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Background: The intestinal microbiota is an important factor in modulating immune-mediated tumor cell destruction. Alterations in the microbiome composition have been linked to reduced efficacy of immune checkpoint inhibitor (ICI) therapies. Therefore, antibiotic treatment (ATB), which modifies the diversity of the gut bacteria populations, could lead to a reduced efficacy of ICI treatments., Methods: This was a retrospective cohort study. Patients with advanced non-small cell lung cancer (NSCLC) treated with anti-programmed cell death ligand-1 (PD-L1) alone, or in combination in three different countries in Latin America were included. After identification, patients were placed into three groups: Non-ATB exposed (no-ATB), exposed within 30 days of the first dose of ICI (pre-ICI ATB) and patients receiving ATB concomitantly with ICI (ICI-ATB). Progression-free survival (PFS), overall survival (OS) and response rates to treatment with ICI were assessed., Results: A total of 140 patients were included, of which 32 patients (23%) received ATB treatment. The most common ATB types were fluoroquinolones and B-lactams. No differences in survival according to antibiotic type were identified. Median OS in patients not exposed to ATB was 40.6 months (95% CI: 32-67.7), compared with 20.3 months (95% CI: 12.1-non-reached [NR]) for patients with pre-ICI ATB treatment and 24.7 months (95% CI: 13-NR) for patients treated with ATB concomitantly with ICI. There were no significant differences in terms of PFS, or response rates across all treatment groups., Conclusions: Antibiotic treatment was associated with reduced OS in Hispanic patients with NSCLC treated with ICIs., (© 2020 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Background: To compare survival outcomes of patients with advanced or metastatic non-small cell lung cancer (NSCLC) who received immunotherapy as first-, second- or beyond line, versus matched patients receiving standard chemotherapy with special characterization of hyperprogressors., Methods: A retrospective cohort study of 296 patients with unresectable/metastatic NSCLC treated with either, first-, second-, third- or fourth-line of immunotherapy was conducted. A matched comparison with a historical cohort of first-line chemotherapy and a random forest tree analysis to characterize hyperprogressors was conducted., Results: Median age was 64 years (range 34-90), 40.2% of patients were female. A total of 91.2% of patients had an Eastern Cooperative Oncology Group (ECOG) performance score ≤ 1. Immunotherapy as first-line was given to 39 patients (13.7%), second-line to 140 (48.8%), and as third-line and beyond to 108 (37.6%). Median overall survival was 12.7 months (95% CI 9.67-14 months) and progression-free survival (PFS) of 4.27 months (95% CI 3.97-5.0). Factors associated with increased survival included treatment with immunotherapy as first-line (P < 0.001), type of response (P < 0.001) and PD-L1 status (P = 0.0039). Compared with the historical cohort, immunotherapy proved to be superior in terms of OS (P = 0.05) but not PFS (P = 0.2). A total of 44 hyperprogressors were documented (19.8%, [95% CI 14.5-25.1%]). Leukocyte count over 5.300 cells/dL was present in both hyperprogressors and long-term responders., Conclusions: Patients who receive immune-checkpoint inhibitors as part of their treatment for NSCLC have better overall survival (OS) compared with matched patients treated with standard chemotherapy, regardless of the line of treatment., (© 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

The management of Non-Small Cell Lung Cancer (NSCLC) has changed dramatically in the last 10 years with an increase in the understanding of the biology and with the development of new and multiple treatments. Chemotherapy being the first systemic treatment used in the setting of advanced disease, proving benefit for patients over palliative care. With the identification of oncogenic drivers, innovative targeted therapies were developed and tested, leading to important changes in the management of certain patients and giving to some of them the possibility to be treated in first line with oral inhibitors. Immunotherapy was then explored as a potential option, with promising results, and data of impact in important endpoints in lung cancer treatments. This chapter explores the different CTLA-4 inhibitors that have been investigated in NSCLC: ipilimumab and tremelimumab, as well as the different immune checkpoint inhibitors: anti PD-1 (nivolumab and pembrolizumab) and PD-L1 (atezolizumab, durvalumab, avelumab, BMS-936559) medications. It also analyzes the different studies that have been developed for NSCLC with these medications, the evidence obtained, and the possible role in the management of patients. Immunotherapy has definitely changed the paradigm on NSCLC treatment, and the future is promising for the benefit of patients.

