Anti-IL-17 Medications Used in the Treatment of Plaque Psoriasis and Psoriatic Arthritis: A Comprehensive Review

Drug safety evaluation of ixekizumab for psoriasis: a review of the current knowledge

INTRODUCTION

Since Anti-IL-17s availability, concerns about their safety have been raised due to the inhibition of physiological activities that IL-17A plays in the immune response against infections. Ixekizumab is a humanized monoclonal antibody specifically targeting IL-17A approved for the treatment of moderate-to-severe psoriasis.

AREAS COVERED

The aim of this review is to evaluate the safety profile of ixekizumab in moderate to severe psoriasis patients. A compressive literature review included article since March 2022.

EXPERT OPINION

in our analysis, most of the reported AEs were mild or moderate and rarely required treatment discontinuation. Among the class specific AEs to consider during ixekizumab treatment, there are the risk of Candida spp infections and the risk of IBD, which both were reported more frequently than if compared with placebo or other biologics (etanercept, ustekinumab, guselkumab). However, the reported candidiasis resulted mild-to moderate, and easily managed. The risk of IBD (both exacerbation and de novo diagnosis) represents a class effect of IL-17 inhibitors, which should be well evaluated before considering starting ixekizumab treatment. the most common AEs were represented by nasopharyngitis, upper respiratory tract infection, and injection-site reactions. The analysed studies confirmed the favourable safety profile of ixekizumab even in more recently published studies.

Lactococcus lactis engineered to deliver hCAP18 cDNA alleviates DNBS-induced colitis in C57BL/6 mice by promoting IL17A and IL10 cytokine expression

With its antimicrobial and immunomodulating properties, the cathelicidin (LL37) plays an important role in innate immune system. Here, we attempted to alleviate chemically induced colitis using a lactococci strain that either directly expressed the precursor to LL37, hCAP18 (LL-pSEC:hCAP18), or delivered hCAP18 cDNA to host cells under the control of the cytomegalovirus promoter (LL-Probi-H1:hCAP18). We also investigated whether the alleviation of symptoms could be explained through modification of the gut microbiota by hCAP18. Mice were administered daily doses of LL-pSEC:hCAP18 or LL-Probi-H1:hCAP18. On day 7, colitis was induced by DNBS. During autopsy, we assessed macroscopic tissue damage in the colon and collected tissue samples for the characterization of inflammation markers and histological analysis. Feces were collected at day 7 for 16S DNA sequencing. We also performed a fecal transplant experiment in which mice underwent colon washing and received feces from Lactococcus lactis-treated mice before DNBS-colitis induction. Treatment with LL-Probi-H1:hCAP18 reduced the severity of colitis symptoms. The protective effects were accompanied by increased levels of IL17A and IL10 in mesenteric lymph node cells. L. lactis administration altered the abundance of Lachnospiraceae and Muribaculaceae. However, fecal transplant from L. lactis-treated mice did not improve DNBS-induced symptoms in recipient mice.

The risk of organ-based comorbidities in psoriasis: a systematic review and meta-analysis

Background

The close relationship between psoriasis and concomitant diseases is widely accepted. However, a comprehensive analysis of organ-based comorbidities in psoriasis is still lacking.

Objective

The authors aimed to present the risk of organ-based comorbidities in psoriasis by comparing the general population.

Methods

The authors retrieved a search of Pubmed, EMBASE, and Cochrane databases for studies reporting organ-based comorbidities in psoriasis versus the general population. Observational studies that met the following criteria were assessed: 1) Psoriasis diagnosis; 2) Cardiovascular or kidney or liver or respiratory or cerebrovascular outcomes; 3) Comparison group of individuals without psoriasis. Pooled Relative Risks (pRRs) and 95% Confidence Intervals (CIs) were calculated by using the random-effect model.

Results

Fifteen observational studies with 216,348 psoriatic patients and 9,896,962 individuals from the general population were included. Psoriasis showed a greater risk of organ-based comorbidities. Compared to the general population, pRR for all organ-based comorbidities was 1.20 (95% CI 1.11‒1.31) in psoriasis, and pRR was lower in mild 0.61 (95% CI 0.46‒0.81) than in moderate/severe patients. pRR was 1.20 (95% CI 1.11‒1.30) for cardiovascular, 1.56 (95% CI 1.20‒2.04), and 1.75 (95% CI 1.33‒2.29) for cerebrovascular and liver diseases, respectively. pRR for coexisting renal and cardiovascular events was 1.09 (95% CI 1.01‒1.18). pRR for coexisting renal and cerebrovascular events was 1.28 (95% CI 0.99‒1.66). pRR for coexisting renal and liver diseases was 1.46 (95% CI 1.10‒1.94). pRR for coexisting cardiovascular and liver diseases was 1.41 (95% CI 1.11‒1.80).

Study limitations

There is heterogeneity.

Conclusion

Psoriasis has a higher risk of single and multiple organ-based comorbidities than the general population. The present study will further improve attention to psoriasis as a systemic inflammatory disease.

Anti-IL-17A ssDNA aptamer ameliorated psoriasis skin lesions in the imiquimod-induced psoriasis mouse model

OBJECTIVES

IL-17 is an important player in the psoriasis pathogenesis, which recruits inflammatory cells to the psoriatic lesions, induced keratinocyte proliferation and plaque formation. Three monoclonal antibodies that block IL-17 have been approved for psoriasis treatment in the last decade. Compared to monoclonal antibodies, aptamers which are single-stranded DNA or RNA, bind with high affinity to proteins or other molecules and are more cost-effective. We previously showed that M2 and M7 anti-IL17A ssDNA aptamers could block IL-17 in vitro. The current study evaluated the therapeutic effects of M2 and M7 anti-IL17A ssDNA aptamers in the imiquimod (IMQ)-induced psoriasis mouse model.

