Cancer biotherapy: review and prospect

Malignant tumors pose a grave threat to the quality of human life. The prevalence of malignant tumors in China is steadily rising. Presently, clinical interventions encompass surgery, radiotherapy, and pharmaceutical therapy in isolation or combination. Nonetheless, these modalities fail to completely eradicate malignant tumor cells, frequently leading to metastasis and recurrence. Conversely, tumor biotherapy has emerged as an encouraging fourth approach in preventing and managing malignant tumors owing to its safety, efficacy, and minimal adverse effects. Currently, a range of tumor biotherapy techniques are employed, including gene therapy, tumor vaccines, monoclonal antibody therapy, cancer stem cell therapy, cytokine therapy, and adoptive cellular immunotherapy. This study aims to comprehensively review the latest developments in biological treatments for malignant tumors.

Molecular insight into renal cancer and latest therapeutic approaches to tackle it: an updated review

Renal cell carcinoma (RCC) is one of the most lethal genitourinary cancers, with the highest mortality rate, and may remain undetected throughout its development. RCC can be sporadic or hereditary. Exploring the underlying genetic abnormalities in RCC will have important implications for understanding the origins of nonhereditary renal cancers. The treatment of RCC has evolved over centuries from the era of cytokines to targeted therapy to immunotherapy. A surgical cure is the primary treatment modality, especially for organ-confined diseases. Furthermore, the urologic oncology community focuses on nephron-sparing surgical approaches and ablative procedures when small renal masses are detected incidentally in conjunction with interventional radiologists. In addition to new combination therapies approved for RCC treatment, several trials have been conducted to investigate the potential benefits of certain drugs. This may lead to durable responses and more extended survival benefits for patients with metastatic RCC (mRCC). Several approved drugs have reduced the mortality rate of patients with RCC by targeting VEGF signaling and mTOR. This review better explains the signaling pathways involved in the RCC progression, oncometabolites, and essential biomarkers in RCC that can be used for its diagnosis. Further, it provides an overview of the characteristics of RCC carcinogenesis to assist in combating treatment resistance, as well as details about the current management and future therapeutic options. In the future, multimodal and integrated care will be available, with new treatment options emerging as we learn more about the disease.

Mechanisms and clinical implications in renal carcinoma resistance: narrative review of immune checkpoint inhibitors

Clear cell renal cell carcinoma (ccRCC) is the most common histological subtype of renal cell carcinoma. The prognosis for patients with ccRCC has improved over recent years with the use of combination therapies with an anti-programmed death-1 (PD-1) backbone. This has enhanced the quality of life and life expectancy of patients with this disease. Unfortunately, not all patients benefit; eventually, most patients will develop resistance to therapy and progress. Recent molecular, biochemical, and immunological research has extensively researched anti-angiogenic and immune-based treatment resistance mechanisms. This analysis offers an overview of the principles underpinning the resistance pathways related to immune checkpoint inhibitors (ICIs). Additionally, novel approaches to overcome resistance that may be considered for the trial context are discussed.

Immunotherapy in non-small cell lung cancer: Past, present, and future directions

Many decades in the making, immunotherapy has demonstrated its ability to produce durable responses in several cancer types. In the last decade, immunotherapy has shown itself to be a viable therapeutic approach for non-small cell lung cancer (NSCLC). Several clinical trials have established the efficacy of immune checkpoint blockade (ICB), particularly in the form of anti-programmed death 1 (PD-1) antibodies, anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibodies and anti-programmed death 1 ligand (PD-L1) antibodies. Many trials have shown progression free survival (PFS) and overall survival (OS) benefit with either ICB alone or in combination with chemotherapy when compared to chemotherapy alone. The identification of biomarkers to predict response to immunotherapy continues to be evaluated. The future of immunotherapy in lung cancer continues to hold promise with the development of combination therapies, cytokine modulating therapies and cellular therapies. Lastly, we expect that innovative advances in technology, such as artificial intelligence (AI) and machine learning, will begin to play a role in the future care of patients with lung cancer.

