Secukinumab, a human anti-interleukin-17A monoclonal antibody, in patients with psoriatic arthritis (FUTURE 2): a randomised, double-blind, placebo-controlled, phase 3 trial

Beyond TNF Inhibitors: New Pathways and Emerging Treatments for Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by psoriasis, synovitis, enthesitis, spondylitis and association with other extra-articular manifestations. Chronic inflammation of involved tissues possibly leads to structural damage and to a reduction in function and quality of life. The treatment of PsA dramatically changed with the introduction of anti-tumor necrosis factor (TNF)-α drugs, which have been shown to reduce the symptoms and signs of the disease, and slow radiographic progression. However, some patients do not respond to anti-TNFα or have a loss of response. Recently, the discovery of new pathogenic mechanisms have made possible the development of new drugs that target pro-inflammatory cytokines, such as interleukin (IL)-12, IL-23 and IL-17, or interfere with cellular pathways involved in skin, joint and entheseal inflammation. New molecules, namely ustekinumab, secukinumab, and apremilast have shown efficacy and safety over the various components of the disease in randomized clinical trials. These drugs have been recently approved for the treatment of PsA and included in new treatment recommendations. Other molecules are currently being tested in phase III clinical trials and are potential new treatment options for PsA. The aim of this review is to update the new pathways involved in the development of the disease and the emerging treatments for PsA beyond TNFα inhibition.

Differential gene and protein expression of chemokines and cytokines in synovial fluid of patients with arthritis

Background

Psoriatic arthritis (PsA), an inflammatory musculoskeletal disease, develops in approximately 30% of patients with psoriasis. Previously, chemokine (C-X-C motif) ligand 10 (CXCL10) was identified as a predictive biomarker of PsA in patients with psoriasis and was reduced after development of PsA. The purpose of the present study was to explore messenger RNA (mRNA) and protein expression of CXCL10 and its receptor, chemokine (C-X-C motif) receptor 3 (CXCR3), in the joints of patients with PsA to gain insight into their role in the pathogenesis of the disease.

Methods

Sera from 47 patients with PsA and 33 healthy control subjects were compared for expression of CXCL10 by Luminex assay. Synovial fluid (SF) was obtained from patients with PsA (n = 40), osteoarthritis (OA; n = 14), gout (n = 8), and rheumatoid arthritis (RA; n = 11) during clinical care. SF mRNA and protein expression of CXCL10, interleukin-17A (IL-17A), CXCR3, TBX21, RORC and/or interferon γ (IFNγ) were compared among the above-mentioned disease groups, as well as in paired SF and serum samples from patients with PsA using real-time polymerase chain reaction and Luminex assays, respectively.

Results

Serum CXCL10 was significantly higher in patients with PsA than in control subjects (p = 0.0007). CXCL10, IL-17A, and TBX21 expression were elevated in SF cells of patients with PsA compared with those of patients with OA and gout, but not those of patients with RA. CXCR3 and RORC were elevated in PsA SF cells compared with all other patient groups. Concordant results were obtained for CXCL10 and IL-17A protein expression. IFNγ was elevated in PsA SF compared with OA SF (p = 0.015). CXCL10 protein expression was substantially increased in SF (median 7283.9 pg/ml, interquartile range [IQR] 1330–10,362 pg/ml) compared with paired serum samples (median 282.06, IQR 180.7–395.8 pg/ml; p = 0.001), whereas IFNγ was significantly reduced (SF median 6.03 pg/ml, IQR 4.47–8.94 pg/ml; versus serum median 23.70 pg/ml, IQR 3.2–104.6 pg/ml; p = 0.001).

Conclusions

CXCL10 may have an important etiological role in PsA that is analogous to that in RA, and it is a candidate biomarker to distinguish PsA from healthy individuals and from patients with OA and gout.

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.

Efficacy and safety of dose escalation of infliximab therapy in Japanese patients with psoriasis: Results of the SPREAD study

Although infliximab is approved for psoriasis, its efficacy is reduced over time in some patients. The aim of this phase III trial is to evaluate efficacy and safety of infliximab dose escalation in Japanese psoriasis patients with loss of efficacy to standard‐dose therapy. Patients with plaque psoriasis, psoriatic arthritis, pustular psoriasis or psoriatic erythroderma who showed loss of efficacy to standard‐dose therapy received infliximab dose escalation (10 mg/kg every 8 weeks) from weeks 0 to 32. Loss of efficacy was defined as not maintaining 50% reduction in the Psoriasis Area and Severity Index (PASI 50) after achieving PASI 75. Efficacy and safety were evaluated up to week 40. Fifty‐one patients received dose escalation and 43 completed the study. PASI 75 and median improvement rate of PASI score at week 40 were 44% and 70.0%, respectively, showing efficacy in skin symptoms. Efficacies in quality of life, nail psoriasis and joint pain were also obtained. Median serum infliximab level increased from less than 0.1 to 1.1 μg/mL from weeks 0 to 40, showing positive correlation between efficacy and serum infliximab level at week 40. Favorable efficacy was observed in patients with detectable serum infliximab levels (≥0.1 μg/mL) at baseline. Incidences of adverse events, serious adverse events, serious infections and serious infusion reactions were 92%, 10%, 4% and 0%, respectively. No marked difference was observed in both efficacy and safety among psoriasis types. No new safety concerns were observed. Infliximab dose escalation was effective and well‐tolerated in psoriasis patients with loss of efficacy to standard‐dose therapy, suggesting that dose escalation may be a useful therapeutic option for these patients.

