An open-label, phase II multicohort study of an oral hypomethylating agent CC-486 and durvalumab in advanced solid tumors

Unveiling the immunomodulatory dance: endothelial cells' function and their role in non-small cell lung cancer

The dynamic interactions between tumor endothelial cells (TECs) and the immune microenvironment play a critical role in the progression of non-small cell lung cancer (NSCLC). In general, endothelial cells exhibit diverse immunomodulatory properties, influencing immune cell recruitment, antigen presentation, and regulation of immune checkpoint expression. Understanding the multifaceted roles of TECs as well as assigning specific functional hallmarks to various TEC phenotypes offer new avenues for targeted development of therapeutic interventions, particularly in the context of advanced immunotherapy and anti-angiogenic treatments. This review provides insights into the complex interplay between TECs and the immune system in NSCLC including discussion of potential optimized therapeutic opportunities.

An Open-Label Phase II Trial of Pembrolizumab, an Immune Checkpoint Inhibitor Alone or in Combination With Oral Azacitidine as Second-Line Therapy for Advanced Head and Neck Squamous Cell Cancers

Background and Aims

Sensitivity to immune checkpoint inhibitor (ICI) therapy depends in part on the genetic and epigenetic makeup of cancer cells, and CD8 T-lymphocytes that mediate immune responses. Epigenetics are heritable reversible changes in gene expression that occur without any changes in the nuclear DNA sequence or DNA copy number.

Primary Objective

i. To determine if non-cytotoxic oral azacytidine when combined with pembrolizumab can improve ORRs of ICI treatment in patients with recurrent/metastatic tumors of head and neck region.

Secondary Objectives

i. To evaluate the clinical effectiveness endpoints and toxicity of oral azacytidine when combined with pembrolizumab. ii. To assess the induction of a T-cell response among the study subjects. iii. To examine the hypotheses on the predictive biomarkers of response to pembrolizumab, and the mechanisms of resistance.

Methods

Our trial is a Phase 2 randomized study of immunotherapy drug pembrolizumab given in combination with azacitidine (HMA). The intervention model includes "Parallel assignment," with the primary purpose of the trial being treatment. The primary effectiveness endpoint is overall RECIST-defined response. To accomplish this goal, 232 patients will be randomized 1:1 (116 in each arm), respectively, to azacitidine plus pembrolizumab or pembrolizumab only groups.

Results

In this trial, molecular profiling of tumor and peripheral blood samples will be conducted which will enable in gaining biological insights for survival benefit. The expected primary outcome assessed at a time frame of 2 years includes the objective response rate of patients measured as per RECIST 1.1 criteria. The secondary outcomes assessed at 2 years include progression-free survival, time to progression, overall survival, and incidence of treatment-emergent adverse events.

Conclusion

The findings of this trial will have translational implications, in terms of immune reprogramming induced by epigenetic therapy among a subset of advanced H & N cancer patients in a clinical setting.

Immunotherapy for hormone receptor‒positive HER2-negative breast cancer

Additional therapies are needed to improve outcomes in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. Research on the potential role of immunotherapy, particularly programmed cell death protein 1/programmed cell death ligand 1 inhibitors, is rapidly expanding in both the early and metastatic settings with some preliminary evidence suggesting benefit when used as part of combination therapy. Several ongoing phase 3 studies should help define their future role in treating these patients.

Epigenetic control of immunoevasion in cancer stem cells

Cancer stem cells (CSCs) are a poorly differentiated population of malignant cells that (at least in some neoplasms) is responsible for tumor progression, resistance to therapy, and disease relapse. According to a widely accepted model, all stages of cancer progression involve the ability of neoplastic cells to evade recognition or elimination by the host immune system. In line with this notion, CSCs are not only able to cope with environmental and therapy-elicited stress better than their more differentiated counterparts but also appear to better evade tumor-targeting immune responses. We summarize epigenetic modifications of DNA and histones through which CSCs evade immune recognition or elimination, and propose that such alterations constitute promising therapeutic targets to increase the sensitivity of some malignancies to immunotherapy.

Progresses and Pitfalls of Epigenetics in Solid Tumors Clinical Trials

Epigenetic dysregulation has long been recognized as a significant contributor to tumorigenesis and tumor maintenance, impacting all recognized cancer hallmarks. Although some epigenetic drugs have received regulatory approval for certain hematological malignancies, their efficacy in treating solid tumors has so far been largely disappointing. However, recent advancements in developing new compounds and a deeper understanding of cancer biology have led to success in specific solid tumor subtypes through precision medicine approaches. Moreover, epigenetic drugs may play a crucial role in synergizing with other anticancer treatments, enhancing the sensitivity of cancer cells to various anticancer therapies, including chemotherapy, radiation therapy, hormone therapy, targeted therapy, and immunotherapy. In this review, we critically evaluate the evolution of epigenetic drugs, tracing their development from initial use as monotherapies to their current application in combination therapies. We explore the preclinical rationale, completed clinical studies, and ongoing clinical trials. Finally, we discuss trial design strategies and drug scheduling to optimize the development of possible combination therapies.

The molecular landscape of T cell exhaustion in the tumor microenvironment and reinvigoration strategies

Immunotherapy has emerged as a promising therapeutic approach for cancer treatment by harnessing the immune system to target cancer cells. However, the efficacy of immunotherapy is hindered by the tumor microenvironment (TME), comprising regulatory T cells (Tregs), macrophages, myeloid-derived suppressor cells (MDSCs), neutrophils, soluble factors (TGF-β, IL-35, IL-10), and hypoxia. These components interact with inhibitory receptors (IRs) on T cells, leading to alterations in T cell transcriptomes, epigenomes, and metabolism, ultimately resulting in T cell exhaustion and compromising the effectiveness of immunotherapy. T cell exhaustion occurs in two phases: pre-exhaustion and exhaustion. Pre-exhausted T cells exhibit reversibility and distinct molecular properties compared to terminally exhausted T cells. Understanding these differences is crucial for designing effective interventions. This comprehensive review summarizes the characteristics of pre-exhausted and exhausted T cells and elucidates the influence of TME components on T cell activity, transcriptomes, epigenomes, and metabolism, ultimately driving T cell exhaustion in cancer. Additionally, potential intervention strategies for reversing exhaustion are discussed. By gaining insights into the mechanisms underlying T cell exhaustion and the impact of the TME, this review aims to inform the development of innovative approaches for combating T cell exhaustion and enhancing the efficacy of immunotherapy in cancer treatment.

