Investigation of selective JAK1 inhibitor GSK2586184 for the treatment of psoriasis in a randomized placebo-controlled phase IIa study

Revisiting Structure-activity Relationships: Unleashing the potential of selective Janus kinase 1 inhibitors

Janus kinases (JAKs), a kind of non-receptor tyrosine kinases, the function has been implicated in the regulation of cell proliferation, differentiation and apoptosis, immune, inflammatory response and malignancies. Among them, JAK1 represents an essential target for modulating cytokines involved in inflammation and immune function. Rheumatoid arthritis, atopic dermatitis, ulcerative colitis and psoriatic arthritis are areas where approved JAK1 drugs have been applied for the treatment. In the review, we provided a brief introduction to JAK1 inhibitors in market and clinical trials. The structures of high active JAK1 compounds (IC50 ≤ 0.1 nM) were highlighted, with primary focus on structure-activity relationship and selectivity. Moreover, the druggability processes of approved drugs and high active compounds were analyzed. In addition, the issues involved in JAK1 compounds clinical application as well as strategies to surmount these challenges, were discussed.

Therapeutic Potential of Targeting the JAK/STAT Pathway in Psoriasis: Focus on TYK2 Inhibition

Psoriasis is an inflammatory skin disease with a chronic relapsing course and an often-detrimental impact on patients' quality of life. Thanks to incredible advances in research over the past few decades, the therapeutic armamentarium of psoriasis is now reasonably broad and structured, with several therapeutic agents that have demonstrated successful long-term control of this condition. However, there are still unfulfilled gaps resulting from the inherent limitations of existing therapies, which have paved the way for the identification of new therapeutic strategies or the improvement of existing ones. A great deal of attention has recently been paid to the JAK/STAT pathway, playing a crucial role in chronic inflammatory skin diseases, including psoriasis. Indeed, in a disease with such a complex pathogenesis, the possibility to antagonize multiple molecular pathways via JAK/STAT inhibition offers an undeniable therapeutic advantage. However, data from clinical trials evaluating the use of oral JAK inhibitors in immune-mediated disorders, such as RA, have arisen safety concerns, suggesting a potentially increased risk of class-specific AEs such as infections, venous thromboembolism, and malignancies. New molecules are currently under investigation for the treatment of psoriasis, such as deucravacitinib, an oral selective inhibitor that binds to the regulatory domain of TYK2, brepocitinib (PF-06700841) and PF-06826647 that bind to the active site in the catalytic domain. Due to the selective TYK2 blockade allowing the inhibition of key cytokine-mediated signals, such as those induced by IL-12 and IL-23, anti-TYK2 agents appear to be very promising as the safety profile seems to be superior compared with pan-JAK inhibitors. The aim of our review is to thoroughly explore the rationale behind the usage of JAK inhibitors in PsO, their efficacy and safety profiles, with a special focus on oral TYK2 inhibitors, as well as to provide a forward-looking update on novel therapeutic strategies targeting the TYK2 pathway in psoriasis.

Inhibition of the JAK-STAT Pathway in the Treatment of Psoriasis: A Review of the Literature

Psoriasis is a highly prevalent dermatological disease associated with an increased systemic inflammatory response. In addition, joint involvement is also present in around 20% of patients. Therefore, treatment modalities used in this condition should be simultaneously effective at improving skin manifestations, reducing inflammation, and addressing psoriatic arthritis when present. Twenty years ago, the introduction of biologic treatments for psoriasis was a turning point in the management of this condition, offering an effective and reasonably safe option for patients whose disease could not be adequately controlled with conventional therapies. At the moment, Janus Kinase inhibitors (JAKis) are a new class of promising molecules in the management of psoriasis. They are orally administered and can show benefits in patients who failed biologic therapy. We conducted a scoping review in order to identify randomized-controlled trials that investigated different JAKis in patients with plaque psoriasis and psoriatic arthritis, with an emphasis on molecules that have been approved by the European Medicines Agency and the Food and Drug Administration. The added value of this study is that it collected information about JAKis approved for two different indications, plaque psoriasis and psoriatic arthritis, in order to provide an integrated understanding of the range of effects that JAKis have on the whole spectrum of psoriasis manifestations.

Short-Term Cardiovascular Complications in Dermatology Patients Receiving JAK-STAT Inhibitors: A Meta-Analysis of Randomized Clinical Trials

Importance

Evolving evidence suggests that patients receiving Janus kinase-signal transducer and activator of transcription inhibitors (JAK-STATi) may be at higher risk of major adverse cardiovascular events (MACE) and venous thromboembolism (VTE). Most existing literature has focused on indications that may confer a higher MACE and VTE risk than that among patients with isolated dermatological indications.

Objective

To evaluate risk of MACE, VTE, serious adverse events (SAEs), and tolerability of systemic JAK-STATi compared with placebo, in those with a dermatologic indication.

Data Sources

A systematic review of the literature was carried out to June 2023, using databases Embase, MEDLINE, SCOPUS, Cochrane Library of Registered Trials, and registered Clinical Trials. The analysis was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. The analysis itself took place in June 2023.

Study Selection

Placebo-controlled randomized clinical trials that compared systemic JAK-STATi with placebo, and investigated the safety in patients with alopecia areata, psoriasis, vitiligo, atopic dermatitis, lichen planus or hidradenitis suppurativa.

Data Extraction and Synthesis

Study selection and data extraction by 2 authors working independently using a standardized template. Crude numbers for MACE, VTE, SAEs, and study discontinuation due to treatment emergent adverse events (TEAEs) were pooled and underwent meta-analysis.

Main Outcomes and Measures

Incidence of MACE, VTE, SAE, and study discontinuation due to TEAEs. Analysis of these values against person exposure years to determine the incidence rate (IR). Risk ratios (RRs) compared incidence rates among treatment and placebo comparator arms.

Results

Forty-five randomized clinical trials were eligible for inclusion, with 12 996 patients receiving active JAK-STATi therapy and 4925 allocated to placebo treatment. Meta-analysis found no significant increase in MACE (I2 = 0.00%; RR, 0.47; 95% CI, 0.28-0.80) or VTE (I2 = 0.00%; RR, 0.46; 95% CI, 0.26-0.80) between placebo and JAK-STATi comparator arms. There was also no significant difference in SAEs (I2 = 12.38%; RR, 0.92; 95% CI, 0.72-1.20) and discontinuations between JAK-STATi and placebo (I2 = 23.55%; RR, 0.94; 95% CI, 0.76-1.19).

