New era of biologic therapeutics in atopic dermatitis

Introduction: Atopic dermatitis (AD) is a common inflammatory skin disease regulated by genetic and environmental factors. Both skin barrier defects and aberrant immune responses are believed to drive cutaneous inflammation in AD. Existing therapies rely largely on allergen avoidance, emollients and topical and systemic immune-suppressants, some with significant toxicity and transient efficacy; no specific targeted therapies are in clinical use today. As our specific understanding of the immune and molecular pathways that cause different subsets of AD increases, a variety of experimental agents, particularly biologic agents that target pathogenic molecules bring the promise of safe and effective therapeutics for long-term use.

Areas covered: This paper discusses the molecular pathways characterizing AD, the contributions of barrier and immune abnormalities to its pathogenesis, and development of new treatments that target key molecules in these pathways. In this review, we will discuss a variety of biologic therapies that are in development or in clinical trials for AD, perhaps revolutionizing treatment of this disease.

Expert opinion: Biologic agents in moderate to severe AD offer promise for controlling a disease that currently lacks good and safe therapeutics posing a large unmet need. Unfortunately, existing treatments for AD aim to decrease cutaneous inflammation, but are not specific for the pathways driving this disease. An increasing understanding of the immune mechanisms underlying AD brings the promise of narrow targeted therapies as has occurred for psoriasis, another inflammatory skin disease, for which specific biologic agents have been demonstrated to both control the disease and prevent occurrence of new skin lesions. Although no biologic is yet approved for AD, these are exciting times for active therapeutic development in AD that might lead to revolutionary therapeutics for this disease.     

The immune microenvironment in vulvar (pre)cancer: review of literature and implications for immunotherapy

ABSTRACT

Introduction: Vulvar squamous cell carcinoma (VSCC) develops via two different pathways: TP53 mutations in a background of lichen sclerosus or a persistent infection with high-risk human papilloma virus (HPV). The latter group of tumor responds better to treatment than the non-virally induced VSCC. This may be explained by a difference in the tumor immune microenvironment (TME).

Areas covered: This review summarizes literature on TME of VSCC and its precursors, and extrapolates this to foster the development of new therapeutic strategies.

Expert opinion: Both types of VSCC and their precursors are infiltrated with variable numbers of M2 macrophages, regulatory T cells and CD8+ T cells, indicating that they express targetable tumor antigens. Type 1 T cell immunity in precursor lesions is associated with fewer recurrences and better clinical responses to immunotherapy. Escape of these lesions and progression toward VSCC is associated with the downregulation of HLA Class I, increased expression of co-inhibitory molecules, infiltration with immunosuppressive cells and the local production of immunosuppressive enzymes and cytokines. More in-depth studies of the VSCC TME are required to fully comprehend the impact of the immune system on VSCC, and subsequently to identify patients who will benefit from immunotherapeutic strategies.     

Biological therapies for psoriasis

Introduction: Biological therapies have revolutionized moderate-to-severe psoriasis treatment. Increased understanding of disease pathogenesis has yielded multiple therapeutic targets involving the IL-23/Th17 pathway, while current therapies continue to be monitored for long-term efficacy and safety.

Areas covered: This review details current understanding of psoriasis immunopathogenesis specifically related to therapeutic targets. Approved and emerging biological psoriasis therapies targeting TNF-α, IL-12/23p40, IL-17 and IL-23p19 are covered. Biological agent uses in special circumstances are reviewed together with the emerging debate on biosimilar therapies and their potential future role in psoriasis and other inflammatory diseases.

Expert opinion: Psoriasis treatment has expanded and has become more effective due to increased understanding of disease pathogenesis. However, lack of efficacy in select psoriasis patients, safety concerns and limited treatment efficacy in psoriasis variants (e.g., pustular) are areas which still need improvement. As such, pharmacogenomics will be of vital importance in future for individualized psoriasis care. Further, a better understanding of the multiple psoriasis comorbidities, especially cardiovascular disease, continues to be of significant interest in the psoriasis community. Last, the emergence of biosimilar agents has the potential to change psoriasis treatment, especially as it relates to better access for the psoriasis community worldwide.     

