A phase 1, double-blind, placebo-controlled study evaluating single subcutaneous administrations of a human interleukin-12/23 monoclonal antibody in subjects with plaque psoriasis

Efficacy and safety of briakinumab vs. etanercept and placebo in patients with moderate to severe chronic plaque psoriasis

BACKGROUND

The anti-interleukin-12/23p40 monoclonal antibody briakinumab has been shown in a phase II study to be effective psoriasis treatment.

OBJECTIVES

The aim of the current study was to assess the efficacy, safety and tolerability of briakinumab compared with etanercept and placebo in patients with moderate to severe chronic plaque psoriasis.

METHODS

In this phase III, 12-week study (M10-114, NCT00691964), 347 patients were randomized in a 2 : 2 : 1 ratio to receive 200 mg briakinumab at weeks 0 and 4 followed by 100 mg briakinumab at week 8 (n = 138); 50 mg of etanercept twice weekly 3-4 days apart at weeks 0-11 (n = 141); or placebo injections matching active treatment (n = 68). The co-primary efficacy endpoints were the proportion of patients achieving a Physician's Global Assessment (PGA) of 0/1 at week 12, and the proportion of patients achieving a Psoriasis Area and Severity Index (PASI) 75 response at week 12.

RESULTS

Of the briakinumab-treated patients, 71·0% achieved a PGA of 0/1 at week 12 as compared with 39·7% of etanercept-treated patients and 2·9% of placebo-treated patients, (P < 0·001, for both comparisons). Of the briakinumab-treated patients 81·9% achieved a PASI 75 response at week 12 as compared with 56·0% of etanercept-treated and 7·4% of placebo-treated patients (P < 0·001, for both comparisons). Serious adverse event rates were reported in four (2·9%) patients receiving briakinumab, one (0·7%) patient receiving etanercept and one (1·5%) placebo-treated patient.

CONCLUSIONS

In patients with moderate to severe psoriasis, briakinumab had superior efficacy to both placebo and etanercept at 12 weeks as administered in this study.

Ustekinumab: differential use in psoriasis

Chronic plaque psoriasis is a systemic disease affecting over 3% of the population, and many patients are unsatisfied with their current treatment regimen. With advances in understanding of the pathophysiology of psoriasis, new therapeutic options are being developed. The newest of these agents, ustekinumab, offers patients rapid results and the convenience of four annual subcutaneous doses, with efficacy and safety profiles comparable with those of other biologics. However, ustekinumab has been on the market in the US for less than 2 years and will require years of extensive use before the full adverse event profile is fully understood. The purpose of this paper is to summarize the treatment options currently available for psoriasis, with an emphasis on ustekinumab in order to give prescribers an overview of the available data and allow them to make educated and informed prescribing decisions.

Development of the IL-12/23 antagonist ustekinumab in psoriasis: past, present, and future perspectives

The development of ustekinumab as a first-in-class anti-interleukin (IL) 12/23p40 therapeutic agent for psoriasis represents an important example of modern and rational drug design and development. Psoriasis is a chronic, systemic, immune-mediated skin disorder with considerable clinical, psychosocial, and economic burden. Ustekinumab is a human monoclonal antibody (mAb) that binds the p40 subunit common to IL-12 and IL-23, key cytokines in psoriasis pathogenesis. The therapeutic mAb was developed using human gamma-1 immunoglobulin (IgG)-expressing transgenic mice, which created a molecule with endogenous IgG(1) biologic properties and low immunogenicity. Ustekinumab was well tolerated in clinical studies and yielded rapid, significant, and sustained efficacy plus improved quality of life/work performance and reduced depression/anxiety. Its pharmacologic properties afford the most convenient dosing regimen among approved biologics, representing a significant advancement in the treatment of moderate to severe psoriasis. Ustekinumab also holds promise for other immune-mediated disorders with significant unmet need.

