Collagens in the extracellular matrix (ECM) provide a physical barrier to tumor immune infiltration, while also acting as a ligand for immune inhibitory receptors. Transforming growth factor-β ...(TGF-β) is a key contributor to shaping the ECM by stimulating the production and remodeling of collagens. TGF-β activation signatures and collagen-rich environments have both been associated with T cell exclusion and lack of responses to immunotherapy. Here, we describe the effect of targeting collagens that signal through the inhibitory leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) in combination with blockade of TGF-β and programmed cell death ligand 1 (PD-L1). This approach remodeled the tumor collagenous matrix, enhanced tumor infiltration and activation of CD8+ T cells, and repolarized suppressive macrophage populations, resulting in high cure rates and long-term tumor-specific protection across murine models of colon and mammary carcinoma. The results highlight the advantage of direct targeting of ECM components in combination with immune checkpoint blockade therapy.
Immunosuppressive entities in the tumor microenvironment (TME) remain a major impediment to immunotherapeutic approaches for a majority of patients with cancer. While the immunosuppressive role of ...transforming growth factor-β (TGF-β) in the TME is well known, clinical studies to date with anti-TGF-β agents have led to limited success. The bifunctional agent bintrafusp alfa (previously designated M7824) has been developed in an attempt to address this issue. Bintrafusp alfa consists of an IgG1 targeting programmed death ligand 1 (PD-L1) moiety fused via peptide linkers to the extracellular domain of two TGF-β receptor II molecules designed to ‘trap’ TGF-β in the TME. This agent is able to bring the TGF-β trap to the TME via its anti-PD-L1 component, thus simultaneously attacking both the immunosuppressive PD-L1 and TGF-β entities. A number of preclinical studies have shown bintrafusp alfa capable of (1) preventing or reverting TGF-β-induced epithelial-mesenchymal transition in human carcinoma cells; this alteration in tumor cell plasticity was shown to render human tumor cells more susceptible to immune-mediated attack as well as to several chemotherapeutic agents; (2) altering the phenotype of natural killer and T cells, thus enhancing their cytolytic ability against tumor cells; (3) mediating enhanced lysis of human tumor cells via the antibody-dependent cell-mediated cytotoxicity mechanism; (4) reducing the suppressive activity of Treg cells; (5) mediating antitumor activity in numerous preclinical models and (6) enhancing antitumor activity in combination with radiation, chemotherapy and several other immunotherapeutic agents. A phase I clinical trial demonstrated a safety profile similar to other programmed cell death protein 1 (PD-1)/PD-L1 checkpoint inhibitors, with objective and durable clinical responses. We summarize here preclinical and emerging clinical data in the use of this bispecific and potentially multifunctional agent.
Tumors evade host immune surveillance through multiple mechanisms, including the generation of a tumor microenvironment that suppresses immune effector function. Secretion of TGFβ and upregulation of ...immune checkpoint programmed cell death ligand-1 (PD-L1) are two main contributors to immune evasion and tumor progression. Here, we examined the efficacy of a first-in-class bifunctional checkpoint inhibitor, the fusion protein M7824, comprising the extracellular domain of human TGFβRII (TGFβ Trap) linked to the C-terminus of human anti-PD-L1 heavy chain (αPD-L1). We demonstrate that M7824 reduces plasma TGFβ1, binds to PD-L1 in the tumor, and decreases TGFβ-induced signaling in the tumor microenvironment in mice. In murine breast and colon carcinoma models, M7824 decreased tumor burden and increased overall survival as compared to targeting TGFβ alone. M7824 treatment promoted CD8+ T cell and NK cell activation, and both of these immune populations were required for optimal M7824-mediated tumor control. M7824 was superior to TGFβ- or αPD-L1-targeted therapies when in combination with a therapeutic cancer vaccine. These findings demonstrate the value of using M7824 to simultaneously target TGFβ and PD-L1/PD-1 immunosuppressive pathways to promote anti-tumor responses and efficacy. The studies also support the potential clinical use of M7824 as a monotherapy or in combination with other immunotherapies, such as therapeutic cancer vaccines, including for patients who have progressed on αPD-L1/αPD-1 checkpoint blockade therapies.
