T-cell Killing Of Tumor Cells Research Articles

Statin drugs enhance responses to immune checkpoint blockade in head and neck cancer models

BackgroundAnti-PD-1 immune checkpoint blockade is approved for first-line treatment of recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), but few patients respond. Statin drugs (HMG-CoA reductase inhibitors) are associated with...

Short-course pembrolizumab and continuous afatinib therapy for recurrent or metastatic head and neck squamous cell carcinoma: a real-world data analysis

ObjectivesThe optimal duration of anti-PD-1 for cancer therapy has not been tested, especially when using combination therapy. Epidermal growth factor receptor (EGFR) pathway blocker was the top compound that enhanced T-cell killing of tumor cells in a high-throughput immune-oncology screen, possibly by stimulate the antigen presentation machinery and other mechanisms. We explored the effect of combination of EGFR inhibition with a short course of anti-PD-1 therapy in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC).MethodWe analyzed the effect of a short course of anti-PD-1 with continuous afatinib on the survival of a real-world cohort of R/M HNSCC patients. Patient characteristics, treatments, efficacies, and toxicities were reviewed and recorded for analysis.ResultsFrom November 2016 to May 2018, 51 consecutive patients received pembrolizumab and afatinib. The cutoff date was June 30, 2022. The most common toxicities (all grades) were diarrhea (62.7%), skin rash (43.1%), mucositis (31.4%), and paronychia (23.5%). The objective response rate was 54.9% (95% confidence interval [CI] 40.3–68.9%). Median progression-free survival was 5.9 months (95% CI: 4.4–7.6 months), and the median overall survival was 10.5 months (95% CI: 6.8–16.5 months). The 12-month, 24-month, 36-month, and 48-month survival rate was 47.0%, 22.5%, 17.7%, and 12.6% respectively.ConclusionsThis retrospective study showed that short course pembrolizumab with afatinib therapy has acceptable efficacy in R/M HNSCC patients. The durable response and long-term survival rates were similar to prospective clinical trials. Short course anti-PD-1 therapy, especially in combination with EGFR blocker, is worth for further prospective study.

Shortened Hinge Design of Fab x sdAb-Fc Bispecific Antibodies Enhances Redirected T-Cell Killing of Tumor Cells.

T cell engager (TCE) antibodies have emerged as promising cancer therapeutics that link cytotoxic T-cells to tumor cells by simultaneously binding to CD3E on T-cells and to a tumor-associated antigen (TAA) expressed by tumor cells. We previously reported a novel bispecific format, the IgG-like Fab x sdAb-Fc (also known as half-IG_VH-h-CH2-CH3), combining a conventional antigen-binding fragment (Fab) with a single domain antibody (sdAb). Here, we evaluated this Fab x sdAb-Fc format as a T-cell redirecting bispecific antibody (TbsAbs) by targeting mEGFR on tumor cells and mCD3E on T cells. We focused our attention specifically on the hinge design of the sdAb arm of the bispecific antibody. Our data show that a TbsAb with a shorter hinge of 23 amino acids (TbsAb.short) showed a significantly better T cell redirected tumor cell elimination than the TbsAb with a longer, classical antibody hinge of 39 amino acids (TbsAb.long). Moreover, the TbsAb.short form mediated better T cell-tumor cell aggregation and increased CD69 and CD25 expression levels on T cells more than the TbsAb.long form. Taken together, our results indicate that already minor changes in the hinge design of TbsAbs can have significant impact on the anti-tumor activity of TbsAbs and may provide a new means to improve their potency.

A Sampling of Highlights from the Literature: Article Recommendations from Our Deputy and Senior Editors.