Novel biologic therapies in development targeting IL-12/IL-23

Recent research has identified the importance of interleukin 12 (IL)-12 and IL-23 in the immunopathogenesis of psoriasis. The p40 subunit common to IL-12 and IL-23 is an attractive target for selective therapy. Clinical study data are available for two anti-IL-12/23 therapies: ustekinumab (CNTO 1275, approved in 2009 for treatment of plaque psoriasis) and ABT-874. The Phase 3 clinical trials PHOENIX 1 and PHOENIX 2 have shown significant benefit for ustekinumab in moderate-to-severe plaque psoriasis, with PASI 75 response rates ranging from 66% at week 12 (after two injections) and rising to 85% at week 24 (after three injections). Withdrawal of treatment led to a gradual return of psoriasis whereas continued therapy every 12 weeks with ustekinumab maintained PASI 75 response. Analysis of safety data demonstrated a safety profile similar to placebo at week 12 and did not reveal any major safety concerns in blocking IL-12 and IL-23 for periods as long as 18 months. Phase 2 data indicate that ABT-874 is also efficacious in the treatment of moderate-to-severe plaque psoriasis across a range of dosing strategies.

Overrepresentation of IL-17A and IL-22 producing CD8 T cells in lesional skin suggests their involvement in the pathogenesis of psoriasis

BACKGROUND

Although recent studies indicate a crucial role for IL-17A and IL-22 producing T cells in the pathogenesis of psoriasis, limited information is available on their frequency and heterogeneity and their distribution in skin in situ.

METHODOLOGY/PRINCIPAL FINDINGS

By spectral imaging analysis of double-stained skin sections we demonstrated that IL-17 was mainly expressed by mast cells and neutrophils and IL-22 by macrophages and dendritic cells. Only an occasional IL-17(pos), but no IL-22(pos) T cell could be detected in psoriatic skin, whereas neither of these cytokines was expressed by T cells in normal skin. However, examination of in vitro-activated T cells by flow cytometry revealed that substantial percentages of skin-derived CD4 and CD8 T cells were able to produce IL-17A alone or together with IL-22 (i.e. Th17 and Tc17, respectively) or to produce IL-22 in absence of IL-17A and IFN-γ (i.e. Th22 and Tc22, respectively). Remarkably, a significant proportional rise in Tc17 and Tc22 cells, but not in Th17 and Th22 cells, was found in T cells isolated from psoriatic versus normal skin. Interestingly, we found IL-22 single-producers in many skin-derived IL-17A(pos) CD4 and CD8 T cell clones, suggesting that in vivo IL-22 single-producers may arise from IL-17A(pos) T cells as well.

CONCLUSIONS/SIGNIFICANCE

The increased presence of Tc17 and Tc22 cells in lesional psoriatic skin suggests that these types of CD8 T cells play a significant role in the pathogenesis of psoriasis. As part of the skin-derived IL-17A(pos) CD4 and CD8 T clones developed into IL-22 single-producers, this demonstrates plasticity in their cytokine production profile and suggests a developmental relationship between Th17 and Th22 cells and between Tc17 and Tc22 cells.

Current status and new developments in the treatment of psoriasis and psoriatic arthritis with biological agents

Psoriasis is a chronic inflammatory disease affecting 1-3% of the general population. Among psoriatic patients, 5-40% are affected by psoriatic arthritis. Due to the chronic nature of the disease, patients suffer from substantial psychological and financial burdens, thus adding to a significantly impaired quality of life. Traditional systemic therapies for psoriasis, such as methotrexate, cyclosporin A, retinoids or PUVA therapy, have a potential for long-term toxicity and may not always provide sufficient improvement of the disease. The development of novel therapies targeting key steps in the pathogenesis of psoriasis and psoriatic arthritis now provide new and efficient treatment options. Biological therapies for the treatment of psoriasis and/or psoriatic arthritis are defined by their mode of action and can be classified into three categories: the T-cell modulating agents (alefacept and efalizumab), the inhibitors of tumour necrosis factor-alpha (TNFalpha blockers, e.g. adalimumab, certolizumab, etanercept, golimumab and infliximab) and the inhibitors of interleukin (IL) 12 and IL-23 (e.g. ustekinumab and briakinumab). This article provides a brief overview of the currently approved biological agents in the European Union and of some newer agents, such as briakinumab, certolizumab and golimumab.

Targeting IL-23 in human diseases

IMPORTANCE OF THE FIELD

IL-23 is one of the most intriguing cytokine for its many immunological functions, which are the basis of its important role in host defense but also of its possible contribution to the pathogenesis of several diseases.