Conclusions and Relevance

This meta-analysis did not identify a significant increase in the risk of MACE and VTE in dermatology patients receiving JAK-STATi for median duration of 16 weeks. The results of this review suggest there is insufficient evidence that JAK-STATi confer an increased risk of cardiovascular complications in dermatological patients, especially when used for short time frames.

Application of JAK inhibitors in paradoxical reaction through immune-related dermatoses

Biologics play a positive and effective role in the treatment of immune-related dermatoses. However, many other immune-related diseases have also manifested along with biologics treatment. Paradoxical reaction through immune-related dermatoses refer to the new onset or exacerbation of other immune-mediated dermatoses (mainly psoriasis and atopic dermatitis) after biologics treatment of inflammatory dermatoses (mainly psoriasis and atopic dermatitis), such as new atopic dermatitis (AD) in psoriasis (PsO) treatment and new PsO in AD treatment. A common genetic background and Inflammatory pathway are possible pathogenesis. Faced with paradoxical reactions, the choice of therapy needs to be directed toward therapies effective for both diseases, such as Janus kinase (JAK) inhibitors. The Janus kinase and signal transducer and activator of transcription (JAK-STAT) pathway plays an important role in the inflammatory pathway, and has been widely used in the treatment of AD and PsO in recent years. This article focuses on JAK inhibitors such as tofacitinib, baricitinib, ruxolitinib, Abrocitinib, upadacitinib, and deucravacitinib, to explore the possible application in treatment of paradoxical reactions. Common side effects, baseline risk factors and safety use of JAK inhibitors were discussed.

New and Emerging Oral/Topical Small-Molecule Treatments for Psoriasis

The introduction of biologic therapies has led to dramatic improvements in the management of moderate-to-severe psoriasis. Even though the efficacy and safety of the newer biologic agents are difficult to match, oral administration is considered an important advantage by many patients. Current research is focused on the development of oral therapies with improved efficacy and safety compared with available alternatives, as exemplified by deucravacitinib, the first oral allosteric Tyk2 inhibitor approved for the treatment of moderate to severe psoriasis in adults. Recent advances in our knowledge of psoriasis pathogenesis have also led to the development of targeted topical molecules, mostly focused on intracellular signaling pathways such as AhR, PDE-4, and Jak-STAT. Tapinarof (an AhR modulator) and roflumilast (a PDE-4 inhibitor) have exhibited favorable efficacy and safety outcomes and have been approved by the FDA for the topical treatment of plaque psoriasis. This revision focuses on the most recent oral and topical therapies available for psoriasis, especially those that are currently under evaluation and development for the treatment of psoriasis.

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.

JAK Inhibitors in Psoriatic Disease

Psoriasis is now considered to be the cutaneous phenotype of a systemic inflammatory condition, recognized under the term Psoriatic Disease (PsD). PsD has several extracutaneous manifestations, such as inflammatory articular and entheseal involvement, leading to psoriatic arthritis (PsA), and the less frequent intestinal and ocular manifestations with colitis/inflammatory bowel disease and uveitis, respectively. There have also been several reports of an increased frequency of comorbidities such as hypertension, diabetes, dyslipidemia, obesity, metabolic syndrome and cardiovascular manifestations during the course of PsD. The link between psoriasis and related comorbidities is considered a long-term disease sequela, often characterized by an unhealthy lifestyle and a consequence of systemic inflammation; hence, psoriasis requires adequate and prompt treatment, with the aim of controlling not only cutaneous manifestations but also extracutaneous manifestations and systemic inflammation. Pharmacological strategies for PsD have significantly increased over recent years. Recently, the targeted synthetic DMARDs, Janus kinase (JAK) inhibitors, tofacitinib and upadacitinib, were added to the therapeutic armamentarium for treating PsA, and deucravacitinib for psoriasis. These oral agents act directly on inflammatory mechanisms underlining the disease, as antagonists of the intracellular JAK signal pathway and, by STAT phosphorylation, inhibit gene proinflammatory cytokine transcription. JAK inhibitors represent a recent additional treatment strategy for PsD management and, among these, tofacitinib and upadacitinib have recently been approved for PsA, and deucravacitinib for psoriasis. In this review we describe ongoing and recent phase II and III randomized controlled trials (RCTs) evaluating the efficacy and safety of investigational JAK inhibitors in psoriasis and PsA.

SOCS-JAK-STAT inhibitors and SOCS mimetics as treatment options for autoimmune uveitis, psoriasis, lupus, and autoimmune encephalitis

Autoimmune diseases arise from atypical immune responses that attack self-tissue epitopes, and their development is intricately connected to the disruption of the JAK-STAT signaling pathway, where SOCS proteins play crucial roles. Conditions such as autoimmune uveitis, psoriasis, lupus, and autoimmune encephalitis exhibit immune system dysfunctions associated with JAK-STAT signaling dysregulation. Emerging therapeutic strategies utilize JAK-STAT inhibitors and SOCS mimetics to modulate immune responses and alleviate autoimmune manifestations. Although more research and clinical studies are required to assess their effectiveness, safety profiles, and potential for personalized therapeutic approaches in autoimmune conditions, JAK-STAT inhibitors and SOCS mimetics show promise as potential treatment options. This review explores the action, effectiveness, safety profiles, and future prospects of JAK inhibitors and SOCS mimetics as therapeutic agents for psoriasis, autoimmune uveitis, systemic lupus erythematosus, and autoimmune encephalitis. The findings underscore the importance of investigating these targeted therapies to advance treatment options for individuals suffering from autoimmune diseases.

Psoriasis: a focus on upcoming oral formulations

INTRODUCTION

Targeted therapies have greatly improved the quality of life of patients with psoriasis. Despite the extensive list of treatments available, multiple new drugs are being developed, especially oral therapies with potential advantages as regards comfort of administration. However, the efficacy and safety of these new oral therapies need to be improved to match those of novel biologics.

AREAS COVERED

We provide a narrative review of the oral therapies for psoriasis that are currently under development, from Jak inhibitors to oral IL-17 and IL-23 inhibitors, among others. A literature search was performed for articles published from 1 January 2020, to 6 June 2023.

EXPERT OPINION

The approval of deucravacitinib, the first Jak inhibitor for the treatment of moderate-to-severe plaque psoriasis, heralds a bright therapeutic future with multiple new oral formulations. A great number of oral treatments with singular mechanism of action, like A3AR agonists, HSP90 inhibitors, ROCK-2 inhibitors, oral TNF inhibitors, oral IL-23 inhibitors, oral IL-17 inhibitors, PD4 inhibitors (orismilast) and several Tyk2 inhibitors, are currently being evaluated in clinical trials and could be suitable for approval in the future. Growing variation in treatment modes of administration will allow dermatologists to better integrate patient preferences in the therapeutic decision process.