GM-CSF pathway correction in pulmonary alveolar proteinosis

Importance of the field: Pulmonary alveolar proteinosis (PAP) is a rare disease in which the abnormalities in surfactant metabolism are caused most often by impairments of GM-CSF pathway at different levels in different disease subsets (congenital, secondary, acquired/idiopathic) and for which there are only few, costly invasive therapeutic methods.

Areas covered in this review: This review discusses these impairments, and their pathogenic and clinical consequences along with potential corrective therapies such as exogenous inhaled GM-CSF.

What the reader will gain: Among the PAP disease subsets, in autoimmune PAP the GM-CSF autoantibodies play a major role in disease pathogenesis and their deleterious pulmonary effects can be blocked efficaciously with inhaled GM-CSF.

Take home message: In PAP correction of the abnormalities of the GM-CSF pathway represent a plausible approach demonstrated to be efficacious also in the case of inhaled GM-CSF used for autoimmune PAP.     

Monoclonal antibodies for asthma and chronic obstructive pulmonary disease

Introduction: In asthma and chronic obstructive pulmonary disease (COPD), the inflammation in the airways cannot always be controlled with conventional therapies, such as inhaled corticosteroids. Addition of more specific anti-inflammatory therapies, such as monoclonal antibodies, against inflammation pathways might improve the disease outcome.

Areas covered: This review individually discusses the major inflammation pathways and their potential blocking monoclonal antibodies in asthma and COPD.

Expert opinion: The current use of omalizumab in asthma provides a good example on the potential therapeutic role of monoclonal antibodies in both asthma and COPD. There are many other monoclonal antibodies which are currently investigated as possible therapies in these diseases. The identification of the disease subsets in which such antibodies might exert the maximum benefit opens the door for personalized medicine and for targeted biological therapy in asthma and COPD.     

Deciphering metabonomics biomarkers-targets interactions for psoriasis vulgaris by network pharmacology

Objectives: Psoriasis vulgaris is a chronic inflammatory and immune-mediated skin disease. 44 metabonomics biomarkers were identified by high-throughput liquid chromatography coupled to mass spectrometry in our previous work, but the roles of metabonomics biomarkers in the pathogenesis of psoriasis is unclear.

Methods: The metabonomics biomarker-enzyme network was constructed. The key metabonomics biomarkers and enzymes were screened out by network analysis. The binding affinity between each metabonomics biomarker and target was calculated by molecular docking. A binding energy-weighted polypharmacological index was introduced to evaluate the importance of target-related pathways.

Results: Long-chain fatty acids, phospholipids, Estradiol and NADH were the most important metabonomics biomarkers. Most key enzymes belonged hydrolase, thioesterase and acyltransferase. Six proteins (TNF-alpha, MAPK3, iNOS, eNOS, COX2 and mTOR) were extensively involved in inflammatory reaction, immune response and cell proliferation, and might be drug targets for psoriasis. PI3K-Akt signaling pathway and five other pathways had close correlation with the pathogenesis of psoriasis and could deserve further research.

Conclusions: The inflammatory reaction, immune response and cell proliferation are mainly involved in psoriasis. Network pharmacology provide a new insight into the relationships between metabonomics biomarkers and the pathogenesis of psoriasis.

• KEY MESSAGES

• ??Network pharmacology was adopted to identify key metabonomics biomarkers and enzymes.

• ??Six proteins were screened out as important drug targets for psoriasis.

• ??A binding energy-weighted polypharmacological index was introduced to evaluate the importance of target-related pathways.

     

T-cell co-stimulatory blockade in transplantation: two steps forward one step back!

Introduction: The concern about nephrotoxicity with calcineurin inhibitors led to the search of novel agents for immunosuppression. Based on the requirement of T-cell co-stimulatory signals to fully activated naïve T cells, it became clear that blocking these pathways could be an appealing therapeutic target. However, some unexpected findings were noticed in the recent clinical trials of belatacept, including a higher rate of rejection, which warranted further investigation with some interesting concepts emerging from the bench.