METHODS

IMQ cream and Vaseline (Vas) were administered on the back skin of C57BL/6 mice as IMQ-induced psoriasis and Vas control groups, respectively. In addition, hydrogel-containing aptamers were topically administered on the back skin of the mice, 10 min before IMQ treatment. Psoriatic lesions were evaluated by histology, clinical factors, and psoriasis area severity index (PASI) score. The mRNA expression levels of inflammatory factors, including IL-17A, IL-1β, and S100a9, were assessed with quantitative reverse transcriptase-polymerase chain reaction in the mice back skin.

RESULTS

Application of anti-IL-17A aptamers significantly ameliorated IMQ-induced keratinocyte proliferation, psoriatic lesions cumulative PASI score, IL-17A, IL-β, and S100a9 inflammatory factors mRNA expression levels (p < 0.05).

CONCLUSION

According to our results, it seems that M2 in high concentration and M7 in low concentration can be appropriate candidates to alleviate psoriasis lesions.

Skin Deep: The Role of the Microbiota in Cutaneous Autoimmunity

The skin microbiota is thought to possibly contribute to the pathogenesis of skin autoimmune diseases. The gut microbiota affects systemically the development and function of the immune system, thereby potentially influencing cutaneous autoimmunity as well. In this paper, we review the role of the gut and skin microbiota in cutaneous autoimmune diseases. Besides direct inflammatory effects at the skin barrier, microbiota may contribute to the pathogenesis of skin autoimmune diseases by metabolites, recall immune cell responses, and permeation of antigens to the subepidermal space. Skin and gut barrier dysfunction may represent a common pathophysiologic process allowing microbiota or its particles to promote autoimmune diseases at barrier surfaces.

An Analysis of IL-10, IL-17A, IL-17RA, IL-23A and IL-23R Expression and Their Correlation with Clinical Course in Patients with Psoriasis

Being one of the most common dermatological inflammatory disorders, psoriasis is a frequent subject of research. It is considered to be a T cell-dependent immune disease whose pathogenesis is influenced by cytokines, such as IL-10, IL-17A, IL-17RA, IL-23A and IL-23R. The present study examines whether the expression of selected genes is correlated with the clinical course of psoriasis, assessed by the PASI, BSA and DLQI scales. Skin biopsies and blood from 60 patients with psoriasis and 24 healthy controls were obtained for RNA isolation. These were subjected to RT-PCR for IL-10, IL-17A, IL-17RA, IL-23A and IL-23R genes. The results were presented as an RQ value. IL-17A and IL-23R expression levels were higher in psoriatic skin compared to controls, while IL-10 expression was lower. A positive correlation was also found between RQ for IL-23A and PASI index. Psoriatic skin is characterised by elevated expression of IL-17A and IL-23R and decreased expression of IL-10. This indicates that the selected cytokines may be one of the factors involved in the pathogenesis and pathomechanism of psoriasis, but more studies need to be made before we can elucidate the exact reason for the unbalance in cytokine expression levels.

The role of IL-17 and anti-IL-17 agents in the immunopathogenesis and management of autoimmune and inflammatory diseases

Interleukin-17 (IL-17) is a proinflammatory cytokine involved in chronic inflammation occurring during the pathogenesis of allergy, malignancy, and autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and psoriasis. IL-17 is produced by multiple cell types of adaptive and innate immunity, including T helper 17 cells, CD8 + T cells, γδ T cells, natural killer T cells, and innate lymphoid cells. Monoclonal antibodies (mAbs) targeting IL-17 and/or IL-17R would be a potential approach to study this therapeutic tool for these diseases. In the current review, we aimed to highlight the characteristics of IL-17 and its important role in the pathogenesis of related diseases. Critical evaluation of the mAbs targeting IL-17A and IL-17 receptors (e.g., Ixekizumab, Secukinumab, and Brodalumab) in various immune-mediated diseases will be provided, and finally, their clinical efficacy and safety will be reported.

Plaque-type psoriasis inhibitors

Psoriasis is a common inflammatory skin disorder, which is mediated by the immune system and affects 1-4% of the world's population. Psoriasis is caused by a complex interaction between the immune system, autoantigens, psoriasis-associated genetic factors, and various environmental factors. As a chronic disease requiring long-term treatment, psoriasis is associated with follow-up costs and an economic burden on the patients, their families, and healthcare systems. The current treatments for moderate-to-severe plaque psoriasis include topical therapy, phototherapy, and systemic drugs consisting of biological/non-biological drugs. Within the past two decades, recent biological therapies for psoriasis have rapidly advanced. Moreover, new bispecific agents have the potential for better disease control, while small molecule drugs offer a future alternative to biological drugs and the more cost-effective, long-term treatment of the disease. The present study aimed to review updated data regarding the inhibitors used to improve plaque psoriasis that contain biologics, bispecific agents, small molecules, and aptamers (either approved or in the research phase).

Perspectives on the Genetic Associations of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a common form of inflammatory spinal arthritis with a complex polygenic aetiology. Genome-wide association studies have identified more than 100 loci, including some involved in antigen presentation (HLA-B27, ERAP1, and ERAP2), some in Th17 responses (IL6R, IL23R, TYK2, and STAT3), and others in macrophages and T-cells (IL7R, CSF2, RUNX3, and GPR65). Such observations have already helped identify potential new therapies targeting IL-17 and GM-CSF. Most AS genetic associations are not in protein-coding sequences but lie in intergenic regions where their direct relationship to particular genes is difficult to assess. They most likely reflect functional polymorphisms concerned with cell type-specific regulation of gene expression. Clarifying the nature of these associations should help to understand the pathogenic pathways involved in AS better and suggest potential cellular and molecular targets for drug therapy. However, even identifying the precise mechanisms behind the extremely strong HLA-B27 association with AS has so far proved elusive. Polygenic risk scores (using all the known genetic associations with AS) can be effective for the diagnosis of AS, particularly where there is a relatively high pre-test probability of AS. Genetic prediction of disease outcomes and response to biologics is not currently practicable.