Pharmaco-Omics in Psoriasis: Paving the Way towards Personalized Medicine

The emergence of high-throughput approaches has had a profound impact on personalized medicine, evolving the identification of inheritable variation to trajectory analyses of transient states and paving the way for the unveiling of response biomarkers. The utilization of the multi-layered pharmaco-omics data, including genomics, transcriptomics, proteomics, and relevant biological information, has facilitated the identification of key molecular biomarkers that can predict the response to therapy, thereby optimizing treatment regiments and providing the framework for a tailored treatment plan. Despite the availability of multiple therapeutic options for chronic diseases, the highly heterogeneous clinical response hinders the alleviation of disease signals and exacerbates the annual burden and cost of hospitalization and drug regimens. This review aimed to examine the current state of the pharmaco-omic approaches performed in psoriasis, a common inflammatory disease of the skin. We sought to identify central studies that investigate the inter-individual variability and explore the underlying molecular mechanisms of drug response progression via biological profiling in psoriatic patients administered with the extended therapeutic armamentarium of psoriasis, incorporating conventional therapies, small molecules, as well as biological drugs that inhibit central pathogenic cytokines involved in the disease pathogenesis.

Itch and Janus Kinase Inhibitors

Itch is a common skin symptom, with complex aetiology and pathogenesis. It is mediated by 2 pathways, the histaminergic and non-histaminergic pathways. Chronic itch is understood to be processed by the latter and is difficult to treat with traditional pruritus therapies. The Janus kinase and signal transducer and activator of transcription pathway is a signalling mechanism that regulates gene expression through various cytokines. Janus kinase inhibitors, which have been tested and used for several autoimmune diseases, have also been shown to be effective for itch through clinical trials and case reports. Janus kinase inhibitors could be a good choice for pruritus in atopic dermatitis, psoriasis, and other diseases, such as prurigo nodularis and lichen planus, with rapid itch relief compared with conventional treatments. The most common adverse effects reported include nasopharyngitis, acne, and elevated blood creatine phosphokinase levels. Janus kinase inhibitors are currently prescribed with warnings about a potential increase in malignancies and cardiovascular diseases and usage in people of older ages. This review aims to provide knowledge about itch and the Janus kinase and signal transducer and activator of transcription pathway and to analyse the current evidence for itch relief by Janus kinase inhibitors.

Efficacy and safety of Janus kinase inhibitors in patients with psoriasis and psoriatic arthritis: a systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy and safety of Janus kinase (JAK) inhibitors (Jakinibs) in the treatment of psoriasis and psoriatic arthritis (PsA).

METHODS

Databases including PubMed, Embase, Web of Science, and Cochrane Library were searched for randomized controlled trials on the efficacy and safety of Jakinibs in treating psoriasis and PsA from inception to July 2021. A systematic review and meta-analysis were performed to estimate pooled relative risk (RR) and 95% confidence interval (CI).

RESULTS

Seventeen clinical trials (16 publications) comprising 6802 patients were included. All Jakinibs demonstrated significantly higher response rates compared with placebo (ACR20: RR 2.09, 95% CI 1.90-2.30; PASI75: RR 4.03, 95% CI 3.13-5.18). Within the subgroup analysis, the response rates defined by ACR20 were highest for filgotinib (RR 2.40, 95% CI 1.67-3.45), followed by upadacitinib, tofacitinib, and deucravacitinib. The proportion of patients achieving PASI75 response in the tofacitinib 10 mg twice daily group was significantly higher than that in the tofacitinib 5 mg group. Regarding safety, the incidence of adverse events (AEs) was significantly higher for Jakinibs compared with placebo (RR 1.17, 95% CI 1.11-1.23). Of note, a considerable increase in the risk of infections including upper respiratory tract and herpes zoster infection was observed among patients in the treatment group. For tofacitinib, upadacitinib, and filgotiniband, infection was the most prevalent AE. Moreover, AEs in the 10 mg tofacitinib group were higher than those in the 5 mg tofacitinib group.

CONCLUSION

Jakinibs are efficacious interventions for the treatment of psoriasis and PsA, but they are associated with an increased risk of AEs when compared with placebo. The long-term efficacy and safety data require further evaluation. Key Points • This systematic review investigated and compared the efficacy and safety of different Jakinibs including the novel selective TYK2 inhibitors. • Jakinibs are efficacious interventions for the treatment of psoriasis and PsA. • A relatively higher dosing schedule of Jakinibs is associated with increased toxicity.

Clinical Implications of Targeting the JAK-STAT Pathway in Psoriatic Disease: Emphasis on the TYK2 Pathway

Cytokines in the interleukin (IL)-23/IL-17 axis are central to psoriasis pathogenesis. Janus kinase (JAK) signal transducer and activator of transcription (STAT) regulates intracellular signalling of several cytokines (including IL-12, 23, 22, 6, 17, and interferon (IFN)-γ) in the IL-23/IL-17 axis, and, as a result, has become a therapeutic target for psoriasis treatment. Although several JAK1-3 inhibitors, with varying degrees of selectivity, have been developed for immune-mediated inflammatory diseases, use in psoriasis is limited by a low therapeutic index as anticipated by signals from other disease indications. More selective inhibition of the JAK family is an area of interest. Specifically, selective tyrosine kinase (TYK)2 inhibition suppresses IL-23/IL-17 axis signalling, and at therapeutic doses, has a favorable safety profile compared to therapeutic doses of JAK1-3 inhibitors. Phase III efficacy and safety data for the selective allosteric TYK2-inhibitor, deucravacitinib, in adult patients with moderate-to-severe plaque psoriasis is promising. Furthermore, phase II clinical trials for ropsacitinib (PF-06826647), a selective TYK2 inhibitor, and brepocitinib (PF-06700841), a JAK1/TYK2 inhibitor, have also demonstrated efficacy and an acceptable safety profile in adult patients with moderate-to-severe plaque psoriasis. Other novel TYK2 allosteric inhibitors, NDI-034858 and ESK-001, are currently being investigated in adult patients with plaque psoriasis. This article reviews the details of the JAK-STAT pathway in psoriasis pathophysiology, the rationale for selective targeting of JAKs in the treatment of psoriasis, and provides clinical perspective on clinical trial data for JAK and TYK2 inhibitors.