AREAS COVERED IN THIS REVIEW

The literature and patents about IL-23 pathway and their targeting in therapeutic potential applications. Findings published within the last 5 years receive particular attention.

WHAT THE READER WILL GAIN

An overview of the emerging role of IL-23 in physiological and pathological conditions and a review of the different approaches (IL-23 pathway-based) currently used for autoimmune diseases and cancer therapies and the results obtained both in preclinical models and in clinical trials.

TAKE HOME MESSAGE

Inhibition/targeting of IL-23 may be a good and novel therapeutic strategy, especially in the treatment of diseases like psoriasis, for which current treatments show more pronounced side effects than those of IL-23-blocking and employed as part of specific patient-tailored therapies in inflammatory bowel diseases.

Targeting IL-17 and Th17 cells in rheumatoid arthritis

Identification of interleukin-17 (IL-17) as a powerful proinflammatory cytokine and the recent recognition of a T-helper cell subset that secretes it have focused attention on the role of IL-17 and Th17 cells in rheumatoid arthritis (RA) and other immune-mediated diseases. While understanding of its role in RA is still evolving, evidence from both animal models and human systems provides a compelling rationale for therapeutic targeting of IL-17 in RA. Both direct and indirect approaches to accomplish this are feasible. Mechanistic studies in the context of clinical trials will be required to understand why some strategies may be preferable from the perspectives of efficacy and safety.

Potential role of ustekinumab in the treatment of chronic plaque psoriasis

Psoriasis is a relatively common, chronic and disabling skin disease, with an immune-related pathogenesis and a genetic background which may be triggered by several environmental factors including smoking and infections. There is no cure but several treatment options are available. The treatment of psoriasis is far from being satisfactory due to impractical modalities of topical treatment and suboptimal safety profile of the systemic treatments available. In the last few years, parallel to an improved understanding of the disease pathogenesis, there has been a boost in research on new agents for the treatment of psoriasis. Ustekinumab, a monoclonal antibody targeting the p40 subunit of interleukin (IL)-12 and IL-23, is one such new agent. Psoriasis and its management are briefly reviewed before focusing on the evidence for ustekinumab in the treatment of chronic plaque psoriasis through a systematic search of the main registries of ongoing trials up to December 2009. Ustekinumab proved to be very effective short term in the control of clinical manifestations in psoriasis compared with placebo and with etanercept. Long-term and comparative data are still limited. There is a need for continuing research on the long-term effectiveness and safety of the drug.

Review of ustekinumab, an interleukin-12 and interleukin-23 inhibitor used for the treatment of plaque psoriasis

The pathogenesis of psoriasis is unknown, although it is generally accepted that this chronic inflammatory skin disorder is a complex autoimmune condition similar to other T-cell mediated disorders. Psoriasis imposes a heavy burden on the lifestyle of those affected due to the psychological, arthritic, and cutaneous morbidities; thus significant research has focused on the genetic and immunologic features of psoriasis in anticipation of more targeted, efficacious, and safe therapies. Recently, CD4(+) T helper (Th) 17 cells and interleukins (IL)-12 and -23 have been important in the pathogenesis of T-cell mediated disorders such as psoriasis and has influenced the development of medications that specifically target these key immunological players. Ustekinumab is a monoclonal antibody belonging to a newly developed class of biological, anti-cytokine medications that notably targets the p40 subunit of both IL-12 and -23, both naturally occurring proteins that are important in regulating the immune system and are understood to play a role in immune-mediated inflammatory disorders. Ustekinumab's safety and efficacy has been evaluated for the treatment of moderate-to-severe plaque psoriasis in 3 phase III clinical trials, 2 placebo-controlled (PHOENIX 1 and 2), and 1 comparator-controlled (ACCEPT) study which proved advantageous in patients who were treatment-naive, previously failed other immunosuppressive medications including cyclosporine or methotrexate, were unresponsive to phototherapy, or were unable to use or tolerate other therapies. Ustekinumab has also been investigated for other indications such as psoriatic arthritis, Crohn's disease, and relapsing/remitting multiple sclerosis. We present a concise review evaluating the evidence that supports the use of ustekinumab in the treatment of plaque psoriasis and other conditions.

