Prospective randomized trial of high-dose interleukin-2 alone or in conjunction with lymphokine-activated killer cells for the treatment of patients with advanced cancer

Immunomodulatory Precision: A Narrative Review Exploring the Critical Role of Immune Checkpoint Inhibitors in Cancer Treatment

An immune checkpoint is a signaling pathway that regulates the recognition of antigens by T-cell receptors (TCRs) during an immune response. These checkpoints play a pivotal role in suppressing excessive immune responses and maintaining immune homeostasis against viral or microbial infections. There are several FDA-approved immune checkpoint inhibitors (ICIs), including ipilimumab, pembrolizumab, and avelumab. These ICIs target cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed death ligand 1 (PD-L1). Furthermore, ongoing efforts are focused on developing new ICIs with emerging potential. In comparison to conventional treatments, ICIs offer the advantages of reduced side effects and durable responses. There is growing interest in the potential of combining different ICIs with chemotherapy, radiation therapy, or targeted therapies. This article comprehensively reviews the classification, mechanism of action, application, and combination strategies of ICIs in various cancers and discusses their current limitations. Our objective is to contribute to the future development of more effective anticancer drugs targeting immune checkpoints.

Immune checkpoint inhibitors in metastatic melanoma therapy (Review)

An increase in the incidence of melanoma has been observed in recent decades, which poses a significant challenge due to its poor prognosis in the advanced and metastatic stages. Previously, chemotherapy and high doses of interleukin-2 were available treatments for melanoma; however, they offered limited survival benefits and were associated with severe toxicities. The treatment of metastatic melanoma has been transformed by new developments in immunotherapy. Immune checkpoint inhibitors (ICIs), monoclonal antibodies that target cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1) and its ligand, PDL-1, have emerged as promising therapeutic options. Commonly used ICIs, such as ipilimumab, nivolumab and pembrolizumab, have been found to be associated with an improved median overall survival, recurrence-free survival and response rates compared to traditional chemotherapies. Combination therapies involving different types of ICIs, such as anti-PD1 with anti-CTLA-4, have further enhanced the overall survival and response rates by targeting various phases of T-cell activation. Additionally, the development of novel biomarkers has facilitated the assessment of responses to ICI therapy, with tissue and serum-based prognostic and predictive biomarkers now available. The increased response observed with ICIs also provides potential for immune-related adverse effects on various organ systems. Further research is required to evaluate the efficacy and safety of various combinations of ICIs, while ongoing clinical trials explore the potential of newer ICIs. Concerns regarding the development of resistance to ICIs also warrant attention. The present review summarizes and discusses the advent of ICIs with a marked significant breakthrough in the treatment of metastatic melanoma, providing improved outcomes compared to traditional therapies.

Identification of immune-related genes and integrated analysis of immune-cell infiltration in melanoma

OBJECTIVE

This study was conducted to screen out immune-related genes in connection with the prognosis of melanoma, construct a prognosis model and explore the relevant mechanisms.

METHODS AND MATERIALS

1973 genes associated with immune system were derived from the Immport database, and RNA-seq data of melanoma and information of patients were searched from the Xena database. Cox univariate analysis, Lasso analysis and Cox multivariate analysis were used to screen out six genes to construct the model. Then the risk scores were estimated for patients based on our constructed prognosis model. Estimate was used to affirm that the model was about immune infiltration, and CIBERSORT was used to screen out immune cells associated with prognosis. TIDE was applied to predict the efficacy of immunotherapy. Finally, GSE65904 and GSE19234 were used to confirm the effectiveness of the model.

RESULTS

ADCYAP1R1, GPI, NTS might cause poor prognosis while IFITM1, KIR2DL4, LIF were more likely conductive to prognosis of melanoma patients and a model of prognosis was constructed on the basis of these six genes. The effectiveness of the model has been proven by the ROC curve, and the miRNAs targeting the screened genes were found out, suggesting that the immune system might impact on the prognosis of melanoma by T cell CD8+, T cell CD4+ memory and NK cells.

CONCLUSIONS

In this study, the screened six genes were associated with the prognosis of melanoma, which was conductive to clinical prognostic prediction and individualized treatment strategy.

Immune microenvironment of cervical cancer and the role of IL-2 in tumor promotion

The tumor microenvironment (TME) is a heterogeneous mixture of resident and tumor cells that maintain close communication through their secretion products. The composition of the TME is dynamic and complex among the different types of cancer, where the immune cells play a relevant role in the elimination of tumor cells, however, under certain circumstances they contribute to tumor development. In cervical cancer (CC) the human papilloma virus (HPV) shapes the microenvironment in order to mediate persistent infections that favors transformation and tumor development. Interleukin-2 (IL-2) is an important TME cytokine that induces CD8+ effector T cells and NKs to eliminate tumor cells, however, IL-2 can also suppress the immune response through Treg cells. Recent studies have shown that CC cells express the IL-2 receptor (IL-2R), that are induced to proliferate at low concentrations of exogenous IL-2 through alterations in the JAK/STAT pathway. This review provides an overview of the main immune cells that make up the TME in CC, as well as the participation of IL-2 in the tumor promotion. Finally, it is proposed that the low density of IL-2 produced by immunocompetent cells is used by tumor cells through its IL-2R as a mechanism to proliferate simultaneously depleting this molecule in order to evade immune response.

Inhibiting N-glycan processing increases the antibody binding affinity and effector function of human natural killer cells

Novel approaches are required to improve the efficacy of immunotherapies and increase the proportion of patients who experience a benefit. Antibody-dependent cell-mediated cytotoxicity (ADCC) contributes to the efficacy of many monoclonal antibodies therapies. Natural killer (NK) cells mediate ADCC, though responses are highly variable and depend on prior treatment as well as other factors. Thus, strategies to increase NK cell activity are expected to improve multiple therapies. Both cytokine treatment and NK cell receptor engineering are being explored to increase ADCC. Post-translational modifications, including glycosylation, are widely recognized as mediators of cellular processes but minimally explored as an alternative strategy to increase ADCC. We evaluated the impact of treatment with kifunensine, an inhibitor of asparagine-linked (N-)glycan processing, on ADCC using primary and cultured human NK cells. We also probed affinity using binding assays and CD16a structure with nuclear magnetic resonance spectroscopy. Treating primary human NK cells and cultured YTS-CD16a cells with kifunensine doubled ADCC in a CD16a-dependent manner. Kifunensine treatment also increased the antibody-binding affinity of CD16a on the NK cell surface. Structural interrogation identified a single CD16a region, proximal to the N162 glycan and the antibody-binding interface, perturbed by the N-glycan composition. The observed increase in NK cell activity following kifunensine treatment synergized with afucosylated antibodies, further increasing ADCC by an additional 33%. These results demonstrate native N-glycan processing is an important factor that limits NK cell ADCC. Furthermore, optimal antibody and CD16a glycoforms are defined that provide the greatest ADCC activity.

Identification of disulfidptosis-related subgroups and prognostic signatures in lung adenocarcinoma using machine learning and experimental validation

Background

Disulfidptosis is a newly identified variant of cell death characterized by disulfide accumulation, which is independent of ATP depletion. Accordingly, the latent influence of disulfidptosis on the prognosis of lung adenocarcinoma (LUAD) patients and the progression of tumors remains poorly understood.

Methods

We conducted a multifaceted analysis of the transcriptional and genetic modifications in disulfidptosis regulators (DRs) specific to LUAD, followed by an evaluation of their expression configurations to define DR clusters. Harnessing the differentially expressed genes (DEGs) identified from these clusters, we formulated an optimal predictive model by amalgamating 10 distinct machine learning algorithms across 101 unique combinations to compute the disulfidptosis score (DS). Patients were subsequently stratified into high and low DS cohorts based on median DS values. We then performed an exhaustive comparison between these cohorts, focusing on somatic mutations, clinical attributes, tumor microenvironment, and treatment responsiveness. Finally, we empirically validated the biological implications of a critical gene, KYNU, through assays in LUAD cell lines.