The efficacy and safety of tofacitinib, peficitinib, solcitinib, baricitinib, abrocitinib and deucravacitinib in plaque psoriasis - A network meta-analysis

Janus kinase (JAK) inhibitors are novel treatment approaches for psoriasis. However, there is no direct comparison of JAK inhibitors in plaque psoriasis. In order to compare the efficacy and safety of JAK inhibitors in psoriasis, we conducted a network meta-analysis using eligible randomized clinical trials (RCTs). The efficacy of JAK inhibitors was evaluated using a 75% improvement in Psoriasis Area and Severity Index (PASI75) from baseline, and the proportion of patients achieving the Physician's Global Assessment (PGA) response. The incidence of treatment-related adverse events (AEs) was also assessed. A total of eight RCTs with tofacitinib, peficitinib, solcitinib, baricitinib, abrocitinib and deucravacitinib were included. A total of 3612 participants who were diagnosed with moderate-to-severe plaque psoriasis were analysed. Overall, JAK inhibitors showed superior PASI75 response over placebo at both 8 and 12 weeks. Among all included JAK inhibitors, tofacitinib 15 mg twice a day (BID) had the highest probability of achieving PASI75 at both 8 and 12 weeks (SUCRA = 0.938 and 0.937, separately), followed by tofacitinib 10 mg BID (SUCRA = 0.905 and 0.908, separately) and deucravacitinib 12 mg once daily (QD) (SUCRA = 0.874 and 0.837, separately). A similar finding was observed for PGA response. Safety assessment showed that all JAK inhibitors had non-inferior safety compared with placebo, except for deucravacitinib 6 mg BID and 12 mg QD. Tofacitinib 2 mg BID was the first-ranked drug for safety profile followed by deucravacitinib 3 mg QD, and tofacitinib 5 mg BID. When comprehensively evaluated the efficacy and safety, tofacitinib (2 mg, 5 mg, 10 mg, 15 mg BID) was superior to other included JAK inhibitors with satisfying PASI75 and PGA response, as well as relatively low incidence of AEs. Our study confirmed that JAK inhibitors had promising treatment efficacy for moderate-to-severe plaque psoriasis. Tofacitinib showed superior efficacy and safety over peficitinib, solcitinib, baricitinib, abrocitinib and deucravacitinib.

Efficacy and safety of JAK inhibitors in the treatment of psoriasis and psoriatic arthritis: a systematic review and meta-analysis

Background

JAK inhibitors are a relatively new class of medications that may be useful in the treatment of moderate-to-severe psoriasis and psoriatic arthritis (PsA). The objective of this study was to determine the efficacy of several JAK inhibitors in treating psoriasis and PsA and examine safety concerns.

Methods

MEDLINE, Cochrane and EMBASE were searched for randomized controlled trials and observational studies comparing any JAK inhibitor to placebo. The primary outcomes were a 75% improvement in the Psoriasis Area and Severity Index (PASI75) and a 20% improvement in the American College of Rheumatology composite score (ACR20). A secondary outcome was the proportion of patients achieving a “0” or “1” on the static Physician Global Assessment scale. Odds ratios were used to compare the proportion of patients reaching these targets in the max dose intervention group vs. the placebo group. A random effects model was used to account for heterogeneity.

Results

In total, 15 RCTs were included in the study and no observational studies. This encompassed 6757 patients in total. When the results were combined, the calculated odds ratio for PASI75 amongst tofacitinib vs. placebo was OR 14.35 [95%CI 7.65, 26.90], for PASI75 amongst non-tofacitinib JAK inhibitors vs. placebo it was OR 6.42 [95%CI 4.89, 8.43], for ACR20 amongst all JAK inhibitors versus placebo was OR 5.87 [95%CI 4.39, 7.85]. There was no significant difference in prevalence of serious adverse events between intervention and control in any of these studies.

Conclusion

JAK inhibitors show promise for safely treating moderate-to-severe psoriasis and psoriatic arthritis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00287-7.

Novel Therapeutic Target(s) for Psoriatic Disease

Psoriasis and psoriatic arthritis, together known as psoriatic disease, is highly prevalent chronic relapsing inflammatory disease affecting skin, joints or both and is associated with several comorbidities such as cardiovascular, metabolic, psychiatric, renal disease etc. The etiopathogenesis of psoriasis is complex and mainly driven by aberrant immune response owing to the genetic susceptibility and various environmental factors such as trauma, infections and drugs. Recent advances in understanding molecular and cellular pathways have identified tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-23, IL-22 as major contributors in psoriasis pathogenesis. Advances in the knowledge of pathophysiology, the interaction of autoinflammation and clinical phenotypes have led to the development of highly effective targeted therapeutic agents which include TNF-α, IL-17, IL-23, IL-1 α/β or IL-36 inhibitors or receptor blockers, small molecule drugs like phosphodiesterase-4 inhibitors (apremilast), Janus kinase (JAK) inhibitors, retinoic acid receptor-related orphan receptor γt (RORγt) inhibitors. These novel drugs have promised the potential of improved disease control. In recent years, the transition from biologics to biosimilars especially with TNF-α inhibitors had significant impact on decreasing health care cost and increasing therapeutic options to the patients. However, selection of right treatment for an individual patient still remains challenging. Moreover, interplay between different epigenetic mechanisms such as the DNA methylation, chromatin modifications and noncoding RNA regulation has recently been started to be deciphered. Enzymes inhibitors involved in epigenetic pathways such as DNA methyltransferases and histone deacetylases demonstrated to restore normal epigenetic patterns in clinical settings and have provided the potential as novel therapeutic targets for psoriasis. In this review, we will discuss novel biologic agents and newer therapeutic approaches in treatment of psoriatic disease.

Evaluation of pregnancy-associated plasma protein-A and some inflammation markers for atherosclerosis in psoriasis patients

Introduction

Psoriasis is a common, chronic inflammatory disease of the skin. Although its relationship with cardiovascular risk factors is one of the main causes of mortality, the association between psoriasis and cardiovascular events is controversial.

Aim

The aim of this study is to measure the levels of hs-CRP and pregnancy-associated plasma protein-A (PAPP-A) related to atherosclerosis in patients with moderate-severe psoriasis and to evaluate their possible association with disease severity.

Material and methods

This study included 45 moderate-severe psoriasis patients without additional risk factors for cardiovascular disease and 45 healthy individuals as a control group.

Results

Serum PAPP-A levels in both groups were given as two different variables, detectable and non- detectable, based on a value of 0.004 U/lL. When PAPP-A levels were compared, there was no statistically significant difference between the groups.

Conclusions

The use of the PAPP-A test in the evaluation of early-stage atherosclerosis in moderate-severe psoriasis patients who do not have additional risk factors for cardiovascular diseases may not be sufficient.