Areas covered: This article aims to review the literature of the B7:CD28 co-stimulatory blockade in transplantation, including the basic immunology behind its development, clinical application and potential limitations.

Expert opinion: Targeting co-stimulatory pathways were found to be much more complex than initially anticipated due to the interplay between not only various co-stimulatory pathways but also various co-inhibitory ones. In addition, co-stimulatory signals have different roles in diverse immune cell types. Therefore, targeting CD28 ligands with cytotoxic T lymphocyte antigen-4 (CTLA4)-Ig may have some deleterious effects, including the inhibition of regulatory T cells, blockade of co-inhibitory signals (CTLA4) and promotion of Th17 cells. Co-stimulatory independence of memory T cells was another unforeseen limitation. Learning how to better integrate co-stimulatory targeting with other immunosuppressive agents will be critical for the improvement of long-term graft survival.     

Immunotherapy of non-small cell lung cancer: report from an international experts panel meeting of the Italian association of thoracic oncology

ABSTRACT

Introduction: The potential long term survival gain, related to immune adaptability and memory, the potential activity across multiple tumour types through targeting the immune system, and the opportunity for combinations offered by the unique mechanism of actions and safety profile of these new agents, all support the role of immunotherapy in the cancer treatment pathway or paradigm.

Areas covered: The authors discuss the recent advances in the understanding of immunology and antitumor immune responses that have led to the development of new immunotherapies, including monoclonal antibodies that inhibit immune checkpoint pathways, such as Programmed Death-1 (PD-1) and Cytotoxic T-Lymphocyte-Associated Antigen 4 (CTLA-4). Currently, two PD-1 inhibitors are available in clinical practice for treatment of advanced non-small cell lung cancer (NSCLC): nivolumab and pembrolizumab.

Expert opinion: Ongoing research will dictate future strategies, including the potential incorporation of immunotherapy in stage dependent treatment settings (early stage locally advanced disease and first line therapy for metastatic disease). Immunotherapy combinations are promising avenues, and careful selection of patients, doses of each agent and information supporting strategies (i.e. concomitant or sequential) is still needed.     

Current and emerging biologic and small molecule therapies for atopic dermatitis

Introduction: Atopic dermatitis (AD) is the most common inflammatory skin disease, yet until recently there were no safe systemic therapies approved for the long-term management of AD in adult patients. A deeper understanding of disease pathogenesis and identification of molecular and cellular changes has resulted in a rapidly evolving pipeline of therapeutics that holds promise for safer long-term control.

Areas covered: In this review, we highlight the growing arsenal of biologic and small molecule antagonists that target pathways implicated in AD pathogenesis. Evidence that AD is driven by multiple immune axes extending beyond the Th2 polarization has resulted in therapies targeting additional pathways, including the Th22, Th17/IL-23, and JAK-STAT pathways. Pruritus, a hallmark of AD, has been linked to multiple mechanisms and various therapeutics have emerged in response to alternative hypotheses.

Expert opinion: Despite the assumption that AD has a common disease mechanism, recent studies indicate that the disorder is characterized by several phenotypes and therapy may need to be tailored to the unique immune traits of specific phenotypes. Targeted therapy should complement and expand our molecular map of AD across the various phenotypic iterations and help push AD pharmacotherapy into a new era of personalized medicine.     

Leptin favors Th17/Treg cell subsets imbalance associated with allergic asthma severity