Results

We identified two DR clusters and there were great differences in overall survival (OS) and tumor microenvironment. We selected the "Least Absolute Shrinkage and Selection Operator (LASSO) + Random Survival Forest (RFS)" algorithm to develop a DS based on the average C-index across different cohorts. Our model effectively stratified LUAD patients into high- and low-DS subgroups, with this latter demonstrating superior OS, a reduced mutational landscape, enhanced immune status, and increased sensitivity to immunotherapy. Notably, the predictive accuracy of DS outperformed the published LUAD signature and clinical features. Finally, we validated the DS expression using clinical samples and found that inhibiting KYNU suppressed LUAD cells proliferation, invasiveness, and migration in vitro.

Conclusions

The DR-based scoring system that we developed enabled accurate prognostic stratification of LUAD patients and provides important insights into the molecular mechanisms and treatment strategies for LUAD.

Adoptive cellular immunotherapy for solid neoplasms beyond CAR-T

In recent decades, immune checkpoint blockade and chimeric antigen receptor T cell (CAR-T) therapy are two milestone achievements in clinical immunotherapy. However, both show limited efficacies in most solid neoplasms, which necessitates the exploration of new immunotherapeutic modalities. The failure of CAR-T and immune checkpoint blockade in several solid neoplasms is attributed to multiple factors, including low antigenicity of tumor cells, low infiltration of effector T cells, and diverse mechanisms of immunosuppression in the tumor microenvironment. New adoptive cell therapies have been attempted for solid neoplasms, including TCR-T, CAR-natural killer cells (CAR-NK), and CAR-macrophages (CAR-M). Compared to CAR-T, these new adoptive cell therapies have certain advantages in treating solid neoplasms. In this review, we summarized the 40-year evolution of adoptive cell therapies, then focused on the advances of TCR-T, CAR-NK, and CAR-M in solid neoplasms and discussed their potential clinical applications.

The NK-92 cell line-30 years later: its impact on natural killer cell research and treatment of cancer

The NK-92 cell line, established in 1992, mirrors all the characteristics of highly active blood natural killer (NK) cells but with much broader and greater cytotoxicity. The cell line was established from the blood cells of a patient with lymphoma and has been made widely available for research since it was deposited into the American Type Culture Collection in 1998. The worldwide distribution of NK-92 cells has led to a plethora of scientific discoveries that have greatly increased the understanding of NK-cell biology. NK-92 cells also have been developed for clinical use, overcoming the challenges of obtaining and expanding NK cells from donor or patient blood. More than 100 patients with cancer have now been treated all over the world with unmodified or genetically engineered NK-92 cells. Modified cells include high-affinity Fc-receptor expressing NK-92 cells (haNK^R) and various chimeric antigen receptor targeted haNK cells (t-haNK^TM). Infusions of either unmodified or modified NK-92 cells have been reported to be safe and efficacious, leading in some cases to disease remission even in patients who had failed multiple previous lines of therapy. It is the purpose of this review to distill the plethora of scientific data on NK-92 cells and its genetic variants, highlighting relevant experimental findings that have contributed to a better understanding of NK cell biology and summarize the therapeutic potential of these cells for treatment of cancer and infections.

Adoptive Cellular Therapy for Metastatic Melanoma: The Road to Commercialization and Treatment Guidelines for Clinicians

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has been gaining promise as a therapeutic option for metastatic melanoma. By harnessing the power of patients' tumor-resident lymphocytes, TIL therapy has shown promise in delivering durable, complete responses for patients who have progressed with other treatments, including checkpoint inhibition. This form of personalized medicine has traditionally been limited to select academic facilities with the infrastructure and resources to generate TIL cells and care for patients during the treatment phase. In this review, the authors discuss the role of TIL therapy for patients with metastatic melanoma, including the current state of therapeutic options, logistics of TIL harvest and infusion, management of infusion-specific toxicities, and foundational steps for surgeons and oncologists to establish cell-based therapies in individual hospitals and cancer centers.

Combination Nivolumab, CD137 Agonism, and Adoptive Cell Therapy with Tumor-Infiltrating Lymphocytes for Patients with Metastatic Melanoma

PURPOSE

Metastatic melanoma is a tumor amenable to immunotherapy in part due to the presence of antigen-specific tumor-infiltrating lymphocytes (TIL). These T cells can be activated and expanded for adoptive cell transfer (ACT), which has resulted in relatively high rates of clinical responses. Similarly, immune checkpoint inhibitors, specifically programmed cell death protein 1 (PD-1) blocking antibodies, augment antitumor immunity and increase the influx of T cells into tumors. Thus, we hypothesized that addition of PD-1 inhibition may improve the outcomes for patients undergoing ACT with TILs.

PATIENTS AND METHODS

Patients with stage III/IV metastatic melanoma with unresectable disease who were anti-PD-1 treatment-naïve were enrolled. TILs were generated in the presence of anti-4-1BB antibody in vitro and expanded for ACT. Patients in cohort 1 received TIL infusion followed by nivolumab. Patients in cohort 2 also received nivolumab prior to surgical harvest and during TIL production.

RESULTS

A total of 11 patients were enrolled, all of whom were evaluated for response, and nine completed ACT. Predominantly CD8+ TILs were successfully expanded from all ACT-treated patients and were tumor reactive in vitro. The trial met its safety endpoint, as there were no protocol-defined dose-limiting toxicity events. The objective response rate was 36%, and median progression-free survival was 5 months. Two nonresponders who developed new metastatic lesions were analyzed to determine potential mechanisms of therapeutic resistance, which included clonal divergence and intrinsic TIL dysfunction.

CONCLUSIONS

Combination therapy with TILs and nivolumab was safe and feasible for patients with metastatic melanoma and provides important insights for future therapeutic developments in ACT with TILs.

Facts and Hopes for Immunotherapy in Renal Cell Carcinoma

Immunotherapy has made a significant impact in many tumors, including renal cell carcinoma (RCC). RCC has been known to be immunoresponsive since the cytokine era of IFNα and IL2, but only a small number of patients had durable clinical benefit. Since then, discoveries of key tumor drivers, as well as an understanding of the contribution of angiogenesis and the tumor microenvironment (TME), has led to advances in drug development, ultimately transforming patient outcomes. Combinations of anti-angiogenic agents with immune checkpoint inhibitors are now standard of care. Current challenges include patient selection for immunotherapy combinations, resistance acquisition, and optimally sequencing therapies. Further discoveries about RCC biology, the TME, and resistance mechanisms will likely pave the way for the next generation of therapies.

Design and Validation of Inducible TurboCARsTM with Tunable Induction and Combinatorial Cytokine Signaling

Although cytokine support can enhance CAR T-cell function, co-administering cytokines or engineering CAR T cells to secrete cytokines can result in toxicities. To mitigate these safety risks, we engineered iTurboCARTM T cells that coexpress a novel inducible Turbo (iTurbo) cytokine signaling domain. iTurbo domains consist of modular components that are customizable to a variety of activating inputs, as well as cytokine signaling outputs multiplexable for combinatorial signaling outcomes. Unlike most canonical cytokine receptors that are heterodimeric, iTurbo domains leverage a compact, homodimeric design that minimizes viral vector cargo. Using an iTurbo domain activated by the clinically validated dimerizer, AP1903, homodimeric iTurbo domains instigated signaling that mimicked the endogenous heterodimeric cytokine receptor. Different iTurbo domains programmed iTurboCAR T cells towards divergent phenotypes and resulted in improved anti-tumor efficacy. iTurbo domains, therefore, offer the flexibility for user-programmable signaling outputs, permitting control over cellular phenotype and function, while minimizing viral cargo footprint.