Bispecific antibodies can activate T cells that target tumor cells expressing mutant RAS and p53 neoantigens (Bridging the Gap by Mike via Flickr)Developing therapeutics that target the mutant RAS and p53 proteins that drive many tumors has proven challenging. Hsiue et al. and Douglass et al. report the development of bispecific antibodies that target mutant p53 and RAS, respectively. After using mass spectrometry to identify a p53 neoantigen, Hsiue et al. screened a phage library to select an scFV specific for the neoantigen–HLA complex. This scFV was used to generate a bispecific antibody that induces T cells to kill tumor cells in a neoantigen-specific manner. Using the same approach, Douglass et al. were able to generate a bispecific antibody that induces T-cell killing of tumor cells expressing mutant RAS. Future studies will investigate whether such bispecific antibodies have therapeutic potential.Hsiue EH-C, …, Zhou S. Science 2021 Mar 5;371:eabc8697.Douglass J, …, Zhou S. Sci Immunol 2021 Mar 1;6:eabd5515.Healthy human T cell (from National Institute of Allergy and Infectious Diseases via Flickr)Consistent with previous studies testing CAR-T cells as a treatment for solid tumors, Srivastava et al. find that in patients with breast or lung cancer expressing receptor tyrosine kinase-like orphan receptor 1 (ROR1) who receive cyclophosphamide/fludarabine pretreatment for lymphodepletion, ROR1 CAR-T cells infiltrate tumors poorly and become dysfunctional rapidly. In mice, adding oxaliplatin to cyclophosphamide for lymphodepletion induces tumor macrophage production of T cell–recruiting chemokines, enhancing tumor infiltration by ROR1 CAR-T cells. These data are clinically relevant, as lymphodepletion with oxaliplatin/cyclophosphamide is shown to improve tumor infiltration by ROR CAR-T cells in a patient with ROR+ breast cancer.Srivastava S, …, Riddell S. Cancer Cell 2021 Feb 8;39:193–208.e10.Killer T cells surround a cancer cell (by Alex Ritter, Jennifer Lippincott Schwartz, and Gillian Griffiths via NCI Visuals Online)Characterizing tumor-specific T cells in the blood has great therapeutic value. Pauken et al. perform single-cell RNA and TCR sequencing of CD8+ T cells in paired blood and tumor samples and identify NKG2D, CD39, and CXCR1 as candidate markers for tumor-specific CD8+ T cells. Lucca et al. perform similar experiments in melanoma patients and show that circulating T cells exhibit similar effector gene signatures as TCR-matched tumor-infiltrating T cells but do not have exhaustion gene signatures. These results help identify selective markers for tumor-specific CD8+ T cells in the blood.Pauken KE, …, Singer M. J Exp Med 2021 Mar 2;218:e20200920.Lucca LE, …, Hafler DA. J Exp Med 2021 Mar 2;218:e20200921.Lactic acid metabolism promotes Tregs (from Fig. 1 of de la Cruz-Lopez, Front Immunol 2019)Immune cell metabolism can impact the efficacy of cancer immunotherapy. Watson et al. show that regulatory T cells (Treg) are metabolically flexible. Treg function and stability are impaired by high-glucose conditions, but Tregs can upregulate pathways involved in lactic acid metabolism, and this maintains their suppressive phenotype in the tumor microenvironment (TME). Zappasodi et al. find that anti–CTLA-4 promotes destabilization of Tregs in the TME. This is dependent on glycolysis and CD28 signaling and results in Tregs gaining a more effector phenotype in tumors lacking LDHA (lactic acid dehydrogenase A). These two articles shed light on the complexity of metabolic regulation occurring in the TME.Watson MJ, …, Delgoffe GM. Nature 2021 Feb 15. DOI: 10.1038/s41586-020-03045-2.Zappasodi R, …, Merghoub T. Nature 2021 Feb 15. DOI: 10.1038/s41586-021-03326-4.Breast tumor microenvironment (by Joseph Szulczewski, David Inman, Kevin Eliceiri, and Patricia Keely via NCI Visuals Online)The landscape of tumor-infiltrating myeloid cells (TIM) among different tumor types remains poorly understood. Cheng et al. perform pan-cancer single-cell transcriptional analysis of TIMs from 210 patients across 15 cancer types. Highlights of the data include: The ratio of TNF+ to VEGFA+ mast cells is associated with prognosis in nasopharyngeal cancer; cDC1-derived LAMP3+ cDCs express higher IL12B and BTLA, whereas cDC2-derived LAMP3+ cDCs show higher expression of CD1E and CCL17; and proangiogenic tumor-associated macrophages have distinct markers in different cancer types. Together, these results point to the heterogeneity of TIMs and new approaches to therapeutic targeting of TIMs.Cheng S, …, Zhang Z. Cell 2021 Feb 4;184:792–809.e23.The gut microbiota can impact immunotherapy (by DataBase Center for Life Science via Wikimedia Commons)The gut microbiome composition correlates with efficacy of immune checkpoint blockade, but whether this can be leveraged to overcome therapy resistance is not clear. Two clinical studies by Davar et al. and Baruch et al. address this and show that fecal microbiota transplantation in combination with anti–PD-1 is safe and efficacious in patients with anti–PD-1 refractory melanoma. Some patients had complete or partial responses, and responders had distinct expression, proteomic, and metabolic signatures, as well as alteration of the microbiota composition. The data from these two clinical studies highlight a novel treatment option to overcome anti–PD-1 resistance in melanoma.Davar D, …, Zarour HM. Science 2021 Feb 5;371:595–602.Baruch EN, …, Boursi B. Science 2021 Feb 5;371:602–9.