A monocyte-keratinocyte-derived co-culture assay accurately identifies efficacies of BET inhibitors as therapeutic candidates for psoriasiform dermatitis

BACKGROUND

Bromodomain and extra-terminal (BET) proteins perform key roles in epigenetic control of gene expression that is involved in inflammatory conditions, including psoriasiform dermatitis (PsD). Predicting which (of many potential available BET inhibitors) will be effective in vivo is challenging.

OBJECTIVE

We determine if a novel in vitro assay that includes two critical cell types involved in human psoriasis can predict the therapeutic potential of specific BET inhibitors in vivo.

METHODS

An in vitro model consisting of U-937 and HaCaT cell co-culture was created to screen small molecule BET antagonists for inhibition of cutaneous inflammatory genes. Efficacious BET inhibitors were tested in a mouse imiquimod (IMQ)-induced PsD model.

RESULTS

In the co-culture system, HaCaT cells exhibited a marked increase in the secretion of a characteristic set of proinflammatory and Th17-associated cytokines. Of the ten commercially-available small molecules targeting BET proteins assayed, most compounds exhibited inhibitory functions at 1 μM against inflammatory activation, but responded variably at lower concentrations. OTX015, a typical representative for most of the compounds, barely inhibited the inflammatory reactions at 0.1 μM. By contrast, ABBV075 was effective in concentrations as low as 0.01 μM. While oral administration OTX015 in IMQ-treated mice reduced disease severity, ABBV075 equally decreased the symptoms and molecular and cellular severity markers at one-tenth of the minimal dosing required for OTX015.

CONCLUSION

In vitro screening system combined with an in vivo animal model, can serve as a convenient pre-clinical screening tool for the selection of BET inhibitors (and possibly other drugs) that may have clinical potential in psoriasis therapy.

Is Psoriasis Treatment a Risk Factor for Inflammatory Bowel Disease?

Inflammatory bowel diseases—ulcerative colitis and Crohn’s disease—are linked with several environmental and genetic risk factors. There are also known drugs able to induce de novo disease or to exacerbate its course. Several autoimmune disorders are more frequent in patients with inflammatory bowel diseases, including psoriasis. The aim of the presented review was to summarise current knowledge on the links between psoriasis therapy and inflammatory bowel diseases. The interleukin-17 inhibitors (secukinumab, brodalumab and ixekizumab) and tumour necrosis factor inhibitor (etanercept), have the potential to induce ulcerative colitis and Crohn’s disease de novo or exacerbate existing but silent diseases. There is no evidence that other biologic agents used in psoriasis are lined with such risk. The biologic drugs for psoriasis differ in their potential to induce or worsen inflammatory bowel diseases. Currently, there are no recommendations in European guidelines to screen patients with psoriasis for inflammatory bowel diseases. However, based on available evidence, inflammatory bowel diseases should not be forgotten on in-depth diagnostics in patients with psoriasis.

Remission of autoimmune diabetes by anti-TCR combination therapies with anti-IL-17A or/and anti-IL-6 in the IDDM rat model of type 1 diabetes

BACKGROUND

The cytokine IL-17 is a key player in autoimmune processes, while the cytokine IL-6 is responsible for the chronification of inflammation. However, their roles in type 1 diabetes development are still unknown.

METHODS

Therefore, therapies for 5 days with anti-IL-17A or anti-IL-6 in combination with a T cell-specific antibody, anti-TCR, or in a triple combination were initiated immediately after disease manifestation to reverse the diabetic metabolic state in the LEW.1AR1-iddm (IDDM) rat, a model of human type 1 diabetes.

RESULTS

Monotherapies with anti-IL-6 or anti-IL-17 showed no sustained anti-diabetic effects. Only the combination therapy of anti-TCR with anti-IL-6 or anti-IL-17 at starting blood glucose concentrations up to 12 mmol/l restored normoglycaemia. The triple antibody combination therapy was effective even up to very high initial blood glucose concentrations (17 mmol/l). The β cell mass was raised to values of around 6 mg corresponding to those of normoglycaemic controls. In parallel, the apoptosis rate of β cells was reduced and the proliferation rate increased as well as the islet immune cell infiltrate was strongly reduced in double and abolished in triple combination therapies.

CONCLUSIONS

The anti-TCR combination therapy with anti-IL-17 preferentially raised the β cell mass as a result of β cell proliferation while anti-IL-6 strongly reduced β cell apoptosis and the islet immune cell infiltrate with a modest increase of the β cell mass only. The triple combination therapy achieved both goals in a complimentary anti-autoimmune and anti-inflammatory action resulting in sustained normoglycaemia with normalized serum C-peptide concentrations.