Immune response and locoregional treatments for peritoneal carcinomatosis

Peritoneal Carcinomatosis (PC) is considered as a terminal disease with short survival. It is treated with palliative therapies, consisting of repeated drainages and sometimes instillation of chemotherapy. Since the nineties, surgery has been combined with more effective systemic chemotherapy, intraperitoneal chemotherapy and hyperthermic intraperitoneal chemotherapy (HIPEC) for the treatment of PC. This combination therapy significantly increases the overall survival of selected PC patients. The understanding of how intraperitoneal chemotherapy and HIPEC can cure patients is still unclear. Experts hypothesized that the efficacy is obtained by the ability of high peritoneal drug exposure and hyperthermia to directly kill cancer cells. Several studies indicate that cancer cells death directly influences the response of the immune system. For this reason, the protective effect of intraperitoneal chemotherapy and HIPEC could be mediated by its ability to kill cancer cells in an immuno-genic way, causing an efficient anticancer immune response. In this review, we investigate the role of the innate peritoneal or locoregional therapy-induced immune response in PC therapy.

Next Generation Natural Killer Cells for Cancer Immunotherapy

In recent years, immunotherapy for cancer has become mainstream with several products now authorized for therapeutic use in the clinic and are becoming the standard of care for some malignancies. Chimeric antigen receptor (CAR)-T cell therapies have demonstrated substantial efficacy for the treatment of hematological malignancies; however, they are complex and currently expensive to manufacture, and they can generate life-threatening adverse events such as cytokine release syndrome (CRS). The limitations of current CAR-T cells therapies have spurred an interest in alternative immunotherapy approaches with safer risk profiles and with less restrictive manufacturing constraints. Natural killer (NK) cells are a population of immune effector cells with potent anti-viral and anti-tumor activity; they have the capacity to swiftly recognize and kill cancer cells without the need of prior stimulation. Although NK cells are naturally equipped with cytotoxic potential, a growing body of evidence shows the added benefit of engineering them to better target tumor cells, persist longer in the host, and be fitter to resist the hostile tumor microenvironment (TME). NK-cell-based immunotherapies allow for the development of allogeneic off-the-shelf products, which have the potential to be less expensive and readily available for patients in need. In this review, we will focus on the advances in the development of engineering of NK cells for cancer immunotherapy. We will discuss the sourcing of NK cells, the technologies available to engineer NK cells, current clinical trials utilizing engineered NK cells, advances on the engineering of receptors adapted for NK cells, and stealth approaches to avoid recipient immune responses. We will conclude with comments regarding the next generation of NK cell products, i.e., armored NK cells with enhanced functionality, fitness, tumor-infiltration potential, and with the ability to overcome tumor heterogeneity and immune evasion.

New Developments in T Cell Immunometabolism and Implications for Cancer Immunotherapy

Despite rapid advances in the field of immunotherapy, the elimination of established tumors has not been achieved. Many promising new treatments such as adoptive cell therapy (ACT) fall short, primarily due to the loss of T cell effector function or the failure of long-term T cell persistence. With the availability of new tools and advancements in technology, our understanding of metabolic processes has increased enormously in the last decade. Redundancy in metabolic pathways and overlapping targets that could address the plasticity and heterogenous phenotypes of various T cell subsets have illuminated the need for understanding immunometabolism in the context of multiple disease states, including cancer immunology. Herein, we discuss the developing field of T cell immunometabolism and its crucial relevance to improving immunotherapeutic approaches. This in-depth review details the metabolic pathways and preferences of the antitumor immune system and the state of various metabolism-targeting therapeutic approaches.

Renal Cell Carcinoma and Kidney Transplantation: A Narrative Review

Kidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). The cancer can be encountered at different steps in the transplant process. RCC found during work-up of a transplant candidate needs treatment and to limit the risk of recurrence usually a mandatory observation period before transplantation is recommended. An observation period may be omitted for candidates with incidentally discovered and excised small RCCs (<3 cm). Likewise, RCC in the donor organ may not always preclude usage if tumor is small (<2 to 4 cm) and removed with clear margins before transplantation. After transplantation, 90% of RCCs are detected in the native kidneys, particularly if acquired cystic kidney disease has developed during prolonged dialysis. Screening for RCC after transplantation has not been found cost-effective. Treatment of RCC in KTRs poses challenges with adjustments of immunosuppression and oncologic treatments. For localized RCC, excision or nephrectomy is often curative. For metastatic RCC, recent landmark trials in the nontransplanted population demonstrate that immunotherapy combinations improve survival. Dedicated trials in KTRs are lacking. Case series on immune checkpoint inhibitors in solid organ recipients with a range of cancer types indicate partial or complete tumor response in approximately one-third of the patients at the cost of rejection developing in ~40%.

A Double-Edged Sword Role of Cytokines in Prostate Cancer Immunotherapy

Prostate cancer (PC) is one of the most common malignancies among men and is the second leading cause of cancer death. PC immunotherapy has taken relatively successful steps in recent years, and these treatments are still being developed and tested. Evidence suggests that immunotherapy using cytokines as essential mediators in the immune system may help treat cancer. It has been shown that cytokines play an important role in anti-tumor defense. On the other hand, other cytokines can also favor the tumor and suppress anti-tumor responses. Moreover, the dose of cytokine in cancer cytokine-based immunotherapy, as well as the side effects of high doses, can also affect the outcomes of treatment. Cytokines can also be determinative in the outcome of other immunotherapy methods used in PC. In this review, the role of cytokines in the pathogenesis of cancer and their impacts on the main types of immunotherapies in the treatment of PC are discussed.

Cell Therapy: Types, Regulation, and Clinical Benefits

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

Beyond Nicotinamide Metabolism: Potential Role of Nicotinamide N-Methyltransferase as a Biomarker in Skin Cancers

Skin cancers (SC) collectively represent the most common type of malignancy in white populations. SC includes two main forms: malignant melanoma and non-melanoma skin cancer (NMSC). NMSC includes different subtypes, namely, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), Merkel cell carcinoma (MCC), and keratoacanthoma (KA), together with the two pre-neoplastic conditions Bowen disease (BD) and actinic keratosis (AK). Both malignant melanoma and NMSC are showing an increasing incidence rate worldwide, thus representing an important challenge for health care systems, also because, with some exceptions, SC are generally characterized by an aggressive behavior and are often diagnosed late. Thus, identifying new biomarkers suitable for diagnosis, as well as for prognosis and targeted therapy is mandatory. Nicotinamide N-methyltransferase (NNMT) is an enzyme that is emerging as a crucial player in the progression of several malignancies, while its substrate, nicotinamide, is known to exert chemopreventive effects. Since there is increasing evidence regarding the involvement of this enzyme in the malignant behavior of SC, the current review aims to summarize the state of the art as concerns NNMT role in SC and to support future studies focused on exploring the diagnostic and prognostic potential of NNMT in skin malignancies and its suitability for targeted therapy.

The Immunotherapy Revolution in Kidney Cancer Treatment: Scientific Rationale and First-Generation Results

The recent discovery of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, including the treatment for renal cell carcinoma (RCC). Following the eras of cytokines and molecularly targeted therapies including vascular endothelial growth factor-directed agents and mammalian target of rapamycin (mTOR) inhibitors, ICIs have become the latest addition to the RCC armamentarium. To understand the scientific rationale behind this revolution in RCC treatment, we have reviewed the fundamental discoveries underlying the transition from old (cytokines) to new (ICIs) immunotherapies. We summarize the pivotal trials (CheckMate 025, CheckMate 214, KEYNOTE-426, JAVELIN Renal 101, IMmotion151) of checkpoint inhibitors for clear cell RCC in various treatment settings. With the availability of many different combination therapies and many more currently under investigation, clear cell RCC treatment is becoming more complex. Patient preferences, disease volumes, and adverse event profiles are essential in determining which option is the best for an individual patient. In the future, biomarkers currently under development could guide these treatment decisions.