Psoriasis

Psoriasis is a chronic, immune-mediated disorder with cutaneous and systemic manifestations and substantial negative effects on patient quality of life. Psoriasis has a strong, albeit polygenic, genetic basis. Whereas approximately half of the accountable genetic effect of psoriasis maps to the major histocompatibility complex, >70 other loci have been identified, many of which implicate nuclear factor-κB, interferon signalling and the IL-23-IL-23 receptor axis. Psoriasis pathophysiology is characterized by abnormal keratinocyte proliferation and immune cell infiltration in the dermis and epidermis involving the innate and adaptive immune systems, with important roles for dendritic cells and T cells, among other cells. Frequent comorbidities are rheumatological and cardiovascular in nature, in particular, psoriatic arthritis. Current treatments for psoriasis include topical agents, photo-based therapies, traditional systemic drugs and biologic agents. Treatments can be used in combination or as monotherapy. Biologic therapies that target specific disease mediators have become a mainstay in the treatment of moderate-to-severe disease, whereas advances in the treatment of mild-to-moderate disease have been limited.

Recent advances in understanding and managing psoriatic arthritis

This article reviews recent advances in psoriatic arthritis (PsA) over the past several years with emphasis on early diagnosis, better understanding of pathogenesis, and new therapeutic approaches. Early diagnosis is important, since people who present late do not fare as well. There are a number of clinical, laboratory, and ultrasound features that can help identify patients destined to develop PsA, and several screening tools have been developed. It is recognized that genetic and epigenetic factors, as well as T cells and cytokines, play a role in the pathogenesis of PsA, and several targets have been identified for therapeutic interventions. New therapies have been developed and tested in PsA and have been found to be highly effective for both skin and joint manifestations of the disease. The expectation is that, in the future, PsA patients will be treated early and more aggressively and that there will not be significant progression of joint damage. Moreover, with effective treatment of the skin and joint disease and management of risk factors for the comorbidities, we can expect to reduce their occurrence and further reduce the excess mortality and reduced quality of life and function in these patients.

Management of psoriatic arthritis in 2016: a comparison of EULAR and GRAPPA recommendations

Psoriatic arthritis (PsA) is a heterogeneous, potentially severe disease. Many therapeutic agents are now available for PsA, but treatment decisions are not always straightforward. To assist in this decision making, two sets of recommendations for the management of PsA were published in 2016 by international organizations - the European League Against Rheumatism (EULAR) and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). In both sets of recommendations, the heterogeneity of PsA is recognized and the place of various drugs in the therapeutic armamentarium is discussed. Such agents include conventional DMARDs, such as methotrexate, and targeted therapies including biologic agents, such as ustekinumab, secukinumab and TNF inhibitors, or the targeted synthetic drug apremilast. The proposed sequential use of these drugs, as well as some other aspects of PsA management, differ between the two sets of recommendations. This disparity is partly the result of a difference in the evaluation process; the focus of EULAR was primarily rheumatological, whereas that of GRAPPA was balanced between the rheumatological and dermatological aspects of disease. In this Perspectives article, we address the similarities and differences between these two sets of recommendations and the implications for patient management.

Secukinumab for ankylosing spondylitis and psoriatic arthritis

The treatment of ankylosing spondylitis (AS) and psoriatic arthritis (PsA) positively changed since the introduction of anti-TNFα drugs. These treatments were shown to reduce the symptoms and signs of the diseases and improve the quality of life. However, a variable percentage of patients do not respond to anti-TNFα or can exhibit a loss of response and, furthermore, despite anti-TNFα drugs' proven efficacy in reducing peripheral radiographic progression in PsA, the impact in reducing radiographic damage in AS is still debated. Recently, the discovery of new pathogenic mechanisms paved the way to the development of new drugs that target other pro-inflammatory cytokines. In particular, the inhibition of interleukin (IL)-17, which is the principal cytokine produced by Th17 lymphocytes, a pro-inflammatory subset involved in both inflammation and new bone formation in AS and PsA, demonstrated promising results. The new molecule secukinumab, an IL-17A inhibitor, showed its efficacy and safety in phase III randomized clinical trials in AS and PsA and is the first non-anti-TNFα biologic approved for the treatment of AS, providing a useful alternative treatment strategy in both diseases. The aim of this article was to review the pathophysiological basis, the efficacy and the safety of secukinumab treatment in AS and PsA patients.

Secukinumab (AIN-457) for the treatment of Psoriasis

Secukinumab (also known as AIN-457) is a human monoclonal antibody targeting IL-17A, which has been recently FDA-approved for the treatment of moderate to severe psoriasis and psoriatic arthritis with coexistent moderate to severe plaque psoriasis based on clinical trials demonstrating excellent efficacy. This review will address the rationale for targeting the IL-23/Th17/IL-17 axis, the role of IL-17 and Th17 cells in psoriasis and other chronic inflammatory diseases, and will examine pre-clinical studies, pharmacologic properties, clinical efficacy, and the safety profile of secukinumab.

Secukinumab is superior to ustekinumab in clearing skin of subjects with moderate-to-severe plaque psoriasis up to 1 year: Results from the CLEAR study

BACKGROUND

Secukinumab demonstrated superior efficacy to ustekinumab at week 4 and week 16 of the CLEAR study, with comparable safety, in subjects with moderate-to-severe plaque psoriasis.

OBJECTIVE

To compare the efficacy and safety of secukinumab and ustekinumab use over 52 weeks.

METHODS

Analysis of 52-week data from CLEAR, a randomized, double-blind, phase 3b study.

RESULTS

Among 676 randomized subjects, secukinumab demonstrated superiority to ustekinumab at week 52 in the proportion of subjects with ≥90% improvement in Psoriasis Area and Severity Index (PASI 90) (76% vs 61% [P < .0001]); PASI 100 responses were 46% versus 36% (P = .0103) and Investigator's Global Assessment responses of clear/almost clear skin were 80% versus 65% (P < .0001). Subjects on secukinumab reported greater reductions in psoriasis-related pain, itching, and scaling, and greater improvement across all quality-of-life measures evaluated (Dermatology Life Quality Index [DLQI], EuroQoL 5-Dimension Health Questionnaire, Work Productivity and Activity Impairment Questionnaire-Psoriasis, and Health Assessment Questionnaire-Disability Index). At week 52, 72% of subjects on secukinumab versus 59% on ustekinumab (P = .0008) reported no impact of skin disease on their lives (DLQI 0/1 response). Safety and tolerability was comparable.