Prospects for breast cancer immunotherapy using microRNAs and transposable elements as objects

One of the directions in treatment of chemoresistant breast cancer (BC) may include new methods of activating the immune response against tumor cells. Clinically used checkpoint inhibition using antibodies to PD-1 and PD-L1 works in some patients, but the lack of biomarkers means number of respondents is low. The possibility of combining this method with chemotherapy is limited by an increased risk of toxic liver damage, development of immune-related pneumonitis, and thyroid dysfunction. This article includes introduction into the clinic of new methods of immunotherapy for BC, among which epigenetic activation of retroelements, double-stranded transcripts of which stimulate the interferon response against the tumor, is promising. For this purpose, inhibitors of DNA methyltransferase*, histone deacetylase* and histone methyltransferase* are used (* subtitles in the main text). Their antitumor effect is also mediated by removal of repressive epigenetic marks from tumor suppressor genes. However, numerous studies have proven the role of retroelements in the carcinogenesis of various malignant neoplasms, including BC. Moreover, endogenous retroviruses HERV-K and LINE1 retrotransposons are planned to be used as diagnostic biomarkers for BC. Therefore, a rational approach to using viral mimicry in antitumor therapy of BC may be the simultaneous suppression of specific retrotransposons (drivers for carcinogenesis) using reverse transcriptase inhibitors and silencing of specific transposons involved in carcinogenesis using complementary microRNAs. To determine possible pathways of influence in this direction, 35 specific transposon-derived microRNAs* changes in BC were identified, which can become guides for targeted therapy of BC.

DNA methylation in human diseases

Aberrant epigenetic modifications, particularly DNA methylation, play a critical role in the pathogenesis and progression of human diseases. The current review aims to reveal the role of aberrant DNA methylation in the pathogenesis and progression of diseases and to discuss the original data obtained from international research laboratories on this topic. In the review, we mainly summarize the studies exploring the role of aberrant DNA methylation as diagnostic and prognostic biomarkers in a broad range of human diseases, including monogenic epigenetics, autoimmunity, metabolic disorders, hematologic neoplasms, and solid tumors. The last section provides a general overview of the possibility of the DNA methylation machinery from the perspective of pharmaceutic approaches. In conclusion, the study of DNA methylation machinery is a phenomenal intersection that each of its ways can reveal the mysteries of various diseases, introduce new diagnostic and prognostic biomarkers, and propose a new patient-tailored therapeutic approach for diseases.

Therapeutic targeting of DNA methylation alterations in cancer

DNA methylation is a critical component of gene regulation and plays an important role in the development of cancer. Hypermethylation of tumor suppressor genes and silencing of DNA repair pathways facilitate uncontrolled cell growth and synergize with oncogenic mutations to perpetuate cancer phenotypes. Additionally, aberrant DNA methylation hinders immune responses crucial for antitumor immunity. Thus, inhibiting dysregulated DNA methylation is a promising cancer therapy. Pharmacologic inhibition of DNA methylation reactivates silenced tumor suppressors and bolster immune responses through induction of viral mimicry. Now, with the advent of immunotherapies and discovery of the immune-modulatory effects of DNA methylation inhibitors, there is great interest in understanding how targeting DNA methylation in combination with other therapies can enhance antitumor immunity. Here, we describe the role of aberrant DNA methylation in cancer and mechanisms by which it promotes tumorigenesis and modulates immune responses. Finally, we review the initial discoveries and ongoing efforts to target DNA methylation as a cancer therapeutic.

Epigenetic modulations in triple-negative breast cancer: Therapeutic implications for tumor microenvironment

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen receptors, progesterone receptors and lacks HER2 overexpression. This absence of critical molecular targets poses significant challenges for conventional therapies. Immunotherapy, remarkably immune checkpoint blockade, offers promise for TNBC treatment, but its efficacy remains limited. Epigenetic dysregulation, including altered DNA methylation, histone modifications, and imbalances in regulators such as BET proteins, plays a crucial role in TNBC development and resistance to treatment. Hypermethylation of tumor suppressor gene promoters and the imbalance of histone methyltransferases such as EZH2 and histone deacetylases (HDACs) profoundly influence tumor cell proliferation, survival, and metastasis. In addition, epigenetic alterations critically shape the tumor microenvironment (TME), including immune cell composition, cytokine signaling, and immune checkpoint expression, ultimately contributing to immune evasion. Targeting these epigenetic mechanisms with specific inhibitors such as EZH2 and HDAC inhibitors in combination with immunotherapy represents a compelling strategy to remodel the TME, potentially overcoming immune evasion and enhancing therapeutic outcomes in TNBC. This review aims to comprehensively elucidate the current understanding of epigenetic modulation in TNBC, its influence on the TME, and the potential of combining epigenetic therapies with immunotherapy to overcome the challenges posed by this aggressive breast cancer subtype.