Cytokine Based Immunotherapy for Cancer and Lymphoma: Biology, Challenges and Future Perspectives

Cytokines regulate both the innate and adaptive immune responses to cancer. Although antitumor activity has been seen for several cytokines in preclinical models, they have had limited success as single therapeutic agents in clinical trials of cancer immunotherapy. However, the possible combinations of cytokines with other immune therapeutics and the advancement in genetic engineering, synthetic biology and cellular and immune therapy has led to the revival of interest in cytokines as anticancer agents. This article will review several immunostimulatory cytokines with anticancer activity, focusing on the those that have been studied in treatment of lymphoma and highlighting recent advances of potential clinical relevance.

Harnessing cytokines and chemokines for cancer therapy

During the past 40 years, cytokines and cytokine receptors have been extensively investigated as either cancer targets or cancer treatments. A strong preclinical rationale supports therapeutic strategies to enhance the growth inhibitory and immunostimulatory effects of interferons and interleukins, including IL-2, IL-7, IL-12 and IL-15, or to inhibit the inflammatory and tumour-promoting actions of cytokines such as TNF, IL-1β and IL-6. This rationale is underscored by the discovery of altered and dysregulated cytokine expression in all human cancers. These findings prompted clinical trials of several cytokines or cytokine antagonists, revealing relevant biological activity but limited therapeutic efficacy. However, most trials involved patients with advanced-stage disease, which might not be the optimal setting for cytokine-based therapy. The advent of more effective immunotherapies and an increased understanding of the tumour microenvironment have presented new approaches to harnessing cytokine networks in the treatment of cancer, which include using cytokine-based therapies to enhance the activity or alleviate the immune-related toxicities of other treatments as well as to target early stage cancers. Many challenges remain, especially concerning delivery methods, context dependencies, and the pleiotropic, redundant and often conflicting actions of many cytokines. Herein, we discuss the lessons learnt from the initial trials of single-agent cytokine-based therapies and subsequent efforts to better exploit such agents for the treatment of solid tumours.

The Current State of Treatment and Future Directions in Cutaneous Malignant Melanoma

Malignant melanoma is the leading cause of death among cutaneous malignancies. While its incidence is increasing, the most recent cancer statistics show a small but clear decrease in mortality rate. This trend reflects the introduction of novel and more effective therapeutic regimens, including the two cornerstones of melanoma therapy: immunotherapies and targeted therapies. Immunotherapies exploit the highly immunogenic nature of melanoma by modulating and priming the patient’s own immune system to attack the tumor. Treatments combining immunotherapies with targeted therapies, which disable the carcinogenic products of mutated cancer cells, have further increased treatment efficacy and durability. Toxicity and resistance, however, remain critical challenges to the field. The present review summarizes past treatments and novel therapeutic interventions and discusses current clinical trials and future directions.

The treatment of advanced melanoma: a review of systemic and local therapies in combination with immune checkpoint inhibitors in phase 1 and 2 clinical trials

INTRODUCTION

While the incidence of melanoma continues to rise, the mortality of the disease appears to have stabilized. This may, in part, be due to the development and application of immune checkpoint inhibitors as standard of care in advanced melanoma. However, many patients do not respond to these therapies alone. Combining immune checkpoint inhibitors with other classes of therapeutics appears to be a promising direction to improve response and survival in advanced melanoma.

AREAS COVERED

This review article aims to discuss phase 1 and 2 clinical trials examining immune checkpoint inhibitors in combination therapy for the treatment of advanced, unresectable melanoma. In particular, these regimens include various kinase inhibitors, tumor-infiltrating lymphocytes, toll-like receptor agonists, cytokines, and oncolytic viral therapies. The combinations under discussion include both systemic and combination systemic/local therapies.

EXPERT OPINION

Drug combinations discussed here appear to be promising therapeutic regimens for advanced melanoma. Improved understanding of the mechanisms of primary, adaptive, and acquired resistance to immune checkpoint inhibitors may guide the development of future combination regimens.