LIMITATIONS

There was no placebo arm.

CONCLUSION

In this head-to-head, double-blind study, secukinumab demonstrated sustained superior efficacy in comparison with ustekinumab in clearing skin through week 52, greater improvement in quality of life, and a favorable and comparable safety profile.

TNFα in the regulation of Treg and Th17 cells in rheumatoid arthritis and other autoimmune inflammatory diseases

TNFα is a principal pro-inflammatory cytokine vital for immunity to infections. However, its excessive production is involved in chronic inflammation and disease pathology in autoimmune diseases. Evidence for its pathogenic role is validated by the fact that its neutralisation by therapeutic agents in vivo is beneficial in ameliorating disease and controlling symptoms. Paradoxically, however, treatment with TNFα inhibitors can either have no clinical effects, or even exacerbate disease in some patients. The explanation for such contradictory outcomes may lay in how and which downstream signalling pathways are activated and drive disease. TNFα causes its effects by binding to either or both of two membrane-bound receptors, TNFR1 and TNFR2. Engagement of the receptors can induce cell death or cell proliferation. T cells both produce and respond to TNFα and depending on whether the cytokine is membrane-bound or soluble and the level of expression of its two receptors, the biological outcome can be distinct. In addition, polymorphisms in genes encoding TNFα and T cell signalling proteins can significantly impact the outcome of TNFα receptor engagement. Early studies revealed that effector T cells in patients with rheumatoid arthritis (RA) are hyporesponsive due to chronic exposure to TNFα. However, recent evidence indicates that the relationship between TNFα and T cell responses is complex and, at times, can be paradoxical. In addition, there is controversy as to the specific effects of TNFα on different T cell subsets. This review will summarise knowledge on how TNFα modulates T cell responses and the effect of engaging either of its two receptors. Furthermore, we discuss how such interactions can dictate the outcome of treatment with TNFα inhibitors.

Secukinumab efficacy in anti-TNF-naive and anti-TNF-experienced subjects with active ankylosing spondylitis: results from the MEASURE 2 Study

BACKGROUND

There is significant unmet need in patients with ankylosing spondylitis (AS) who have inadequate response or intolerance to anti-tumour necrosis factor (TNF) treatment. Secukinumab, an anti-interleukin-17A monoclonal antibody, significantly improved signs and symptoms of AS in the MEASURE 2 study (NCT01649375).

METHODS

Subjects with active AS (N=219) received secukinumab (150 or 75 mg) or placebo at baseline, weeks 1, 2, 3 and 4, and every 4 weeks thereafter. Randomisation was stratified by prior anti-TNF use: anti-TNF-naive or inadequate response/intolerance to one anti-TNF (anti-TNF-IR). The primary endpoint was Assessment of SpondyloArthritis International Society criteria (ASAS) 20 at week 16.

RESULTS

At week 16, 68.2% of anti-TNF-naive subjects treated with secukinumab 150 mg achieved ASAS20 compared with 31.1% treated with placebo (p<0.001). In the anti-TNF-IR group, 50.0% of subjects treated with secukinumab 150 mg achieved an ASAS20 response compared with 24.1% treated with placebo (p<0.05). Numerically greater improvements were observed with secukinumab than with placebo for most secondary endpoints. Clinical responses were sustained through week 52.

CONCLUSIONS

Secukinumab 150 mg provided sustained improvements in signs and symptoms of AS in anti-TNF-naive and anti-TNF-IR subjects through 52 weeks of therapy.

TRIAL REGISTRATION NUMBER

NCT01649375.

Secukinumab for the treatment of psoriatic arthritis

INTRODUCTION

Secukinumab (Cosentyx) is an interleukin-17A (IL-17A) inhibitor administered subcutaneously. Through 2016, it had received approval in a number of countries, including the USA, Japan and in the EU for the treatment of plaque psoriasis, psoriatic arthritis (PsA) and ankylosing spondylitis (AS).

AREAS COVERED

This review addresses the mechanism of action, efficacy and safety of secukinumab observed in clinical studies of patients with PsA. Data from recent studies of secukinumab in psoriasis, PsA and AS are included. Expert commentary: Secukinumab appears to be effective in improving various aspects of PsA, including improvements in psoriatic skin, enthesitis and dactylitis, as well as inhibition of the radiographic progression of peripheral arthritis. Secukinumab was in general well tolerated; the most common adverse events were nasopharyngitis, headache, and upper respiratory tract infection.

The many faces of interleukin-17 in inflammatory skin diseases

Interleukin (IL)-17 is an emerging target for inflammatory skin disorders. Given the remarkable success of its therapeutic inhibition in psoriasis, the pathogenic role of this cytokine is being explored in other immune-mediated diseases. Interestingly, IL-17 is linked to particular skin conditions where its activation coincides with disease flares. The leading hypothesis for its contribution to proinflammatory signalling cascades is driving inflammasome activation. However, IL-17 stimulation also releases a range of noninflammasome-related cytokines from human skin. Furthermore, a role in cytotoxic responses and an important interplay with the microbiome is hypothesized. While treatment failure would be surprising in neutrophilic dermatoses, the picture might be more complex in lymphocyte-mediated conditions. Nonetheless, increasing insights into the pathogenesis suggest that beneficial responses are also probable in the latter conditions. Study of this pathway in the skin reveals some intriguing aspects of the IL-17-related immunological network.

Ixekizumab, an interleukin-17A specific monoclonal antibody, for the treatment of biologic-naive patients with active psoriatic arthritis: results from the 24-week randomised, double-blind, placebo-controlled and active (adalimumab)-controlled period of the phase III trial SPIRIT-P1

OBJECTIVE

To assess the safety and efficacy of ixekizumab, a monoclonal antibody that inhibits interleukin-17A, in a double-blind phase III trial enrolling patients with active psoriatic arthritis (PsA).

