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Simple Summary: According to the Society for Immunotherapy of Cancer, primary resistance to immune checkpoint inhibitor (ICI) treatment is defined as progression of disease within 6 months of ICI treatment with patients receiving at least 6 weeks of ICI monotherapy. We evaluated factors predictive of primary resistance to ICI monotherapy in 108 advanced non-small-cell lung cancer patients. The prevalence of primary resistance was 54.6%. The majority of patients were male, smokers, received pembrolizumab and had adenocarcinoma histology. We found that female gender, an elevated neutrophil-to-lymphocyte ratio of ≥3 at 6 weeks and a later line of immunotherapy treatment (≥2 lines) were key factors in predicting primary resistance to ICI monotherapy in advanced NSCLC. Introduction: Primary resistance to immune checkpoint inhibitors (ICI) is observed in routine clinical practice. We sought to determine factors predictive of primary resistance to ICI monotherapy, defined by the Society for Immunotherapy of Cancer (SITC) as progression within 6 months of ICI treatment with patients receiving at least 6 weeks of ICI monotherapy, in patients with advanced non-small-cell lung cancer (NSCLC). Method: Patients with stage IV NSCLC treated with at least 6 weeks of single-agent ICI at two tertiary hospitals in Singapore were included. A multivariate logistic regression model was utilised to elucidate factors predictive of primary resistance to ICI. Results: Of the 108 eligible patients, 59 (54.6%) experienced primary resistance. The majority were male (65.7%), smokers (66.3%), Chinese (79.6%), had adenocarcinoma (76.9%), received Pembrolizumab (55.6%) and received immunotherapy treatment in the later line setting (≥2 lines) (61.1%). Female gender (aOR = 3.16, p = 0.041), a sixth-week neutrophil-to-lymphocyte ratio (NLR) of ≥3) (aOR = 3.454, p = 0.037) and a later line of immunotherapy treatment (≥2 lines) (aOR = 2.676, p = 0.040) were factors predictive of primary resistance to ICI monotherapy in patients with advanced NSCLC. Conclusions: Using SITC criteria, an elevated NLR (≥3) at 6 weeks, female gender and a later line of immunotherapy treatment (≥2 lines) were predictive factors of developing primary resistance to ICI monotherapy in patients with advanced NSCLC. [ABSTRACT FROM AUTHOR]

Simple Summary: Resistance to antiangiogenic therapy represents a challenge in the therapeutic approach for hepatocellular carcinoma (HCC). The advent of immune checkpoint inhibitors (ICIs) seems to be a solution to this issue; however, other gaps have emerged since they have only been shown to provide benefit in approximately 20% of patients. Combination strategies have introduced in clinical development to overcome this issue. This review deals with the resistance to antiangiogenic drugs by focusing on two protagonists, the tumor microenvironment and vascular normalization, to offer possible overcoming strategies. Antiangiogenic drugs were the only mainstay of advanced hepatocellular carcinoma (HCC) treatment from 2007 to 2017. However, primary or secondary resistance hampered their efficacy. Primary resistance could be due to different molecular and/or genetic characteristics of HCC and their knowledge would clarify the optimal treatment approach in each patient. Several molecular mechanisms responsible for secondary resistance have been discovered over the last few years; they represent potential targets for new specific drugs. In this light, the advent of checkpoint inhibitors (ICIs) has been a new opportunity; however, their use has highlighted other issues: the vascular normalization compared to a vessel pruning to promote the delivery of an active cancer immunotherapy and the development of resistance to immunotherapy which leads to a better selection of patients as candidates for ICIs. Nevertheless, the combination of antiangiogenic therapy plus ICIs represents an intriguing approach with high potential to improve the survival of these patients. Waiting for results from ongoing clinical trials, this review depicts the current knowledge about the resistance to antiangiogenic drugs in HCC. It could also provide updated information to clinicians focusing on the most effective combinations or sequential approaches in this regard, based on molecular mechanisms. [ABSTRACT FROM AUTHOR]