Immersion in the search for effective cancer immunotherapies

Real innovations in medicine and science are historic and singular; the stories behind each occurrence are precious. At Molecular Medicine we have established the Anthony Cerami Award in Translational Medicine to document and preserve these histories. The monographs recount the seminal events as told in the voice of the original investigators who provided the crucial early insight. These essays capture the essence of discovery, chronicling the birth of ideas that created new fields of research and launched trajectories that persisted and ultimately influenced how disease is prevented, diagnosed, and treated. In this volume, the Cerami Award Monograph is by Steven A. Rosenberg, Chief of Surgery at the National Cancer Institute in Bethesda, Maryland, USA. A pioneer in the development of immunotherapies and gene therapies for advanced cancers, this is the story of Dr. Rosenberg’s scientific journey.

Advances in Lipid-Based Nanoparticles for Cancer Chemoimmunotherapy

Nanomedicines have shown great potential in cancer therapy; in particular, the combination of chemotherapy and immunotherapy (namely chemoimmunotherapy) that is revolutionizing cancer treatment. Currently, most nanomedicines for chemoimmunotherapy are still in preclinical and clinical trials. Lipid-based nanoparticles, the most widely used nanomedicine platform in cancer therapy, is a promising delivery platform for chemoimmunotherapy. In this review, we introduce the commonly used immunotherapy agents and discuss the opportunities for chemoimmunotherapy mediated by lipid-based nanoparticles. We summarize the clinical trials involving lipid-based nanoparticles for chemoimmunotherapy. We also highlight different chemoimmunotherapy strategies based on lipid-based nanoparticles such as liposomes, nanodiscs, and lipid-based hybrid nanoparticles in preclinical research. Finally, we discuss the challenges that have hindered the clinical translation of lipid-based nanoparticles for chemoimmunotherapy, and their future perspectives.

Utilizing Immunocytokines for Cancer Therapy

Cytokine therapy for cancer has indicated efficacy in certain diseases but is generally accompanied by severe toxicity. The field of antibody-cytokine fusion proteins (immunocytokines) arose to target these effector molecules to the tumor environment in order to expand the therapeutic window of cytokine therapy. Pre-clinical evidence has shown the increased efficacy and decreased toxicity of various immunocytokines when compared to their cognate unconjugated cytokine. These anti-tumor properties are markedly enhanced when combined with other treatments such as chemotherapy, radiotherapy, and checkpoint inhibitor antibodies. Clinical trials that have continued to explore the potential of these biologics for cancer therapy have been conducted. This review covers the in vitro, in vivo, and clinical evidence for the application of immunocytokines in immuno-oncology.

Sex-specific hormone changes during immunotherapy and its influence on survival in metastatic renal cell carcinoma

Renal cell carcinoma (RCC) is a highly vascularized and immunogenic tumor, being an ideal candidate for checkpoint blockade-based immunotherapy. Accordingly, checkpoint inhibitors have demonstrated clinical efficacy in patients with metastatic RCC (mRCC). Sex-specific differences in cancer immunotherapy may be explained by the interaction of sex hormone signaling, genetic and environmental factors, affecting the innate and adaptive immune response in men and women in different ways. The aim of this prospective study was to monitor for the first time changes in sex hormones including luteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH ratio and 17-ß-estradiol (E2) in 22 mRCC patients (12 male and 10 female) receiving nivolumab therapy. In contrast to female patients, male patients showed a significant increase in E2 (p = 0.006) and LH/FSH ratio (p = 0.013) from the beginning of nivolumab therapy to week 12 of follow-up. Moreover, survival analysis revealed a significant negative association between LH/FSH ratio and progression-free survival (PFS) (p = 0.022) as well as between therapy response (p = 0.009) in males compared to females at interim evaluation (week 6/8). Our findings may therefore be the first reference to sex hormone changes during immunotherapy.

Recent advances in the management of cutaneous malignant melanoma: our case cohort

Decades of research into the management of cutaneous malignant melanoma have proven it to be a 'tough nut to crack', and its incidence has continued to increase over the last 30 years. Surgery remains a gold standard for early-stage melanoma with five-year survival of 98% for stage I disease, and 90% for stage II. Nonetheless, patients with stage III disease are at a higher risk, resulting in local recurrence as well as distant metastasis. Research regarding the control of metastatic malignant melanoma of the head and neck has evolved. Currently the search is on to understand metastatic malignant melanoma as a heterogeneous disease both at the molecular and clinical level. This paper focuses on the latest systemic therapy for metastatic disease of the head and neck, including cytotoxic chemotherapy, immunotherapy, and target therapy. The new eighth edition of tumour staging, and the sequelae for malignant melanoma, sentinel lymph node biopsy (SLNB), surgical intervention, and its benefits and shortfalls, are discussed. Also, the outcome of our cohort series of patients with metastatic cutaneous malignant melanoma who were treated with systemic combination therapy in Dorset is presented.

On the Shoulders of Giants: The Evolution of Renal Cell Carcinoma Treatment-Cytokines, Targeted Therapy, and Immunotherapy

The treatment of advanced renal cell carcinoma (RCC) has evolved dramatically over the past 30 years, as has a better understanding of the biology of the disease, knowledge of multiple subtypes with distinct molecular abnormalities, and improved comprehension of the perturbed pathways that lead to the development and growth of RCC. This is no longer a monolithic disease, although the majority of tumors are of the clear cell subtype. However, progress is being made in other subtypes as well, as molecular profiles are better understood and as new agents show activity. Immunotherapies remain a major category of treatment, from cytokines to checkpoint inhibitors to ex vivo activated cellular therapy. Antiangiogenesis tyrosine kinase inhibitors are also an important part of the armamentarium. Because these approaches have evolved, we are now in the era of combination therapy using agents of differing mechanisms to try to achieve synergy to increase response rates and create durable responses leading to prolonged survival. Renal cell carcinoma as a tumor is unique in that there has always been a subset of patients who achieve complete responses that last for many years without subsequent treatment. Thus, the goal of further development is to enlarge this subset using new therapeutic approaches and to achieve further durable responses and treatment-free survival.

Cryopreservation impairs 3-D migration and cytotoxicity of natural killer cells

Natural killer (NK) cells are important effector cells in the immune response to cancer. Clinical trials on adoptively transferred NK cells in patients with solid tumors, however, have thus far been unsuccessful. As NK cells need to pass stringent safety evaluation tests before clinical use, the cells are cryopreserved to bridge the necessary evaluation time. Standard degranulation and chromium release cytotoxicity assays confirm the ability of cryopreserved NK cells to kill target cells. Here, we report that tumor cells embedded in a 3-dimensional collagen gel, however, are killed by cryopreserved NK cells at a 5.6-fold lower rate compared to fresh NK cells. This difference is mainly caused by a 6-fold decrease in the fraction of motile NK cells after cryopreservation. These findings may explain the persistent failure of NK cell therapy in patients with solid tumors and highlight the crucial role of a 3-D environment for testing NK cell function.