Various Uses of PD1/PD-L1 Inhibitor in Oncology: Opportunities and Challenges

The occurrence and development of cancer are closely related to the immune escape of tumor cells and immune tolerance. Unlike previous surgical, chemotherapy, radiotherapy and targeted therapy, tumor immunotherapy is a therapeutic strategy that uses various means to stimulate and enhance the immune function of the body, and ultimately achieves the goal of controlling tumor cells.With the in-depth understanding of tumor immune escape mechanism and tumor microenvironment, and the in-depth study of tumor immunotherapy, immune checkpoint inhibitors represented by Programmed Death 1/Programmed cell Death-Ligand 1(PD-1/PD-L1) inhibitors are becoming increasingly significant in cancer medication treatment. employ a variety of ways to avoid detection by the immune system, a single strategy is not more effective in overcoming tumor immune evasion and metastasis. Combining different immune agents or other drugs can effectively address situations where immunotherapy is not efficacious, thereby increasing the chances of success and alternative access to alternative immunotherapy. Immune combination therapies for cancer have become a hot topic in cancer treatment today. In this paper, several combination therapeutic modalities of PD1/PD-L1 inhibitors are systematically reviewed. Finally, an analysis and outlook are provided in the context of the recent advances in combination therapy with PD1/PD-L1 inhibitors and the pressing issues in this field.

Interleukin-2 signals converge in a lymphoid-dendritic cell pathway that promotes anticancer immunity

Tumor-infiltrating dendritic cells (DCs) correlate with effective anticancer immunity and improved responsiveness to anti-PD-1 checkpoint immunotherapy. However, the drivers of DC expansion and intratumoral accumulation are ill-defined. We found that interleukin-2 (IL-2) stimulated DC formation through innate and adaptive lymphoid cells in mice and humans, and this increase in DCs improved anticancer immunity. Administration of IL-2 to humans within a clinical trial and of IL-2 receptor (IL-2R)-biased IL-2 to mice resulted in pronounced expansion of type 1 DCs, including migratory and cross-presenting subsets, and type 2 DCs, although neither DC precursors nor mature DCs had functional IL-2Rs. In mechanistic studies, IL-2 signals stimulated innate lymphoid cells, natural killer cells, and T cells to synthesize the cytokines FLT3L, CSF-2, and TNF. These cytokines redundantly caused DC expansion and activation, which resulted in improved antigen processing and correlated with favorable anticancer responses in mice and patients. Thus, IL-2 immunotherapy-mediated stimulation of DCs contributes to anticancer immunity by rendering tumors more immunogenic.

Current and future drug combination strategies based on programmed death-1/programmed death-ligand 1 inhibitors in non-small cell lung cancer

ABSTRACT

In recent years, immune checkpoint inhibitors (ICIs) have made breakthroughs in the field of lung cancer and have become a focal point for research. Programmed death-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor monotherapy was the first to break the treatment pattern for non-small cell lung cancer (NSCLC). However, owing to the limited benefit of ICI monotherapy at the population level and its hyper-progressive phenomenon, it may not meet clinical needs. To expand the beneficial range of immunotherapy and improve its efficacy, several research strategies have adopted the use of combination immunotherapy. At present, multiple strategies, such as PD-1/PD-L1 inhibitors combined with chemotherapy, anti-angiogenic therapy, cytotoxic T-lymphocyte-associated protein 4 inhibitors, and radiotherapy, as well as combined treatment with new target drugs, have been evaluated for clinical practice. To further understand the current status and future development direction of immunotherapy, herein, we review the recent progress of ICI combination therapies for NSCLC.

The Immunotherapy Landscape in Renal Cell Carcinoma

The past 30 years have borne witness to a gradual evolution in the treatment landscape of advanced renal cell carcinoma (aRCC). Early immunotherapy approaches such as interferon-α and high-dose interleukin-2 (IL-2) therapy in this immunogenic tumor provided durable responses in only a minority of patients and came with toxic side effects. A growing understanding of the tumor biology elucidated pathways of tumorigenesis, which in turn revealed novel targets amenable to targeted therapies. Inhibition of angiogenesis and cell signaling emerged as cornerstones of treatment with the approval of bevacizumab and several pan-kinase and tyrosine kinase inhibitors. Though effective, their use has been limited by low rates of durable response, resistance, and side effects. The immunotherapy revolution of the past decade has led to immunotherapy-based combination regimens such as ipilimumab plus nivolumab, pembrolizumab plus axitinib, and avelumab plus axitinib, displacing single agent anti-angiogenic therapy in the first-line setting by demonstrating durable responses and improved survival over sunitinib. These immunotherapy-based combinations define first-line standard of care for aRCC today. The pipeline of second-line agents for consideration in patients who have disease progression despite immunotherapy regimens is robust but still in early stages of development.