IL-17A in Psoriasis and Beyond: Cardiovascular and Metabolic Implications

Interleukin 17A (IL-17A) is one of the currently known six members of the IL-17 cytokine family and is implicated in immune responses to infectious pathogens and in the pathogenesis of inflammatory autoimmune diseases like psoriasis. Psoriatic skin is characterized by high expression of IL-17A and IL-17F, which act on immune and non-immune cell types and strongly contribute to tissue inflammation. In psoriatic lesions, IL-17A, IL-17E, and IL-17F are involved in neutrophil accumulation, followed by the formation of epidermal micro abscesses. IL-17A together with other Th17 cytokines also upregulates the production of several chemokines that are implicated in psoriasis pathogenesis. IL17A-targeting antibodies show an impressive clinical efficacy in patients with psoriasis. Studies have reported an improvement of at least 75% as measured by the psoriasis area and severity index (PASI) in >80% of patients treated with anti-IL-17A therapy. Psoriasis skin manifestations, cardiovascular as well as metabolic disease in psoriasis appear to share pathogenic mechanisms evolving around IL-17A and its proinflammatory role. Thus, anti-IL-17A therapy not only improves skin manifestations of psoriasis, but also cardiovascular inflammation as well as metabolic factors and different domains of psoriatic arthritis (PsA) including peripheral arthritis, enthesitis, dactylitis, and axial involvement. This review summarizes the biological role of IL-17A, before reviewing currently available data on its role in the physiology and pathophysiology of the skin, as well as the cardiovascular and the metabolic system. In conclusion, clinical recommendations for patients with moderate to severe psoriasis based on the current available data are given.

Anti-inflammatory Therapies for Cardiovascular Disease: Signaling Pathways and Mechanisms

Cardiovascular diseases (CVD) are the clinical manifestation of atherosclerosis, a chronic inflammatory disease promoted by several risk factors such as dyslipidemia, type 2 diabetes mellitus, hypertension, and smoking. Acute CVD events are the result of an unresolved inflammatory chronic state that promotes the rupture of unstable plaque lesions. Of note, the existing intensive therapies modify risk factors but do not prevent life-threatening recurrent ischemic events in high-risk patients, who have a residual inflammatory risk displayed by increased C-reactive protein (CRP) levels. Better understanding of the role of innate and adaptive immunity in plaque development and rupture has led to intensive investigation of anti-inflammatory strategies for CVD. Some of them are being tested in specific clinical trials and use lower doses of existing medications originally developed for other inflammatory diseases such as rheumatoid arthritis and psoriasis, which have high CVD risk. Other investigations are retrospective and meta-analyses of existing clinical trials that evaluate the incidence of CVD in these inflammatory diseases. Others are based on preclinical testing such as vaccines. In this article, we summarize the main anti-inflammatory strategies and associated molecular mechanisms that are being evaluated in preclinical or clinical CVD studies.

Personalized medicine-concepts, technologies, and applications in inflammatory skin diseases

The current state, tools, and applications of personalized medicine with special emphasis on inflammatory skin diseases like psoriasis and atopic dermatitis are discussed. Inflammatory pathways are outlined as well as potential targets for monoclonal antibodies and small-molecule inhibitors.

From randomized clinical trials to real life data. An Italian clinical experience with ixekizumab and its management

Interleukin(IL)-17 inhibitors display higher efficacy than both TNFi and IL-12/23i, which increased the goal psoriasis area severity index (PASI) from 75 to PASI 90 or even PASI 100. Ixekizumab, a recombinant, humanized IgG4 monoclonal antibody targeting IL-17A displayed a high efficacy and safety in RCTs, namely UNCOVER-2 and UNCOVER-3. However, few studies examined real-life data for these medications, and those which exist highlight discrepancies in efficacy and safety between RCTs and real-life data, likely due to the heterogeneity of patients treated outside of trials. Thus, we performed a single center large prospective observational study (RLSD) that enrolled 47 psoriatic patients followed for 20 weeks and we compared the obtained data with the UNCOVER studies. At week 20 in RLSD versus UNCOVER-3 both PASI-90 and PASI-100 results were similar, whilst at week 12, the RLSD cohort obtained higher PASI 90 (76 vs 69,3%) and PASI-100 (55 vs 39%) than UNCOVER cohorts. Interestingly we also reported higher injection-site related pain that disappeared after week 12. In conclusion, real-life data together with RCTs contribute to enrich the information background available to dermatologists in daily practice.

Brodalumab: A Review in Moderate to Severe Plaque Psoriasis

Brodalumab (Kyntheum^®) is a human anti-interleukin-17 receptor A (IL-17RA) monoclonal antibody available for use in patients with moderate to severe plaque psoriasis. In the phase III AMAGINE trials in this patient population, 12 weeks of induction therapy with subcutaneous brodalumab was superior to placebo in terms of the proportion of patients with ≥ 75% improvement in the Psoriasis Area and Severity Index score (PASI 75) and the proportion of patients with a static Physician Global Assessment score of 0 or 1. Brodalumab was also superior to ustekinumab for PASI 100 (i.e. complete skin clearance) at week 12. Health-related quality of life (HR-QOL) outcomes improved to a significantly greater extent with brodalumab than with placebo. Moreover, brodalumab was more effective than placebo in patients with difficult-to-treat nail or scalp psoriasis. Brodalumab was generally well tolerated, with low rates of immunogenicity. Efficacy was sustained and brodalumab remained well tolerated during up to 52 weeks of maintenance therapy. Thus, subcutaneous brodalumab is a useful addition to the treatment options currently available for patients with moderate to severe plaque psoriasis.

Selective Interleukin-23 p19 Inhibition: Another Game Changer in Psoriasis? Focus on Risankizumab

The history of psoriasis treatment has been marked by several milestones. Corticosteroids, cyclosporine, tumor necrosis factor alpha (TNF-α) inhibitors and, more recently, interleukin (IL)-17A inhibitors have revolutionized the treatment of psoriasis, each in its own way and time. The IL-23/IL-17 axis is currently considered to be crucial in the pathogenesis of psoriasis and selective IL-23p19 inhibition may bring several advantages with respect to IL-12/23p40 inhibition, or distal blockade of IL-17A or its receptor. In fact, IL-12 axis inhibition does not appear to be essential in psoriasis and IL-12 inhibition may even have a negative effect in the treatment of psoriasis and have potential risks in tumor immune surveillance and in host defense against intracellular pathogens. On the other hand, contrary to IL-17 inhibition, IL-23p19 blockade does not increase the risk of candida infection, nor is it associated with inflammatory bowel disease worsening. Several IL-23p19 inhibitors are currently being developed for the treatment of psoriasis, such as tildrakizumab, guselkumab, and risankizumab. Although clinical data on risankizumab is still scarce, it has shown characteristics that signify a major advance in the treatment of this disease, offering comparable or higher efficacy than IL-17 inhibitors, without the safety concerns of this therapeutic class, combined with the excellent dosing regimen of ustekinumab. Currently, only phase II trial data is available; thus, the results of the large phase III trials will be essential to establish the efficacy and safety profile of risankizumab and its value in the biological armamentarium for the treatment of psoriatic patients.