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

Epigenetic modulation of antitumor immunity and immunotherapy response in breast cancer: biological mechanisms and clinical implications

Breast cancer (BC) is the most common non-skin cancer and the second leading cause of cancer death in American women. The initiation and progression of BC can proceed through the accumulation of genetic and epigenetic changes that allow transformed cells to escape the normal cell cycle checkpoint control. Unlike nucleotide mutations, epigenetic changes such as DNA methylation, histone posttranslational modifications (PTMs), nucleosome remodeling and non-coding RNAs are generally reversible and therefore potentially responsive to pharmacological intervention. Epigenetic dysregulations are critical mechanisms for impaired antitumor immunity, evasion of immune surveillance, and resistance to immunotherapy. Compared to highly immunogenic tumor types, such as melanoma or lung cancer, breast cancer has been viewed as an immunologically quiescent tumor which displays a relatively low population of tumor-infiltrating lymphocytes (TIL), low tumor mutational burden (TMB) and modest response rates to immune checkpoint inhibitors (ICI). Emerging evidence suggests that agents targeting aberrant epigenetic modifiers may augment host antitumor immunity in BC via several interrelated mechanisms such as enhancing tumor antigen presentation, activation of cytotoxic T cells, inhibition of immunosuppressive cells, boosting response to ICI, and induction of immunogenic cell death (ICD). These discoveries have established a highly promising basis for using combinatorial approaches of epigenetic drugs with immunotherapy as an innovative paradigm to improve outcomes of BC patients. In this review, we summarize the current understanding of how epigenetic processes regulate immune cell function and antitumor immunogenicity in the context of the breast tumor microenvironment. Moreover, we discuss the therapeutic potential and latest clinical trials of the combination of immune checkpoint blockers with epigenetic agents in breast cancer.

Targeting the epigenome to reinvigorate T cells for cancer immunotherapy

Cancer immunotherapy using immune-checkpoint inhibitors (ICIs) has revolutionized the field of cancer treatment; however, ICI efficacy is constrained by progressive dysfunction of CD8+ tumor-infiltrating lymphocytes (TILs), which is termed T cell exhaustion. This process is driven by diverse extrinsic factors across heterogeneous tumor immune microenvironment (TIME). Simultaneously, tumorigenesis entails robust reshaping of the epigenetic landscape, potentially instigating T cell exhaustion. In this review, we summarize the epigenetic mechanisms governing tumor microenvironmental cues leading to T cell exhaustion, and discuss therapeutic potential of targeting epigenetic regulators for immunotherapies. Finally, we outline conceptual and technical advances in developing potential treatment paradigms involving immunostimulatory agents and epigenetic therapies.

Immunological Assessment of Recent Immunotherapy for Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent malignancy with increased incidence and mortality rates worldwide. Traditional treatment approaches have attempted to efficiently target CRC; however, they have failed in most cases, owing to the cytotoxicity and non-specificity of these therapies. Therefore, it is essential to develop an effective alternative therapy to improve the clinical outcomes in heterogeneous CRC cases. Immunotherapy has transformed cancer treatment with remarkable efficacy and overcomes the limitations of traditional treatments. With an understanding of the cancer-immunity cycle and tumor microenvironment evolution, current immunotherapy approaches have elicited enhanced antitumor immune responses. In this comprehensive review, we outline the latest advances in immunotherapy targeting CRC and provide insights into antitumor immune responses reported in landmark clinical studies. We focused on highlighting the combination approaches that synergistically induce immune responses and eliminate immunosuppression. This review aimed to understand the limitations and potential of recent immunotherapy clinical studies conducted in the last five years (2019-2023) and to transform this knowledge into a rational design of clinical trials intended for effective antitumor immune responses in CRC.

Efficacy and safety of immune checkpoint inhibitors in Proficient Mismatch Repair (pMMR)/ Non-Microsatellite Instability-High (non-MSI-H) metastatic colorectal cancer: a study based on 39 cohorts incorporating 1723 patients

PURPOSE

This study was designed to investigate the efficacy and safety of immune checkpoint inhibitors (ICIs)-based therapy in proficient mismatch repair (pMMR)/non-microsatellite instability-high (non-MSI-H) metastatic colorectal cancer (mCRC).

METHODS

Electronic databases were screened to identify relevant trials. The primary endpoints were pooled objective response rate (ORR) and disease control rate (DCR). Stratified analysis was accomplished on ICIs-based regimens, treatment lines and RAS status.

RESULTS

Totally, 1723 mCRC patients from 39 cohorts were included. The pooled ORR, DCR, 12-month overall survival (OS) rate and 6-month progression-free survival (PFS) rate of ICIs-based therapy in pMMR/non-MSI-H mCRC were 8.5% (95% CI: 4.4%-13.5%), 48.2% (95% CI: 37.8%-58.6%), 52.3% (95% CI: 46.4%-58.1%) and 32.8% (95% CI: 23.5%-42.7%) respectively. As a whole, no significantly differences were shown between ICIs-based and non-ICIs-based therapy for pMMR/non-MSI-H mCRC in terms of both PFS (HR = 1.0, 95% CI: 0.9-1.1, P = 0.91) and OS (HR = 1.0, 95% CI: 0.9-1.2, P = 0.51). It was worth noting that the addition of ICIs to anti-vascular endothelial growth factor (VEGF) agent plus chemotherapy displayed excellent efficacy in pMMR/non-MSI-H mCRC (ORR = 42.4%, 95% CI: 10.0%-78.6%; DCR = 92.0%, 95% CI: 68.3%-100.0%; 12-month OS rate = 71.4%, 95% CI: 50.0%-89.1%; 6-month PFS rate = 55.2%, 95% CI: 24.8%-83.8%; and PFS (compared with non-ICIs-based therapy): HR = 0.9, 95% CI: 0.8-1.0, P = 0.02), especially served as first-line therapy (ORR = 74.2%, 95% CI: 61.4%-85.4%; DCR = 98.7%, 95% CI: 92.0%-100.0%); and without additional treatment related adverse events (TRAEs) were observed.

CONCLUSIONS

ICIs-based combination therapy, especially the addition of ICIs to first-line anti-VEGF agent plus chemotherapy, is promising in pMMR/non-MSI-H mCRC with good efficacy and controllable toxicity.