Poorly inflamed carcinomas do not respond well to immune checkpoint blockade. Converting the tumour microenvironment into a functionally inflamed immune hub would extend the clinical benefit of ...immune therapy to a larger proportion of cancer patients. Here we show, by using comprehensive single-cell transcriptome, proteome, and immune cell analysis, that Entinostat, a class I histone deacetylase inhibitor, facilitates accumulation of the necrosis-targeted recombinant murine immune-cytokine, NHS-rmIL12, in experimental mouse colon carcinomas and poorly immunogenic breast tumours. This combination therapy reprograms the tumour innate and adaptive immune milieu to an inflamed landscape, where the concerted action of highly functional CD8
T cells and activated neutrophils drive macrophage M1-like polarization, leading to complete tumour eradication in 41.7%-100% of cases. Biomarker signature of favourable overall survival in multiple human tumor types shows close resemblance to the immune pattern generated by Entinostat/NHS-rmIL12 combination therapy. Collectively, these findings provide a rationale for combining NHS-IL12 with Entinostat in the clinical setting.
Bintrafusp alfa (anti-PD-L1/TGFβRII) is a first-in-class bifunctional agent designed to act both as a checkpoint inhibitor and as a “trap” for TGFβ in the tumor microenvironment (TME). This article ...is designed to review the preclinical studies interrogating the mode of action of bintrafusp alfa and to present a comprehensive overview of recent bintrafusp alfa clinical studies. Preclinical studies have demonstrated that bintrafusp alfa immune-mediating and antitumor activity can be enhanced by combining it with a human papillomavirus (HPV) therapeutic cancer vaccine, a tumor-targeting interleukin 12 (IL-12) immunocytokine and/or an IL-15 superagonist. The importance of TGFβ in HPV-associated malignancies is also reviewed. The clinical studies reviewed span extended phase I cohorts in patients with a spectrum of malignancies, two randomized phase II studies in lung and one in biliary tract cancers in which bintrafusp alfa did not demonstrate superiority over standard-of-care therapies, and provocative results in patients with HPV-associated malignancies, where as a monotherapy, bintrafusp alfa has shown response rates of 35%, compared to overall response rate (ORR) of 12–24% seen with other Food and Drug Administration (FDA)-approved or standard-of-care agents. This article also reviews preliminary phase II study results of patients with HPV+ malignancies employing bintrafusp alfa in combination with an HPV therapeutic vaccine and a tumor-targeting IL-12 immunocytokine in which the combination therapy outperforms standard-of-care therapies in both checkpoint naïve and checkpoint refractory patients. This review thus provides an example of the importance of conducting clinical studies in an appropriate patient population – in this case, exemplified by the role of TGFβ in HPV-associated malignancies. This review also provides preclinical and preliminary clinical study results of the combined use of multiple immune-modulating agents, each designed to engage different immune components and tumor cells in the TME.
To provide the foundation for combining immunotherapy to induce tumor antigen-specific T cells with proton radiation therapy to exploit the activity of those T cells.
Using cell lines of tumors ...frequently treated with proton radiation, such as prostate, breast, lung, and chordoma, we examined the effect of proton radiation on the viability and induction of immunogenic modulation in tumor cells by flow cytometric and immunofluorescent analysis of surface phenotype and the functional immune consequences.
These studies show for the first time that (1) proton and photon radiation induced comparable up-regulation of surface molecules involved in immune recognition (histocompatibility leukocyte antigen, intercellular adhesion molecule 1, and the tumor-associated antigens carcinoembryonic antigen and mucin 1); (2) proton radiation mediated calreticulin cell-surface expression, increasing sensitivity to cytotoxic T-lymphocyte killing of tumor cells; and (3) cancer stem cells, which are resistant to the direct cytolytic activity of proton radiation, nonetheless up-regulated calreticulin after radiation in a manner similar to non-cancer stem cells.
These findings offer a rationale for the use of proton radiation in combination with immunotherapy, including for patients who have failed radiation therapy alone or have limited treatment options.
Certain chemotherapeutic regimens trigger cancer cell death while inducing dendritic cell maturation and subsequent immune responses. However, chemotherapy‐induced immunogenic cell death (ICD) has ...thus far been restricted to select agents. In contrast, several chemotherapeutic drugs modulate antitumor immune responses, despite not inducing classic ICD. In addition, in many cases tumor cells do not die after treatment. Here, using docetaxel, one of the most widely used cancer chemotherapeutic agents, as a model, we examined phenotypic and functional consequences of tumor cells that do not die from ICD. Docetaxel treatment of tumor cells did not induce ATP or high‐mobility group box 1 (HMGB1) secretion, or cell death. However, calreticulin (CRT) exposure was observed in all cell lines examined after chemotherapy treatment. Killing by carcinoembryonic antigen (CEA), MUC‐1, or PSA‐specific CD8+ CTLs was significantly enhanced after docetaxel treatment. This killing was associated with increases in components of antigen‐processing machinery, and mediated largely by CRT membrane translocation, as determined by functional knockdown of CRT, PERK, or CRT‐blocking peptide. A docetaxel‐resistant cell line was selected (MDR‐1+, CD133+) by continuous exposure to docetaxel. These cells, while resistant to direct cytostatic effects of docetaxel, were not resistant to the chemomodulatory effects that resulted in enhancement of CTL killing. Here, we provide an operational definition of “immunogenic modulation,” where exposure of tumor cells to nonlethal/sublethal doses of chemotherapy alters tumor phenotype to render the tumor more sensitive to CTL killing. These observations are distinct and complementary to ICD and highlight a mechanism whereby chemotherapy can be used in combination with immunotherapy.
