewon Youn ◽  
Chang-Ki Min

Abstract Abstract 3563 Poster Board III-500 The therapeutic potential of allogeneic hematopoietic stem cell transplantation (HSCT) relies on the graft-versus-leukemia (GVL) effect to eradicate residual tumor cells by immunologic mechanisms. However, the relationship of conditioning intensity to GVL effect has not been clearly established independent of immunosuppression or the tolerance induced by mixed donor-host chimerism. Using a murine allogeneic HSCT model, we have compared two total body irradiation (TBI) doses (1,300 vs. 900 cGy), both of which provided complete donor engraftment and elimination of host lympho-hematopoetic cells. We used C57BL/6 (H-2b) → B6D2F1 (H-2b/d) model of GVHD, which differ at major and minor histocompatibility loci, to address the role of conditioning intensity on the GVL effect. Lethally irradiated (either 900 or 1300 cGy) recipient mice were transplanted with either C57BL/6 (allogeneic) or B6D2F1 (syngeneic) bone marrow (5 × 106) and spleen T cells (1 × 106) on day 0 and then P815 (H-2d) mastocytoma cells (1 × 106) injected subcutaneously on day 1 to generate a GVL model. As expected, GVHD morbidity after the higher TBI dose was aggravated compared to the lower TBI dose (P<.05). Among the syngeneic recipients, the injection of P815 cells into the recipient skin led to progressive tumor growth and death of about 100% 21 days after transplant regardless of the TBI dose. In contrast, tumor growth was remarkably suppressed and tumor death was not observed in the allogeneic recipients. Surprisingly, tumors in the allogeneic recipients receiving 1300 cGy TBI exhibited markedly delayed growth in vivo compared to those with 900 cGy (tumor volume on day 42, 428 vs. 8735mm3, P<.01), which was associated with an increase in the in vivo cytotoxicity using comparing the clearance of infused allogeneic B cells labeled with CFSE reflecting the enhanced alloimmune reactivity. To ask whether the diminished GVL effect after the lower TBI dose was due to reduced production of inflammatory cytokines, we measured the levels of TNF-α or IFN-γ in recipient sera on days 6, 28 and 42 after transplantation and did not find any significant difference according to the intensity of radiation dose (P>.05). In parallel, the in vitro P815-specific TNF-α or IFN-γ responses of splenocytes were comparable between the two doses. The percentages of donor T cells to undergo proliferation or apoptosis in response to alloantigens in vivo between the two TBI doses also were comparable (P>.05). Collectively, these data indicate that the impaired ability of alloreacive T cells to inhibit tumor growth after the lower TBI dose was not attributed to an intrinsic defect in T-cell expansion and activation. We next analyzed the spleen for the number of donor CD4+ and CD8+ T cells and observed no difference between the two TBI doses. In contrast to spleen, the number of CD8+ but not CD4+ T cells from the recipients that had received 1300 cGy was significantly increased in the skin (P<05). The effector function of donor CD8+ and CD4+ cells in both spleen and tumor tissue was examined by intracellular staining for IFN-γ. In the spleen, the percentages of CD8+ and CD4+ T cells expressing IFN-γ were not different between the two TBI doses. (5.9% vs 4.8%, P>.05, and 7.6% vs. 6.5%, P>.05 respectively) By contrast, 45.5% and 50.3% of CD8+ and CD4+ T cells, respectively, isolated from the tumor tissue of recipients receiving the higher TBI dose were IFN-γ; secreting cells, whereas only 25.5% and 16.3% of those cells from the tumor tissue of recipients treated with the lower dose showed this phenotype (P<.01 and <.05, respectively). After the higher TBI dose, secondary lymphoid organ homing receptors including CD62L and CCR7 were down-regulated on donor CD8+ T cells while CD44 expression was up-regulated compared to the lower TBI dose, which may facilitate migration to the tumor sites. In summary, the higher TBI dose (1300 vs. 900 cGy) resulted in significantly enhanced GVL effect, and the alterations in effector T cell trafficking into tumor tissue are the most likely mechanism. Moreover, T-cell activation and function were largely comparable between these conditioning regimens. This provides the rationale for targeting T cell trafficking by inflammation, possibly in combination with integrin or chemokine receptor agonists as a new therapeutic approach in leukemia relapse after allogeneic HSCT. Disclosures: No relevant conflicts of interest to declare.