Transposable elements as essential elements in the control of gene expression

Interspersed repetitions called transposable elements (TEs), commonly referred to as mobile elements, make up a significant portion of the genomes of higher animals. TEs contribute in controlling the expression of genes locally and even far away at the transcriptional and post-transcriptional levels, which is one of their significant functional effects on gene function and genome evolution. There are different mechanisms through which TEs control the expression of genes. First, TEs offer cis-regulatory regions in the genome with their inherent regulatory features for their own expression, making them potential factors for controlling the expression of the host genes. Promoter and enhancer elements contain cis-regulatory sites generated from TE, which function as binding sites for a variety of trans-acting factors. Second, a significant portion of miRNAs and long non-coding RNAs (lncRNAs) have been shown to have TEs that encode for regulatory RNAs, revealing the TE origin of these RNAs. Furthermore, it was shown that TE sequences are essential for these RNAs' regulatory actions, which include binding to the target mRNA. By being a member of cis-regulatory and regulatory RNA sequences, TEs therefore play essential regulatory roles. Additionally, it has been suggested that TE-derived regulatory RNAs and cis-regulatory regions both contribute to the evolutionary novelty of gene regulation. Additionally, these regulatory systems arising from TE frequently have tissue-specific functions. The objective of this review is to discuss TE-mediated gene regulation, with a particular emphasis on the processes, contributions of various TE types, differential roles of various tissue types, based mostly on recent studies on humans.

Reshaping the tumour immune microenvironment in solid tumours via tumour cell and immune cell DNA methylation: from mechanisms to therapeutics

In recent years, the tumour microenvironment (TME) of solid tumours has attracted more and more attention from researchers, especially those non-tumour components such as immune cells. Infiltration of various immune cells causes tumour immune microenvironment (TIME) heterogeneity, and results in different therapeutic effects. Accumulating evidence showed that DNA methylation plays a crucial role in remodelling TIME and is associated with the response towards immune checkpoint inhibitors (ICIs). During carcinogenesis, DNA methylation profoundly changes, specifically, there is a global loss of DNA methylation and increased DNA methylation at the promoters of suppressor genes. Immune cell differentiation is disturbed, and exclusion of immune cells from the TME occurs at least in part due to DNA methylation reprogramming. Therefore, pharmaceutical interventions targeting DNA methylation are promising. DNA methyltransferase inhibitors (DNMTis) enhance antitumor immunity by inducing transcription of transposable elements and consequent viral mimicry. DNMTis upregulate the expression of tumour antigens, mediate immune cells recruitment and reactivate exhausted immune cells. In preclinical studies, DNMTis have shown synergistic effect when combined with immunotherapies, suggesting new strategies to treat refractory solid tumours.

Ovarian Cancer—Insights into Platinum Resistance and Overcoming It

Ovarian cancer is the most lethal gynecologic malignancy. Platinum-based chemotherapy is the backbone of treatment for ovarian cancer, and although the majority of patients initially have a platinum-sensitive disease, through multiple recurrences, they will acquire resistance. Platinum-resistant recurrent ovarian cancer has a poor prognosis and few treatment options with limited efficacy. Resistance to platinum compounds is a complex process involving multiple mechanisms pertaining not only to the tumoral cell but also to the tumoral microenvironment. In this review, we discuss the molecular mechanism involved in ovarian cancer cells’ resistance to platinum-based chemotherapy, focusing on the alteration of drug influx and efflux pathways, DNA repair, the dysregulation of epigenetic modulation, and the involvement of the tumoral microenvironment in the acquisition of the platinum-resistant phenotype. Furthermore, we review promising alternative treatment approaches that may improve these patients’ poor prognosis, discussing current strategies, novel combinations, and therapeutic agents.

Ascertaining QUAZARs: slow-motion and light-speed development of oral azacitidine and decitabine

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are devastating diseases that frequently rely on the use of parenteral hypomethylating agents (HMAs), either as monotherapy or in combination, as first-line treatment for many patients. Two new oral HMAs, decitabine/cedazuridine (DC) for use in place of azacitidine or decitabine in MDS, and azacitidine (CC-486) for use as maintenance treatment in AML, were recently approved by the FDA. We will discuss the development of these oral HMAs, including the advantages/disadvantages in transitioning to oral HMAs and an in depth look at the pivotal phase III trials that led to their FDA approval - ASCERTAIN for DC and QUAZAR-AML-001 for CC-486. We also review how these agents have been and are being studied in other malignancies, and examine the future role that these exciting novel agents will play in both MDS and AML.

Therapeutic challenge for immunotherapy targeting cold colorectal cancer: A narrative review

Cold colorectal tumors are not likely to trigger a robust immune response and tend to suppress the immune response. There may be three reasons. First, the complex tumor microenvironment of cold colorectal cancer (CRC) leads to tolerance and clearance of immunotherapy. Second, the modification and concealment of tumor-specific targets in cold CRC cause immune escape and immune response interruption. Finally, the difference in number and function of immune cell subsets in patients with cold CRC makes them respond poorly to immunotherapy. Therefore, we can only overcome the challenges in immunotherapy of cold CRC through in-depth research and understanding the changes and mechanisms in the above three aspects of cold CRC.

Efficacy of immune checkpoint inhibitor monotherapy or combined with other small molecule-targeted agents in ovarian cancer

Ovarian cancer is the most lethal female reproductive system tumour. Despite the great advances in surgery and systemic chemotherapy over the past two decades, almost all patients in stages III and IV relapse and develop resistance to chemotherapy after first-line treatment. Ovarian cancer has an extraordinarily complex immunosuppressive tumour microenvironment in which immune checkpoints negatively regulate T cells activation and weaken antitumour immune responses by delivering immunosuppressive signals. Therefore, inhibition of immune checkpoints can break down the state of immunosuppression. Indeed, Immune checkpoint inhibitors (ICIs) have revolutionised the therapeutic landscape of many solid tumours. However, ICIs have yielded modest benefits in ovarian cancer. Therefore, a more comprehensive understanding of the mechanistic basis of the immune checkpoints is needed to improve the efficacy of ICIs in ovarian cancer. In this review, we systematically introduce the mechanisms and expression of immune checkpoints in ovarian cancer. Moreover, this review summarises recent updates regarding ICI monotherapy or combined with other small-molecule-targeted agents in ovarian cancer.