Most cancers express tumor antigens that can be recognized by T cells of the host. The fact that cancers become clinically evident nonetheless implies that immune escape must occur. Two major subsets of human melanoma metastases have been identified based on gene expression profiling. One subgroup has a T cell-inflamed phenotype that includes expression of chemokines, T cell markers, and a type I IFN signature. In contrast, the other major subset lacks this phenotype and has been designated as non-T cell-inflamed. The mechanisms of immune escape are likely distinct in these two phenotypes, and therefore the optimal immunotherapeutic interventions necessary to promote clinical responses may be different. The T cell-inflamed tumor microenvironment subset shows the highest expression of negative regulatory factors, including PD-L1, IDO, FoxP3 + Tregs, and evidence for T cell-intrinsic anergy. Therapeutic strategies to overcome these inhibitory mechanisms are being pursued, and anti-PD-1 mAbs have been FDA approved. The presence of multiple inhibitory mechanisms in the same tumor microenvironment argues that combination therapies may be advantageous, several of which are in clinical testing. A new paradigm may be needed to promote de novo inflammation in cases of the non-T cell-infiltrated tumor microenvironment. Natural innate immune sensing of tumors appears to occur via the host STING pathway, type I IFN production, and cross-priming of T cells via CD8α + DCs. New strategies are being developed to engage this pathway therapeutically, such as through STING agonists. The molecular mechanisms that mediate the presence or absence of the T cell-inflamed tumor microenvironment are being elucidated using parallel genomics platforms. The first oncogene pathway identified that mediates immune exclusion is the Wnt/β-catenin pathway, suggesting that new pharmacologic strategies to target this pathway should be developed to restore immune access to the tumor microenvironment.

A pre-existing T cell-inflamed tumor microenvironment has prognostic utility and also can be predictive for response to contemporary cancer immunotherapies. The generation of a spontaneous T cell response against tumor-associated antigens depends on innate immune activation, which drives type I interferon (IFN) production. Recent work has revealed a major role for the STING pathway of cytosolic DNA sensing in this process. This cascade of events contributes to the activation of Batf3-lineage dendritic cells (DCs), which appear to be central to anti-tumor immunity. Non-T cell-inflamed tumors lack chemokines for Batf3 DC recruitment, have few Batf3 DCs, and lack a type I IFN gene signature, suggesting that failed innate immune activation may be the ultimate cause for lack of spontaneous T cell activation and accumulation. With this information in hand, new strategies for triggering innate immune activation and Batf3 DC recruitment are being developed, including novel STING agonists for de novo immune priming. Ultimately, the successful development of effective innate immune activators should expand the fraction of patients that can respond to immunotherapies, such as with checkpoint blockade antibodies.