METHODS

Patients naive to biologic therapy with active PsA were randomised to subcutaneous injections of placebo (N=106), adalimumab 40 mg once every 2 weeks (active reference; N=101), ixekizumab 80 mg once every 2 weeks (IXEQ2W) (N=103), or ixekizumab 80 mg once every 4 weeks (IXEQ4W) (N=107). Both ixekizumab regimens included a 160-mg starting dose. The primary objective was to assess the superiority of IXEQ2W or IXEQ4W versus placebo as measured by the proportion of patients achieving an American College of Rheumatology 20 (ACR20) response at week 24.

RESULTS

Significantly more patients treated with ixekizumab achieved an ACR20 response with IXEQ2W (62.1%) or IXEQ4W (57.9%) than placebo (30.2%) (p≤0.001; non-responder imputation method). Disease activity and functional disability were significantly improved with both ixekizumab doses versus placebo at weeks 12 and 24, and there was significantly less progression of structural damage at week 24 (p≤0.01). Clearance of plaque psoriasis was greater with ixekizumab than placebo (p≤0.001). Efficacy results with adalimumab, the active reference arm, showed significant improvements versus placebo. Treatment-emergent adverse events were more frequent with ixekizumab (65.7-66.4%) and adalimumab (64.4%) than placebo (47.2%) (p<0.05).

CONCLUSIONS

In biologic-naive patients with active PsA, ixekizumab treatment resulted in improvements in disease activity and physical function, as well as in the inhibition of structural damage progression. Overall, adverse events were more frequent in all active groups compared with placebo.

TRIAL REGISTRATION NUMBER

NCT01695239; EudraCT2011-002326-49; Results.

Safety of secukinumab in the treatment of psoriasis

INTRODUCTION

Secukinumab is a human monoclonal antibody that selectively targets and neutralizes interleukin (IL)-17A, a cytokine that is normally involved in mucocutaneous defense against extracellular organisms and is abnormally expressed in psoriasis. In 2015, secukinumab was the first IL-17A inhibitor approved for the treatment of moderate-to-severe psoriasis.

AREAS COVERED

This review evaluates the safety profile of secukinumab for the treatment of moderate-to-severe psoriasis and its role in the clinical landscape. A literature search was performed for articles published through February 2016; additional data from a pooled safety analysis of 10 Phase II and III secukinumab studies were reviewed.

EXPERT OPINION

Collectively, these studies show that secukinumab demonstrates a highly favorable safety profile, especially compared with commonly used psoriasis treatments such as methotrexate and TNF-α blockers. More specifically, secukinumab carries no increased risks for end-organ toxicities, serious infection, multiple sclerosis, reactivation of latent tuberculosis or hepatitis B, leukemia/lymphoma, and nonmelanoma skin cancer. Mucocutaneous candidiasis is a common side effect and occurs at a rate of 3.55/100 subject-years with secukinumab 300 mg, yet these infections usually do not interfere with maintenance of secukinumab therapy. The combination of proven efficacy and safety make secukinumab an excellent new treatment choice for individuals with moderate-to-severe psoriasis.

Binding site elucidation and structure guided design of macrocyclic IL-17A antagonists

Interleukin-17A (IL-17A) is a principal driver of multiple inflammatory and immune disorders. Antibodies that neutralize IL-17A or its receptor (IL-17RA) deliver efficacy in autoimmune diseases, but no small-molecule IL-17A antagonists have yet progressed into clinical trials. Investigation of a series of linear peptide ligands to IL-17A and characterization of their binding site has enabled the design of novel macrocyclic ligands that are themselves potent IL-17A antagonists.

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.

Progression of fibrosis in patients with chronic viral hepatitis is associated with IL-17(+) neutrophils

BACKGROUND & AIMS

The pro-inflammatory cytokine IL-17 plays a crucial role in liver diseases associated with hepatic fibrosis and increased risk of cancer development. Nevertheless, the cellular source of this cytokine has never been characterized in patients with liver fibrosis.

METHODS

In this study, we investigated liver biopsies from 49 patients with chronic viral hepatitis at different stages of liver fibrosis. We monitored IL-17 production by intracellular flow cytometry, immunofluorescence and immunohistochemical in situ stainings, allowing a precise quantification, characterization and localization of IL-17(+) cells.

RESULTS

Density of IL-17(+) cells increased with the stage of liver fibrosis specifically in fibrotic septa and portal areas (correlation coefficient r = 0.7373; P < 0.0001). Data clearly show that the frequency of intrahepatic IL-17(+) lymphocytes (including T, NKT and NK cells) was independent on stage of liver fibrosis, and we observed no statistical differences in number of IL-17(+) macrophages during progression of fibrosis. On the other hand, the number of IL-17(+) neutrophils in fibrotic septa and portal areas strongly correlated with the stages of fibrosis (correlation coefficient r = 0.6986; P < 0.0001), contributing significantly to total IL-17 production in liver tissue.

CONCLUSIONS

Our data indicate that neutrophils represent an important source of IL-17 in the human liver, especially in late fibrosis stages. Inhibition of this specific harmful subset of neutrophils may offer therapeutic opportunities in fibrotic liver.

