Tofacitinib in the management of active psoriatic arthritis: patient selection and perspectives

Janus-kinase inhibitors in dermatology: A review of their use in psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease

Recent studies on molecular pathways have elucidated novel therapeutic approaches in inflammatory and autoimmune skin disorders. Specifically, the dysregulation of the Janus kinase signal transducer and activator of transcription (JAK-STAT) cascade plays a central role in the pathogenesis of many skin conditions. JAK inhibitors, with their ability to selectively target immune responses, are potential treatment options. Using the National Library of Medicine, we provide a comprehensive review of the use of United States Food and Drug Administration (FDA)-approved and emerging JAK or tyrosine kinase 2 (TYK2) inhibitors in a wide range of dermatologic conditions, including psoriasis, vitiligo, systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. In patients with psoriasis, oral deucravacitinib (TYK2 inhibitor) has been approved as a once-daily therapy with demonstrated superiority and efficacy over apremilast and placebo and tolerable safety profiles. In patients with vitiligo, topical ruxolitinib (JAK1 inhibitor) is approved as a twice-daily treatment for repigmentation. The efficacy of several other JAK inhibitors has also been demonstrated in several clinical trials and case studies for systemic lupus erythematosus, hidradenitis suppurativa, dermatomyositis, lichen planus, lichen planopilaris, sarcoidosis and graft-versus-host disease. Further investigations with long-term clinical trials are necessary to confirm their utility in treatment and safety for these diseases.

Advances in Current Drugs and Formulations for the Management of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease with a complex pathophysiology. Treatment of AD remains challenging owing to the presence of a wide spectrum of clinical phenotypes and limited response to existing therapies. However, recent genetic, immunological, and pathophysiological insights into the disease mechanism resulted in the invention of novel therapeutic drug candidates. This review provides a comprehensive overview of current therapies and assesses various novel drug delivery strategies currently under clinical investigation. Further, this review majorly emphasizes on various topical treatments including emollient therapies, barrier repair agents, topical corticosteroids (TCS), phosphodiesterase 4 (PDE4) inhibitors, calcineurin inhibitors, and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors. It also discusses biological and systemic therapies, upcoming treatments based on ongoing clinical trials. Additionally, this review scrutinized the use of pharmaceutical inactive ingredients in the approved topical dosage forms for AD treatment.

An overview of psoriatic arthritis including clinical manifestations, assessment, diagnostic criteria, investigations, drug management and GRAPPA guidelines

Psoriatic arthritis (PsA) is a chronic and often progressive inflammatory disease, occurring in up to 30% of patients with psoriasis. Assessment of patients with PsA requires consideration of all disease domains, including peripheral arthritis, axial disease, enthesitis, dactylitis, skin psoriasis, psoriatic nail disease, uveitis and inflammatory bowel disease. Co-morbidities and related conditions should all be considered including: obesity, metabolic syndrome, cardiovascular disease, anxiety/depression, liver disease, chronic infections, malignancy, osteoporosis, fibromyalgia and reproductive health.

Tofacitinib combined with leflunomide for treatment of psoriatic arthritis with IgA nephropathy: a case report with literature review

Psoriasis is a systemic inflammatory disease that is associated with increased risk of several diseases, such as psoriatic arthritis (PsA), inflammatory bowel disease, and cardiovascular diseases. About 20 to 30% patients with psoriasis subsequently develop PsA. IgA nephropathy is the most common primary glomerular disease world-wide. Psoriasis and IgA nephropathy appear to be associated, but the mechanism underlying this connection is unclear. Tofacitinib and leflunomide are common treatments for psoriatic arthritis. We administered tofacitinib combined with leflunomide to a 38-year-old female patient who presented with PsA and IgA nephropathy. After treatment, she experienced significant reductions in the psoriatic lesions, pain in the right knee joint, and proteinuria. Administration of tofacitinib combined with leflunomide for treatment of a patient who had PsA complicated with IgA nephropathy led to significant resolution of the symptoms of both conditions. These results suggest similarities in the pathogenesis of PsA and IgA nephropathy and a possible new treatment for IgA nephropathy.

Janus Kinase Inhibitors for the Management of Patients With Inflammatory Bowel Disease

In recent years, knowledge about the pathophysiology of inflammatory bowel disease (IBD) has led to the development of novel therapies and biologics with differing mechanisms of action. A major innovation has been the development of small molecules. Tofacitinib was the first pan-Janus kinase (Jak) inhibitor approved for the treatment of IBD, targeting the 4 isoforms of cytokine-associated Jaks (Jak1, Jak2, Jak3, and tyrosine-protein kinase 2). Compared with biologic agents, novel small molecules have a short half-life, a rapid onset of action, and no immunogenicity, but they are associated with a potentially increased risk of off-target side effects. These differences in properties between biologic and oral small molecule therapies may be important when considering their relative treatment positioning and role in clinical practice. Although tofacitinib has been demonstrated to be highly effective as both first- and second-line therapy for ulcerative colitis, concerns about safety, including the risk of infection, venous thromboembolism, major adverse cardiovascular events, and malignancy, have dampened enthusiasm for its widespread use. Subsequently, several Jak inhibitors with more selective profiles, and potentially improved safety while maintaining treatment efficacy, are currently in late-stage clinical trials for use in patients with IBD. This article summarizes the current data regarding the use, safety, and efficacy of Jak inhibitors in patients with IBD.