2019 ◽  
Author(s):  
Sean J. Judge ◽  
Mio Yanagisawa ◽  
Ian R. Sturgill ◽  
Sarah B. Bateni ◽  
Alicia A. Gingrich ◽  
...  

AbstractBackgroundWe have previously reported radiation-induced sensitization of canine osteosarcoma (OSA) to natural killer (NK) therapy, including results from a first-in-dog clinical trial. Here, we report correlative analyses of blood and tissue specimens for signals of immune activation in trial subjects.MethodsAmong 10 dogs treated with palliative radiotherapy (RT) and intra-tumoral adoptive NK transfer, we performed ELISA on serum cytokines, flow cytometry for immune phenotype of PBMCs, and PCR on tumor tissue for immune-related gene expression. We then queried The Cancer Genome Atlas (TCGA) to evaluate the association of cytotoxic/immune-related gene expression with human sarcoma survival.ResultsUpdated survival analysis revealed five 6-month survivors, including one dog who lived 17.9 months. Using feeder line co-culture for NK expansion, we observed maximal activation of dog NK cells on day 17 – 19 post isolation with near 100% expression of granzyme B and NKp46 and high cytotoxic function in the injected NK product. Among dogs on trial, we observed a trend for higher baseline serum IL-6 to predict worse lung metastasis-free and overall survival (P=0.08). PCR analysis revealed low absolute gene expression of CD3, CD8, and NKG2D in untreated OSA. Among treated dogs, there was marked heterogeneity in the expression of immune-related genes pre- and post-treatment, but increases in CD3 and CD8 gene expression were higher among dogs that lived > 6 months compared to those who did not. Analysis of the TCGA confirmed significant differences in survival among human sarcoma patients with high and low expression of genes associated with greater immune activation and cytotoxicity (CD3e, CD8a, IFN-γ, perforin, and CD122/IL-2 receptor beta).ConclusionsUpdated results from a first-in-dog clinical trial of palliative RT and autologous NK cell immunotherapy for OSA illustrate the translational relevance of companion dogs for novel cancer therapies. Similar to human studies, analyses of immune markers from canine serum, PBMCs, and tumor tissue are feasible and provide insight into potential biomarkers of response and resistance.


2020 ◽  
Author(s):  
Yi-Jun Kim ◽  
Kwangsoo Kim ◽  
Soo Yeon Seo ◽  
Juyeon Yu ◽  
Il Han Kim ◽  
...  

Abstract The time-sequential change in immune-related gene expression of the glioblastoma cell line after irradiation was evaluated to speculate the effect of combined immunotherapy with radiotherapy. The U373 MG glioblastoma cell line was irradiated with 6 Gy single dose. Next-generation sequencing (NGS) transcriptome data was generated before irradiation (control), and at 6, 24, and 48 hours post-irradiation. Immune-related pathways were analyzed at each time period. The same analyses were also performed for A549 lung cancer and U87 MG glioblastoma cell lines. Western blotting confirmed the programmed death-ligand 1 (PD-L1) expression levels over time. In the U373 MG cell line, neutrophil-mediated immunity, type I interferon signaling, antigen cross-presentation to T cell, and interferon-γ signals began to increase significantly at 24 hours and were upregulated until 48 hours after irradiation. The results were similar to those of the A549 and U87 MG cell lines. Without T cell infiltration, PD-L1 did not increase even with upregulated interferon-γ signaling in cancer cells. In conclusions, In the glioblastoma cell line, immune-related signals were significantly upregulated at 24 hours after irradiation. Therefore, the time interval between daily radiotherapy might not be enough to expect full immune responses by combined immune checkpoint inhibitors and newly infiltrating immune cells after irradiation.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3089-3089 ◽  
Author(s):  
Roy S. Herbst ◽  
Hendrik-Tobias Arkenau ◽  
Emiliano Calvo ◽  
Johanna C. Bendell ◽  
Nicolas Penel ◽  
...  