BackgroundObesity has often been associated with severe allergic asthma (AA). Here, we analyzed the frequency of different circulating CD4⁺T‐cell subsets from lean, overweight and obese AA patients.MethodsMononuclear cells from peripheral blood were obtained from 60 AA patients and the frequency of different CD4⁺T‐cell subsets and type 1 regulatory B cells (Br1) was determined by cytometry. The effect of obese‐related leptin dose on cytokine production and Treg cell function in AA‐derived CD4⁺ T cell cultures was evaluated by ELISA and 3H thymidine uptake, respectively. Leptin levels were quantified in the plasma by ELISA. According to the BMI, patients were stratified as lean, overweight and obese.ResultsAA severity, mainly among obese patients, was associated with an expansion of hybrid Th2/Th17 and Th17‐like cells rather than classic Th2‐like cells. On the other hand, the frequencies of Th1‐like, Br1 cells and regulatory CD4⁺ T‐cell subsets were lower in patients with severe AA. While percentages of the hybrid Th2/Th17 phenotype and Th17‐like cells positively correlated with leptin levels, the frequencies of regulatory CD4⁺ T‐cell subsets and Br1 cells negatively correlated with this adipokine. Interestingly, the obesity‐related leptin dose not only elevated Th2 and Th17 cytokine levels, but also directly reduced the Treg function in CD4⁺ T cell cultures from lean AA patients.ConclusionIn summary, our results indicated that obesity might increase AA severity by favoring the expansion of Th17‐like and Th2/Th17 cells and decreasing regulatory CD4⁺T cell subsets, being adverse effects probably mediated by leptin overproduction.     

Immune checkpoint blockade as a potential therapeutic target in non-small cell lung cancer

ABSTRACT

Introduction: The recent emergence of immune checkpoint blockade therapy and the progression of immunobiology in cancer have spurred an increasing interest in the immunotherapy for advanced non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICIs), designed to directly target immune inhibitory molecules, have demonstrated efficacy in the treatment of patients with advanced NSCLC.

Areas covered: In the present article, the authors summarize the mechanism, efficacy and safety of major ICIs for the treatment of advanced or metastatic NSCLC. Combinations of different ICIs or conventional therapy and/or targeted agents for NSCLC treatment in clinical trials are also updated. In addition, immune-related adverse events and the roles of inhibitory immune checkpoint molecules as potential biomarkers in the immune checkpoint blockade therapy for NSCLC are emphatically elucidated.

Expert opinion: Immunotherapies targeting the immune checkpoint pathways have shown potential to generate durable responses and improve survival for NSCLC patients. Although the toxicity profile of this immunotherapy is manageable, immune-related adverse events and drug resistance may cause therapeutic failure. Therefore, a better understanding of the mechanisms underpinning its function and the potential side effects of ICIs, as well as the identification of predictive biomarkers for patient selection are essential.     

Positioning ustekinumab in moderate-to-severe ulcerative colitis: new kid on the block

ABSTRACT

Introduction: Ulcerative colitis (UC) is a chronic relapsing disorder of the colonic tract. Dysregulated innate and adaptive immune pathways contribute to intestinal inflammation in IBD, and cytokines, including IL-12 and IL-23, play a key role. The blockade of both IL-12 and IL-23 may have an impact on different pathways of inflammation and could be effective for the treatment of inflammatory bowel diseases.

Ustekinumab is a fully human IgG1κ monoclonal antibody which binds to the shared p40 protein subunit of IL-12 and ?23. It is currently approved for several immune-mediated diseases such as moderate to severe plaque psoriasis, psoriatic arthritis, and Crohn’s disease, and has shown promising results in UC.

Areas covered: A review of the literature was performed to understand several aspects including the role of IL-12 and ?23 in UC, the potential therapeutic role of ustekinumab in inflammatory bowel disease, and the positioning of ustekinumab in the therapeutic algorithm of UC, based on extrapolated data from available randomized clinical trials.

Expert opinion: Ustekinumab is effective and safe in UC, and shows potential advantages compared to other drugs in moderate-to-severe UC.     

Noncanonical Wnt as a prognostic marker in prostate cancer: “you can’t always get what you Wnt”

ABSTRACT

Introduction: Wnt signaling is important for normal development, cell proliferation, and cell differentiation. However, aberrations in the pathway can lead to tumorigenesis and cancer progression. Recent genome-wide studies have demonstrated the frequent occurrence of Wnt pathway alterations in prostate cancer. Although alterations in the canonical Wnt pathway in prostate cancer may have an impact on prognosis, recent studies suggest that the noncanonical Wnt pathway also plays an important role in disease progression and treatment resistance.