Beyond conventional immune-checkpoint inhibition - novel immunotherapies for renal cell carcinoma

The management of advanced-stage renal cell carcinoma (RCC) has been transformed by the development of immune-checkpoint inhibitors (ICIs). Nonetheless, most patients do not derive durable clinical benefit from these agents. Importantly, unlike other immunotherapy-responsive solid tumours, most RCCs have only a moderate mutational burden, and paradoxically, high levels of tumour CD8+ T cell infiltration are associated with a worse prognosis in patients with this disease. Building on the successes of antibodies targeting the PD-1 and CTLA4 immune checkpoints, multiple innovative immunotherapies are now in clinical development for the treatment of patients with RCC, including ICIs with novel targets, co-stimulatory pathway agonists, modified cytokines, metabolic pathway modulators, cell therapies and therapeutic vaccines. However, the successful development of such novel immune-based treatments and of immunotherapy-based combinations will require a disease-specific framework that incorporates a deep understanding of RCC immunobiology. In this Review, using the structure provided by the well-described cancer-immunity cycle, we outline the key steps required for a successful antitumour immune response in the context of RCC, and describe the development of promising new immunotherapies within the context of this framework. With this approach, we summarize and analyse the most encouraging targets of novel immune-based therapies within the RCC microenvironment, and review the landscape of emerging antigen-directed therapies for this disease.

Combinatorial Approaches to the Treatment of Advanced Melanoma

The treatment landscape for patients with advanced melanoma has dramatically improved over the past decade, leading to unprecedented survival. Despite the robust activity of single-agent immune-checkpoint blockade with anti-CTLA-4 or anti-PD-1 agents, and the efficacy of targeted therapies capable of interrupting aberrant signaling resulting from BRAF mutations, the benefit from these therapies is not universal. Advanced understanding of immune and molecular processes underlying melanoma tumorigenesis has demonstrated the promise of combined, multidrug regimens. We discuss the currently available evidence that supports using combinatorial approaches in advanced melanoma treatment and provide insights into promising new combination strategies under investigation.

NKTR-214 immunotherapy synergizes with radiotherapy to stimulate systemic CD8+ T cell responses capable of curing multi-focal cancer

Background

High-dose radiotherapy (RT) is known to be immunogenic, but is rarely capable of driving clinically relevant abscopal antitumor immunity as monotherapy. RT is known to increase antigen presentation, type I/II interferon responses, and immune cell trafficking to irradiated tumors. Bempegaldesleukin (NKTR-214) is a CD122-preferential interleukin 2 (IL-2) pathway agonist that has been shown to increase tumor-infiltrating lymphocytes, T cell clonality, and increase PD-1 expression. NKTR-214 has increased drug half-life, decreased toxicity, and increased CD8⁺ T cell and natural killer cell stimulation compared with IL-2.

Methods

Animals bearing bilateral subcutaneous MCA-205 fibrosarcoma or CT26 colorectal tumors were treated with NKTR-214, RT, or combination therapy, and tumor growth of irradiated and abscopal lesions was assessed. Focal RT was delivered using a small animal radiation research platform. Peripheral and tumor-infiltrating immune phenotype and functional analyses were performed by flow cytometry. RNA expression profiling from both irradiated and abscopal lesions was performed using microarray.

Results

We demonstrate synergy between RT of a single tumor and NKTR-214 systemic therapy resulting in dramatically increased cure rates of mice bearing bilateral tumors compared with RT or NKTR-214 therapy alone. Combination therapy resulted in increased magnitude and effector function of tumor-specific CD8⁺ T cell responses and increased trafficking of these T cells to both irradiated and distant, unirradiated, tumors.

Conclusions

Given the increasing role of hypofractionated and stereotactic body RT as standard of care treatments in the management of locally advanced and metastatic cancer, these data have important implications for future clinical trial development. The combination of RT and NKTR-214 therapy potently stimulates systemic antitumor immunity and should be evaluated for the treatment of patients with locally advanced and metastatic solid tumors.