Colorectal Cancer Immunotherapy: Options and Strategies

Colorectal cancer is the third most common cancer in the world with increasing incidence and mortality rates globally. Standard treatments for colorectal cancer have always been surgery, chemotherapy and radiotherapy which may be used in combination to treat patients. However, these treatments have many side effects due to their non-specificity and cytotoxicity toward any cells including normal cells that are growing and dividing. Furthermore, many patients succumb to relapse even after a series of treatments. Thus, it is crucial to have more alternative and effective treatments to treat CRC patients. Immunotherapy is one of the new alternatives in cancer treatment. The strategy is to utilize patients' own immune systems in combating the cancer cells. Cancer immunotherapy overcomes the issue of specificity which is the major problem in chemotherapy and radiotherapy. The normal cells with no cancer antigens are not affected. The outcomes of some cancer immunotherapy have been astonishing in some cases, but some which rely on the status of patients' own immune systems are not. Those patients who responded well to cancer immunotherapy have a better prognostic and better quality of life.

The immunology of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and comprises several subtypes with unique characteristics. The most common subtype (~70% of cases) is clear-cell RCC. RCC is considered to be an immunogenic tumour but is known to mediate immune dysfunction in large part by eliciting the infiltration of immune-inhibitory cells, such as regulatory T cells and myeloid-derived suppressor cells, into the tumour microenvironment. Several possible mechanisms have been proposed to explain how these multiple tumour-infiltrating cell types block the development of an effective anti-tumour immune response, including inhibition of the activity of effector T cells and of antigen presenting cells via upregulation of suppressive factors such as checkpoint molecules. Targeting immune suppression using checkpoint inhibition has resulted in clinical responses in some patients with RCC and combinatorial approaches involving checkpoint blockade are now standard of care in patients with advanced RCC. However, a substantial proportion of patients do not benefit from checkpoint blockade. The identification of reliable biomarkers of response to checkpoint blockade is crucial to facilitate improvements in the clinical efficacy of these therapies. In addition, there is a need for the development of other immune-based strategies that address the shortcomings of checkpoint blockade, such as adoptive cell therapies.

CAR T cells: continuation in a revolution of immunotherapy

The recent clinical successes of immunotherapy, as a result of a broader and more profound understanding of cancer immunobiology, and the leverage of this knowledge to effectively eradicate malignant cells, has revolutionised the field of cancer therapeutics. Immunotherapy is now considered the fifth pillar of cancer care, alongside surgery, chemotherapy, radiotherapy, and targeted therapy. Recently, the success of genetically modified T cells that express chimeric antigen receptors (CAR T cells) has generated considerable excitement. CAR T-cell therapy research and development has built on experience generated by laboratory research and clinical investigation of lymphokine-activated killer cells, tumour-infiltrating lymphocytes, and allogeneic haemopoietic stem-cell transplantation for cancer treatment. This Review aims to provide a background on the field of adoptive T-cell therapy and the development of genetically modified T cells, most notably CAR T-cell therapy. Many challenges exist to optimise efficacy, minimise toxicity, and broaden the application of immunotherapies based on T cells.

Development and characterisation of NKp44-based chimeric antigen receptors that confer T cells with NK cell-like specificity

Objectives

One of the reasons as to why chimeric antigen receptors (CAR)-T cell therapy for malignancies other than CD19- or BCMA-positive tumors has yet to produce remarkable progress is the paucity of targetable antigens. NKp44 is only expressed by activated natural killer cells and detects a variety of transformed cells, while it reportedly does not react with normal tissues. The aim of this study is to develop CAR-T cell that can target multiple types of tumor cells.

Methods

We created a series of novel CAR constructs in first-generation (1G) and second-generation (2G) CAR format with the extracellular immunoglobulin-like domain of NKp44 (NKp44-CAR).

Results

Transduction of the best 1G construct into human primary T cells led to specific cytotoxic effects and cytokine secretion upon encountering multiple types of neoplastic cells including AML, T-ALL and childhood solid tumors. Replacement of the extracellular hinge domain of NKp44 with that of CD8α resulted in diminished CAR function. The 1G NKp44-CAR-T cells exhibited significantly better tumor control in long-term co-culture assays compared with activated NK cells, as well as with NK cells transduced with identical NKp44-CAR. T cells transduced with the best 2G-CAR construct with 4-1BB co-stimulatory domain proliferated at significantly higher levels upon single antigen exposure and showed significantly better tumor control compared with the 1G-CAR and 2G-CAR with CD28 co-stimulatory domain.

Conclusions

NKp44-based CAR endows T cells with NK cell-like anti-tumor specificity. The CAR gene created in this study will be useful for the development of novel gene-modified T-cell immunotherapy.

Gut Bacteria Composition Drives Primary Resistance to Cancer Immunotherapy in Renal Cell Carcinoma Patients

BACKGROUND

The development of immune checkpoint blockade (ICB) has revolutionized the clinical outcome of renal cell carcinoma (RCC). Nevertheless, improvement of durability and prediction of responses remain unmet medical needs. While it has been recognized that antibiotics (ATBs) decrease the clinical activity of ICB across various malignancies, little is known about the direct impact of distinct intestinal nonpathogenic bacteria (commensals) on therapeutic outcomes of ICB in RCC.

OBJECTIVE

To evaluate the predictive value of stool bacteria composition for ICB efficacy in a cohort of advanced RCC patients.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively collected fecal samples from 69 advanced RCC patients treated with nivolumab and enrolled in the GETUG-AFU 26 NIVOREN microbiota translational substudy phase 2 trial (NCT03013335) at Gustave Roussy. We recorded patient characteristics including ATB use, prior systemic therapies, and response criteria. We analyzed 2994 samples of feces from healthy volunteers (HVs). In parallel, preclinical studies performed in RCC-bearing mice that received fecal transplant (FMT) from RCC patients resistant to ICB (NR-FMT) allowed us to draw a cause-effect relationship between gut bacteria composition and clinical outcomes for ICB. The influence of tyrosine kinase inhibitors (TKIs) taken before starting nivolumab on the microbiota composition has also been assessed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Metagenomic data (MG) from whole genome sequencing (WGS) were analyzed by multivariate and pairwise comparisons/fold ratio to identify bacterial fingerprints related to ATB or prior TKI exposure and patients' therapeutic response (overall response and progression-free survival), and compared with the data from cancer-free donors.

RESULTS AND LIMITATIONS

Recent ATB use (n = 11; 16%) reduced objective response rates (from 28% to 9%, p < 0.03) and markedly affected the composition of the microbiota, facilitating the dominance of distinct species such as Clostridium hathewayi, which were also preferentially over-represented in stools from RCC patients compared with HVs. Importantly, TKIs taken prior to nivolumab had implications in shifting the microbiota composition. To establish a cause-effect relationship between gut bacteria composition and ICB efficacy, NR-FMT mice were successfully compensated with either FMT from responding RCC patients or beneficial commensals identified by WGS-MG (Akkermansia muciniphila and Bacteroides salyersiae).

CONCLUSIONS

The composition of the microbiota is influenced by TKIs and ATBs, and impacts the success of immunotherapy. Future studies will help sharpen the role of these specific bacteria and their potential as new biomarkers.

PATIENT SUMMARY

We used quantitative shotgun DNA sequencing of fecal microbes as well as preclinical models of fecal or bacterial transfer to study the association between stool composition and (pre)clinical outcome to immune checkpoint blockade. Novel insights into the pathophysiological relevance of intestinal dysbiosis in the prognosis of kidney cancer may lead to innovative therapeutic solutions, such as supplementation with probiotics to prevent primary resistance to therapy.