Areas covered: We review the literature with regard to the potential prognostic significance of noncanonical Wnt signaling in prostate cancer. After a brief overview of the canonical and noncanonical Wnt pathways, we discuss the preclinical and clinical evidence for activation of Wnt signaling in prostate cancer. We focus on clinical evidence for noncanonical Wnt pathway components to serve as potential prognostic biomarkers.

Expert opinion: Although many therapeutic options are available for men with prostate cancer, there remains an unmet need for prognostic and predictive biomarkers to precisely guide clinical management. Early evidence suggests that components of the noncanonical Wnt pathway may serve as prognostic biomarkers. However, prospective validation studies are necessary before these biomarkers can be routinely applied in the clinic.     

Induced regulatory T cells in inhibitory microenvironments created by cancer

Introduction: Regulatory T cells (Tregs) accumulating in the peripheral circulation and tumor sites of patients contribute to tumor escape from the host immune system. Tregs encompass subsets of immune cells with distinct phenotypic and functional properties. Whereas natural (n) or thymic-derived (t) Tregs regulate responses to self-antigens, inducible (i) or peripheral (p) Tregs generated and expanded in regulatory microenvironments control immune responses to a broad variety of antigens.

Areas covered: Tregs accumulating in the tumor microenvironment (TME) are contextually regulated. They acquire phenotypic and functional attributes imposed by the inhibitory molecular pathways operating in situ. Several molecular pathways active in human cancer are reviewed. The pathways may differ from one tumor to another, and environmentally induced Tregs may be functionally distinct. Potential therapeutic strategies for selective silencing of iTregs are considered in the light of the newly acquired understanding of their phenotypic and functional diversity.

Expert opinion: Human Tregs accumulating in cancer comprise ‘bad’ subsets, which inhibit antitumor immunity, and ‘good’ anti-inflammatory subsets, which maintain tolerance to self and benefit the host. Future therapeutic strategies targeting Tregs will need to discriminate between these Treg subsets and will need to consider reprogramming strategies instead of Treg elimination. Re-establishment of effective antitumor immune responses in cancer patients without disturbing a normal homeostatic T-cell balance will greatly benefit from insights into inhibitory pathways engaged by human tumors.     

Non-antigen-specific and antigen-specific immune therapies for chronic hepatitis B: evidences from laboratory benches and patient's bedsides

Introduction: Due to unsatisfactory therapeutic efficacy and considerable side effects of antiviral drugs in patients with chronic hepatitis B (CHB), immunotherapy has emerged as an alternative approach. CHB immunotherapy may be categorized into two main types: i) non-antigen-specific immune therapy and ii) hepatitis B virus (HBV) antigen-specific immune therapy. Although different immune modulators have been used in CHB patients for the last two to three decades, the nature and design of ongoing regimens of immunotherapeutic approaches need considerable modifications.

Areas covered: In this review, the authors have outlined the relevant immunotherapies for CHB patients that have been used for the last two to three decades. The mechanisms underlying the limited therapeutic efficacy of available therapeutic agents for CHB patients have been discussed to aid in the development of an effective therapeutic approach for these patients.

Expert opinion: Circumstantial evidence indicates that a better regimen of immunotherapy may be developed using different HBV-related antigens or combinations of two or more HBV-related antigens, or combinations of HBV-related antigens and antiviral drugs. However, the capacity of ‘inducible immunity' by immune modulators to cure or block progression of liver diseases in CHB patients needs to be addressed.     

The importance of correctly timing cancer immunotherapy

Introduction: The treatment options for cancer—surgery, radiotherapy and chemotherapy—are now supplemented with immunotherapy. Previously underappreciated but now gaining strong interest are the immune modulatory properties of the three conventional modalities. Moreover, there is a better understanding of the needs and potential of the different immune therapeutic platforms. Key to improved treatment will be the combinations of modalities that complete each other’s shortcomings.