Novel archetype in psoriasis management bridging molecular dynamics in exploring novel therapies

Psoriasis is an autoimmune chronic inflammatory condition of skin affecting 125 million populaces around the globe. It is implicated as a result of multifaceted phenomena involving various cell and subcell activities with the aid of numerous cellular and molecular components including signaling aisle and regulatory proteins owing to the development of such hyperproliferative dermatological conditions. This involves a deeply complex and conflicting pathology owing to genetic and immunological deviations resulting from the unusual presentation of different signaling pathways and regulatory proteins. Explorations of these biomarkers and intervention of molecular and cellular processes in psoriasis are yet to be investigated and could be an exceptional aspect for understanding pathology with successful targeting of disease. In the presented study, we have integrated molecular insights, including signaling molecules, pathways, and proteins implicated in pathogenesis, and we have attempted to link this knowledge to the targeting of these phenomena in order to manage the conditions precisely. Further, therapeutic delivery approaches for targeting distinct layers of skin have also been investigated based on the application of different nanocarriers for successful psoriasis treatment.

Janus Kinase Inhibitors in Dermatology: Part 2: Applications in Psoriasis, Atopic Dermatitis, and Other Dermatoses

Dermatologists' interest in the Janus-associated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been growing as evidence builds to support its key role in the pathogenesis of inflammatory skin diseases. Because certain proinflammatory cytokines use the JAK/STAT pathway for signal transduction, it has become a promising therapeutic target in diseases where selective modulation of the immune system can be useful. We aim to review current knowledge of the JAK/STAT signaling pathway and its role in immune-mediated skin diseases. In the second part of the review we cover the efficacy and safety of oral and topical JAK inhibitors in the treatment of psoriasis, atopic dermatitis, and other skin diseases.

Polymers in topical delivery of anti-psoriatic medications and other topical agents in overcoming the barriers of conventional treatment strategies

In recent decades, topical treatments to dermal disorders have shown ineffectiveness in delivering the medication at a particular location without a suitable drug carrier. Psoriasis treatment is hindered because of the ineffective delivery and efficacy of conventional pharmaceutical treatment. In conventional medication formulation approach, it is difficult to breach the transdermal layer of a skin membrane for topical drugs, i.e. cyclosporine, methotrexate. This problem is further complicated by extreme disease-associated conditions such as hyperkeratosis and irritation. Intending to assure better drug delivery carriers, this review emphasizes the therapeutic efficacy of polymers and their potential to deliver the drug into the deeper layer of the skin membrane. The polymers are essential in structural and physiochemical perspectives as it works as a carrier for the medication. A vast variety of delivery carriers is available nowadays but their applicability in such dermal cases like psoriasis is still lacking due to less knowledge on an appropriate polymer. The current investigation of suitable polymer would assist in brushing our expertise to optimize the advantages of a wide spectrum of polymers to fulfill the topical targeting of psoriasis.

Therapeutics targeting the IL-23 and IL-17 pathway in psoriasis

Psoriasis is a chronic inflammatory disease characterised by sharply demarcated erythematous and scaly skin lesions accompanied by systemic manifestations. Classified by WHO as one of the most serious non-infectious diseases, psoriasis affects 2-3% of the global population. Mechanistically, psoriatic lesions result from hyperproliferation and disturbed differentiation of epidermal keratinocytes that are provoked by immune mediators of the IL-23 and IL-17 pathway. Translational immunology has had impressive success in understanding and controlling psoriasis. Psoriasis is the first disease to have been successfully treated with therapeutics that directly block the action of the cytokines of this pathway; in fact, therapeutics that specifically target IL-23, IL-17, and IL-17RA are approved for clinical use and show excellent efficacy. Furthermore, inhibitors of IL-23 and IL-17 intracellular signalling, such as TYK2 or RORγt, are in clinical development. Although therapies that target the IL-23 and IL-17 pathway also improve psoriatic arthritis symptoms, their effects on long-term disease modification and psoriasis-associated comorbidities still need to be explored.

Janus Kinase Inhibitors in Dermatology: Part 2: Applications in Psoriasis, Atopic Dermatitis, and Other Dermatoses

Dermatologists' interest in the Janus-associated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been growing as evidence builds to support its key role in the pathogenesis of inflammatory skin diseases. Because certain proinflammatory cytokines use the JAK/STAT pathway for signal transduction, it has become a promising therapeutic target in diseases where selective modulation of the immune system can be useful. We aim to review current knowledge of the JAK/STAT signaling pathway and its role in immune-mediated skin diseases. In the second part of the review we cover the efficacy and safety of oral and topical JAK inhibitors in the treatment of psoriasis, atopic dermatitis, and other skin diseases.

Points to consider for the treatment of immune-mediated inflammatory diseases with Janus kinase inhibitors: a consensus statement

OBJECTIVES

Janus kinase inhibitors (JAKi) have been approved for use in various immune-mediated inflammatory diseases. With five agents licensed, it was timely to summarise the current understanding of JAKi use based on a systematic literature review (SLR) on efficacy and safety.

METHODS

Existing data were evaluated by a steering committee and subsequently reviewed by a 29 person expert committee leading to the formulation of a consensus statement that may assist the clinicians, patients and other stakeholders once the decision is made to commence a JAKi. The committee included patients, rheumatologists, a gastroenterologist, a haematologist, a dermatologist, an infectious disease specialist and a health professional. The SLR informed the Task Force on controlled and open clinical trials, registry data, phase 4 trials and meta-analyses. In addition, approval of new compounds by, and warnings from regulators that were issued after the end of the SLR search date were taken into consideration.

RESULTS

The Task Force agreed on and developed four general principles and a total of 26 points for consideration which were grouped into six areas addressing indications, treatment dose and comedication, contraindications, pretreatment screening and risks, laboratory and clinical follow-up examinations, and adverse events. Levels of evidence and strengths of recommendations were determined based on the SLR and levels of agreement were voted on for every point, reaching a range between 8.8 and 9.9 on a 10-point scale.

CONCLUSION

The consensus provides an assessment of evidence for efficacy and safety of an important therapeutic class with guidance on issues of practical management.

Points to consider for the treatment of immune-mediated inflammatory diseases with Janus kinase inhibitors: a consensus statement

OBJECTIVES

Janus kinase inhibitors (JAKi) have been approved for use in various immune-mediated inflammatory diseases. With five agents licensed, it was timely to summarise the current understanding of JAKi use based on a systematic literature review (SLR) on efficacy and safety.