Common gamma chain cytokines and CD8 T cells in cancer

Overcoming exhaustion-associated dysfunctions and generating antigen-specific CD8 T cells with the ability to persist in the host and mediate effective long-term anti-tumor immunity is the final aim of cancer immunotherapy. To achieve this goal, immuno-modulatory properties of the common gamma-chain (γ_c) family of cytokines, that includes IL-2, IL-7, IL-15 and IL-21, have been used to fine-tune and/or complement current immunotherapeutic protocols. These agents potentiate CD8 T cell expansion and functions particularly in the context of immune checkpoint (IC) blockade, shape their differentiation, improve their persistence in vivo and alternatively, influence distinct aspects of the T cell exhaustion program. Despite these properties, the intrinsic impact of cytokines on CD8 T cell exhaustion has remained largely unexplored impeding optimal therapeutic use of these agents. In this review, we will discuss current knowledge regarding the influence of relevant γ_c cytokines on CD8 T cell differentiation and function based on clinical data and preclinical studies in murine models of cancer and chronic viral infection. We will restate the place of these agents in current immunotherapeutic regimens such as IC checkpoint blockade and adoptive cell therapy. Finally, we will discuss how γ_c cytokine signaling pathways regulate T cell immunity during cancer and whether targeting these pathways may sustain an effective and durable T cell response in patients.

And Now for Something Completely Different: Immunotherapy Beyond Checkpoints in Melanoma

Advances in the understanding of biology and therapy of melanoma have occurred at an astonishing pace over the past approximately 15 years, and successful melanoma therapy has led the way for similar advances in many other solid tumors that are continuing to improve outcomes for all patients with cancer. Although the 2018 Nobel Prize was awarded to two investigators who discovered that therapeutic targeting of immune checkpoints held the key to major patient benefits, there are many additional immunotherapeutic strategies that warrant further study and discussion at scientific and medical meetings. This article provides the newest information on three areas of immunotherapy that have been successfully applied to melanoma and continue to pave the way for new developments: cytokines, adoptive cell therapies (ADTs), and intratumoral injection of immunomodulatory agents.

Pretreatment Innate Cell Populations and CD4 T Cells in Blood Are Associated With Response to Immune Checkpoint Blockade in Melanoma Patients

The development of changes in T cells, referred to as T cell exhaustion, has been suggested as a cause of primary or acquired resistance to immunotherapy by immune checkpoint blockade (ICB). A limited number of studies, largely performed on tumor infiltrating lymphocytes (TILs), has provided evidence in support of this hypothesis, but whether similar changes occur in circulating blood lymphocytes has received little attention. In the present study, a comprehensive analysis of peripheral blood leukocytes from 42 patients taken over the course of treatment with anti-PD-1 was undertaken. The patients included those grouped as responders (who did not progress), primary non-responders (primary resistance) and those with acquired resistance (who initially responded then subsequently progressed). Analysis included surface markers of exhaustion, production of cytokines following in vitro stimulation, and assessment of transcription factor levels associated with T cell exhaustion. There were differences in innate cell populations between responders and non-responders at baseline and maintained throughout therapy. Frequencies of total and classical CD14⁺CD16^- monocytes were higher and the major subset of NK cells (CD16^hiCD56⁺) was significantly smaller in the primary resistance group compared with responders. However, differences in peripheral blood expression of exhaustion markers were not evident between the treatment groups. T cell exhaustion markers were expressed in practically all patients and the major observation was an increase in CD39 on CD4 T cells during treatment. The results confirm the association of Eomes transcription factor with T cell exhaustion but levels of expression and the ratio with T-bet over Eomes did not differ between the patient groups. Thus, peripheral blood expression of T cell exhaustion markers does not distinguish between responders and non-responders to anti-PD-1 therapy. CD4 T cell expression of IFNγ also differed in pre-treatment samples, indicating that predictors of response unrelated to exhaustion may be present in peripheral blood. The association of response with innate cell populations and CD4 T cell responses requires further study.

PD-1/PD-L1 Blockade Therapy in Advanced Non-Small-Cell Lung Cancer: Current Status and Future Directions

This article summarizes the latest clinical applications of PD‐1/PD‐L1 blockade therapy in advanced non‐small cell lung cancer (NSCLC) worldwide and in China, reporting the bottlenecks related to the use of this therapy in clinic. An exploration of the underlying mechanism of PD‐1/PD‐L1 blockade therapy and biomarker identification will maximize the application of immune checkpoint inhibitors in advanced NSCLC and facilitate bedside‐to‐bench studies in cancer immunotherapy.

The use of immune checkpoint inhibitors (ICIs) has become one of the most promising approaches in the field of cancer therapy. Unlike the current therapies that target tumor cells, such as chemotherapy, radiotherapy, or targeted therapy, ICIs directly restore the exhausted host antitumor immune responses mediated by the tumors. Among multiple immune modulators identified, the programmed cell death protein 1 (PD‐1)/programmed cell death protein ligand 1 (PD‐L1) axis leading to the exhaustion of T‐cell immunity in chronic infections and tumors has been widely investigated. Therefore, blocking antibodies targeting PD‐1 or PD‐L1 have been developed and approved for the treatment of various advanced cancers, including non‐small‐cell lung cancer (NSCLC), making them the most successful ICIs. Compared with chemotherapy or radiotherapy, PD‐1/PD‐L1 blockade therapy significantly improves the durable response rate and prolongs long‐term survival with limited adverse effects in both monotherapy and combination therapy for advanced NSCLC. However, extensive challenges exist for further clinical applications, such as a small fraction of benefit population, primary and acquired resistance, the lack of predictive and prognostic biomarkers, and treatment‐related adverse effects. In this article, we summarize the latest clinical applications of PD‐1/PD‐L1 blockade therapy in advanced NSCLC worldwide, as well as in China, and discuss the bottlenecks related to the use of this therapy in clinical practice. An exploration of the underlying mechanism of PD‐1/PD‐L1 blockade therapy and biomarker identification will maximize the application of ICIs in advanced NSCLC and facilitate bedside‐to‐bench studies in cancer immunotherapy as well.

Implications for Practice.

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD‐1) and programmed cell death protein ligand 1 (PD‐L1) display apparent benefits for the treatment of advanced non‐small‐cell lung cancer (NSCLC). However, the clinical applications of these therapies are challenged by the limited benefit population with additional high economic burden and adverse events. This review discusses the bottlenecks of ICI therapy in clinical practice and provides appropriate guidance in the development of predictive biomarkers, the establishment of the criteria for combining PD‐1/PD‐L1 blockade therapy with the existing therapies, and the management of adverse events observed both in monotherapy and combination therapy, which will help maximize the applications of ICIs in advanced NSCLC.

Engineering Newcastle Disease Virus as an Oncolytic Vector for Intratumoral Delivery of Immune Checkpoint Inhibitors and Immunocytokines

Newcastle disease virus (NDV) is an attractive candidate for oncolytic immunotherapy due to its ability to replicate in tumor cells and potentially to overcome the inherently immunosuppressive nature of the tumor microenvironment. The advent of checkpoint blockade immunotherapy over the past few years represents a paradigm shift in cancer therapy. However, the prevalence of severe immune-related adverse events with CTLA4 and PD1 pathway blockade in clinical studies, especially in combination therapy groups, is a cause for concern. Immunotherapies with cytokines have also been extensively explored, but they have been associated with adverse events in clinical trials. Oncolytic vectors engineered to express checkpoint blockade antibodies and cytokines could provide an avenue for reducing the clinical toxicity associated with systemic therapy by concentrating the immunomodulatory payload at the site of disease. In this study, we engineered six different recombinant viruses: NDVs expressing checkpoint inhibitors (rNDV-anti-PD1 and rNDV-anti-PDL1); superagonists (rNDV-anti-CD28); and immunocytokines, where the antibodies are fused to an immunostimulatory cytokine, such as interleukin 12 (IL-12) (rNDV-anti-CD28-murine IL-12 [mIL-12], rNDV-anti-PD1-mIL-12, and rNDV-anti-PDL1-mIL-12). These six engineered viruses induced tumor control and survival benefits in both highly aggressive unilateral and bilateral B16-F10 murine melanoma models, indicative of an abscopal effect. The data represent a strong proof of concept on which further clinical evaluation could build.IMPORTANCE Checkpoint inhibitor therapy has shown tremendous efficacy, but also frequent and often severe side effects-especially when multiple drugs of the class are used simultaneously. Similarly, many investigational immunotherapy agents, which have shown promise in animal models, have failed in clinical trials due to dose-limiting toxicity when administered systemically. This study utilized a murine melanoma model to evaluate the efficacy of intratumoral injections of recombinant NDVs engineered to express multiple immunotherapeutic proteins with well-documented side effects in humans. Our results indicate that intratumoral administration of these recombinant NDVs, particularly when combined with systemic CTLA4 checkpoint inhibition, exerts a robust effect in treated and nontreated tumors, indicative of a systemic antitumoral response. The intratumoral delivery of rNDVs expressing immunotherapeutic proteins may be an effective method of targeting the immune cell populations most relevant for antitumoral immunity and allowing us to restrict the use of systemic immunotherapy agents.