Ustekinumab

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Ustekinumab: lessons learned from targeting interleukin-12/23p40 in immune-mediated diseases

Interleukin (IL)-12 and IL-23 are related cytokines that have been implicated in the pathogenesis of several immune-mediated disorders. IL-12 and IL-23 are heterodimers made up of a common p40 subunit complexed to unique p35 (IL-12) or p19 (IL-23) subunits. Ustekinumab is a human monoclonal antibody that specifically binds the p40 subunit of IL-12/23. Ustekinumab prevents IL-12 and IL-23 from binding their cell surface receptor complexes, thereby blocking the T helper (Th) 1 (IL-12) and Th17 (IL-23) inflammatory pathways. Here, we discuss the preclinical and human translational data supporting a role for IL-12/23 in the pathogenesis of immune-mediated disorders, and how that rationale was challenged in the clinic during the course of the ustekinumab development program in several indications including psoriasis, psoriatic arthritis, Crohn's disease, and multiple sclerosis. We review the key efficacy and safety data in each of these immune-mediated diseases and compare and contrast the safety lessons learned from IL-12/23 genetically-deficient mice and humans in context of the overall clinical trial experience with ustekinumab.

Effective treatment of psoriasis with etanercept is linked to suppression of IL-17 signaling, not immediate response TNF genes

BACKGROUND

TNF inhibitors have revolutionized the treatment of psoriasis vulgaris as well as psoriatic and rheumatoid arthritis and Crohn disease. Despite our understanding that these agents block TNF, their complex mechanism of action in disease resolution is still unclear.

OBJECTIVE

To analyze globally the genomic effects of TNF inhibition in patients with psoriasis, and to compare genomic profiles of patients who responded or did not respond to treatment.

METHODS

In a clinical trial using etanercept TNF inhibitor to treat psoriasis vulgaris (n = 15), Affymetrix gene arrays were used to analyze gene profiles in lesional skin at multiple time points during drug treatment (baseline and weeks 1, 2, 4, and 12) compared with nonlesional skin. Patients were stratified as responders (n = 11) or nonresponders (n = 4) on the basis of histologic disease resolution. Cluster analysis was used to define gene sets that were modulated with similar magnitude and velocity over time.

RESULTS

In responders, 4 clusters of downregulated genes and 3 clusters of upregulated genes were identified. Genes downmodulated most rapidly reflected direct inhibition of myeloid lineage immune genes. Upregulated genes included the stable dendritic cell population genes CD1c and CD207 (langerin). Comparison of responders and nonresponders revealed rapid downmodulation of innate IL-1beta and IL-8 sepsis cascade cytokines in both groups, but only responders downregulated IL-17 pathway genes to baseline levels.

CONCLUSION

Although both responders and nonresponders to etanercept inactivated sepsis cascade cytokines, response to etanercept is dependent on inactivation of myeloid dendritic cell genes and inactivation of the T(H)17 immune response.

New biologics for psoriasis and psoriatic arthritis

The prevalence of psoriasis is estimated to be 2.2% in the United States, and 6-39% of patients with psoriasis also develop psoriatic arthritis. New advances have been made in developing treatment options. A new human tumor necrosis factor (TNF)-alpha antibody, golimumab, has been shown to significantly improve symptoms of psoriatic arthritis. In addition, clinical trials of certolizumab pegol, a PEGylated Fab' fragment of an anti-TNF-alpha monoclonal antibody, show promising results for treating rheumatoid arthritis and suggest that it may be applicable for treating psoriasis and psoriatic arthritis in the future. New biologic therapies also include antibodies to interleukin-12 and interleukin-23. Phase II studies suggest that ustekinumab is effective in alleviating symptoms of psoriasis and psoriatic arthritis. However, longer studies with radiographic evaluation will be required before their impact on joint destruction can be assessed.