RNAI-MEDIATED SILENCING OF MATRIX METALLOPROTEINASE 1 IN EPIDERMAL KERATINOCYTES INFLUENCES THE BIOLOGICAL EFFECTS OF INTERLEUKIN 17A

Matrix metalloproteinases (MMPs) are important for the pathogenesis of psoriasis and other autoimmune disorders. In the extracellular matrix, accumulation of proinflammatory cytokines, such as interleukin 17A (IL-17A), leads to induction of several MMPs, including MMP1. MMPs change the composition and other properties of the extracellular matrix. These changes facilitate tissue remodeling and promote the development of psoriatic plaques. The aim of this study was to explore how MMP1 silencing might influence the biological effects of IL-17A on migration and proliferation of human epidermal keratinocytes and the expression of genes involved in their division and differentiation. The experiments were performed with MMP1-deficient and control epidermal keratinocytes, HaCaT-MMP1 and HaCaT-KTR, respectively. Cell proliferation and migration were assessed by comparative analysis of the growth curves and scratch assay, respectively. To quantify cell migration, representative areas of cell cultures were photographed at the indicated time points and compared to each other. Changes in gene expression were analyzed by real-time PCR. The obtained results demonstrated that MMP1 silencing in the cells treated with IL-17A resulted in downregulation of MMP9 and -12, FOSL1, CCNA2, IVL, KRT14 and -17 as well as upregulation of MMP2, CCND1 and LOR. Moreover, MMP1 silencing led to a decrease in cell proliferation and an impairment of cell migration. Thus, MMP1-deficiency in epidermal keratinocytes can be beneficial for psoriasis patients that experience an accumulation of IL-17 in lesional skin. Knocking MMP1 down could influence migration and proliferation of epidermal keratinocytes in vivo, as well as help to control the expression of MMP1, -2, -9 и -12, CCNA2, CCND1, KRT14 and -17 that are crucial for the pathogenesis of psoriasis.

T Cell Hierarchy in the Pathogenesis of Psoriasis and Associated Cardiovascular Comorbidities

The key role of T cells in the pathogenesis of cutaneous psoriasis has been well described in the last decade and the knowledge of the relative role of the different subsets of T cells in psoriasis pathogenesis has considerably evolved. Now, it is clear that IL-17A-producing T cells, including Th17/Tc17, have a central role in the pathogenesis of cutaneous psoriasis and therapies blocking the IL-17A pathway show high clinical efficacy. By contrast, the contribution of IFNγ-producing T cells has progressively become less clear because of the lack of efficacy of anti-IFNγ antibodies in clinical studies. In parallel, the role of CD8⁺ T cells specific for self-antigens has been revived and increasing evidence now indicates that in psoriatic skin the majority CD8⁺ T cells are present in the form of epidermal tissue-resident memory T cells. In the last years it also emerged the possibility of a contribution of T cell recirculation in the pathogenesis of psoriasis and its systemic manifestations. The aim of this review is to define a hierarchy for the different subsets of T cells in the T cell-mediated inflammatory cascade in psoriatic skin. This analysis will possibly help to distinguish the subsets that initiate the disease, those involved in the establishment of the self-sustaining amplification loop that leads to the cutaneous clinical manifestations and finally the subsets that act as downstream players in established lesions. Specific T cell subpopulations finally will be considered for their possible role in propagating inflammation at distant sites and for representing a link with systemic inflammation and cardiovascular comorbidities.

JAK inhibition as a therapeutic strategy for immune and inflammatory diseases

This corrects the article DOI: 10.1038/nrd.2017.201.

Signs of innate immune activation and premature immunosenescence in psoriasis patients

Psoriasis is a chronic inflammatory disease that affects skin and is associated with systemic inflammation and many serious comorbidities ranging from metabolic syndrome to cancer. Important discoveries about psoriasis pathogenesis have enabled the development of effective biological treatments blocking the T helper 17 pathway. However, it has not been settled whether psoriasis is a T cell-mediated autoimmune disease or an autoinflammatory disorder that is driven by exaggerated innate immune signalling. Our comparative gene expression and hierarchical cluster analysis reveal important gene circuits involving innate receptors. Innate immune activation is indicated by increased absent in melanoma 2 (AIM2) inflammasome gene expression and active caspase 1 staining in psoriatic lesional skin. Increased eomesodermin (EOMES) expression in lesional and non-lesional skin is suggestive of innate-like virtual memory CD8+ T cell infiltration. We found that signs of systemic inflammation were present in most of the patients, correlated with the severity of the disease, and pointed to IL-6 involvement in the pathogenesis of psoriatic arthritis. Among the circulating T cell subpopulations, we identified a higher proportion of terminally differentiated or senescent CD8+ T cells, especially in patients with long disease duration, suggesting premature immunosenescence and its possible implications for psoriasis co-morbidities.