Targeting Cancer with Genetically Engineered TCR T Cells

The adoptive cell transfer (ACT) of genetically engineered T cell receptor (TCR) T cells is one of the burgeoning fields of immunotherapy, with promising results in current clinical trials. Presently, clinicaltrials.gov has over 200 active trials involving adoptive cell therapy. The ACT of genetically engineered T cells not only allows the ability to select for TCRs with desired properties such as high-affinity receptors and tumor reactivity but to further enhance those receptors allowing for better targeting and killing of cancer cells in patients. Moreover, the addition of genetic material, including cytokines and cytokine receptors, can increase the survival and persistence of the T cell allowing for complete and sustained remission of cancer targets. The potential for improvement in adoptive cell therapy is limitless, with genetic modifications targeting to improve weaknesses of ACT and to thus enhance receptor affinity and functional avidity of the genetically engineered T cells.

The CD26/DPP4-inhibitor vildagliptin suppresses lung cancer growth via macrophage-mediated NK cell activity

CD26/dipeptidyl peptidase 4 (DPP4) is a transmembrane protein which is expressed by various malignant cells. We found that the expression of CD26/DPP4 was significantly higher in lung adenocarcinoma samples in our own patient cohort compared to normal lung tissue. We therefore hypothesize that the inhibition of CD26/DPP4 can potentially suppress lung cancer growth. The CD26/DPP4 inhibitor vildagliptin was employed on Lewis Lung Carcinoma (LLC) cell line and a human lung adenocarcinoma (H460) cell line. Two weeks after subcutaneous injection of tumor cells into C57BL/6 and CD1/nude mice, the size of LLC and H460 tumors was significantly reduced by vildagliptin. Immunohistochemically, the number of macrophages (F4/80+) and NK cells (NKp46+) was significantly increased in vildagliptin-treated tumor samples. Mechanistically, we found in vitro that lung cancer cell lines expressed increased levels of surfactant protein upon vildagliptin treatment thereby promoting the pro-inflammatory activity of macrophages. By the depletion of macrophages with clodronate and by using NK cell deficient (IL-15-/-) mice, tumors reversed to the size of controls, suggesting that indeed macrophages and NK cells were responsible for the observed tumor-suppressing effect upon vildagliptin treatment. FACS analysis showed tumor-infiltrating NK cells to express tumor necrosis-related apoptosis-inducing ligand (TRAIL) which induced the intra-cellular stress marker γH2AX. Accordingly, we found upregulated γH2AX in vildagliptin-treated tumors and TRAIL-treated cell lines. Moreover, the effect of vildagliptin-mediated enhanced NK cell cytotoxicity could be reversed by antagonizing the TRAIL receptor. Our data provide evidence that the CD26/DPP4-inhibitor vildagliptin reduces lung cancer growth. We could demonstrate that this effect is exerted by surfactant-activated macrophages and NK cells that act against the tumor via TRAIL-mediated cytotoxicity.

NK cell-based therapeutics for lung cancer

Introduction: Lung cancer is a devastating disease with poor overall survival. Despite significant advances in the treatment of lung cancers using radiochemotherapy, targeted therapies and/or immune therapies prognosis remains poor. The capacity of natural killer (NK) cells to provide a first line of defense that can bridge and orchestrate innate and 'downstream' adaptive immune responses renders them to be an ideal platform on which to base new cancer therapeutics.Areas covered: We provide an overview of the mechanisms controlling the effector functions of NK cells, tumor-directed immune escape, the impact and influence of NK cells on the development of effective, protective anti-tumor immunity and the therapeutic potential of combined cytokine-, complement-dependent- and antibody-dependent cellular cytotoxicity (CDC/ADCC), NK-92-, KIR mismatch- and CAR-NK cell-based therapies.Expert opinion: Despite promising results of immuno-oncological approaches, a relevant proportion of patients do not profit from these therapies, partly due to an ineffective NK cell activation, a lack of tumor-specific NK cells, an upregulated expression of checkpoint pathways, and a low mutational burden, which hinders the development of long-term adaptive immunity. Strategies that re-activate NK cells in combination with other therapies are therefore likely to be beneficial for the clinical outcome of patients with lung cancer.Abbreviations: ADCC: antibody-dependent cell-mediated cytotoxicity; ALK: anaplastic lymphoma kinase; CAR: chimeric antigen receptor; CDC: complement-dependent cytotoxicity; CEACAM-1: carcinoembryonic antigen-related cell adhesion molecule 1; DC: dendritic cell; DNAM: activating, maturation receptor; EGFR, epidermal growth factor receptor; EMT: epithelial-to-mesenchymal transition; EpCAM: epithelial cell adhesion molecule; GM-CSF: granulocyte monocyte colony stimulating factor; HIF: hypoxia inducible factor; IDO, indoleamine 2,3-dioxygenase; IFN: interferon; IL: interleukin; ITIM/ITAM: immune tyrosine-based inhibitory/activatory motif; KIR: killer cell immunoglobulin-like receptor; LAG-3: lymphocyte activation gene 3; MDSC: myeloid derived suppressor cells; MICA/B: MHC class I-related proteins A/B; MHC: major histocompatibility complex; mTOR: mechanistic target of rapamycin; NCAM: neuronal adhesion molecule; NCR: natural cytotoxicity receptor; NK: natural killer; NSCLC: non-small cell lung cancer; PD-1: programmed cell death 1; PS: phosphatidylserine; SCLC: small cell lung cancer; STAT: signal transducer and activator of transcription; TAM: tumor-associated M2 macrophages; TCR: T cell receptor; TIGIT: T cell immunoglobulin and ITIM domain; Tim-3: T cell immunoglobulin- and mucin domain-containing 3; TNF: tumor necrosis factor; ULBP: UL16-binding protein.

Immune-checkpoint inhibitors for the treatment of metastatic melanoma: a model of cancer immunotherapy

Melanoma has always been described as an immunogenic tumor. Despite that, until 2011 the standard of care in metastatic melanoma was chemotherapy, with low response rates and no clear impact on overall survival. Melanoma was the first cancer type to drive the use of immune-checkpoint inhibitors into clinical practice, which revolutionized the therapeutic paradigm not only in melanoma, but also in an increasing number of tumors. In this review, the preclinical bases and the main clinical studies that led to the approval of immune-checkpoint inhibitors in advanced melanoma will be described with insights on novel combinations of treatments and on prognostic and predictive biomarkers.