Landscape of Immunotherapy in Genitourinary Malignancies

The past decade has witnessed a revolution in the development of immune checkpoint inhibitors for the treatment of multiple tumor types, including genitourinary cancers. Immune checkpoint inhibitors have notably improved the treatment outcomes of patients with metastatic renal cell carcinoma and metastatic urothelial carcinoma. In prostate cancer, the role of immunotherapy with checkpoint inhibitors is not yet established except for microsatellite instability high (MSI-H) tumors. Other immunotherapeutic approaches that have been explored in these malignancies include cytokines, vaccines, and cellular therapy. Ongoing studies are exploring the use of immunotherapy combinations as well as combination with chemotherapy and targeted therapy in these types of tumors. The use of immunotherapy beyond the metastatic setting is an active area of research. Moreover, there is great interest in biomarker development to predict response to immunotherapy and risk of toxicity. This book chapter is a comprehensive review of immunotherapeutic approaches, both approved and investigational, for the treatment of renal cell carcinoma, urothelial carcinoma, and prostate cancer.

Engineering IL-2 to Give New Life to T Cell Immunotherapy

Interleukin-2 (IL-2) is integral to immune system regulation. Its opposing immunostimulatory and immunosuppressive actions make it an attractive therapeutic target for cancer and autoimmune diseases. A challenge in developing IL-2-directed anticancer therapies has been how to stimulate effector T cells (Teffs) without inducing regulatory T cells (Tregs) in the tumor microenvironment; conversely, IL-2 therapy for autoimmune diseases requires Treg induction without further stimulation of Teffs. High-dose IL-2 is approved for melanoma and renal cell carcinoma, but its therapeutic value is limited by a need for frequent dosing at specialist centers, its short half-life, severe toxicity, and a lack of efficacy in most patients. Re-engineered IL-2 therapeutics are designed to have longer in vivo half-lives, target specific IL-2 receptor conformations to stimulate specific T cell subsets, or localize to target tissues to optimize efficacy and reduce toxicity. We discuss recent studies that elucidate the potential of newly engineered IL-2-based therapeutics for cancer and autoimmune diseases.

The Value of PD-L1 Expression as Predictive Biomarker in Metastatic Renal Cell Carcinoma Patients: A Meta-Analysis of Randomized Clinical Trials

Immune checkpoint inhibitors (ICIs) are soluble antibodies that have dramatically changed the outcomes including overall survival in a subset of kidney tumors, specifically in renal cell carcinoma (RCC). To date, there is no a single predictive biomarker approved to be used to select the patients that achieve benefit from ICIs targeting. It seems reasonable to analyze whether the programmed death-ligand 1 (PD-L1) expression could be useful. To assess the role of PD-L1 expression as a potential predictive biomarker for benefit of ICIs in RCC patients, we performed a search of randomized clinical trials (RCTs) comparing ICIs (monotherapy or in combination with other therapies) to standard of care in metastatic RCC patients according to PRISMA guidelines. Trials must have included subgroup analyses evaluating the selected outcomes (progression-free survival (PFS) and overall survival (OS)) in different subsets of patients according to PD-L1 expression on tumor samples. Hazard ratios with confidence intervals were used as the measure of efficacy between groups. A total of 4635 patients (six studies) were included (ICIs arm: 2367 patients; standard of care arm: 2268 patients). Globally, PFS and OS results favored ICIs. Differential expression of PD-L1 on tumor samples could select a subset of patients who could benefit more in terms of PFS (those with higher levels; p-value for difference between subgroups: <0.0001) but it did not seem to impact in OS results (p-value for difference: 0.63). As different methods to assess PD-L1 positivity were used among trials, this heterogeneity could have an influence on the results. PD-L1 could represent a biomarker to test PFS in clinical trials but its value for OS is less clear. In this meta-analysis, the usefulness of PD-L1 expression as a predictive biomarker to select treatment in metastatic RCC patients was not clearly shown.