SK, Montero E, Pai HV, Palanivelu DV, Melarkode R, Nair P. T cell activation and differentiation is modulated by a CD6 domain 1 antibody Itolizumab

CD6 is associated with T-cell modulation and is implicated in several autoimmune diseases. We previously demonstrated that Itolizumab, a CD6 domain 1 (CD6D1) specific humanized monoclonal antibody, inhibited the proliferation and cytokine production by T lymphocytes stimulated with anti-CD3 antibody or when co-stimulated with ALCAM. Aberrant IL-17 producing CD4+ helper T-cells (Th17) have been identified as pivotal for the pathogenesis of certain inflammatory autoimmune disorders, including psoriasis. Itolizumab has demonstrated efficacy in human diseases known to have an IL-17 driven pathogenesis. Here, in in vitro experiments we show that by day 3 of human PBMC activation using anti-CD3 and anti-CD28 co-stimulation in a Th17 polarizing milieu, 15-35% of CD4+ T-cells overexpress CD6 and there is an establishment of differentiated Th17 cells. Addition of Itolizumab reduces the activation and differentiation of T cells to Th17 cells and decreases production of IL-17. These effects are associated with the reduction of key transcription factors pSTAT3 and RORγT. Further, transcription analysis studies in these conditions indicate that Itolizumab suppressed T cell activation by primarily reducing cell cycle, DNA transcription and translation associated genes. To understand the mechanism of this inhibition, we evaluated the effect of this anti-human CD6D1 mAb on ALCAM-CD6 as well as TCR-mediated T cell activation. We show that Itolizumab but not its F(ab')2 fragment directly inhibits CD6 receptor hyper-phosphorylation and leads to subsequent decrease in associated ZAP70 kinase and docking protein SLP76. Since Itolizumab binds to CD6 expressed only on human and chimpanzee, we developed an antibody binding specifically to mouse CD6D1. This antibody successfully ameliorated the incidence of experimental autoimmune encephalitis in the mice model. These results position CD6 as a key molecule in sustaining the activation and differentiation of T cells and an important target for modulating autoimmune diseases.

Interleukin-17 inhibition: role in psoriasis and inflammatory bowel disease

INTRODUCTION

Interleukin 17 (IL-17) antagonism provides a highly effective approach for treating psoriasis. Exacerbations of inflammatory bowel disease have been reported in anti-IL-17 psoriasis trials.

AIM

To characterize the relationship between IL-17 inhibition and inflammatory bowel disease.

METHODS

A review of English-language articles was performed. Search terms included IL-17, psoriasis, inflammatory bowel disease, secukinumab, ixekizumab and brodalumab.

RESULTS

IL-17 A inhibition, IL-17RA inhibition and IL-17 knockout led to induction or exacerbation of colitis in mouse models. The placebo groups fared better than the treatment group in controlled trials of anti-IL-17 antibody and anti-IL-17 receptor for Crohn's disease (CD). A brodalumab study (N = 1576) revealed one reported CD case. An ixekizumab study (N = 3736) evaluating moderate-to-severe psoriasis, four patients reported CD and seven reported UC while ixekizumab every 2 weeks led to a moderate exacerbation of UC in one patient and new-onset CD in one patient. A secukinumab study (N = 3430) revealed exposure adjusted incidence rates of 0.11 and 0.15 per 100 patient-years for CD and UC, respectively.

DISCUSSION

Anti-IL-17 medications are associated with IBD exacerbation. Caution should be used in prescribing these medications in patients with diagnosed IBD or personal history suggestive of IBD.

Safety and Efficacy of Brodalumab for Moderate-to-Severe Plaque Psoriasis: A Systematic Review and Meta-Analysis

BACKGROUND

Psoriasis is an inflammatory skin disease that affects 2-3% of the worldwide population. The interleukin-17 cytokine family has been proven to play a central role in the pathogenesis of psoriasis. Brodalumab is a novel biologic agent that targets interleukin-17 molecules and their receptors. We aimed to evaluate the safety and efficacy of brodalumab as a therapeutic agent for moderate-to-severe psoriasis in a meta-analysis framework.

METHODS

A computer literature search of PubMed, OVID, Cochrane Central, EMBASE, EBSCO, Scopus, and Web of Science was conducted using relevant keywords. Data were extracted from eligible trials and analyzed using RevMan (Version 5.3 for windows) and OpenMeta [Analyst] software.

RESULTS

Six clinical trials (n = 4118 patients) were pooled in the final analysis. The pooled effect size favored brodalumab over placebo in terms of the Psoriasis Area and Severity Index (PASI) 75 [risk ratio (RR) = 12.61, 95% confidence interval (CI) 9.74-16.34], PASI 90 (RR = 28.72, 95% CI 18.34-44.98), and PASI 100 (RR = 61.23, 95% CI 25.48-147.17). Analysis of secondary outcomes showed that brodalumab was superior to placebo in terms of static physician's global assessment (RR = 32.53, 95% CI 13.80-76.69) and psoriasis symptoms inventory scores (RR = 14.70, 95% CI 8.38-25.78). Meta-regression analysis found a significant linear association between the brodalumab dose and the effect size on PASI and psoriasis symptoms inventory scores. The rate of overall adverse events was slightly higher in the brodalumab group (RR = 1.13, 95% CI 1.06-1.22); however, none of the individual adverse events were significantly higher in the brodalumab group, compared to the placebo group.

CONCLUSION

Brodalumab showed an acceptable safety profile and a robust efficacy in the treatment of moderate-to-severe plaque psoriasis. However, the current evidence is insufficient to confirm maintenance of these results in the long term; therefore, larger studies with longer follow-up periods are required.