MCPIP1 Suppresses the NF-κB Signaling Pathway Through Negative Regulation of K63-Linked Ubiquitylation of TRAF6 in Colorectal Cancer

The abnormal activation of the nuclear factor-kappa B (NF-κB) signaling pathway is an important precipitating factor for the inception and development of colorectal cancer (CRC), one of the most common tumors worldwide. As a pro-apoptotic transcription factor, monocyte chemotactic protein-induced protein 1 (MCPIP1) has been closely associated with many tumor types. In the present study, the expression of MCPIP1 was firstly discovered reduced in CRC tissues and correlated with poor patient prognosis. The decreased expression was caused by promoter hypermethylation. Overexpressed MCPIP1 was found to inhibit the proliferative and migratory abilities of CRC cells, whereas knockdown of MCPIP1 produced the opposite result. The subsequent investigation demonstrated that MCPIP1 exerted its "anti-cancer" effect by suppression of the NF-κB signaling pathway through negative regulation of K63-linked ubiquitylation of TNF receptor associated factor 6 (TRAF6). Therefore, our results indicate a prognostic marker for CRC and a theoretical basis for MCPIP1 as a treatment.

Targeted drug delivery system for ovarian cancer microenvironment: Improving the effects of immunotherapy

Immunotherapies have shown modest benefits in the current clinical trials for ovarian cancer. The tumor microenvironment (TME) in an immunosuppressive phenotype contributes to this “failure” of immunotherapy in ovarian cancer. Many stromal cell types in the TME (e.g., tumor-associated macrophages and fibroblasts) have been identified as having plasticity in pro- and antitumor activities and are responsible for suppressing the antitumor immune response. Thus, the TME is an extremely valuable target for adjuvant interventions to improve the effects of immunotherapy. The current strategies targeting the TME include: 1) eliminating immunosuppressive cells or transforming them into immunostimulatory phenotypes and 2) inhibiting their immunosuppressive or pro-tumor production. Most of the effective agents used in the above strategies are genetic materials (e.g., cDNA, mRNA, or miRNA), proteins, or other small molecules (e.g., peptides), which are limited in their target and instability. Various formulations of drug delivery system (DDS) have been designed to realize the controlled release and targeting delivery of these agents to the tumor sites. Nanoparticles and liposomes are the most frequently exploited materials. Based on current evidence from preclinical and clinical studies, the future of the DDS is promising in cancer immunotherapy since the combination of agents with a DDS has shown increased efficacy and decreased toxicities compared with free agents. In the future, more efforts are needed to further identify the hallmarks and biomarkers in the ovarian TME, which is crucial for the development of more effective, safe, and personalized DDSs.

Exploring glioblastoma stem cell heterogeneity: Immune microenvironment modulation and therapeutic opportunities

Despite its growing use in cancer treatment, immunotherapy has been virtually ineffective in clinical trials for gliomas. The inherently cold tumor immune microenvironment (TIME) in gliomas, characterized by a high ratio of pro-tumor to anti-tumor immune cell infiltrates, acts as a seemingly insurmountable barrier to immunotherapy. Glioma stem cells (GSCs) within these tumors are key contributors to this cold TIME, often functioning indirectly through activation and recruitment of pro-tumor immune cell types. Furthermore, drivers of GSC plasticity and heterogeneity (e.g., reprogramming transcription factors, epigenetic modifications) are associated with induction of immunosuppressive cell states. Recent studies have identified GSC-intrinsic mechanisms, including functional mimicry of immune suppressive cell types, as key determinants of anti-tumor immune escape. In this review, we cover recent advancements in our understanding of GSC-intrinsic mechanisms that modulate GSC-TIME interactions and discuss cutting-edge techniques and bioinformatics platforms available to study immune modulation at high cellular resolution with exploration of both malignant (i.e., GSC) and non-malignant (i.e., immune) cell fractions. Finally, we provide insight into the therapeutic opportunities for targeting immunomodulatory GSC-intrinsic mechanisms to potentiate immunotherapy response in gliomas.

Combinatorial Strategies With PD-1/PD-L1 Immune Checkpoint Blockade for Breast Cancer Therapy: Mechanisms and Clinical Outcomes

As an emerging antitumor strategy, immune checkpoint therapy is one of the most promising anticancer therapies due to its long response duration. Antibodies against the programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) axis have been extensively applied to various cancers and have demonstrated unprecedented efficacy. Nevertheless, a poor response to monotherapy with anti-PD-1/PD-L1 has been observed in metastatic breast cancer. Combination therapy with other standard treatments is expected to overcome this limitation of PD-1/PD-L1 blockade in the treatment of breast cancer. In the present review, we first illustrate the biological functions of PD-1/PD-L1 and their role in maintaining immune homeostasis as well as protecting against immune-mediated tissue damage in a variety of microenvironments. Several combination therapy strategies for the combination of PD-1/PD-L1 blockade with standard treatment modalities have been proposed to solve the limitations of anti-PD-1/PD-L1 treatment, including chemotherapy, radiotherapy, targeted therapy, antiangiogenic therapy, and other immunotherapies. The corresponding clinical trials provide valuable estimates of treatment effects. Notably, several combination options significantly improve the response and efficacy of PD-1/PD-L1 blockade. This review provides a PD-1/PD-L1 clinical trial landscape survey in breast cancer to guide the development of more effective and less toxic combination therapies.

Inhibiting DNA methylation improves antitumor immunity in ovarian cancer

Cancer cells resist the immune response in a process known as immune editing or immune evasion. Therapies that target the immune system have revolutionized cancer treatment; however, immunotherapies have been ineffective for the majority of ovarian cancer cases. In this issue of the JCI, Chen, Xie, et al. hypothesized that hypomethylating agent (HMA) treatment would induce antitumor immunity to sensitize patients with ovarian cancer to anti-PD-1 immunotherapy. The authors performed a phase II clinical trial to test the combination of guadecitabine, a second-generation HMA, along with pembrolizumab, an immune checkpoint inhibitor of PD-1. The trial included a group of 35 patients with platinum-resistant ovarian cancer. While the clinical benefit from the combined HMA plus immune checkpoint blockade regimen was lower than hoped, the correlate analyses gave important information about which patients with ovarian cancer may be more likely to respond to immune therapy.