Abstract IA11: Overcoming immune evasion in pediatric brain tumors

Abstract Many immunotherapies act by enhancing T-cell killing of tumor cells. Cytotoxic T cells recognize antigens presented by class I major histocompatibility complex (MHC-I) proteins on tumor cells. Our studies suggest that medulloblastomas and high-grade gliomas lacking the p53 tumor suppressor do not express surface MHC-I and are therefore resistant to immune rejection. Mechanistically, this is because p53 regulates expression of the peptide transporter Tap1 and the aminopeptidase Erap1, which are required for MHC-I trafficking to the cell surface. Treatment with tumor necrosis factor or lymphotoxin beta receptor agonist rescues expression of Erap1, Tap1, and MHC-I on p53 mutant tumor cells. In vivo, TNF treatment prolongs survival and markedly augments the efficacy of the immune checkpoint inhibitor anti-PD-1. These studies identify p53 as a key regulator of immune evasion in vivo and suggest that TNF could be used to enhance sensitivity of p53-mutant tumors to immunotherapy. Citation Format: Alexandra Garancher, Hiromichi Suzuki, Svasti Haricharan, Meher B. Masihi, Jessica M. Rusert, Paula S. Norris, Florent Carrette, Megan M. Romero, Sorana A. Morrissy, Patryk Skowron, Florence M.G. Cavalli, Hamza Farooq, Vijay Ramaswamy, Alaide Morcavallo, Jacob J. Henderson, James M. Olson, Yoon-Jae Cho, Xiao-Nan Li, Louis Chesler, Marco A. Marra, Oren J. Becher, Linda M. Bradley, Carl F. Ware, Michael D. Taylor, Robert J. Wechsler-Reya. Overcoming immune evasion in pediatric brain tumors [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr IA11.

A High-Throughput Immune-Oncology Screen Identifies EGFR Inhibitors as Potent Enhancers of Antigen-Specific Cytotoxic T-lymphocyte Tumor Cell Killing.

We developed a screening assay in which luciferized ID8 expressing OVA was cocultured with transgenic CD8+ T cells specifically recognizing the model antigen in an H-2b-restricted manner. The assay was screened with a small-molecule library to identify compounds that inhibit or enhance T cell-mediated killing of tumor cells. Erlotinib, an EGFR inhibitor, was the top compound that enhanced T-cell killing of tumor cells. Subsequent experiments with erlotinib and additional EGFR inhibitors validated the screen results. EGFR inhibitors increased both basal and IFNγ-induced MHC class-I presentation, which enhanced recognition and lysis of tumor cell targets by CD8+ cytotoxic T lymphocytes. The ID8 cell line was also transduced to constitutively express Cas9, and a pooled CRISPR screen, utilizing the same target tumor cell/T-cell assay, identified single-guide (sg)RNAs targeting EGFR that sensitized tumor cells to T cell-mediated killing. Combination of PD-1 blockade with EGFR inhibition showed significant synergistic efficacy in a syngeneic model, further validating EGFR inhibitors as immunomodulatory agents that enhance checkpoint blockade. This assay can be screened in high-throughput with small-molecule libraries and genome-wide CRISPR/Cas9 libraries to identify both compounds and target genes, respectively, that enhance or inhibit T-cell recognition and killing of tumor cells. Retrospective analyses of squamous-cell head and neck cancer (SCCHN) patients treated with the combination of afatinib and pembrolizumab demonstrated a rate of clinical activity exceeding that of each single agent. Prospective clinical trials evaluating the combination of an EGFR inhibitor and PD-1 blockade should be conducted.

Increased Tumor Glycolysis Characterizes Immune Resistance to Adoptive T Cell Therapy

Adoptive Tcell therapy (ACT) produces durable responses in some cancer patients; however, most tumors are refractory to ACT and the molecular mechanisms underlying resistance are unclear. Using two independent approaches, we identified tumor glycolysis as a pathway associated with immune resistance in melanoma. Glycolysis-related genes were upregulated in melanoma and lung cancer patient samples poorly infiltrated by Tcells. Overexpression of glycolysis-related molecules impaired Tcell killing of tumor cells, whereas inhibition of glycolysis enhanced Tcell-mediated antitumor immunity invitro and invivo. Moreover, glycolysis-related gene expression was higher in melanoma tissues from ACT-refractory patients, and tumor cells derived from these patients exhibited higher glycolytic activity. We identified reduced levels of IRF1 and CXCL10 immunostimulatory molecules in highly glycolytic melanoma cells. Our findings demonstrate that tumor glycolysis is associated with the efficacy of ACT and identify the glycolysis pathway as a candidate target for combinatorial therapeutic intervention.