METHODS

Existing data were evaluated by a steering committee and subsequently reviewed by a 29 person expert committee leading to the formulation of a consensus statement that may assist the clinicians, patients and other stakeholders once the decision is made to commence a JAKi. The committee included patients, rheumatologists, a gastroenterologist, a haematologist, a dermatologist, an infectious disease specialist and a health professional. The SLR informed the Task Force on controlled and open clinical trials, registry data, phase 4 trials and meta-analyses. In addition, approval of new compounds by, and warnings from regulators that were issued after the end of the SLR search date were taken into consideration.

RESULTS

The Task Force agreed on and developed four general principles and a total of 26 points for consideration which were grouped into six areas addressing indications, treatment dose and comedication, contraindications, pretreatment screening and risks, laboratory and clinical follow-up examinations, and adverse events. Levels of evidence and strengths of recommendations were determined based on the SLR and levels of agreement were voted on for every point, reaching a range between 8.8 and 9.9 on a 10-point scale.

CONCLUSION

The consensus provides an assessment of evidence for efficacy and safety of an important therapeutic class with guidance on issues of practical management.

JAK Inhibitors for Treatment of Psoriasis: Focus on Selective TYK2 Inhibitors

Despite advances in the treatment of psoriasis, there is an unmet need for effective and safe oral treatments. The Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) pathway plays a significant role in intracellular signalling of cytokines of numerous cellular processes, important in both normal and pathological states of immune-mediated inflammatory diseases. Particularly in psoriasis, where the interleukin (IL)-23/IL-17 axis is currently considered the crucial pathogenic pathway, blocking the JAK-STAT pathway with small molecules would be expected to be clinically effective. However, relative non-specificity and low therapeutic index of the available JAK inhibitors have delayed their integration into the therapeutic armamentarium of psoriasis. Current research appears to be focused on Tyrosine kinase 2 (TYK2), the first described member of the JAK family. Data from the Phase II trial of BMS-986165-a selective TYK2 inhibitor-in psoriasis have been published and clinical results are encouraging, with a large Phase III programme ongoing. Further, the selective TYK2 inhibitor PF-06826647 is being tested in moderate-to-severe psoriasis in a Phase II clinical trial. Brepocitinib, a potent TYK2/JAK1 inhibitor, is also being evaluated, as both oral and topical treatment. Results of studies with TYK2 inhibitors will be important in assessing the clinical efficacy and safety of these drugs and their place in the therapeutic armamentarium of psoriasis. This article reviews current data on the impact of JAK inhibitors in the treatment of adult patients with moderate-to-severe psoriasis.

Psoriasis: pathological mechanisms, current pharmacological therapies, and emerging drug delivery systems

Psoriasis is a chronic autoimmune skin disorder triggered by either genetic factors, environmental factors, life style, or a combination thereof. Clinical investigations have identified pathogenesis, such as T cell and cytokine-mediated, genetic disposition, antimicrobial peptides, lipocalin-2, galectin-3, vaspin, fractalkine, and human neutrophil peptides in the progression of psoriasis. In addition to traditional therapies, newer therapeutics, including phosphodiesterase type 4 (PDE4) inhibitors, Janus kinase (JAK) inhibitors, monoclonal antibodies (mAbs), gene therapy, anti-T cell therapy, and phytoconstituents have been explored. In this review, we highlight nanotechnology-related developments for psoriasis treatment, including patented delivery systems and therapeutics currently in clinical trials.

New JAK inhibitors for the treatment of psoriasis and psoriatic arthritis

Psoriasis is a common inflammatory skin disease that can be associated with various pathological conditions among which arthritis is a frequent comorbidity. Based on the current pathogenetic model, development of psoriasis is mainly driven by the IL-23/IL-17A axis. Though the therapeutic armamentarium is expanding in the latest years, new therapies are needed because of the lack or loss of response or intolerance/contraindication to the currently approved drugs. The most recently developed drugs for the treatment of psoriasis and psoriatic arthritis specifically target cytokines, cytokine receptors, and intracellular signaling transducers that are involved in the pathogenesis of psoriasis. Janus kinase (JAK) pathway transduces signals of multiple cytokines, such as TNF-α, IL-23, IL-12, IFN, IL-6, IL-17, that have resulted crucial in the induction and maintenance of psoriasis inflammation. Thereby, JAK-1, JAK-3, TYK-2 belonging to the JAK family, have been identified as valid therapeutic targets in the treatment of psoriasis. Nowadays, different JAK inhibitors have been investigated in clinical trials showing promising results in terms of efficacy and safety. In this review, we systematically collected publications and data related to JAK inhibitors used in psoriasis and psoriatic arthritis providing the state-of-the-art on this new class of molecules in the treatment of these diseases.

Janus kinases (JAKs): The efficient therapeutic targets for autoimmune diseases and myeloproliferative disorders

The Janus kinases or JAKs are a family of intracellular tyrosine kinases that play an essential role in the signaling of numerous cytokines that have been implicated in the pathogenesis of autoimmune diseases and myeloproliferative disorders. JAKs are activated upon ligand induced receptor homo- or heterodimerization, which results in the immediate phosphorylation of tyrosine residues and the phosphotyrosines then serve as docking sites for cytoplasmic signal transducer and activator of transcription (STAT) proteins which become phosphorylated by the JAKs upon recruitment to the receptor complex. The phosphorylated STAT proteins dimerize and travel to the cellular nucleus, where they act as transcription factors. Interfering in the JAK-STAT pathway has yielded the only approved small molecule kinase inhibitors for immunological indications. Numerous medicinal chemistry studies are currently aimed at the design of novel and potent inhibitors for JAKs. Additionally, whether the second-generation inhibitors which possessed selectivity for JAKs are more efficient are under research. This Perspective summarizes the progress in the discovery and development of JAKs inhibitors, including the potential binding site and approaches for identifying small-molecule inhibitors, as well as future therapeutic perspectives in autoimmune diseases and myeloproliferative disorders are also put forward in order to provide reference and rational for the drug discovery of novel and potent JAKs inhibitors.

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.

JAK-inhibitors. New players in the field of immune-mediated diseases, beyond rheumatoid arthritis

Janus kinase (JAK)/signal transducers and activators of transcription (STATs) are a group of molecules associated with one of the major pathways through which many cytokines exert and integrate their function, and as such they are increasingly recognized as playing critical role in the pathogenesis subserving various immune-mediated diseases, including RA, PsA, SpAs, IBD, skin disorders (e.g. alopecia areata, atopic dermatitis), single-gene disorders like interferonopathies, and others. JAKs are the key initiating players of the JAK/STAT pathway. Upon binding of their respective effector molecules (cytokines, IFNs, growth factors and others) to type I and type II receptors, JAKs are activated, and through phosphorylation of themselves and of other molecules (including STATs), they mediate signal transduction to the nucleus. A class of drugs—called JAK inhibitors or JAKinibs—that block one or more JAKs has been developed in the last decade, and now numbers >20 members. Although, so far, JAK inhibitors have been marketed only for RA and PsA, these drugs have been tested in phase 2 and phase 3 clinical trials for other inflammatory conditions and beyond. In this review, we summarize the clinical data, including efficacy and safety, available for JAK inhibitors used in some immune-mediated conditions other than RA.