Interactions of the Immune System with Skin and Bone Tissue in Psoriatic Arthritis: A Comprehensive Review

Cutaneous psoriasis (e.g., psoriasis vulgaris (PsV)) and psoriatic arthritis (PsA) are complex heterogeneous diseases thought to have similar pathophysiology. The soluble and cellular mediators of these closely related diseases are being elucidated through genetic approaches such as genome-wide association studies (GWAS), as well as animal and molecular models. Novel therapeutics targeting these mediators (IL-12, IL-23, IL-17, IL-17 receptor, TNF) are effective in treating both the skin and joint manifestations of psoriasis, reaffirming the shared pathophysiology of PsV and PsA. However, the molecular and cellular interactions between skin and joint disease have not been well characterized. Clearly, PsV and PsA are highly variable in terms of their clinical manifestations, and this heterogeneity can partially be explained by differences in HLA-associations (HLA-Cw*0602 versus HLA-B*27, for example). In addition, there are numerous other genetic susceptibility loci (LCE3, CARD14, NOS2, NFKBIA, PSMA6, ERAP1, TRAF3IP2, IL12RB2, IL23R, IL12B, TNIP1, TNFAIP3, TYK2) and geoepidemiologic factors that contribute to the wide variability seen in psoriasis. Herein, we review the complex interplay between the genetic, cellular, ethnic, and geographic mediators of psoriasis, focusing on the shared mechanisms of PsV and PsA.

Secukinumab: a promising therapeutic option in spondyloarthritis

Psoriatic arthritis (PsA) is the second most common chronic inflammatory joint disease. Ankylosing spondylitis (AS) is another less common but equally chronic and disabling spondyloarthritis (SpA). Therapeutic agents for the treatment of these diseases have been somewhat lacking as compared with those available for rheumatoid arthritis, which represents a significant challenge for both the treating physician and the pharmaceutical industry. A promising development for our understanding of the physiopathology of PsA and AS involves new targets to interrupt IL-17 and IL-12/IL-23 pathways. Up to 30-40 % of SpA patients have inadequate or poor response, or are intolerant to anti-TNF therapies. Therefore, there has been a clear unmet medical need in an important group of these patients. As a result, new therapeutic targets have emerged for the treatment of both axial and peripheral SpA. Interleukin 17 (IL-17) is a pro-inflammatory cytokine that is increased in psoriatic lesions as well as in the synovial fluid of patients with PsA and in sites of enthesitis in SpA. IL-23 has been shown to play an important role in the polarization of CD4+ T-cells to become IL-17 producers. Based on these evidences, blockade of the cytokine IL-17 or its receptors was considered to have therapeutic implications for the treatment of psoriasis, as well as PsA and AS.This article presents a thorough review of an IL-17 A blocking agent, its mechanism of action, its clinical efficacy and its therapeutic safety.

The IL-17-Th1/Th17 pathway: an attractive target for lung cancer therapy?

INTRODUCTION

There is strong pharmaceutical development of agents targeting the IL-17-TH17 pathway for the treatment of psoriasis (Ps) and psoriatic arthritis (PsA). Lung cancer accounts for 28% of all cancer-related deaths worldwide, and roughly 80% of patients with newly-diagnosed non-small cell lung cancer (NSCLC) present with metastatic disease, with a poor prognosis of around 12 months. Therefore, there is a high unmet medical need for the development of new and potent systemic treatments in this deadly disease. The emergence of immunotherapies such as anti-PD-1 or anti-PDL1 as candidate therapies in non-small cell lung cancer (NSCLC) indicates that targeting critical immuno-modulatory cytokines including those within the IL-17-Th1/Th17 axis may have proven benefit in the treatment of lung cancer. Areas covered: In this review we describe the current evidence for aberrant IL-17-Th1/Th17 settings in cancer, particularly with regard to targeting this axis in NSCLC. We further discuss the current agents under pharmaceutical development which could potentially target this axis, and discuss the current limitations and areas of concern regarding the use of these in lung cancer. Expert opinion: Current evidence suggests that moving forward agents targeting the IL-17-Th1/Th17 pathway may have novel new oncoimmunology indications in the treatment paradigm for NSCLC.

Rebamipide prevents peripheral arthritis and intestinal inflammation by reciprocally regulating Th17/Treg cell imbalance in mice with curdlan-induced spondyloarthritis

Background

Spondyloarthritis (SpA) usually manifests as arthritis of the axial and peripheral joints but can also result in extra-articular manifestations such as inflammatory bowel disease. Proinflammatory cytokine interleukin-17 (IL-17) plays a crucial role in the pathogenesis of SpA. Rebamipide inhibits signal transducer and activator of transcription 3 that controls IL-17 production and Th17 cell differentiation. This study examined the effect of rebamipide on SpA development.

Methods

SKG ZAP-70^W163C mice were immunized with curdlan to induce SpA features. The mice were then intraperitoneally injected with rebamipide or vehicle 3 times a week for 14 weeks and their clinical scores were evaluated. Histological scores of the paw and spine and the length of the gut were measured at sacrifice. Immunohistochemical staining of IL-17 and tumor necrosis factor-α (TNF-α) was performed using tissue samples isolated from the axial joints, peripheral joints, and gut. Spleen tissue samples were isolated from both rebamipide- or vehicle-treated mice with SpA at 14 weeks after curdlan injection to determine the effect of rebamipide on Th17 and regulatory T (Treg) cell differentiation.

Results

Rebamipide decreased the clinical and histological scores of the peripheral joints. The total length of the gut was preserved in rebamipide-treated mice. IL-17 and TNF-α expression in the spine, peripheral joints, and gut was lower in rebamipide-treated mice than in control mice. Th17 cell differentiation was suppressed whereas Treg cell differentiation was upregulated in the spleen of rebamipide-treated mice.

Conclusion

Rebamipide exerted beneficial effects in mice with SpA by preventing peripheral arthritis and intestinal inflammation and by regulating Th17/Treg cell imbalance, suggesting that it can be used as a potential therapeutic agent for treating arthritis to SpA patients.