Emerging therapeutic agents for advanced non-small cell lung cancer

Advanced non-small cell lung cancer (NSCLC) is the most common type of lung cancer, with a poor prognosis and no known cure. Survival time is often short because of limited treatment options. Recent advances in targeted therapy and immunotherapy have changed the landscape for the treatment of advanced NSCLC. In the last 10 years, the US Food and Drug Administration (FDA) has approved more than 17 new medications for this devastating disease and more are coming. Molecular and immunogenic testing makes personalized medicine possible for patients with advanced NSCLC. The new medications provide promising efficacy and safety resulting in improved long-term survival for a significant number of patients. In this review, we summarize the recent advances in advanced/metastatic NSCLC therapeutics with a specific focus on first in-human or early-phase I/II clinical trials. These drugs either offer better alternatives to current standard drugs in the same class or are a completely new class of drugs with novel mechanisms of action. Advances are divided into (1) targeted agents, (2) antibody-drug conjugates, and (3) immunotherapies. Finally, we present a brief review of the emerging agents and ongoing clinical studies.

Learning from clinical trials of neoadjuvant checkpoint blockade

Neoadjuvant checkpoint inhibition, in which the therapy is administered before surgery, is a promising new approach to managing bulky but resectable melanoma, and is also being explored in other cancers. This strategy has a high pathologic response rate, which correlates with survival outcomes. The fact that biopsies are routinely available provides a unique opportunity for understanding the responses to therapy and carrying out reverse translation in which these data are used to select therapies in the clinic or in trials that are more likely to improve patient outcomes. In this Perspective, we discuss the rationale for neoadjuvant immunotherapy in resectable solid tumors based on preclinical and human translational data, summarize the results of recent clinical trials and ongoing research, and focus on future directions for enhancing reverse translation.

Role of Immunotherapy in Triple-Negative Breast Cancer

Immune checkpoint inhibitors (ICIs) have led to durable clinical remissions in many metastatic cancers. However, the single-agent efficacy of ICIs in breast cancer is low, including in triple-negative breast cancer (TNBC), which has several key characteristics that enhance ICI responses. Strategies to improve anticancer immune responses in TNBC are urgently needed to extend survival for patients with metastatic disease. This review presents ICI monotherapy response rates and discusses combination strategies with chemotherapy, targeted therapies, and novel immunotherapies. It concludes with a summary of immunotherapy biomarkers in TNBC and a call to action for future directions of research critical to advancing the efficacy of immunotherapy for patients with TNBC.

Towards individualized therapy for metastatic renal cell carcinoma

Over the past decade, the treatment landscape for patients with metastatic renal cell carcinoma (RCC) has evolved dramatically. The therapeutic options available have expanded and now include immune-checkpoint inhibitors, novel targeted agents and combination strategies, and thus optimal patient selection and treatment sequencing are increasingly pertinent for optimizing clinical outcomes. A better understanding of the underlying biology of the tumour and its microenvironment continues to drive the inception of new diagnostic and therapeutic approaches. Furthermore, many biomarkers robustly associated with treatment and disease-specific outcomes have been identified, and their integration into clinical decision-making for patients with advanced-stage disease will soon become a reality. Herein, we review relevant aspects of the molecular biology of metastatic RCC, with an emphasis on predictive and prognostic biomarkers, and suggest tailored algorithms to individualize and guide treatment approaches for specific subgroups of patients.

Tumor Microenvironment Dynamics in Clear-Cell Renal Cell Carcinoma

Renal cell carcinoma stands out as one of the most immune-infiltrated tumors in pan-cancer comparisons. Features of the tumor microenvironment heavily affect disease biology and may affect responses to systemic therapy. With evolving frontline options in the metastatic setting, several immune checkpoint blockade regimens have emerged as efficacious, and there is growing interest in characterizing features of tumor biology that can reproducibly prognosticate patients and/or predict the likelihood of their deriving therapeutic benefit. Herein, we review pertinent characteristics of the tumor microenvironment with dedicated attention to candidate prognostic and predictive signatures as well as possible targets for future drug development. SIGNIFICANCE: Tumor microenvironment features broadly characterizing angiogenesis and inflammatory signatures have shown striking differences in response to immune checkpoint blockade and antiangiogenic agents. Integration of stromal and immune biomarkers may hence produce predictive and prognostic signatures to guide management with existing regimens as well as future drug development.