Yin and yang of interleukin-17 in host immunity to infection

The interleukin-17 (IL-17) family cytokines, such as IL-17A and IL-17F, play important protective roles in host immune response to a variety of infections such as bacterial, fungal, parasitic, and viral. The IL-17R signaling and downstream pathways mediate induction of proinflammatory molecules which participate in control of these pathogens. However, the production of IL-17 can also mediate pathology and inflammation associated with infections. In this review, we will discuss the yin-and-yang roles of IL-17 in host immunity to pathogens.

Efficacy of ixekizumab compared to etanercept and placebo in patients with moderate-to-severe plaque psoriasis and non-pustular palmoplantar involvement: results from three phase 3 trials (UNCOVER-1, UNCOVER-2 and UNCOVER-3)

BACKGROUND

Palmoplantar psoriasis has significant physical and emotional impact on patients and can be difficult to treat.

OBJECTIVE

To evaluate the efficacy of ixekizumab in the treatment of patients with moderate-to-severe plaque psoriasis and moderate-to-severe non-pustular palmoplantar involvement.

METHODS

In three phase 3, double-blind, placebo-controlled trials, patients with moderate-to-severe non-pustular plaque psoriasis [UNCOVER-1 (N = 1296), UNCOVER-2 (N = 1224), UNCOVER-3 (N = 1346)] were randomized to subcutaneous 80 mg ixekizumab every 2 or 4 weeks (Q2W, Q4W), after a 160-mg starting dose, or placebo through week 12. Additional UNCOVER-2 and UNCOVER-3 cohorts were randomized to 50 mg etanercept biweekly. Patients entering the open-label long-term extension (UNCOVER-3) received ixekizumab Q4W weeks 12-60. Moderate-to-severe palmoplantar involvement was defined as Palmoplantar Psoriasis Area and Severity Index (PPASI) ≥8.

RESULTS

Twenty-eight percent of UNCOVER-1, UNCOVER-2 and UNCOVER-3 patients had baseline palmoplantar involvement (PPASI ≥0, n = 1092) and 9.1% (n = 350) had moderate-to-severe involvement, with mean baseline PPASI ~20, PASI ~24, and most (>60%) had static Physician's Global Assessment ≥4. Higher percentages of patients treated with ixekizumab vs. placebo or etanercept achieved PPASI 50 (approximately 80% vs. 32.9%, 67.8%; ixekizumab, placebo, etanercept, respectively) and PPASI 75 (approximately 70% vs. 18.8%, 44.1%; ixekizumab, placebo, etanercept, respectively) at week 12 (all P < 0.05). PPASI 100 was achieved by higher percentages of ixekizumab-treated patients vs. placebo (approximately 50% vs. 8.2%, P < 0.001) and ixekizumab Q2W-treated patients vs. etanercept (51.8% vs. 32.2%, P < 0.05). Outcomes were maintained or improved in patients continuing on ixekizumab Q4W through week 60. Differences between ixekizumab and placebo or etanercept were statistically significant as early as week 1.

CONCLUSION

In a subpopulation analysis of patients from phase 3 trials with moderate-to-severe non-pustular palmoplantar involvement and moderate-to-severe plaque psoriasis, ixekizumab treatment resulted in greater and more rapid improvements than placebo and etanercept at week 12; improvements were sustained with continued treatment.

Emerging targeted therapies for plaque psoriasis - impact of ixekizumab

BACKGROUND

Recent studies into the pathogenesis of psoriasis have identified the importance of interleukin 17 (IL-17) in disease activity and have thus provided a new target for biologic therapy. Ixekizumab, the most recent US Food and Drug Administration (FDA)-approved anti-IL-17 biologic agent, appears to be a promising medication for patients suffering from moderate-to-severe plaque psoriasis.

METHODS

We reviewed the results of phase III trials for ixekizumab in order to assess the efficacy, safety, and impact on quality of life of this agent in the treatment of plaque psoriasis. Additionally, we compared these results to phase II and phase III trials for other biologic psoriasis medications including the anti-IL-23 agents tildrakizumab and guselkumab, the combined anti-IL-12 and anti-IL-23 agent ustekinumab, and the anti-IL-17 agents brodalumab and secukinumab.

RESULTS

Pooled results from individual studies demonstrate that among the most efficacious dosing regimens of these anti-interleukin therapies, ixekizumab achieves higher Psoriasis Area and Severity Index 75 rates and similar or higher static Physician Global Assessment 0-1 rates than the other anti-IL-17 and anti-IL-23 agents. The safety profile of ixekizumab is similar to these agents, with nasopharyngitis, upper respiratory infection, headache, arthralgia, and injection-site erythema as the most commonly reported adverse events.

CONCLUSION

Ixekizumab is a highly efficacious, newly FDA-approved treatment for moderate-to-severe plaque psoriasis that demonstrates a robust clinical response, significant improvement in patient quality of life, and a favorable safety profile.

Interactions between Type 1 Interferons and the Th17 Response in Tuberculosis: Lessons Learned from Autoimmune Diseases

The classical paradigm of tuberculosis (TB) immunity, with a central protective role for Th1 responses and IFN-γ-stimulated cellular responses, has been challenged by unsatisfactory results of vaccine strategies aimed at enhancing Th1 immunity. Moreover, preclinical TB models have shown that increasing IFN-γ responses in the lungs is more damaging to the host than to the pathogen. Type 1 interferon signaling and altered Th17 responses have also been associated with active TB, but their functional roles in TB pathogenesis remain to be established. These two host responses have been studied in more detail in autoimmune diseases (AID) and show functional interactions that are of potential interest in TB immunity. In this review, we first identify the role of type 1 interferons and Th17 immunity in TB, followed by an overview of interactions between these responses observed in systemic AID. We discuss (i) the effects of GM-CSF-secreting Th17.1 cells and type 1 interferons on CCR2⁺ monocytes; (ii) convergence of IL-17 and type 1 interferon signaling on stimulating B-cell activating factor production and the central role of neutrophils in this process; and (iii) synergy between IL-17 and type 1 interferons in the generation and function of tertiary lymphoid structures and the associated follicular helper T-cell responses. Evaluation of these autoimmune-related pathways in TB pathogenesis provides a new perspective on recent developments in TB research.