The IL-23/Th17 axis in the immunopathogenesis of psoriasis

Abnormal production of inflammatory mediators is believed to play an important role in the pathogenesis of psoriasis. Emerging data, both in mice and in humans, put the spotlight on a new subset of T helper (Th) cells, in part characterized by their production of IL-17 and accordingly named Th17 cells. Here, we review the development, characterization, and function of human Th17 cells as well as the crucial role of IL-23 in the context of Th17-cell-dependent chronic inflammation in psoriasis. We further discuss recent clinical trials targeting the IL-23/Th17 axis in psoriasis.

From interleukin-23 to T-helper 17 cells: human T-helper cell differentiation revisited

Protracted inflammation leading to dysregulation of effector T-cell responses represents a common feature of a wide range of autoimmune diseases. The interleukin-12 (IL-12)/T-helper 1 (Th1) pathway was thought to be responsible for the pathogenesis of multiple chronic inflammatory diseases, including psoriasis, inflammatory bowel disease, arthritis, or multiple sclerosis, mainly through their production of interferon-gamma and its effects on macrophage activation and chemokine production. However, this initial concept of T-cell-mediated chronic inflammation required an adjustment with the discovery of an IL-12-related cytokine, designated IL-23. IL-23 was rapidly recognized for its involvement in the establishment of chronic inflammation and in the development of a Th cell subset producing IL-17, designated Th17, which is distinct from the previously reported Th1 and Th2 populations. This review aims to describe the characterization of IL-23 and its receptor, its biological activities, as well as its involvement in the development of human Th17 cells and autoimmunity.

Reconciling id, ego, and superego within interleukin-23

The study of interleukin-23 (IL-23) over the past 8 years has led to the realization that cellular immunity is far more complex than previously appreciated, because it is controlled by additional newly identified players. From the analysis of seemingly straightforward cytokine regulation of autoimmune diseases, many limitations of the established paradigms emerged that required reevaluation of the 'rules' that govern the initiation and maintenance of immune responses. This information led to a major revision of the T-helper 1 (Th1)/Th2 hypothesis and discovery of an unexpected link between transforming growth factor-beta-dependent Th17 and inducible regulatory T cells. The aim of this review is to explore the multiple characteristics of IL-23 with respect to its 'id' in autoimmunity, 'ego' in T-cell help, and 'superego' in defense against mucosal pathogens.

Efficacy and safety of ustekinumab, a human interleukin-12/23 monoclonal antibody, in patients with psoriasis: 52-week results from a randomised, double-blind, placebo-controlled trial (PHOENIX 2)

BACKGROUND

Ustekinumab, a human monoclonal antibody against interleukins 12 and 23, has shown therapeutic potential for psoriasis. This study assessed the efficacy and safety of ustekinumab in psoriasis patients and assessed dosing intensification in partial responders.

METHODS

In this multicentre, phase III, double-blind, placebo-controlled study, 1230 patients with moderate-to-severe psoriasis (defined by a psoriasis area and severity index [PASI] score > or =12, and at least 10% total body surface area involvement) were randomly assigned to receive ustekinumab 45 mg (n=409) or 90 mg (n=411) at weeks 0 and 4, then every 12 weeks, or placebo (n=410). Partial responders (ie, patients achieving > or =50% but <75% improvement from baseline in PASI) were re-randomised at week 28 to continue dosing every 12 weeks or escalate to dosing every 8 weeks. Both randomisations were done with a minimisation method via a centralised interactive voice response. The primary endpoint was the proportion of patients achieving at least 75% improvement in PASI (PASI 75) at week 12. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00307437.

FINDINGS

All randomised patients were included in the efficacy analysis. 273 (66.7%) patients receiving ustekinumab 45 mg, 311 (75.7%) receiving ustekinumab 90 mg, and 15 (3.7%) receiving placebo achieved the primary endpoint (difference in response rate 63.1%, 95% CI 58.2-68.0, p<0.0001 for the 45 mg group vs placebo and 72.0%, 67.5-76.5, p<0.0001 for the 90 mg group vs placebo). More partial responders at week 28 who received ustekinumab 90 mg every 8 weeks achieved PASI 75 at week 52 than did those who continued to receive the same dose every 12 weeks (22 [68.8%] vs 11 [33.3%]; difference in response rate 35.4%, 95% CI 12.7-58.1, p=0.004). There was no such response to changes in dosing intensity in partial responders treated with ustekinumab 45 mg. During the placebo-controlled phase, 217 (53.1%) patients in the 45 mg group, 197 (47.9%) in the 90 mg group, and 204 (49.8%) in the placebo group experienced adverse events; serious adverse events were seen in eight (2.0%) patients in the 45 mg group, five (1.2%) in the 90 mg group, and eight (2.0%) in the placebo group.