3089 Background: In Study JVDF (NCT02443324), we combined ramucirumab (VEGFR2 antagonist) and pembrolizumab (PD-1 antagonist) to simultaneously target the tumor microenvironment and immune checkpoints in patients with advanced non-small cell lung cancer (NSCLC), gastric or gastroesophageal junction adenocarcinoma (G/GEJ), urothelial carcinoma (UC) or biliary tract cancer (BTC). We reported that this combination was associated with increased antitumor activity in patients with PD-L1 positive tumors by immunohistochemistry (IHC) compared with PD-L1 negative tumors.1) Here we explore the association between baseline gene expression profiles and clinical outcomes. Methods: JVDF was a nonrandomized phase 1a/b trial that treated patients with intravenous ramucirumab at 8 mg/kg on days 1 and 8 (G/GEJ, BTC) or 10 mg/kg on day 1 (G/GEJ, NSCLC, UC) plus pembrolizumab (200 mg day 1) every 3 weeks.1 Baseline tumor samples from 53 patients across 7 study cohorts were analyzed with the NanoString PanCancer Immune Profiling Panel for RNA expression and the DAKO PD-L1 IHC 22C3 pharmDx assay for PD-L1 protein expression. Clinical outcomes included progression-free survival (PFS), overall survival (OS), and objective response rate (ORR). Results: Across cohorts, PD-L1 gene expression was correlated with increased IFNγ gene expression and immune-related gene signatures (T effector, T cell-inflamed (TIS)), and trended with PD-L1 protein expression. Expression of immune checkpoint-related genes and myeloid-derived suppressor cell /regulatory T cell markers was increased in the NSCLC TPS≥50% PD-L1 IHC subgroup (N=8), while no clear pattern of expression was observed in other cohorts. Higher T effector and TIS scores appeared associated with better survival and response in NSCLC cohorts (mean TIS: 1.21±0.80 in responders (N=7) vs -0.13±0.57 in non-responders (N=7); p=0.004), and a trend was observed in G/GEJ cohorts (mean TIS: -0.18±0.30 (N=5) vs -0.39±0.21 (N=13); p=0.207). Of note, partial responses and stable disease were also observed in NSCLC and G/GEJ patients with a low baseline inflammatory signature score. Additional analyses are ongoing and will be presented. Conclusions: Baseline PD-L1 gene and protein expression tends to correlate with immune-related gene expression, and an inflamed tumor microenvironment may be associated with better clinical outcomes with ramucirumab and pembrolizumab. However, interpretation is limited by lack of control arm and sample size.1) Herbst et al. Lancet Oncol. 2019 Aug; 20 (8):1109-1123. Clinical trial information: NCT02443324 .


Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 368 ◽  
Author(s):  
Georgios Aindelis ◽  
Angeliki Tiptiri-Kourpeti ◽  
Evangeli Lampri ◽  
Katerina Spyridopoulou ◽  
Eleftheria Lamprianidou ◽  
...  

The role of dietary probiotic strains on host anti-cancer immune responses against experimental colon carcinoma was investigated. We have previously shown that Lactobacillus casei administration led to tumor growth suppression in an experimental colon cancer model. Here, we investigated the underlying immune mechanisms involved in this tumor-growth inhibitory effect. BALB/c mice received daily live lactobacilli per os prior to the establishment of a syngeneic subcutaneous CT26 tumor. Tumor volume, cytokine production, T cell differentiation and migration, as well as tumor cell apoptosis were examined to outline potential immunomodulatory effects following L. casei oral intake. Probiotic administration in mice resulted in a significant increase in interferon gamma (IFN-γ), Granzyme B and chemokine production in the tumor tissue as well as enhanced CD8+ T cell infiltration, accompanied by a suppression of tumor growth. Cytotoxic activity against cancer cells was enhanced in probiotic-fed compared to control mice, as evidenced by the elevation of apoptotic markers, such as cleaved caspase 3 and poly (ADP-ribose) polymerase 1 (PARP1), in tumor tissue. Oral administration of Lactobacillus casei induced potent Th1 immune responses and cytotoxic T cell infiltration in the tumor tissue of tumor-bearing mice, resulting in tumor growth inhibition. Thus, the microorganism may hold promise as a novel dietary immunoadjuvant in raising protective anti-cancer immune responses.


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