Role of Janus Kinase Inhibitors in Therapy of Psoriasis

Janus kinases inhibitors are molecules that target Janus kinases-signal transducers and activators of transcription (JAK/STAT). They inhibit this intracellular signal pathway, blocking the gene transcription of crucial proinflammatory cytokines that play a central role in the pathogenesis of many inflammatory and autoimmune diseases, including psoriasis. This process reduces psoriatic inflammation. The JAK inhibitors are divided into two generations. The first generation of JAK inhibitors blocks two or more different Janus kinases. The second generation is more specified and blocks only one type of Janus kinase and has less side effects than the first generation. Tofacitinib, ruxolitinib and baricitinib belong to first generation JAK inhibitors and decernotinib and filgotinib belong to second group. This narrative review summarizes the role of Janus kinase inhibitors in the therapy of psoriasis. Oral JAK inhibitors show promise for efficacy and safety in the treatment of psoriasis. Studies to date do not indicate that JAK inhibitors are superior to recent biologic drugs in terms of efficacy. However, JAK inhibitors, due to their lack of increased incidence of side effects compared to other biologic drugs, can be included in the psoriasis treatment algorithm because they are orally taken. Nevertheless, further studies are needed to evaluate long-term treatment effects with these drugs.

Role of the IL-23/IL-17 Pathway in Rheumatic Diseases: An Overview

Interleukin-23 (IL-23) is a pro-inflammatory cytokine composed of two subunits, IL-23A (p19) and IL-12/23B (p40), the latter shared with Interleukin-12 (IL-12). IL-23 is mainly produced by macrophages and dendritic cells, in response to exogenous or endogenous signals, and drives the differentiation and activation of T helper 17 (Th17) cells with subsequent production of IL-17A, IL-17F, IL-6, IL-22, and tumor necrosis factor α (TNF-α). Although IL-23 plays a pivotal role in the protective immune response to bacterial and fungal infections, its dysregulation has been shown to exacerbate chronic immune-mediated inflammation. Well-established experimental data support the concept that IL-23/IL-17 axis activation contributes to the development of several inflammatory diseases, such as PsA, Psoriasis, Psoriatic Arthritis; AS, Ankylosing Spondylitis; IBD, Inflammatory Bowel Disease; RA, Rheumatoid Arthritis; SS, Sjogren Syndrome; MS, Multiple Sclerosis. As a result, emerging clinical studies have focused on the blockade of this pathogenic axis as a promising therapeutic target in several autoimmune disorders; nevertheless, a greater understanding of its contribution still requires further investigation. This review aims to elucidate the most recent studies and literature data on the pathogenetic role of IL-23 and Th17 cells in inflammatory rheumatic diseases.

JAK/STAT Activation: A General Mechanism for Bone Development, Homeostasis, and Regeneration

The Janus kinase (JAK) signal transducer and activator of transcription (STAT) signaling pathway serves as an important downstream mediator for a variety of cytokines, hormones, and growth factors. Emerging evidence suggests JAK/STAT signaling pathway plays an important role in bone development, metabolism, and healing. In this light, pro-inflammatory cytokines are now clearly implicated in these processes as they can perturb normal bone remodeling through their action on osteoclasts and osteoblasts at both intra- and extra-articular skeletal sites. Here, we summarize the role of JAK/STAT pathway on development, homeostasis, and regeneration based on skeletal phenotype of individual JAK and STAT gene knockout models and selective inhibition of components of the JAK/STAT signaling including influences of JAK inhibition in osteoclasts, osteoblasts, and osteocytes.

Development of JAK inhibitors for the treatment of immune-mediated diseases: kinase-targeted inhibitors and pseudokinase-targeted inhibitors

JAKs are a family of intracellular tyrosine kinases consisting of four members, JAK1, JAK2, JAK3, and TYK2. They are key components of the JAK-STAT pathway that transmit signals of many cytokines involved in the pathogenesis of numerous immune-mediated diseases and have been major molecular targets in developing new drugs for the treatment of such diseases. Some small-molecule inhibitors of JAKs have been approved by the FDA for rheumatoid arthritis, psoriatic arthritis, and inflammatory bowel disease. Now, newer JAK inhibitors with isoform-selectivity among the four different JAKs are being developed, with the aim of improving clinical outcomes compared with earlier developed drugs with pan-JAK inhibition. Most of these selective inhibitors target the kinase domains of JAKs, functioning through the traditional inhibition mode of kinases; but recently those that target their pseudokinase domains, allosterically inhibiting the enzymes, have been under development. In this review, key characteristics, efficacy, and safety of FDA-approved and representative drugs in late stages of development are briefly described in order to provide clinical implications with respect to JAK inhibitor selectivity and future development perspectives. The recent development of pseudokinase-targeted inhibitors of JAKs is also included.

Systemic Treatment of Psoriasis with JAK Inhibitors: A Review

Psoriasis is a prevalent chronic inflammatory disease. The inflammatory response is driven by T cells and mediated by multiple cytokines such as tumor necrosis factor and the interleukins IL-17 and IL-23. Moderate-to-severe psoriasis is treated systemically, using either biologics or conventional treatments with small-molecule drugs. The newer biologics are very effective and well tolerated, but not all patients respond to treatment with biologics, so there is a need for new treatment options for psoriasis. Janus kinase (JAK) inhibitors are a new drug class that may be of use in this respect. These inhibitors are already on the market for rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. They block the intracellular signal pathway mediated by JAK and signal transducer and activator of transcription (STAT) proteins, thereby inhibiting gene transcription of proinflammatory cytokines. JAK inhibitors are currently being tested as potential treatments for psoriasis. They have shown clinical efficacy as measured by the Psoriasis Area and Severity Index 75 response in both phase 2 and 3 trials, and appear to be well tolerated overall. This review provides an overview of the mechanisms underlying the actions of JAK inhibitors in psoriasis, together with the results of clinical trials testing their efficacies when used to treat the disease.