Current and emerging systemic therapies for cutaneous metastatic melanoma

INTRODUCTION

Melanoma therapies have evolved rapidly, and initial successes have translated into survival gains for patients with advanced melanoma. Both targeted and immune-therapy now have evidence in earlier stage disease. There are many new agents and combinations of treatments in development as potential future treatment options. This highlights the need for a reflection on current treatment practice trends that are guiding the development of potential new therapies.

AREAS COVERED

In this review, the authors discuss the evidence for currently approved therapies for cutaneous melanoma, including adjuvant therapy, potential new biomarkers, and emerging treatments with early phase clinical trial data. The authors have searched both the PubMed and clinicaltrials.gov databases for published clinical trials and discuss selected landmark trials of current therapies and of investigational treatment strategies with early evidence for the treatment of melanoma.

EXPERT OPINION

Significant efficacy has been demonstrated with both immune checkpoint inhibitors and targeted therapies in treating advanced melanoma. A multitude of novel therapies are in development and there is need for instructive biomarker assessment to identify patients likely to respond or be refractory to current therapies, to identify mechanisms of resistance and to direct further treatment options to patients based on individual disease biology.

Immunotherapy Toxicities

Immune checkpoint inhibitors (ICIs) are therapeutic antibodies that target regulatory molecules on T cells and represent the most widely used FDA-approved class of immunotherapy. ICIs are associated with unique immune-mediated toxicities called immune-related adverse events. These toxicities may affect any organ system, and their precise mechanisms of action remain under investigation. Current evidence suggests that activation of T cells is involved, although other components of the immune response have been implicated. This article summarizes toxicities, potential mechanisms of action, management strategies, and other clinical considerations. Unique mechanisms of action and immune-related toxicities of other FDA-approved classes of immunotherapy are reviewed.

Mechanisms of Primary and Secondary Resistance to Immune Checkpoint Inhibitors in Cancer

Immune checkpoint inhibitors (ICPis) have revolutionized cancer therapy with broad activities against a wide range of malignancies. However, in many malignancies their efficacy remains limited due to the primary resistance. Furthermore, a high percentage of patients develop progression due to the secondary resistance even after obtaining a response or achieving a stable disease. In this review, we will discuss the mechanisms that underlie the primary and secondary resistance to ICPis in cancer immunotherapy and provide an overview to impart a broad understanding of the critical issues that are encountered in clinical oncology practice.

Conceptual Framework for Therapeutic Development Beyond Anti-PD-1/PD-L1 in Urothelial Cancer

Platinum-based chemotherapy has been the standard of care in advanced urothelial cancer, but long-term outcomes have remained poor. Immune checkpoint inhibitors, with their favorable toxicity profiles and noteworthy efficacy, have steered a new era in advanced urothelial cancer, with five agents targeting the PD-1/PD-L1 pathway approved by the U.S. Food and Drug Administration (FDA). However, most patients do not achieve response, whereas immunotherapy-related adverse events may cause morbidity, increased health care use, and-rarely-mortality. Therefore, there is an urgent need for additional therapeutic modalities across the disease spectrum. A plethora of clinical trials are ongoing in various disease settings, including chemotherapy regimens, radiotherapy, antibody-drug conjugates, agents targeting additional immune checkpoint pathways, vaccine, cytokines, adoptive cell therapies, as well as targeted and anti-angiogenic agents. Two agents, enfortumab vedotin and erdafitinib, have breakthrough designation by the FDA but are not approved yet (at the time of this paper's preparation). Novel combinations with various treatment modalities and optimal sequencing of active therapies are being investigated in prospective clinical trials. Evaluation of new treatments has met with substantial challenges for many reasons, for example, molecular heterogeneity, clonal evolution, and genomic instability. In the era of precision molecular medicine, and because patients do not respond uniformly to current therapies, there is a growing need for identification and validation of biomarkers that can accurately predict treatment response and assist in patient selection. Here, we review current updates and future directions of experimental therapeutics in urothelial cancer, including examples (but not an exhaustive list) of ongoing clinical trials.