Simple Summary: Immune checkpoint inhibitors (ICIs) had been explored extensively in patients affected by unresectable hepatocellular carcinoma. These agents were expected to be the keystones of the disease's first-line treatment because they were theoretically able to revert the immune suppressive tumor microenvironment of the cancerous liver, and because of their manageable safety profile. However, when used as monotherapies, they showed important activity and efficacy limitations. In this mini-review, we summarize the characteristics of the different ICIs-based regimens which constitute the present gold standard of first-line treatment, then, moving from their shortcomings, we discuss the rationale supporting the strategies currently under investigation: systemic triplets and new paradigms of immune-therapeutic agents such as CAR-T and vaccines. Immune checkpoint inhibitors (ICIs) are a key component of different stages of hepatocellular carcinoma (HCC) treatment, particularly in the first line of treatment. A lesson on the primary resistance which hampers their efficacy and activity was learned from the failure of the trials which tested them as first-line mono-therapies. Despite the combination of anti-PD(L)1 agents with anti-VEGF, anti CTLA4, or TKIs demonstrating relevant improvements in efficacy, the "doublets strategy" still shows room for improvement, due to a limited overall survival benefit and a high rate of progressive disease as best response. In this review, we discuss the results from the currently tested doublet strategies (i.e., atezolizumab+bevacizumab, durvalumab+tremelimumab with a mention to the newly presented ICIs/TKIs combinations), which highlight the need for therapeutic improvement. Furthermore, we examine the rationale and provide an overview of the ongoing trials testing the treatment intensification strategy with triplet drugs: anti-PD1+anti-CTLA4+anti-VEGF/TKIs and anti-PD1+anti-VEGF+alternative immunity targets. Lastly, we report on the alternative strategy to integrate ICIs into the new paradigm of immune therapeutics constituted by CAR-T and anti-cancer vaccines. This review provides up-to-date knowledge of ongoing clinical trials of the aforementioned strategies and critical insight into their mechanistic premises. [ABSTRACT FROM AUTHOR]

Background: Primary resistance to immunotherapy can be observed in approximately 40–65% of the stage IV melanoma patients treated with immune checkpoint inhibitors. A minority of the patients receive a second-line therapy, and the clinical benefit is small. Patients and methods: Stage IV melanoma patients treated with first-line PD-1-based immunotherapy between January 2015 and December 2018 were investigated. Primary resistance was defined as progressive disease (PD) at the time of the first tumor assessment after starting immunotherapy. Patients with complete response, partial response, and stable disease were classified as having disease control (DC). Overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan–Meier estimator. Univariate and multivariate logistic regression analyses were performed to determine prognostic factors associated with OS. Results: Three hundred and nineteen patients were included, and 40% had primary resistance to immunotherapy. The median follow-up time was 22 months. Patients with primary resistance had 1-, 2-, and 3-year OS rates of 41%, 15%, and 10%, respectively, compared to 91%, 81%, and 65% for the patients who achieved DC. The following independently significant prognostic factors for OS were identified: protein S100B level and primary tumor localization. There was a statistically significant difference for OS (p < 0.0001) but not for PFS (p = 0.230) when analyzing risk groups formed with a combination of these two variables (low-, intermediate-, and high-risk subgroups). Conclusions: Melanoma patients with primary resistance to immunotherapy have a dismal prognosis. Response at the first tumor assessment after starting immunotherapy is a stronger prognostic factor for the further course of the disease than pretreatment risk factors. [ABSTRACT FROM AUTHOR]

Cancer immunotherapies, including checkpoint inhibitors, adoptive T cell transfer and therapeutic cancer vaccines, have shown promising response rates in clinical trials. Unfortunately, there is an increasing number of patients in which initially regressing tumors start to regrow due to an immunotherapy-driven acquired resistance. Studies on the underlying mechanisms reveal that these can be similar to well-known tumor intrinsic and extrinsic primary resistance factors that precluded the majority of patients from responding to immunotherapy in the first place. Here, we discuss primary and secondary immune resistance and point at strategies to identify potential new mechanisms of immune evasion. Ultimately, this may lead to improved immunotherapy strategies with improved clinical outcomes. [ABSTRACT FROM AUTHOR]

The development of new systemic agents has led us into a "golden era" of management of metastatic renal cell carcinoma (RCC). Certainly, the approval of immune-checkpoint inhibitors and the combination of these with targeted compounds has irreversibly changed clinical scenarios. A deeper knowledge of the molecular mechanisms that correlate with tumor development and progression has made this revolution possible. In this amazing era, novel challenges are awaiting us in the clinical management of metastatic RCC. Of these, the development of reliable criteria which are able to predict tumor response to treatment or primary and acquired resistance to systemic treatments still remain an unmet clinical need. Thanks to the availability of data provided by studies evaluating genomic assessments of the disease, this goal may no longer be out of reach. In this review, we summarize current knowledge about genomic alterations related to primary and secondary resistance to target therapy and immune-checkpoint inhibitors in RCC. [ABSTRACT FROM AUTHOR]