INTERPRETATION

Although treatment with ustekinumab every 12 weeks is effective for most patients with moderate-to-severe psoriasis, intensification of dosing to once every 8 weeks with ustekinumab 90 mg might be necessary to elicit a full response in patients who only partially respond to the initial regimen.

Dendritic cells and cytokines in human inflammatory and autoimmune diseases

Dendritic cells (DCs) produce cytokines and are susceptible to cytokine-mediated activation. Thus, interaction of resting immature DCs with TLR ligands, for example nucleic acids, or with microbes leads to a cascade of pro-inflammatory cytokines and skewing of T cell responses. Conversely, several cytokines are able to trigger DC activation (maturation) via autocrine, for example TNF and plasmacytoid DCs, and paracrine, for example type I IFN and myeloid DCs, pathways. By controlling DC activation, cytokines regulate immune homeostasis and the balance between tolerance and immunity. The increased production and/or bioavailability of cytokines and associated alterations in DC homeostasis have been implicated in various human inflammatory and autoimmune diseases. Targeting these cytokines with biological agents as already is the case with TNF and IL-1 represents a success of immunology and the coming years will expand the range of cytokines as therapeutic targets in autoinflammatory and autoimmune pathology.

Identification of cellular pathways of "type 1," Th17 T cells, and TNF- and inducible nitric oxide synthase-producing dendritic cells in autoimmune inflammation through pharmacogenomic study of cyclosporine A in psoriasis

Therapeutic modulation of psoriasis with targeted immunosuppressive agents defines inflammatory genes associated with disease activity and may be extrapolated to a wide range of autoimmune diseases. Cyclosporine A (CSA) is considered a "gold standard" therapy for moderate-to-severe psoriasis. We conducted a clinical trial with CSA and analyzed the treatment outcome in blood and skin of 11 responding patients. In the skin, as expected, CSA modulated genes from activated T cells and the "type 1" pathway (p40, IFN-gamma, and STAT-1-regulated genes). However, CSA also modulated genes from the newly described Th17 pathway (IL-17, IL-22, and downstream genes S100A12, DEFB-2, IL-1beta, SEPRINB3, LCN2, and CCL20). CSA also affected dendritic cells, reducing TNF and inducible NO synthase (products of inflammatory TNF- and inducible NO synthase-producing dendritic cells), CD83, and IL-23p19. We detected 220 early response genes (day 14 posttreatment) that were down-regulated by CSA. We classified >95% into proinflammatory or skin resident cells. More myeloid-derived than activated T cell genes were modulated by CSA (54 myeloid genes compared with 11 lymphocyte genes), supporting the hypothesis that myeloid derived genes contribute to pathogenic inflammation in psoriasis. In circulating mononuclear leukocytes, in stark contrast, no inflammatory gene activity was detected. Thus, we have constructed a genomic signature of successful treatment of psoriasis which may serve as a reference to guide development of other new therapies. In addition, these data also identify new gene targets for therapeutic modulation and may be applied to wide range of autoimmune diseases.

Th17 cells: a new therapeutic target in inflammatory dermatoses

Th17 cells, named for their secretion of interleukin-17 (IL-17), are a new class of T-cells involved in a wide range of cutaneous autoimmune and inflammatory conditions. An overactive Th17 cell response in the skin can produce damaging results. There appears to be a partial role for the Th17 axis in the pathogenesis of a range of dermatological diseases including allergic contact dermatitis, atopic dermatitis, psoriasis, and scleroderma. Immunologists have also discovered a unique association between Th17 cells and cutaneous T-cell lymphoma. The Th17 branch has been linked to a number of additional systemic inflammatory diseases with significant cutaneous pathology such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, and Behcet's disease. Newly developed treatment modalities for neutralizing the Th17 branch of the immune system are proving to be valuable additions to the current therapeutic armamentarium.