Abstract B182: IGN004 is an antibody-interferon-alpha fusion protein against a novel tumor-associated antigen with both direct anti-tumor and immunostimulatory effects

Abstract Background: Antibody-IFNα fusion proteins represent a cancer therapeutic with properties of an antibody-drug conjugate and an immunotherapeutic agent, having both direct anti-tumor and immune-activating effects. These powerful molecules have the potential to target the anti-tumor cytotoxic effects of IFN to the tumor and to change the immunosuppressive tumor microenvironment to activate anti-tumor immunity. We previously reported the activity of IGN002, a recombinant anti-CD20-IFNα fusion protein, against human non-Hodgkin B-cell lymphomas (Yamada et al, JCO 2013). We now report the in vitro and in vivo anti-tumor activity of IGN004, an antibody-IFNα fusion protein against a novel tumor associated antigen expressed by many solid and liquid tumors. Methods: IGN004 was evaluated against a panel of human non-small cell lung cancer (NSCLC), melanoma, multiple myeloma (MM), and acute myeloid leukemia (AML) cell lines. Antigen expression was assessed by flow cytometry and immunohistochemistry (IHC). Anti-proliferative activity was measured by MTS assay. MHC, costimulatory, and coinhibitory molecule expression was assessed by flow cytometry. T-cell killing of tumor cells by TALL-104 effector cells was assessed by MTS assay. Human tumor cell line and patient-derived xenografts were grown in immunodeficient mice. Results: IGN004 antibody bound to the majority of tumor cell lines investigated, including melanoma, NSCLC, AML, and MM. In addition, IGN004 antibody also bound to nearly 100% of the primary solid tumor samples tested by IHC. IGN004 induced stronger growth inhibition than the unfused antibody and IFNα. Incubation of tumor cells with IGN004 caused an increase in surface expression of MHC class I, PD-L1, and OX-40L. In an in vitro T-cell killing assay using TALL-104 cells as effectors and NSCLC cells as targets, treatment of tumor cells with IGN004 led to increased effector cell killing of tumor targets (69.2% killing without IGN004 vs. 100% killing with IGN004; p = 0.001). The enhanced T-cell killing was observed even with concentrations at the sub-picomolar level (EC50 = 0.87 pM). Importantly, IGN004 demonstrated robust in vivo efficacy against MM, AML, melanoma, and NSCLC xenografts, including patient-derived tumors. Against U266 MM xenografts, IGN004 fusion protein caused complete regression of all established tumors and achieved long-term survival in 62.5% of mice. IGN004 unfused antibody caused a significant delay in tumor progression (p=0.002 vs. vehicle) but did not achieve long-term survival (p=0003 vs. IGN004 fusion protein). When efficacy was tested against a panel of patient-derived NSCLC xenografts, IGN004 fusion protein demonstrated efficacy against 7/11 tumor models, including tumor regression in 3. Against a patient-derived xenograft model of melanoma, IGN004 unfused antibody was ineffective while IGN004 fusion protein inhibited the growth of the tumors. In a patient-derived xenograft model of AML, IGN004 treatment caused a reduction in the percentage of AML cells in the blood, spleen and bone marrow, compared to PBS treated animals. Conclusions: IGN004 demonstrated robust in vitro and in vivo anti-tumor activity against both solid and liquid tumors. Treatment of tumor cells with IGN004 caused an increase in surface expression of MHC class I, PD-L1, and OX-40L. IGN004 demonstrated the ability to enhance the effector T-cell-mediated killing of NSCLC cells in an in vitro assay using the TALL-104 cell line as effectors and NSCLC cell lines as targets. Against both cell line and patient-derived human xenograft tumors IGN004 had robust in vivo anti-tumor efficacy. These results support the further development of IGN004 as a potent targeted cancer immunotherapeutic agent that also has direct anti-tumor effects. Citation Format: Kristopher Steward, Michael Gresser, Raj Sachdev, Sanjay Khare. IGN004 is an antibody-interferon-alpha fusion protein against a novel tumor-associated antigen with both direct anti-tumor and immunostimulatory effects. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B182.