Emerging Topical and Systemic JAK Inhibitors in Dermatology

Accumulating data on cellular and molecular pathways help to develop novel therapeutic strategies in skin inflammation and autoimmunity. Examples are psoriasis and atopic dermatitis, two clinically and immunologically well-defined disorders. Here, the elucidation of key pathogenic factors such as IL-17A/IL-23 on the one hand and IL-4/IL-13 on the other hand profoundly changed our therapeutic practice. The knowledge on intracellular pathways and governing factors is shifting our attention to new druggable molecules. Multiple cytokine receptors signal through Janus kinases (JAKs) and associated signal transducer and activators of transcription (STATs). Inhibition of JAKs can simultaneously block the function of multiple cytokines. Therefore, JAK inhibitors (JAKi) are emerging as a new class of drugs, which in dermatology can either be used systemically as oral drugs or locally in topical formulations. Inhibition of JAKs has been shown to be effective in various skin disorders. The first oral JAKi have been recently approved for the treatment of rheumatoid arthritis and psoriatic arthritis. Currently, multiple inhibitors of the JAK/STAT pathway are being investigated for skin diseases like alopecia areata, atopic dermatitis, dermatomyositis, graft-versus-host-disease, hidradenitis suppurativa, lichen planus, lupus erythematosus, psoriasis, and vitiligo. Here, we aim to discuss the immunological basis and current stage of development of JAKi in dermatology.

Targeting the Janus Kinase Family in Autoimmune Skin Diseases

Autoimmune skin diseases are characterized by significant local and systemic inflammation that is largely mediated by the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway. Advanced understanding of this pathway has led to the development of targeted inhibitors of Janus kinases (JAKinibs). As a class, JAK inhibitors effectively treat a multitude of hematologic and inflammatory diseases. Growing evidence suggests that JAK inhibitors are efficacious in atopic dermatitis, alopecia areata, psoriasis, and vitiligo. Additional evidence suggests that JAK inhibition might be broadly useful in dermatology, with early reports of efficacy in several other conditions. JAK inhibitors can be administered orally or used topically and represent a promising new class of medications. Here we review the evolving data on the role of the JAK-STAT pathway in inflammatory dermatoses and the potential therapeutic benefit of JAK-STAT antagonism.

Itch: From mechanism to (novel) therapeutic approaches

Itch is a common sensory experience that is prevalent in patients with inflammatory skin diseases, as well as in those with systemic and neuropathic conditions. In patients with these conditions, itch is often severe and significantly affects quality of life. Itch is encoded by 2 major neuronal pathways: histaminergic (in acute itch) and nonhistaminergic (in chronic itch). In the majority of cases, crosstalk existing between keratinocytes, the immune system, and nonhistaminergic sensory nerves is responsible for the pathophysiology of chronic itch. This review provides an overview of the current understanding of the molecular, neural, and immune mechanisms of itch: beginning in the skin, proceeding to the spinal cord, and eventually ascending to the brain, where itch is processed. A growing understanding of the mechanisms of chronic itch is expanding, as is our pipeline of more targeted topical and systemic therapies. Our therapeutic armamentarium for treating chronic itch has expanded in the last 5 years, with developments of topical and systemic treatments targeting the neural and immune systems.

Tyrosine Kinases in Autoimmune and Inflammatory Skin Diseases

Tyrosine kinases relay signals from diverse leukocyte antigen receptors, innate immune receptors, and cytokine receptors, and therefore mediate the recruitment and activation of various leukocyte populations. Non-receptor tyrosine kinases of the Jak, Src, Syk, and Btk families play major roles in various immune-mediated disorders, and small-molecule tyrosine kinase inhibitors are emerging novel therapeutics in a number of those diseases. Autoimmune and inflammatory skin diseases represent a broad spectrum of immune-mediated diseases. Genetic and pharmacological studies in humans and mice support the role of tyrosine kinases in several inflammatory skin diseases. Atopic dermatitis and psoriasis are characterized by an inflammatory microenvironment which activates cytokine receptors coupled to the Jak-Stat signaling pathway. Jak kinases are also implicated in alopecia areata and vitiligo, skin disorders mediated by cytotoxic T lymphocytes. Genetic studies indicate a critical role for Src-family kinases and Syk in animal models of autoantibody-mediated blistering skin diseases. Here, we review the various tyrosine kinase signaling pathways and their role in various autoimmune and inflammatory skin diseases. Special emphasis will be placed on identification of potential therapeutic targets, as well as on ongoing preclinical and clinical studies for the treatment of inflammatory skin diseases by small-molecule tyrosine kinase inhibitors.

Roles of JAK2 in Aging, Inflammation, Hematopoiesis and Malignant Transformation

Clonal alterations in hematopoietic cells occur during aging and are often associated with the establishment of a subclinical inflammatory environment. Several age-related conditions and diseases may be initiated or promoted by these alterations. JAK2 mutations are among the most frequently mutated genes in blood cells during aging. The most common mutation within the JAK2 gene is JAK2-V617F that leads to constitutive activation of the kinase and thereby aberrant engagement of downstream signaling pathways. JAK2 mutations can act as central drivers of myeloproliferative neoplasia, a pre-leukemic and age-related malignancy. Likewise, hyperactive JAK-signaling is a hallmark of immune diseases and critically influences inflammation, coagulation and thrombosis. In this review we aim to summarize the current knowledge on JAK2 in clonal hematopoiesis during aging, the role of JAK-signaling in inflammation and lymphocyte biology and JAK2 function in age-related diseases and malignant transformation.