Secukinumab for rheumatology: development and its potential place in therapy

Rheumatic disease is not a single disorder, but a group of more than 100 diseases that affect joints, connective tissues, and/or internal organs. Although rheumatic diseases like rheumatoid arthritis (RA), psoriatic arthritis, and ankylosing spondylitis (AS) differ in their pathogenesis and clinical presentation, the treatment of these inflammatory disorders overlaps. Non-steroid anti-inflammatory drugs are used to reduce pain and inflammation. Additional disease-modifying anti-rheumatic drugs are prescribed to slowdown disease progression, and is in RA more frequently and effectively applied than in AS. Biologicals are a relatively new class of treatments that specifically target cytokines or cells of the immune system, like tumor necrosis factor alpha inhibitors or B-cell blockers. A new kid on the block is the interleukin-17 (IL-17) inhibitor secukinumab, which has been recently approved by the US Food and Drug Administration for moderate-to-severe plaque psoriasis, psoriatic arthritis, and AS. IL-17 is a proinflammatory cytokine that has an important role in host defense, but its proinflammatory and destructive effects have also been linked to pathogenic processes in autoimmune diseases like RA and psoriasis. Animal models have greatly contributed to further insights in the potential of IL-17 blockade in autoimmune and autoinflammatory diseases, and have resulted in the development of various potential drugs targeting the IL-17 pathway. Secukinumab (AIN457) is a fully human monoclonal antibody that selectively binds to IL-17A and recently entered the market under the brand name Cosentyx(®). By binding to IL-17A, secukinumab prevents it from binding to its receptor and inhibits its ability to trigger inflammatory responses that play a role in the development of various autoimmune diseases. With secukinumab being the first in class to receive Food and Drug Administration approval, this article will further focus on this new biologic agent and review the milestones in its development and marketing.

Efficacy of Subcutaneous Secukinumab in Patients with Active Psoriatic Arthritis Stratified by Prior Tumor Necrosis Factor Inhibitor Use: Results from the Randomized Placebo-controlled FUTURE 2 Study

OBJECTIVE

To determine the effect of prior tumor necrosis factor inhibitor (TNFi) therapy on secukinumab efficacy in psoriatic arthritis (PsA).

METHODS

Patients were randomized to secukinumab 300 mg, 150 mg, 75 mg, or placebo.

RESULTS

American College of Rheumatology 20 responses at Week 24 with secukinumab 300 mg, 150 mg, 75 mg, and placebo were 58.2%, 63.5%, 36.9%, and 15.9% in TNFi-naive (n = 258), and 45.5%, 29.7%, 14.7%, and 14.3% in TNFi-exposed patients (n = 139), respectively. Week 52 responses with secukinumab 300 mg, 150 mg, and 75 mg were 68.7%, 79.4%, and 58.5% in TNFi-naive, and 54.5%, 37.8%, and 35.3% in TNFi-exposed patients, respectively.

CONCLUSION

Secukinumab was efficacious in TNFi-naive and TNFi-exposed patients with PsA, with greatest improvements in TNFi-naive patients.

Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects

INTRODUCTION

Topical, systemic, oral disease modifying, and biologic agents are part of the armamentarium to manage psoriatic disease. The choice of therapy depends upon disease severity, relevant co-morbidities and patient preference. There is great variability in patient response with these agents, and there is still no clear method of selecting the preferred therapeutic agent for efficacy or lack of adverse events.

AREAS COVERED

This article will review the pharmacogenetic and pharmacogenomic targets that are currently known with respect to psoriasis vulgaris, and the most frequent co-morbidity of psoriasis, psoriatic arthritis.

EXPERT OPINION

Presently, no clinically actionable biomarker exists for any therapeutic agent used to treat psoriasis or psoriatic arthritis. The lack of validated outcome measures and conflicting results of open-label studies conducted may be attributed to a multitude of issues that confound discovery. Consequently, studies have been underpowered to identify genes or genetic variants worth translating to clinical practice. In order to achieve a pharmacogenetic/pharmacogenomic signature, improvements in study design of future investigations are required, including carefully designed prospective studies. It is imperative to combine known clinical, serological, and molecular markers with consistent outcomes and an adequate health economic evaluation before they can be adopted widely in clinical practice.

Autoinflammation and HLA-B27: Beyond Antigen Presentation

HLA-B27 associated disorders comprise a group of inflammatory conditions which have in common an association with the HLA class I molecule, HLA-B27. Given this association, these diseases are classically considered disorders of adaptive immunity. However, mounting data are challenging this assumption and confirming that innate immunity plays a more prominent role in pathogenesis than previously suspected. In this review, the concept of autoinflammation is discussed and evidence is presented from human and animal models to support a key role for innate immunity in HLA-B27 associated disorders.

The Role of IL-17 in the Pathogenesis of Psoriasis and Update on IL-17 Inhibitors for the Treatment of Plaque Psoriasis

BACKGROUND

Major advances have been made in the understanding of the pathophysiology of psoriasis.

OBJECTIVES

The authors review the role of interleukin (IL) 17 in the pathogenesis of psoriasis and provide updates on approved and investigational therapies targeting IL-17 and the IL-17 receptor.

METHODS

A PubMed search was performed for relevant literature.

CONCLUSION

The IL-23/Th17 signaling pathway (including IL-17) plays a central role in the pathogenesis of psoriasis. Biologic agents that block IL-17 (secukinumab and ixekizumab) or its receptor (brodalumab) are effective and safe for the treatment of psoriasis.

Inhibiting complex IL-17A and IL-17RA interactions with a linear peptide

IL-17A is a pro-inflammatory cytokine that has been implicated in autoimmune and inflammatory diseases. Monoclonal antibodies inhibiting IL-17A signaling have demonstrated remarkable efficacy, but an oral therapy is still lacking. A high affinity IL-17A peptide antagonist (HAP) of 15 residues was identified through phage-display screening followed by saturation mutagenesis optimization and amino acid substitutions. HAP binds specifically to IL-17A and inhibits the interaction of the cytokine with its receptor, IL-17RA. Tested in primary human cells, HAP blocked the production of multiple inflammatory cytokines. Crystal structure studies revealed that two HAP molecules bind to one IL-17A dimer symmetrically. The N-terminal portions of HAP form a β-strand that inserts between two IL-17A monomers while the C-terminal section forms an α helix that directly blocks IL-17RA from binding to the same region of IL-17A. This mode of inhibition suggests opportunities for developing peptide antagonists against this challenging target.