Cytokines in clinical cancer immunotherapy

Cytokines are soluble proteins that mediate cell-to-cell communication. Based on the discovery of the potent anti-tumour activities of several pro-inflammatory cytokines in animal models, clinical research led to the approval of recombinant interferon-alpha and interleukin-2 for the treatment of several malignancies, even if efficacy was only modest. These early milestones in immunotherapy have been followed by the recent addition to clinical practice of antibodies that inhibit immune checkpoints, as well as chimeric antigen receptor T cells. A renewed interest in the anti-tumour properties of cytokines has led to an exponential increase in the number of clinical trials that explore the safety and efficacy of cytokine-based drugs, not only as single agents, but also in combination with other immunomodulatory drugs. These second-generation drugs under clinical development include known molecules with novel mechanisms of action, new targets, and fusion proteins that increase half-life and target cytokine activity to the tumour microenvironment or to the desired effector immune cells. In addition, the detrimental activity of immunosuppressive cytokines can be blocked by antagonistic antibodies, small molecules, cytokine traps or siRNAs. In this review, we provide an overview of the novel trends in the cytokine immunotherapy field that are yielding therapeutic agents for clinical trials.

Rational combination of cancer immunotherapy in melanoma

The recent advances in cancer immunotherapy with unprecedented success in therapy of advanced melanoma represent a turning point in the landscape of melanoma treatment. Given the complexity of activation of immunological system and the physiologic multifactorial homeostatic mechanisms controlling immune responses, combinatorial strategies are eagerly needed in melanoma therapy. Nevertheless, rational selection of immunotherapy combinations should be more biomarker-guided, including not only the cancer immunogram, PD-L1 expression, interferon gene expression signature, mutational burden, and tumor infiltration by CD8+ T cells but also intratumoral T cell exhaustion and microbiota composition. In this review, we summarize the rationale to develop combination treatment strategies in melanoma and discuss biological background that could help to design new combinations in order to improve patients' outcome.

[Hot topics about early clinical trials at ASCO congress 2018: News pathways, new targets, new associations]

Looking at the results of the early trials presented at the 2018 American Society of Clinical Oncology (ASCO) conference can help identify the molecules and strategies that will potentially enter the practices of tomorrow. It is in this spirit that this subject has justified the attention of residents in oncology and the writing of this synthesis. Molecules that can represent breakthrough innovations are presented as well as new therapeutics under development acting on targets already validated in clinical practice and early data of checkpoint inhibitors in combination with different immunomodulators, as well as new strategies for immunotherapies (vaccines and cell therapy).

The Cancer Immunogram as a Framework for Personalized Immunotherapy in Urothelial Cancer

CONTEXT

The abysmal outlook of urothelial cancer (UC) has changed with the introduction of immunotherapy. Still, many patients do not respond and distinctive biomarkers are currently lacking. The rise of this novel armamentarium of immunotherapy treatments, in combination with the complex biology of an immunological tumor response, warrants the development of a comprehensive framework that can provide an overview of important immunological processes at play in individual patients.

OBJECTIVE

To develop a comprehensive framework based on tumor- and host-specific parameters to understand immunotherapy response in UC. This framework can inform rational, biology-driven clinical trials and ultimately guide us toward individualized patient treatment.

EVIDENCE ACQUISITION

A literature review was conducted on UC immunotherapy, clinical trial data, and biomarkers of response to checkpoint inhibition.

EVIDENCE SYNTHESIS

Here, we propose a UC immunogram, based on currently available clinical and translational data. The UC immunogram describes several tumor- and host-specific parameters that are required for successful immunotherapy treatment. These seven parameters are tumor foreignness, immune cell infiltration, absence of inhibitory checkpoints, general performance and immune status, absence of soluble inhibitors, absence of inhibitory tumor metabolism, and tumor sensitivity to immune effectors.

CONCLUSIONS

Longitudinal integration of individual patient parameters may ultimately lead to personalized and dynamic immunotherapy, to adjust to the Darwinian forces that drive tumor evolution. Incorporating multiparameter biomarkers into quantitative predictive models will be a key challenge to integrate the immunogram into daily clinical practice.

PATIENT SUMMARY

Here, we propose the urothelial cancer immunogram, a novel way of describing important immunological characteristics of urothelial cancer patients and their tumors. Seven characteristics determine the chance of having an immunological tumor response. Using this immunogram, we aim to better understand why some patients respond to immunotherapy and some do not, to ultimately improve anticancer therapy.