Area covered: Tumor-specific T-cells are required for optimal immunotherapy. In this review, the authors focus on the correct timing of different types of chemotherapeutic agents or immune modulators and immunotherapeutic drugs, not only for the activation and expansion of tumor-specific T-cells but also to support and enhance their anti-tumor efficacy.

Expert opinion: At an early phase of disease, clinical success can be obtained using single treatment modalities but at later disease stages, combinations of several modalities are required. The gain in success is determined by a thorough understanding of the direct and indirect immune effects of the modalities used. Profound knowledge of these effects requires optimal tuning of immunomonitoring. This will guide the appropriate combination of treatments and allow for correct sequencing the order and interval of the different therapeutic modalities.     

Mesenchymal stem cell therapy for chronic renal failure

Importance of the field: Chronic kidney disease (CKD) has become a worldwide public health problem. Renal transplantation is the treatment of choice for end-stage renal disease, but is limited by a small number of organ donors and the immune barrier. To overcome these problems, new therapeutic strategies for tissue repair have recently emerged.

Areas covered in this review: We discuss the therapeutic potential of mesenchymal stem cells (MSCs) in kidney injury and examine the latest reports providing evidence supporting MSC efficacy in the treatment of chronic renal failure (CRF).

What the reader will gain: MSCs improve histological and functional outcomes in various CRF model systems. Paracrine effects rather than transdifferentiation might result in the prevention of progressive renal failure. In addition, MSCs can reprogram kidney cell differentiation, and modulate neo-kidney transplantation in CRF.

Take home message: Although many practical problems remain to be addressed, treatment with MSCs will enter the mainstream of CRF treatment.     

Anti-MADCAM therapy for ulcerative colitis

ABSTRACT

Introduction: The mucosal addressin cell adhesion molecule-1 (MAdCAM-1) plays a key role in the endothelial adhesion and migration of lymphocytes to sites of inflammation in inflammatory bowel disease. Therapies that target this pathway appear to be a promising therapeutic approach in the management of ulcerative colitis (UC).

Areas covered: This review provides a summary of the preclinical and available clinical data on the safety and efficacy of ontamalimab (SHP647), a fully human monoclonal antibody that binds and inhibits the action of MAdCAM-1.

Expert opinion: Intestinal immune cell trafficking is emerging as an important component in the pathogenesis of UC. Ontamalimab (SHP647) inhibits this process by preventing the binding of integrins found on the surface of lymphocytes and the endothelial ligand adhesion molecule MAdCAM-1. This monoclonal antibody has already demonstrated safety and efficacy in phase II clinical trials. Its targeted mechanism of action suggests a superior safety profile as compared with the current systemic immunosuppressive therapies. Results from the phase III trials are awaited to establish ontamalimab (SHP647) as a therapeutic option in the management of UC.     

Treatment of severe asthma: entering the era of targeted therapy

Introduction: It is estimated that 5 – 10% of asthma patients suffer from severe asthma. Severe asthma is associated with increased morbidity and mortality. These patients are not controlled with currently available treatments and therefore additional treatment options are needed. Asthma is a heterogeneous disease, and different asthma patient groups probably have different underlying pathophysiology. Novel therapies with, for example, monoclonal antibodies that target certain immunological pathways have become available. These novel treatments are not effective in all patients but only in certain phenotypes.

Areas covered: This review covers the current evidence and novel developments in treatment with monoclonal antibodies in different asthma phenotypes. This includes monoclonal antibodies against IgE, against interleukin (IL)-5 and antibodies targeting IL-13 pathways. Although there is a certain overlap between patient groups benefiting from these treatments, a more detailed identification of responder profiles for these therapies is needed for personalized therapy.

Expert opinion: In recent years, novel monoclonal antibodies have been developed, which are a promising addition to existing therapy in the treatment of severe asthma with eosinophilic inflammation and Th2-driven disease. We expect that several of the new antibodies will become available for clinical practice. In addition, it must be acknowledged that so far no effective strategies are available for patients with non-eosinophilic asthma and further research and development is necessary for this patient group.