Ixekizumab: A Review in Moderate to Severe Plaque Psoriasis

Ixekizumab (Taltz^®) is a subcutaneously administered, humanized anti-interleukin-17A monoclonal antibody indicated for the treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy (USA and EU) or phototherapy (USA). In the phase 3 UNCOVER trials in this patient population, ixekizumab was superior to placebo or etanercept in terms of the proportion of patients achieving a ≥75% reduction from baseline in the Psoriasis Area and Severity Index and in those achieving a static Physician Global Assessment score of 0 or 1, after 12 weeks of induction treatment. Clinical responses to ixekizumab were seen as early as week 1. Patients receiving ixekizumab also reported improvements in health-related quality of life, itching, and work productivity. Clinical responses to ixekizumab were sustained during additional 48 weeks of maintenance treatment. Ixekizumab was generally well tolerated and exhibited low immunogenicity in the UNCOVER trials during up to 60 weeks of therapy. Currently available data indicate that ixekizumab is an effective and generally well tolerated treatment option for patients with moderate to severe plaque psoriasis. It has the potential advantage of one maintenance dose for every 4 weeks.

The Juvenile Psoriatic Arthritis Cohort in the CARRA Registry: Clinical Characteristics, Classification, and Outcomes

Objective.

Children with clinically diagnosed juvenile psoriatic arthritis (JPsA) who were enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry (CARRA-JPsA) were classified according to pediatric International League of Associations for Rheumatology (ILAR) and adult criteria [Classification criteria for Psoriatic Arthritis (CASPAR)]. Data on demographic and clinical features at baseline and 1-year followup were analyzed and compared.

Methods.

Cross-sectional analysis was performed of CARRA-JPsA patients enrolled between May 2010 and December 2013 and stratified according to age at disease onset (≤ or > 4 yrs). Features of patients fulfilling ILAR and CASPAR criteria were compared at baseline and followup using chi square, Fisher’s exact, Mann-Whitney-McNemar, Wilcoxon signed rank, and t tests, as appropriate.

Results.

Among 361 children enrolled as CARRA-JPsA, 72.02% had symptom onset at > 4 years of age, with a male predominance and high prevalence of enthesitis. At followup, statistically significant improvements were reported in arthritis, dactylitis, enthesitis, psoriasis, sacroiliitis, and nail pitting, but not in health questionnaire (HQ) scores. Of the patients, 80.5% fulfilled ILAR criteria for JPsA. Fifty-two patients, whose disease fulfilled CASPAR criteria but had not been included in the JPsA cohort, manifested more enthesitis, sacroiliitis, inflammatory bowel disease and uveitis and less psoriasis.

Conclusion.

The data support division of patients with JPsA into 2 clinical subgroups, according to age at disease onset. Improvement in objective findings did not correlate with changes in HQ scores. Pediatric rheumatologists currently do not diagnose JPsA in all children whose disease manifestations meet CASPAR criteria. Unification of adult and pediatric PsA classification criteria warrants consideration.

Pharmacologic modulation of RORγt translates to efficacy in preclinical and translational models of psoriasis and inflammatory arthritis

The IL-23/IL-17 pathway is implicated in autoimmune diseases, particularly psoriasis, where biologics targeting IL-23 and IL-17 have shown significant clinical efficacy. Retinoid-related orphan nuclear receptor gamma t (RORγt) is required for Th17 differentiation and IL-17 production in adaptive and innate immune cells. We identified JNJ-54271074, a potent and highly-selective RORγt inverse agonist, which dose-dependently inhibited RORγt-driven transcription, decreased co-activator binding and promoted interaction with co-repressor protein. This compound selectively blocked Th17 differentiation, significantly reduced IL-17A production from memory T cells, and decreased IL-17A- and IL-22-producing human and murine γδ and NKT cells. In a murine collagen-induced arthritis model, JNJ-54271074 dose-dependently suppressed joint inflammation. Furthermore, JNJ-54271074 suppressed IL-17A production in human PBMC from rheumatoid arthritis patients. RORγt-deficient mice showed decreased IL-23-induced psoriasis-like skin inflammation and cytokine gene expression, consistent with dose-dependent inhibition in wild-type mice through oral dosing of JNJ-54271074. In a translational model of human psoriatic epidermal cells and skin-homing T cells, JNJ-54271074 selectively inhibited streptococcus extract-induced IL-17A and IL-17F. JNJ-54271074 is thus a potent, selective RORγt modulator with therapeutic potential in IL-23/IL-17 mediated autoimmune diseases.

T Helper Cell Subsets in Clinical Manifestations of Psoriasis

Psoriasis is a chronic inflammatory skin disease, which is associated with systemic inflammation and comorbidities, such as psoriatic arthritis and cardiovascular diseases. The autoimmune nature of psoriasis has been established only recently, conferring a central role to epidermal CD8 T cells recognizing self-epitopes in the initial phase of the disease. Different subsets of helper cells have also been reported as key players in the psoriasis pathogenesis. Here, we reviewed the knowledge on the role of each subset in the psoriatic cascade and in the different clinical manifestations of the disease. We will discuss the role of Th1 and Th17 cells in the initiation and in the amplification phase of cutaneous inflammation. Moreover, we will discuss the recently proposed role of tissue resident Th22 cells in disease memory in sites of recurrent psoriasis and the possible involvement of Th9 cells. Finally, we will discuss the hypothesis of a link between T helper cell subsets recirculating from the skin and the systemic manifestations of psoriasis.