Role of Transposable Elements in Genome Stability: Implications for Health and Disease

Most living organisms have in their genome a sizable proportion of DNA sequences capable of mobilization; these sequences are commonly referred to as transposons, transposable elements (TEs), or jumping genes. Although long thought to have no biological significance, advances in DNA sequencing and analytical technologies have enabled precise characterization of TEs and confirmed their ubiquitous presence across all forms of life. These findings have ignited intense debates over their biological significance. The available evidence now supports the notion that TEs exert major influence over many biological aspects of organismal life. Transposable elements contribute significantly to the evolution of the genome by giving rise to genetic variations in both active and passive modes. Due to their intrinsic nature of mobility within the genome, TEs primarily cause gene disruption and large-scale genomic alterations including inversions, deletions, and duplications. Besides genomic instability, growing evidence also points to many physiologically important functions of TEs, such as gene regulation through cis-acting control elements and modulation of the transcriptome through epigenetic control. In this review, we discuss the latest evidence demonstrating the impact of TEs on genome stability and the underling mechanisms, including those developed to mitigate the deleterious impact of TEs on genomic stability and human health. We have also highlighted the potential therapeutic application of TEs.

Immune checkpoint blockades in gynecological cancers: A review of clinical trials

Advanced and recurrent gynecological cancers are associated with a poor prognosis and there is still a lack of effective treatments. Immune checkpoint blockade (ICB) therapy is an important element of cancer-targeted therapy and immunotherapy. The programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) pathways are the two main targets of ICB. In this study, we provide a comprehensive review of clinical evidence concerning ICB therapy in gynecological cancers and discuss future implications. All clinical trials of ICB therapy in gynecological cancers were reviewed. We searched ClinicalTrials.gov to collect data from completed and ongoing clinical trials. The clinical evidence regarding the efficacy of ICB agents in gynecological cancers were discussed. Six phase III clinical trials have reported their results of primary outcomes, and a total of 25 phase II clinical trials have been completed. As revealed in phase III trials, pembrolizumab (a PD-1 antibody) improved the overall survival and progression-free survival in endometrial cancer patients with mismatch repair deficiency and cervical cancer patients with expressions of PD-L1. Based on these findings, pembrolizumab was approved by the Food and Drug Administration and European Medicines Agency as a cancer medication used to treat certain patients with endometrial cancer or cervical cancer. Other PD-1 antibodies, including dostarlimab and cemiplimab, also showed antitumor efficacy in clinical trials. Dostarlimab treatment showed an encouraging response rate in endometrial cancer patients with mismatch repair deficiency. Cemiplimab treatment led to a longer overall survival and a lower risk of death than chemotherapy among patients with recurrent cervical cancer. Three completed phase III trials investigated anti-PD-L1 agents (atezolizumab and avelumab) in the treatment of ovarian cancer. The results were not encouraging. Other strategies of ICB therapy which had showed potential clinical benefit in the treatment of gynecological cancers in early-phase trials need to be further evaluated in late-stage trials. The antitumor efficacy of ICB therapy is promising, and the key to making further progress in the treatment of gynecological cancers is to identify more biomarkers and explore innovative combination treatments with other targeted therapies.

Epi-immunotherapy for cancers: rationales of epi-drugs in combination with immunotherapy and advances in clinical trials

Over the last two decades, several epi-drugs, immune checkpoint inhibitors (ICIs) and adoptive cell therapies have received clinical approval for use in certain types of cancer. However, monotherapy with epi-drugs or ICIs has shown limited efficacy in most cancer patients. Epigenetic agents have been shown to regulate the crosstalk between the tumor and host immunity to alleviate immune evasion, suggesting that epi-drugs can potentially synergize with immunotherapy. In this review, we discuss recent insights into the rationales of incorporating epigenetic therapy into immunotherapy, called epi-immunotherapy, and focus on an update of current clinical trials in both hematological and solid malignancies. Furthermore, we outline the future challenges and strategies in the field of cancer epi-immunotherapy.

The emerging role of immune checkpoint inhibitors for the treatment of breast cancer

INTRODUCTION

Breast cancer has traditionally been viewed as immunogenically 'cold,' but two immune checkpoint inhibitors have been approved in combination with chemotherapy for PD-L1 positive advanced triple-negative breast cancer (TNBC), and pembrolizumab was also recently approved for early stage TNBC. As the landscape is rapidly evolving, a comprehensive review of checkpoint inhibitors in breast cancer is needed to aid clinicians in selecting appropriate candidates for therapy, and to highlight ongoing promising studies in this area and topics in need of further investigation.

AREA COVERED

This review summarizes the latest evidence from completed and ongoing trials of immune checkpoint inhibitors. Ongoing studies were identified using a search of ClinicalTrials.gov with the term 'breast cancer' along with specific checkpoint inhibitor agents.

EXPERT OPINION

A number of novel combination strategies are under investigation to enhance response and overcome resistance to immunotherapy, with promising preliminary data from checkpoint inhibitors targeting TIGIT, combinations with small molecule inhibitors such as lenvatinib, and injectable agents directly influencing the immune microenvironment. As immunotherapy enters into the curative setting, biomarkers predictive of immunotherapy benefit are needed, as PD-L1 status has not been a helpful discriminator in completed trials in early-stage breast cancer.

Transposable element regulation and expression in cancer

Approximately 45% of the human genome is composed of transposable elements (TEs). Expression of these elements is tightly regulated during normal development. TEs may be expressed at high levels in embryonic stem cells but are epigenetically silenced in terminally differentiated cells. As part of the global 'epigenetic dysregulation' that cells undergo during transformation from normal to cancer, TEs can lose epigenetic silencing and become transcribed, and, in some cases, active. Here, we summarize recent advances detailing the consequences of TE activation in cancer and describe how these understudied residents of our genome can both aid tumorigenesis and potentially be harnessed for anticancer therapies.

Evolution of Immunotherapy for Ovarian Cancer from a Bird's-Eye Perspective: A Text-Mining Analysis of Publication Trends and Topics

Objectives

Ovarian tumors are among the most prominent gynecological malignancies and have a poor prognosis. Immunotherapy has undergone incredible progress in the past two decades. Our study aimed to use a bibliometric approach to identify research trends in ovarian cancer immunotherapy.