Cryopreserved Human Natural Killer Cells Exhibit Potent Antitumor Efficacy against Orthotopic Pancreatic Cancer through Efficient Tumor-Homing and Cytolytic Ability (Running Title: Cryopreserved NK Cells Exhibit Antitumor Effect)

Pancreatic cancer is known to be highly aggressive, and desmoplasia-induced accumulation of extracellular matrix (ECM), which is a hallmark of many pancreatic cancers, severely restricts the therapeutic efficacy of both immunotherapeutics and conventional chemotherapeutics due to the ECM functioning as a major physical barrier against permeation and penetration. In the case of cell-based immunotherapeutics, there are several other bottlenecks preventing translation into clinical use due to their biological nature; for example, poor availability of cell therapeutic in a readily usable form due to difficulties in production, handling, shipping, and storage. To address these challenges, we have isolated allogeneic natural killer (NK) cells from healthy donors and expanded them in vitro to generate cryopreserved stocks. These cryopreserved NK cells were thawed to evaluate their therapeutic efficacy against desmoplastic pancreatic tumors, ultimately aiming to develop a readily accessible and mass-producible off-the-shelf cell-based immunotherapeutic. The cultured NK cells post-thawing retained highly pure populations of activated NK cells that expressed various activating receptors and a chemokine receptor. Furthermore, systemic administration of NK cells induced greater in vivo tumor growth suppression when compared with gemcitabine, which is the standard chemotherapeutic used for pancreatic cancer treatment. The potent antitumor effect of NK cells was mediated by efficient tumor-homing ability and infiltration into desmoplastic tumor tissues. Moreover, the infiltration of NK cells led to strong induction of apoptosis, elevated expression of the antitumor cytokine interferon (IFN)-γ, and inhibited expression of the immunosuppressive transforming growth factor (TGF)-β in tumor tissues. Expanded and cryopreserved NK cells are strong candidates for future cell-mediated systemic immunotherapy against pancreatic cancer.

An Update on Adoptive T-Cell Therapy and Neoantigen Vaccines

Adoptive T-cell therapy using tumor-infiltrating lymphocytes (TILs) has demonstrated long-lasting antitumor activity in select patients with advanced melanoma. Cancer vaccines have been used for many decades and have shown some promise but overall relatively modest clinical activity across cancers. Technological advances in genome sequencing capabilities and T-cell engineering have had substantial impact on both adoptive cell therapy and the cancer vaccine field. The ability to identify neoantigens-a class of tumor antigens that is truly tumor specific and encoded by tumor mutations through rapid and relatively inexpensive next-generation sequencing-has already demonstrated the critical importance of these antigens as targets of antitumor-specific T-cell responses in the context of immune checkpoint blockade and other immunotherapies. Therapeutically targeting these antigens with either adoptive T-cell therapy or vaccine approaches has demonstrated early promise in the clinic in patients with advanced solid tumors. Chimeric antigen receptor (CAR) T cells, which are engineered by fusing an antigen-specific, single-chain antibody (scFv) with signaling molecules of the T-cell receptor (TCR)/CD3 complex creating an antibody-like structure on T cells that recognizes antigens independently of major histocompatibility complex (MHC) molecules, have demonstrated remarkable clinical activity in patients with advanced B-cell malignancies, leading to several approvals by the U.S. Food and Drug Administration (FDA).

Medical Options for the Adjuvant Treatment and Management of Pediatric Melanoma

Although melanoma is a rare diagnosis in the pediatric population, advances in the management of adults with melanoma offer the prospect of promising therapeutic options for children. At this time, medical management is not considered curative but may reduce the risk of recurrence or prolong survival. Surgical management remains the mainstay of treatment. Medical therapy of pediatric melanoma is not thought to have a role for in situ, early-stage, or localized disease, but adjuvant therapy may have a role in improving the prognosis of patients with positive sentinel lymph node biopsy (SLNB), spread beyond the regional lymph node basin, metastatic disease, or recurrent disease. Medical treatment options include immunotherapies, particularly checkpoint inhibitors, and targeted therapies, which have provided improved toxicity profiles compared with traditional chemotherapy regimens in the setting of advanced disease. There is a growing body of pediatric-specific data relevant to the use of adjuvant therapies for advanced melanoma in children.

Combining Immune Checkpoint Inhibitors: Established and Emerging Targets and Strategies to Improve Outcomes in Melanoma

The immune system employs several checkpoint pathways to regulate responses, maintain homeostasis and prevent self-reactivity and autoimmunity. Tumor cells can hijack these protective mechanisms to enable immune escape, cancer survival and proliferation. Blocking antibodies, designed to interfere with checkpoint molecules CTLA-4 and PD-1/PD-L1 and counteract these immune suppressive mechanisms, have shown significant success in promoting immune responses against cancer and can result in tumor regression in many patients. While inhibitors to CTLA-4 and the PD-1/PD-L1 axis are well-established for the clinical management of melanoma, many patients do not respond or develop resistance to these interventions. Concerted efforts have focused on combinations of approved therapies aiming to further augment positive outcomes and survival. While CTLA-4 and PD-1 are the most-extensively researched targets, results from pre-clinical studies and clinical trials indicate that novel agents, specific for checkpoints such as A2AR, LAG-3, IDO and others, may further contribute to the improvement of patient outcomes, most likely in combinations with anti-CTLA-4 or anti-PD-1 blockade. This review discusses the rationale for, and results to date of, the development of inhibitory immune checkpoint blockade combination therapies in melanoma. The clinical potential of new pipeline therapeutics, and possible future therapy design and directions that hold promise to significantly improve clinical prognosis compared with monotherapy, are discussed.

The challenges and molecular approaches surrounding interleukin-2-based therapeutics in cancer

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IL2-based cancer therapies are limited by their toxicity and pleiotropy.

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Current engineering approaches target IL2 half-life and cell/receptor specificity.

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IL2 may enhance the efficacy of checkpoint inhibitors and CAR-T-based therapies.

Interleukin-2 has had a long history as a promising cancer therapeutic, being capable of eliciting complete and durable remissions in patients with metastatic renal cell carcinoma and metastatic melanoma. Despite high toxicity and efficacy limited to only certain patient subpopulations and cancer types, the prospective use of novel, engineered IL2 formats in combination with the presently expanding repertoire of immuno-oncological targets remains very encouraging. This is possible due to the significant research efforts in the IL2 field that have yielded critical structural and biological insights that have made IL2 more effective and more broadly applicable in the clinic. In this review, we discuss some of the molecular approaches that have been used to further improve IL2 therapy for cancer.

Overcoming Resistance to Natural Killer Cell Based Immunotherapies for Solid Tumors

Despite advances in the diagnostic and therapeutic modalities, the prognosis of several solid tumor malignancies remains poor. Different factors associated with solid tumors including a varied genetic signature, complex molecular signaling pathways, defective cross talk between the tumor cells and immune cells, hypoxic and immunosuppressive effects of tumor microenvironment result in a treatment resistant and metastatic phenotype. Over the past several years, immunotherapy has emerged as an attractive therapeutic option against multiple malignancies. The unique ability of natural killer (NK) cells to target cancer cells without antigen specificity makes them an ideal candidate for use against solid tumors. However, the outcomes of adoptive NK cell infusions into patients with solid tumors have been disappointing. Extensive studies have been done to investigate different strategies to improve the NK cell function, trafficking and tumor targeting. Use of cytokines and cytokine analogs has been well described and utilized to enhance the proliferation, stimulation and persistence of NK cells. Other techniques like blocking the human leukocyte antigen-killer cell receptors (KIR) interactions with anti-KIR monoclonal antibodies, preventing CD16 receptor shedding, increasing the expression of activating NK cell receptors like NKG2D, and use of immunocytokines and immune checkpoint inhibitors can enhance NK cell mediated cytotoxicity. Using genetically modified NK cells with chimeric antigen receptors and bispecific and trispecific NK cell engagers, NK cells can be effectively redirected to the tumor cells improving their cytotoxic potential. In this review, we have described these strategies and highlighted the need to further optimize these strategies to improve the clinical outcome of NK cell based immunotherapy against solid tumors.