What's new?
Some chemotherapies not only kill cancer cells, but also enhance immune responses against those cells. In this study, the authors found that when tumor cells were exposed to nonlethal doses of docetaxel, they became more sensitive to killing by cytotoxic T lymphocytes. This process appears to be mediated by a number of molecules, including calreticulin. Even tumor cells that were resistant to docetaxel became more susceptible to lysis by CTLs. These results suggest that chemotherapy combined with immunotherapy might improve outcomes in patients who have failed chemotherapy alone.
Immune checkpoint blockade (ICB) targeting the programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) fails to provide clinical benefit for most cancer patients due to primary or acquired ...resistance. Drivers of ICB resistance include tumor antigen processing/presentation machinery (APM) and IFNγ signaling mutations. Thus, there is an unmet clinical need to develop alternative therapies for these patients. To this end, we have developed a CRISPR/Cas9 approach to generate murine tumor models refractory to PD-1/-L1 inhibition due to APM/IFNγ signaling mutations. Guide RNAs were employed to delete B2m, Jak1, or Psmb9 genes in ICB-responsive EMT6 murine tumor cells. B2m was deleted in ICB-responsive MC38 murine colon cancer cells. We report a detailed development and validation workflow including whole exome and Sanger sequencing, western blotting, and flow cytometry to assess target gene deletion. Tumor response to ICB and immune effects of gene deletion were assessed in syngeneic mice. This workflow can help accelerate the discovery and development of alternative therapies and a deeper understanding of the immune consequences of tumor mutations, with potential clinical implications.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Immunotherapy targeting PD-1/PD-L1 fails to induce clinical responses in most patients with solid cancers. N-803, formerly ALT-803, is an IL-15 superagonist mutant and dimeric IL-15RαSushi-Fc fusion ...protein complex that enhances CD8
T and NK cell expansion and function and exhibits anti-tumor efficacy in preclinical models. Previous in vitro studies have shown that IL-15 increases PD-L1 expression, a negative regulator of CD8
T and NK cell function. Most reported preclinical studies administered N-803 intraperitoneally not subcutaneously, the current clinical route of administration. N-803 is now being evaluated clinically in combination with PD-1/PD-L1 inhibitors. However, the mechanism of action has not been fully elucidated. Here, we examined the anti-tumor efficacy and immunomodulatory effects of combining N-803 with an anti-PD-L1 antibody in preclinical models of solid carcinomas refractory to anti-PD-L1 or N-803.
Subcutaneous N-803 and an anti-PD-L1 monoclonal antibody were administered as monotherapy or in combination to 4T1 triple negative breast and MC38-CEA colon tumor-bearing mice. Anti-tumor efficacy was evaluated, and a comprehensive analysis of the immune-mediated effects of each therapy was performed on the primary tumor, lung as a site of metastasis, and spleen.
We demonstrate that N-803 treatment increased PD-L1 expression on immune cells in vivo, supporting the combination of N-803 and anti-PD-L1. N-803 plus anti-PD-L1 was well-tolerated, reduced 4T1 lung metastasis and MC38-CEA tumor burden, and increased survival as compared to N-803 and anti-PD-L1 monotherapies. Efficacy of the combination therapy was dependent on both CD8
T and NK cells and was associated with increased numbers of these activated immune cells in the lung and spleen. Most alterations to NK and CD8
T cell phenotype and number were driven by N-803. However, the addition of anti-PD-L1 to N-803 significantly enhanced CD8
T cell effector function versus N-803 and anti-PD-L1 monotherapies, as indicated by increased Granzyme B and IFNγ production, at the site of metastasis and in the periphery. Increased CD8
T cell effector function correlated with higher serum IFNγ levels, without related toxicities, and enhanced anti-tumor efficacy of the N-803 plus anti-PD-L1 combination versus either monotherapy.
We provide novel insight into the mechanism of action of N-803 plus anti-PD-L1 combination and offer preclinical proof of concept supporting clinical use of N-803 in combination with checkpoint inhibitors, including for patients non- and/or minimally responsive to either monotherapy.