Methods

Literature on this topic published from 2000-2020 was retrieved from the Web of Science Core Citation database and analyzed using the bibliometric analysis software VOSviewer and CiteSpace.

Results

A total of 1729 articles on ovarian cancer immunotherapy published from January 2000 to December 2020 were identified. The number of published articles increased each year, from 40 in 2000 to 209 in 2020. These publications were from 61 countries, and the USA showed a dominant position in publication output, total citations, and average number of citations per paper. Co-citation networks revealed 14 subtopics. 'PD-L1 expression,' 'tumor reactive til,' and 'parp inhibitor' are the current potential subtopics. Furthermore, we determined research trends according to the timeline analysis.

Conclusion

Our study exhaustively describes the development and summarizes the research trends of ovarian cancer immunotherapy over the past 20 years.

Molecular methods for increasing the effectiveness of ovarian cancer treatment: a systematic review

Background: The aim of the current study is to analyze and summarize the latest research on improving therapy in ovarian cancer. Materials & methods: Data analysis was based on a review of publications from 2011 to 2021 in the PubMed database with use of the search terms including 'EGFR ovarian cancer', 'folate receptor inhibitors ovarian cancer', 'VEGF ovarian cancer', 'PDGF ovarian cancer' and 'CTLA-4 ovarian cancer'. Results: 6643 articles were found; 238 clinical trials and randomized control trials were analyzed; 122 studies were rejected due to inconsistency with the topic of the work. Conclusion: Extensive research on the treatment of ovarian cancer increases the chance of developing the most effective therapy suited to the individual needs of the patient.

High-dose VitC plus oncolytic adenoviruses enhance immunogenic tumor cell death and reprogram tumor immune microenvironment

Preclinical and clinical studies have validated the antitumor effects of several oncolytic viruses (OVs). However, the efficacy of OVs is limited when they are administered as monotherapies. Combination therapy is a promising direction for oncolytic virotherapy in the future. A high dose of vitamin C (VitC) exerts anticancer effects by triggering the accretion of substantial amounts of reactive oxygen species (ROS). OVs can induce immunogenic tumor cell death and elicit an antitumor immune response. ROS play an important role in immunogenic cell death (ICD). This study aimed to explore whether high-dose VitC in combination with oncolytic adenoviruses (oAds) exhibited a synergistic antitumor effect. High-dose VitC synergized with oAds against tumor by enhancing immunogenic tumor cell death. Combination therapy with high-dose VitC and oAds significantly increased the number of T cells in the tumor microenvironment (TME) and promoted the activation of T cells. Furthermore, the antitumor effect of the combination therapy was CD8⁺ T cell dependent. In addition, combination therapy with high-dose VitC and oAds reprogramed the immunosuppressive TME. Our study provides a new strategy for combination therapy of OVs.

Pembrolizumab plus azacitidine in patients with chemotherapy refractory metastatic colorectal cancer: a single-arm phase 2 trial and correlative biomarker analysis

BACKGROUND

DNA mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) is not responsive to pembrolizumab monotherapy. DNA methyltransferase inhibitors can promote antitumor immune responses. This clinical trial investigated whether concurrent treatment with azacitidine enhances the antitumor activity of pembrolizumab in mCRC.

METHODS

We conducted a phase 2 single-arm trial evaluating activity and tolerability of pembrolizumab plus azacitidine in patients with chemotherapy-refractory mCRC (NCT02260440). Patients received pembrolizumab 200 mg IV on day 1 and azacitidine 100 mg SQ on days 1-5, every 3 weeks. A low fixed dose of azacitidine was chosen in order to reduce the possibility of a direct cytotoxic effect of the drug, since the main focus of this study was to investigate its potential immunomodulatory effect. The primary endpoint of this study was overall response rate (ORR) using RECIST v1.1., and secondary endpoints were progression-free survival (PFS) and overall survival (OS). Tumor tissue was collected pre- and on-treatment for correlative studies.

RESULTS

Thirty chemotherapy-refractory patients received a median of three cycles of therapy. One patient achieved partial response (PR), and one patient had stable disease (SD) as best confirmed response. The ORR was 3%, median PFS was 1.9 months, and median OS was 6.3 months. The combination regimen was well-tolerated, and 96% of treatment-related adverse events (TRAEs) were grade 1/2. This trial was terminated prior to the accrual target of 40 patients due to lack of clinical efficacy. DNA methylation on-treatment as compared to pre-treatment decreased genome wide in 10 of 15 patients with paired biopsies and was significantly lower in gene promoter regions after treatment. These promoter demethylated genes represented a higher proportion of upregulated genes, including several immune gene sets, endogenous retroviral elements, and cancer-testis antigens. CD8+ TIL density trended higher on-treatment compared to pre-treatment. Higher CD8+ TIL density at baseline was associated with greater likelihood of benefit from treatment. On-treatment tumor demethylation correlated with the increases in tumor CD8+ TIL density.

CONCLUSIONS

The combination of pembrolizumab and azacitidine is safe and tolerable with modest clinical activity in the treatment for chemotherapy-refractory mCRC. Correlative studies suggest that tumor DNA demethylation and immunomodulation occurs. An association between tumor DNA demethylation and tumor-immune modulation suggests immune modulation and may result from treatment with azacitidine. Trial registration ClinicalTrials.gov, NCT02260440. Registered 9 October 2014, https://clinicaltrials.gov/ct2/show/NCT02260440 .

A systematic review of phase II trials exploring anti-PD-1/PD-L1 combinations in patients with solid tumors

BACKGROUND

A high number of combinations of PD-1/PD-L1 inhibitors with other anti-cancer therapies are in clinical development. The usefulness of phase II trials in evaluating their efficacy and safety is unclear.

MATERIALS AND METHODS

We performed a systematic search on PubMed and Cochrane Library for phase II trials of PD-1/PD-L1 inhibitors in combination with other anti-cancer therapies (systemic therapy and/or radiotherapy) published between January 1st 2018 and December 31st 2020. Study design, primary endpoint and main outcomes were registered for each paper.