Chronic inflammation in the tumor microenvironment and evasion of the antitumor effector immune response are two of the emerging hallmarks required for oncogenesis and cancer progression. The innate immune system not only plays a critical role in perpetuating these tumor-promoting hallmarks but also in developing antitumor adaptive immune responses. Thus, understanding the dual role of the innate system in cancer immunology is required for the design of combined immunotherapy strategies able to tackle established tumors. Here, we review recent advances in the understanding of the role of cell populations and soluble components of the innate immune system in cancer, with a focus on complement, the adapter molecule Stimulator of Interferon Genes, natural killer cells, myeloid cells, and B cells., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Immune response to tumors can be successfully oriented for therapeutic purposes, as shown by the clinical efficacy of checkpoint blockade in extending the survival of patients with certain solid and hematologic neoplasms. Nonetheless, numerous patients do not benefit from these new treatments. Tumor-specific CD8(+) T lymphocytes, either endogenously revived by checkpoint interference or adoptively transferred after in vitro expansion and retargeting, can be extremely efficient in controlling metastatic disease but have to overcome a number of restraints imposed by growing tumors. This immune escape relies on a profound modification of the tumor environment, which is rendered less permissive to lymphocyte arrival, persistence, and functional activity. We review here emerging findings on the main negative circuits limiting the efficacy of cancer immunotherapy, as well as novel and conventional approaches that can translate into rational combination therapies., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Despite recent clinical advances in immunotherapy, a fraction of cancer patients fails to respond to these interventions. Evidence from preclinical mouse models as well as clinical samples has provided evidence that the extent of activated T cell infiltration within the tumor microenvironment is associated with clinical response to immunotherapies including checkpoint blockade. Therefore, understanding the molecular mechanisms mediating the lack of T cell infiltration into the tumor microenvironment will be instrumental for the development of new therapeutic strategies to render those patients immunotherapy responsive. Recent data have suggested that major sources of intersubject heterogeneity include differences in somatic mutations in specific oncogene pathways between cancers of individual subjects and also environmental factors including commensal microbial composition. Successful identification of such causal factors should lead to new therapeutic approaches that may facilitate T cell entry into noninflamed tumors and expand the fraction of patients capable of responding to novel immunotherapies., (© 2016 Elsevier Inc. All rights reserved.)

Novel immunotherapy approaches are transforming the treatment of cancer, yet many patients remain refractory to these agents. One hypothesis is that immunotherapy fails because of a tumor microenvironment that fails to support recruitment of immune cells, including CD8(+) T cells. Therefore, new approaches designed to initiate a de novo antitumor immune response from within the tumor microenvironment are being pursued. Recent evidence has indicated that spontaneous activation of the Stimulator of Interferon Genes (STING) pathway within tumor-resident dendritic cells leads to type I IFN production and adaptive immune responses against tumors. This pathway is activated in the presence of cytosolic DNA that is detected by the sensor cyclic GMP-AMP synthase (cGAS) and generates cyclic GMP-AMP (cGAMP), which binds and activates STING. As a therapeutic approach, intratumoral injection of STING agonists has demonstrated profound therapeutic effects in multiple mouse tumor models, including melanoma, colon, breast, prostate, and fibrosarcoma. Better characterization of the STING pathway in human tumor recognition, and the development of new pharmacologic approaches to engage this pathway within the tumor microenvironment in patients, are important areas for clinical translation., (©2015 American Association for Cancer Research.)

For tumor antigen-specific T cells to effectively control the growth of cancer cells in vivo, they must gain access to, and function within, the tumor microenvironment. While tumor antigen-based vaccines and T cell adoptive transfer strategies can result in clinical benefit in a subset of patients, most of the patients do not respond clinically. Even for tumor-infiltrating lymphocyte (TIL)-based adoptive transfer for patients with metastatic melanoma, which can provide tumor shrinkage in around 50% of treated individuals, many patients are not eligible, in part because there are not sufficient TIL present in the resected tumor. Thus, the denominator is in fact larger, and it has been suggested that absence of TIL may be a marker for poor efficacy of immunotherapies in general. While qualitative and/or quantitative features of the T cells are important considerations for efficacy, a major component of primary resistance likely can be attributed to the tumor microenvironment. Data are accumulating suggesting that two major categories of immune resistance within the tumor microenvironment may exist: failure of T cell trafficking due to low levels of inflammation and lack of chemokines for migration, and dominant suppression through immune inhibitory mechanisms. New therapeutic interventions are being guided by these observations, and preliminary clinical success is validating this working model., (Copyright © 2013. Published by Elsevier Ltd.)