Increased Th17 cells and IL-17A exist in patients with B cell acute lymphoblastic leukemia and promote proliferation and resistance to daunorubicin through activation of Akt signaling

BACKGROUND

Immune regulation is crucial for the pathogenesis of B-cell acute lymphoblastic leukemia (B-ALL). It has been reported that Th17 cells as a newly identified subset of CD4(+) T cells are involved in the pathogenesis of several hematological disorders. However, the role of Th17 cells in the pathophysiology of B-ALL is still unclear.

METHODS

The frequencies of T cells were determined by flow cytometry in the peripheral blood and bone marrow of 44 newly diagnosed B-ALL patients and 25 age-matched healthy donors. The cell viability and apoptosis were determined by CCK-8 assay and Annexin V staining, respectively. Western blot was applied to identify the level of Akt and Stat3 phosphorylation.

RESULTS

We assessed and observed a significantly increased frequency of Th17 cells and a drastically decreased frequency of Th1 cells in peripheral blood mononuclear cells and bone marrow mononuclear cells from newly diagnosed B-ALL patients compared with healthy donors. Furthermore, increased levels of Th17-related cytokines including IL-17, IL-21, IL-23, IL-1β, and IL-6 were presented in between blood and marrow in B-ALL patients. Both IL-17A and IL-21, two Th17-secreted cytokines, induced the proliferation of B-ALL cell line Nalm-6 and patient B-ALL cells isolated from B-ALL patients, herein either cytokine led to the phosphorylation of Akt and Stat3. Additionally, IL-17A promoted resistance to daunorubicin via activation of Akt signaling and the PI3K/Akt inhibitor LY294002 or perifosine almost completely rescued daunorubicin-induced cell death in B-ALL cells.

CONCLUSIONS

Our findings suggest that elevated Th17 cells secrete IL-17A by which promotes the proliferation and resistance to daunorubicin in B-ALL cells through activation of Akt signaling. Th17 cells may represent a novel target to improve B-ALL immunotherapy.

A Review of Psoriasis, Therapies, and Suicide

Many chronic medical disorders are associated with psychiatric morbidity. Yet the psychological burden of these disorders often goes unnoticed. In dermatology, psoriasis has a higher association with psychiatric illness, including depression and suicide risk, compared with many other conditions. Studies suggest that effective treatment of psoriasis results in the improvement of psychiatric morbidity, particularly depression and anxiety. New biologic treatments for psoriasis may offer help beyond clearing of the skin in these patients and may lead to a reduction of psychiatric morbidity. Although concerns have been raised regarding the potential link between interleukin-17R blockade in the treatment of psoriasis and suicide, current literature provides no evidence to support this association.

New therapies for psoriasis and psoriatic arthritis

PURPOSE OF REVIEW

Over the last several years, novel immunologic pathways pivotal in the development of the pathobiology of psoriasis and psoriatic arthritis (PsA) have been revealed. These discoveries catalyzed a search for new treatment targets resulting in many new therapies that are now available for patients with psoriatic disease.

RECENT FINDINGS

Helper T cells that secrete interleukin-17 (TH17) along with CD8+ cells, innate lymphocyte cells, and gamma delta T cells are important in the pathogenesis of psoriasis and PsA. Recently, agents that target interleukin-17, the interleukin-17 receptor, and interleukin-23 (antip19) have been approved or are in clinical trials. Apremilast, a new oral agent, was approved for the treatment of psoriasis and PsA.

SUMMARY

Secukinumab, an interleukin-17A antibody, has been approved for treatment of psoriasis and PsA in the United States. It is effective with a good safety profile. Ixekizumab, another anti-interleukin-17A antibody, is currently in clinical trials and brodalumab, an interleukin-17 receptor antagonist, was removed from clinical trials because of safety concerns despite demonstrated efficacy in psoriasis and PsA. Targeting interleukin-23 with antibodies to p19 is another approach with encouraging results in psoriasis. Apremilast, an oral agent, approved to treat psoriasis and PsA demonstrates moderate efficacy with an excellent safety record. The role of tofacitinib in psoriatic disease remains to be determined pending a safety review in psoriasis and completion of PsA trials.

Secukinumab: A New Treatment Option for Psoriatic Arthritis

INTRODUCTION

Psoriatic arthritis (PsA) is an immune-mediated chronic inflammatory arthropathy associated with impaired physical function and reduced quality of life. Biologic therapies that target tumor necrosis factor (anti-TNF) have significantly improved clinical outcomes. Partial, non- and transient responses remain common comprising significant unmet clinical need. New therapies with novel modes of action are urgently required.

OBJECTIVES

The interleukin (IL)-17 pathway has recently been attributed a critical role in the pathogenesis of spondyloarthritides. Herein, we review data from clinical studies with secukinumab, a novel fully human IgG1κ anti-IL-17A monoclonal antibody (mAb), in patients with active PsA.

RESULTS

Across two pivotal phase 3 studies, secukinumab provided significant and sustained reductions in the signs and symptoms of PsA, inhibition of radiographic progression, and improved patient-reported outcomes and measures of quality of life. The primary efficacy endpoint, a ≥20% improvement from baseline according to the American College of Rheumatology 20 (ACR20) response at Week 24, was significantly higher in patients treated with secukinumab compared with placebo, with improvements sustained through at least 52 weeks. Clinical benefits were seen with secukinumab regardless of concomitant methotrexate treatment and in patients who were either anti-TNF-naïve or who were inadequate responders to anti-TNF therapy. Secukinumab was well-tolerated, with a safety profile consistent with that previously reported in psoriasis trials. The most common adverse events were nasopharyngitis, upper respiratory tract infections, and headache.

CONCLUSION

Secukinumab offers an effective new addition to the available treatment options for PsA. Regulatory submissions have been filed worldwide, with the first approvals recently obtained in Japan and Europe. Future studies are required to define the optimal timing and strategic use of this novel treatment modality.