RESULTS

119 articles reporting on 65 regimens were included in our analysis. Backbone agents were more frequently PD-1 inhibitors (pembrolizumab = 47, nivolumab = 41, camrelizumab = 3) followed by anti-PD-L1 (durvalumab = 19, atezolizumab = 6, avelumab = 3). Therapeutic partners were other immunotherapeutic agents (n = 46), targeted therapies (n = 40), chemotherapy (n = 22) or radiotherapy (n = 11). The majority of articles reported on single-arm trials (n = 87, 73%) and response rate was the most frequent primary endpoint (n = 69, 58%). Objective responses, registered in 109 (92%) articles, ranged between 0% and 91%. The incidence of grade 3 or higher treatment-related adverse events, clearly reported in 97 (82%) articles, spanned from 0 to 100%. Five combinations received regulatory approval by Food and Drug Administration or European Medicine Agency for 9 different indications, based on the results of a phase II trial (n = 3) or on a confirmatory phase III trial (n = 6).

CONCLUSIONS

The landscape of phase II trials evaluating PD-1/PD-L1 inhibitors with other anticancer therapies is heterogeneous. Combinations of two immunotherapeutic agents have been the most investigated. Only a minority of indications (8%) granted regulatory approval.

Novel classes of immunotherapy for breast cancer

Immune-checkpoint inhibitors have profoundly changed the treatment landscape for many tumor types. Despite marked improvements in disease control for highly immunogenic cancers, the clinical impact of checkpoint inhibitors in breast cancers to date is limited. Breast cancer is a heterogeneous disease with different levels of PD-L1 expression and variable tumor microenvironment (TME) composition according to molecular subtype. With emerging evidence of the role of different factors involved in immune evasion, there are promising new immunotherapy targets that will reshape early drug development for metastatic breast cancer. This review examines the available evidence for existing and emerging immuno-oncology (IO) approaches including small molecules targeting different regulators of the cancer-immunity cycle.

Treatment Efficacy of Immune Checkpoint Inhibitors for Patients with Advanced or Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis

The treatment efficacy of immune checkpoint inhibitors (ICIs) in colorectal cancer (CRC) has been reported heterogeneously across clinical trials. We conducted a systematic review and meta-analysis to evaluate the efficacy of ICIs in patients with advanced/metastatic CRC. Ovid-Medline was searched to identify clinical trials providing the efficacy outcomes of overall response rate (ORR) or disease control rate (DCR). The pooled ORR and DCR were estimated across all studies and subgroups. Meta-regression was performed to find the influencing factors for treatment efficacy. A total of thirty studies (1870 patients) were eligible. The overall ORR and DCR were 20.1% and 58.5%, respectively, but these results were heterogeneous across studies. Multivariate meta-regression revealed that microsatellite phenotype (odds ratio of MSI-H/dMMR versus MSS/pMMR: 1.67, p < 0.001) and drug regimen (odds ratio of monotherapy versus combination therapy: 1.07, p = 0.019) were the source of heterogeneity and also significantly influenced factors for the efficacy of the treatment. Although the efficacy of ICIs as a first-line therapy was higher than that of ICIs as the second- or more-line therapy (ORR: 51.5% vs. 13.4%, DCR: 85% vs. 49.5%), multivariate regression showed that the line of therapy was not a significant factor for the treatment efficacy. Our study suggests that the microsatellite phenotype and drug regimen, rather than the line of treatment, are the primary factors influencing the treatment response among advanced/metastatic CRC patients treated with an ICI-based regimen.

How metabolism bridles cytotoxic CD8+ T cells through epigenetic modifications

In the direct competition for metabolic resources between cancer cells and tumor-infiltrating CD8+ T cells, the latter are bound to lose out. These effector lymphocytes are therefore rendered exhausted or dysfunctional. Emerging insights into the mechanisms of T cell unresponsiveness in the tumor microenvironment (TME) point towards epigenetic mechanisms as crucial regulatory factors. In this review, we discuss the effects of characteristic components of the TME, i.e. glucose/amino acid dearth with elevated levels of reactive oxygen species (ROS), on DNA methylation and histone modifications in CD8+ T cells. We then take a closer look at the translational potential of epigenetic interventions that aim to improve current immunotherapeutic strategies, including the adoptive transfer of T cell receptor (TCR) or chimeric antigen receptor (CAR) engineered T cells.

Immune-Related Mutational Landscape and Gene Signatures: Prognostic Value and Therapeutic Impact for Head and Neck Cancer

Simple Summary

Immunotherapy has emerged as a standard-of-care for most human malignancies, including head and neck cancer, but only a limited number of patients exhibit a durable clinical benefit. An urgent medical need is the establishment of accurate response predictors, which is handicapped by the growing body of molecular, cellular and clinical variables that modify the complex nature of an effective anti-tumor immune response. This review summarizes more recent efforts to elucidate immune-related mutational landscapes and gene expression signatures by integrative analysis of multi-omics data, and highlights their potential therapeutic impact for head and neck cancer. A better knowledge of the underlying principles and relevant interactions could pave the way for rational therapeutic combinations to improve the efficacy of immunotherapy, in particular for those cancer patients at a higher risk for treatment failure.

Abstract

Immunotherapy by immune checkpoint inhibition has become a main pillar in the armamentarium to treat head and neck cancer and is based on the premise that the host immune system can be reactivated to successfully eliminate cancer cells. However, the response rate remains low and only a small subset of head and neck cancer patients achieves a durable clinical benefit. The availability of multi-omics data and emerging computational technologies facilitate not only a deeper understanding of the cellular composition in the tumor immune microenvironment but also enables the study of molecular principles in the complex regulation of immune surveillance versus tolerance. These knowledges will pave the way to apply immunotherapy more precisely and effectively. This review aims to provide a holistic view on how the immune landscape dictates the tumor fate and vice versa, and how integrative analysis of multi-omics data contribute to our current knowledge on the accuracy of predictive biomarkers and on a broad range of factors influencing the response to immunotherapy in head and neck cancer.