New developments in the management of psoriasis and psoriatic arthritis: a focus on apremilast

Psoriatic arthritis: latest treatments and their place in therapy

Psoriatic arthritis (PsA) is a heterogeneous chronic inflammatory disease that may affect peripheral and axial joints, entheses, skin and nails, and other organs. Treatment with nonsteroidal anti-inflammatory drugs, steroid and disease-modifying antirheumatic drugs had been the backbone of traditional management of PsA for many years. However, improvement in our understanding of immunopathogenesis of PsA has led to new immunomodulatory therapies. Introduction of novel agents has raised the bar for treatment and helped drive research into additional therapeutic options.

Animal models of rheumatoid arthritis: How informative are they?

Animal models of arthritis are widely used to de-convolute disease pathways and to identify novel drug targets and therapeutic approaches. However, the high attrition rates of drugs in Phase II/III rates means that a relatively small number of drugs reach the market, despite showing efficacy in pre-clinical models. There is also increasing awareness of the ethical issues surrounding the use of animal models of disease and it is timely, therefore, to review the relevance and translatability of animal models of arthritis. In this paper we review the most commonly used animal models in terms of their pathological similarities to human rheumatoid arthritis as well as their response to drug therapy. In general, the ability of animal models to predict efficacy of biologics in man has been good. However, the predictive power of animal models for small molecules has been variable, probably because of differences in the levels of target knockdown achievable in vivo.

Inhibitors of phosphodiesterase 4 (PDE 4): A new therapeutic option in the treatment of psoriasis vulgaris and psoriatic arthritis

Psoriasis vulgaris and psoriatic arthritis are inflammatory diseases in which inflammation and sustained inducing lesions result from immune disorders associated with overactivity of T cells that produce multiple proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α) and interleukin (IL): IL-2, IL-12, IL-17, IL-22 or IL-23. Modern treatment of these diseases is focused on reducing the inflammatory process responsible for the development of the disease. In recent years, the treatment of psoriasis is developing at a dynamic rate. Such therapeutic advances are contributed to the possibility of patient therapy through the use of some registered biologic agents, such as TNF-α inhibitors (infliximab, etanercept and adalimumab), and an inhibitor of the p40 subunit common to IL-12 and IL-23 (ustekinumab). In addition to the already registered medications for the indications mentioned above, there is a large group of preparations that are currently undergoing clinical trials in Europe, Canada and the United States, which provides hopes of therapy efficacy and safety.

METEORIN-LIKE is a cytokine associated with barrier tissues and alternatively activated macrophages

Cytokines are involved in many functions of the immune system including initiating, amplifying and resolving immune responses. Through bioinformatics analyses of a comprehensive database of gene expression (BIGE: Body Index of Gene Expression) we observed that a small secreted protein encoded by a poorly characterized gene called meteorin-like (METRNL), is highly expressed in mucosal tissues, skin and activated macrophages. Further studies indicate that Metrnl is produced by Alternatively Activated Macrophages (AAM) and M-CSF cultured bone marrow macrophages (M2-like macrophages). In the skin, METRNL is expressed by resting fibroblasts and IFNγ-treated keratinocytes. A screen of human skin-associated diseases showed significant over-expression of METRNL in psoriasis, prurigo nodularis, actinic keratosis and atopic dermatitis. METRNL is also up-regulated in synovial membranes of human rheumatoid arthritis. Taken together, these results indicate that Metrnl represents a novel cytokine, which is likely involved in both innate and acquired immune responses.

Psoriatic arthritis: Epidemiology, diagnosis, and treatment

Our understanding of psoriatic arthritis has evolved as new knowledge of the disease has emerged. However, the exact prevalence of psoriatic arthritis is unknown, and its pathogenesis has not been fully elucidated. Genetic, environmental, and immunologic factors have all been implicated in disease development. Early diagnosis and treatment have become primary objectives in clinical rheumatology. Psoriatic arthritis not only causes functional impairment, but also increases mortality risk of patients. The advent of new therapeutic agents capable of arresting the progression of joint damage is expected. However, early psoriatic arthritis assessment remains limited. The objectives of this article are to outline the epidemiology, diagnosis, and treatment of psoriatic arthritis and to suggest a paradigm for identifying early psoriatic arthritis patients.

Bioassay-guided chemical study of the anti-inflammatory effect of Senna villosa (Miller) H.S. Irwin & Barneby (Leguminosae) in TPA-induced ear edema

Senna villosa (Miller) is a plant that grows in México. In traditional Mexican medicine, it is used topically to treat skin infections, pustules and eruptions and to heal wounds by scar formation. However, studies of its potential anti-inflammatory effects have not been performed. The aim of the present study was to determine the anti-inflammatory effect of extracts from the leaves of Senna villosa and to perform a bioassay-guided chemical study of the extract with major activity in a model of ear edema induced by 12-O-tetradecanoylphorbol 13-acetate (TPA). The results reveal that the chloroform extract from Senna villosa leaves has anti-inflammatory and anti-proliferative properties. Nine fractions were obtained from the bioassay-guided chemical study, including a white precipitate from fractions 2 and 3. Although none of the nine fractions presented anti-inflammatory activity, the white precipitate exhibited pharmacological activity. It was chemically characterized using mass spectrometry and infrared and nuclear magnetic resonance spectroscopy, resulting in a mixture of three aliphatic esters, which were identified as the principal constituents: hexyl tetradecanoate (C20H40O2), heptyl tetradecanoate (C21H42O2) and octyl tetradecanoate (C22H44O2). This research provides, for the first time, evidence of the anti-inflammatory and anti-proliferative properties of compounds isolated from Senna villosa.

Clinical potential of apremilast in the treatment of psoriatic arthritis

Psoriatic arthritis (PsA) is a frequent chronic inflammatory disease characterized by joint and skin involvement, and by typical extra-articular manifestations. Although the pathogenesis of PsA is still under investigation, the available evidence suggests the importance of the patient’s genetic background, microbial or environmental triggers, and an imbalance in the adaptive and acquired immune system, resulting in the production of inflammatory mediators. New therapeutic approaches have been proposed, among them the use of modulators of intracellular signals and gene transcription such as PDE4-inhibiting compounds, which are able to modulate the activity of transcription factors such as CREB and NF-κB and therefore the synthesis of inflammatory mediators, resulting in immunoregulation. This paper summarizes the mechanism of action of apremilast, a PDE4 inhibitor, and the clinical data available on its clinical efficacy and safety profile in the treatment of PsA patients.

Biological therapies for spondyloarthritis

Biological therapies and new imaging techniques have changed the therapeutic and diagnostic approach to spondyloarthritis. In patients with axial spondyloarthritis, tumor necrosis factor α (TNFα) inhibitor treatment is currently the only effective therapy in patients for whom conventional therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) has failed. TNFα inhibitor treatment is more effective in preventing articular damage in peripheral joints than in axial ones. It is important to treat patients at an early stage of disease to reduce disease progression; moreover it is necessary to identify causes of therapy inefficacy in preventing joint damage in the axial subset.

Drug therapies in dermatology

This article explores the current and emerging therapies for skin disease, with a particular focus on chronic plaque psoriasis and metastatic malignant melanoma. We discuss the current biological therapies used for psoriasis and those on the horizon, including small molecules and biosimilars. We also summarise the recent advances in the use of novel therapeutic agents in other dermatological diseases and outline the promise of translational research and stratified medicine approaches in dermatology. Better matching of patients with therapies is anticipated to have a major effect on both clinical practice and the development of new drugs and diagnostics.