FUNDING

Novartis Pharma.

Difficult-To-Treat Juvenile Idiopathic Arthritis: Current and Future Options

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood and is usually treated with non-steroidal anti-inflammatory drugs or disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate or sulfasalazine. However, not all patients respond to these treatments, and toxicities may limit long-term use or diminish compliance. With advances in pharmacotherapy and the development of new therapeutic agents, there have been improvements in treatment of both systemic and non-systemic JIA, particularly with biologic agents such as anti-tumor necrosis factor (TNF)-α, anti-interleukin (IL)-1, and anti-IL6. Anti-cell therapies, such as co-stimulator blockers or anti-CD20, small molecules, and biosimilars represent new areas of interest, and, while many are not yet currently commercially available for use in children, preliminary studies appear to be promising. In the present article, the authors review therapeutic strategies for the different JIA subtypes, mainly according to guidelines and recommendations. Newer and possible future treatments for arthritis, already approved in adults but currently under study in children, are also discussed. Drugs currently in development plans for rheumatoid arthritis, which hopefully will also be useful for JIA patients in the future, are also mentioned in this paper.

IL-17-producing γδ T cells enhance bone regeneration

Immune responses are crucial not only for host defence against pathogens but also for tissue maintenance and repair after injury. Lymphocytes are involved in the healing process after tissue injury, including bone fracture and muscle damage. However, the specific immune cell subsets and mediators of healing are not entirely clear. Here we show that γδ T cells produce IL-17A, which promotes bone formation and facilitates bone fracture healing. Repair is impaired in IL-17A-deficient mice due to a defect in osteoblastic bone formation. IL-17A accelerates bone formation by stimulating the proliferation and osteoblastic differentiation of mesenchymal progenitor cells. This study identifies a novel role for IL-17-producing γδ T cells in skeletal tissue regeneration.

γδ T cells are innate-like lymphocytes that regulate immune responses by producing IL-17A or IFN-γ, but have no known role in bone healing. Here the authors show a nonimmune bone-regenerative function of IL-17A produced by the Vγ6+ subset in mice.

Emerging drugs for psoriatic arthritis

INTRODUCTION

The majority of Psoriatic Arthritis patients experience a good clinical response to anti-Tumor Necrosis Factor (TNF)-α therapies. However, treatment failure with anti-TNF-α can represent a relevant clinical problem.

AREAS COVERED

We review the efficacy and safety profile of biological therapies that have been reported from randomized, controlled trials in phase II and phase III available in Pubmed Database for agents targeting IL-12/23p40 antibody (ustekinumab) and IL-17 (secukinumab), inhibitor of phosphodiesterase 4, (apremilast), and of JAK/STAT pathways (tofacitinib) and CTLA4 co-stimulation (abatacept) in Psoriatic Arthritis.

EXPERT OPINION

In Psoriatic Arthritis, main emerging drugs are represented by the fully human monoclonal IL-12/23p40 antibody, ustekinumab, the agent targeting IL-17, secukinumab, and the inhibitor of phosphodiesterase 4, apremilast. Results on T cell co-stimulation inhibition by abatacept are insufficient both in psoriasis and in PsA. In vitro investigations on JAK/STAT pathways in PsA suggest that tofacitinib could represent a further valuable therapeutic option. Emerging biological treatments other than anti-TNF agents, ustekinumab, secukinumab and apremilast appear promising for Psoriatic Arthritis and recent studies have showed a good efficacy and an acceptable safety profile; however, further and long-term studies are advocated.

Indirect comparisons of the efficacy of subsequent biological agents in patients with psoriatic arthritis with an inadequate response to tumor necrosis factor inhibitors: a meta-analysis

Significant portion of patients with psoriatic arthritis (PsA) could not tolerate or do not have a satisfactory response to either non-steroidal anti-inflammatory drugs (NSAIDs), non-biologic disease-modifying anti-rheumatic drugs (DMARDs), or even TNF inhibitors. Non-TNF inhibitor biologic agents have emerged as second-line therapy in such situation. However, the comparative efficacy of these agents remains unknown as head-to-head randomized controlled trials (RCTs) are not available. RCTs examining the efficacy of non-TNF inhibitor biologic agents in patients with PsA who experienced inadequate response or intolerance of TNF inhibitors were identified. If more than one RCT was available for a given biologic agent, the pooled odds ratio (OR) and 95 % confidence interval (CI) of achieving 20 % improvement according to American College of Rheumatology criteria (ACR20) response across trials were calculated. The pooled OR for each biologic agent was then compared using the indirect comparison technique. Five RCTs of four non-TNF inhibitor biologic agents, including abatacept, secukinumab, ustekinumab, and apremilast, with 675 participants were identified and included in the data analyses. We found no significant difference in any comparisons, with the p values ranging from 0.14 to 0.98. Our study demonstrates that the likelihood of achieving the ACR20 response in patients with TNF inhibitor experience is not significantly different between the four non-TNF biologic agents. However, the interpretation of this analysis is limited by the small sample sizes. Head-to-head comparisons are still required to confirm the comparative efficacy.

Clinical and economic review of secukinumab for moderate-to-severe plaque psoriasis

Secukinumab represents the first IL-17A antagonist among the available biologic therapies approved for moderate-to-severe plaque psoriasis management. Secukinumab demonstrated greater efficacy over placebo, etanercept and ustekinumab in patients that had limited benefit from non-biologic systemic therapies and phototherapy. Despite standard-of-care systemic therapies being more likely to be cost-effective at this time, a Canadian cost-utility analysis found secukinumab to display benefit in quality-of-life gains in moderate-to-severe plaque psoriasis patients, and greater cost-effectiveness when compared to other biologic systemic therapies. Determination of the true economic value of secukinumab amongst the available therapies for moderate-to-severe plaque psoriasis will require continued economic evaluation.