Itch: an under-recognized problem in psoriasis

Psoriasis has historically been considered a nonpruritic dermatosis, in contrast with atopic dermatitis. Thus, itch has often been underappreciated and overlooked in psoriasis. However, increasing evidence over the past decade has shown that itch can be one of the most prevalent and burdensome symptoms associated with psoriasis, affecting almost every patient to some degree. Itch can involve the entire body, although it predominantly affects the legs, hands, back, body and especially the scalp. Uncontrolled itch can significantly impact all aspects of the well-being and quality of life of the patient. While there has been some progress in trying to better understand the pathophysiology of itch in psoriasis, more research effort and interest are needed. This under-recognition of itch in psoriasis is clearly reflected in the dearth of treatment options targeting itch despite significant advancement in treating the lesions themselves. Recently, however, clinical studies have begun to include itch as a study outcome. The resulting data have demonstrated concomitant antipruritic benefits and improved Psoriasis Area and Severity Index (PASI) scores with mainstay treatments for psoriasis, such as topical corticosteroids and vitamin D analogs, phototherapies, and various systemics and biologics. This article takes a closer look at this debilitating symptom, reviewing the available epidemiology data for psoriatic itch, presenting the current understanding of psoriatic itch pathophysiology and highlighting important clinical data for various treatment options for itch. Practical considerations for increasing the recognition of itch as well as improving its management in psoriasis are also provided.

A JAK1 Selective Kinase Inhibitor and Tofacitinib Affect Macrophage Activation and Function

BACKGROUND

Janus kinases (JAKs) mediate cytokine signaling involved in inflammatory bowel disease. The pan-JAK inhibitor tofacitinib has shown efficacy in the treatment of ulcerative colitis. However, concerns regarding adverse events due to their wide spectrum inhibition fueled efforts to develop selective JAK inhibitors. Given the crucial role of myeloid cells in intestinal immune homeostasis, we evaluated the effect of pan-JAK and selective JAK inhibitors on pro- and anti-inflammatory macrophage polarization and function (M1/M2) and in experimental colitis.

METHODS

Murine bone marrow-derived macrophages or human monocytes were treated using JAK1 and JAK3 selective inhibitors (JAK1i;JAK3i) and tofacitinib and were evaluated by transcriptional, functional, and metabolic analyses. In vivo, oral administration of JAK1i and tofacitinib (10 or 30 mg/kg) was tested in both acute and acute rescue dextran sodium sulfate (DSS) colitis.

RESULTS

Both tofacitinib and JAK1i but not JAK3i effectively inhibited STAT1 phosphorylation and interferon gamma-induced transcripts in M1 polarized macrophages. Strikingly, transcriptional profiling suggested a switch from M1 to M2 type macrophages, which was supported by increased protein expression of M2-associated markers. In addition, both inhibitors enhanced oxidative phosphorylation rates. In vivo, JAK1i and tofacitinib did not protect mice from acute DSS-induced colitis but ameliorated recovery from weight loss and disease activity during acute rescue DSS-induced colitis at the highest dose.

CONCLUSION

JAK1i and tofacitinib but not JAK3i induce phenotypical and functional characteristics of anti-inflammatory macrophages, suggesting JAK1 as the main effector pathway for tofacitinib in these cells. In vivo, JAK1i and tofacitinib modestly affect acute rescue DSS-induced colitis.

Selective JAKinibs: Prospects in Inflammatory and Autoimmune Diseases

Cytokines, many of which signal through the JAK-STAT (Janus kinase-Signal Transducers and Activators of Transcription) pathway, play a central role in the pathogenesis of inflammatory and autoimmune diseases. Currently three JAK inhibitors have been approved for clinical use in USA and/or Europe: tofacitinib for rheumatoid arthritis, psoriatic arthritis and ulcerative colitis, baricitinib for rheumatoid arthritis, and ruxolitinib for myeloproliferative neoplasms. The clinical JAK inhibitors target multiple JAKs at high potency and current research has focused on more selective JAK inhibitors, almost a dozen of which currently are being evaluated in clinical trials. In this narrative review, we summarize the status of the pan-JAK and selective JAK inhibitors approved or in clinical trials, and discuss the rationale for selective targeting of JAKs in inflammatory and autoimmune diseases.

Neurons and Microglia; A Sickly-Sweet Duo in Diabetic Pain Neuropathy

Diabetes is a common condition characterized by persistent hyperglycemia. High blood sugar primarily affects cells that have a limited capacity to regulate their glucose intake. These cells include capillary endothelial cells in the retina, mesangial cells in the renal glomerulus, Schwann cells, and neurons of the peripheral and central nervous systems. As a result, hyperglycemia leads to largely intractable complications such as retinopathy, nephropathy, hypertension, and neuropathy. Diabetic pain neuropathy is a complex and multifactorial disease that has been associated with poor glycemic control, longer diabetes duration, hypertension, advanced age, smoking status, hypoinsulinemia, and dyslipidemia. While many of the driving factors involved in diabetic pain are still being investigated, they can be broadly classified as either neuron -intrinsic or -extrinsic. In neurons, hyperglycemia impairs the polyol pathway, leading to an overproduction of reactive oxygen species and reactive nitrogen species, an enhanced formation of advanced glycation end products, and a disruption in Na⁺/K⁺ ATPase pump function. In terms of the extrinsic pathway, hyperglycemia leads to the generation of both overactive microglia and microangiopathy. The former incites a feed-forward inflammatory loop that hypersensitizes nociceptor neurons, as observed at the onset of diabetic pain neuropathy. The latter reduces neurons' access to oxygen, glucose and nutrients, prompting reductions in nociceptor terminal expression and losses in sensation, as observed in the later stages of diabetic pain neuropathy. Overall, microglia can be seen as potent and long-lasting amplifiers of nociceptor neuron activity, and may therefore constitute a potential therapeutic target in the treatment of diabetic pain neuropathy.

Protein biomarker for psoriasis: A systematic review on their role in the pathomechanism, diagnosis, potential targets and treatment of psoriasis

Psoriasis is defined as a long-lasting multifactorial inflammatory autoimmune skin condition precisely characterized by delimited, erythematic papules with adherent shiny scales. The conditions are led by hyperproliferative responses of epidermis due to hyperactivation and immature keratinocytes production. The psoriatic skin consists of the thickened epidermal layer, in concurrence with inflammatory exudates in the dermis mainly of dendritic cells, neutrophils, T cells, and macrophages, contributing to the distinct manifestation of psoriatic lesions. It consents to multifaceted and discrete pathology due to the genetic and immunological alteration resulting from abnormal expression of various regulatory and structural proteins. These proteins are associated with various cellular and sub-cellular activities. Therefore, the presence of protein in a pathological cellular environment in the psoriatic lesions as well as in serum could be a great avenue for the insight of pathomechanism, anticipation and diagnosis of psoriasis. Research of protein biomarker in psoriasis is yet a developing realm to be explored by both fundamental and clinical researchers. This review is an attempt to assimilate the current discoveries and revelations of different proteins as a biomarker and their importance in pathogenesis, diagnosis, treatment, and anticipation of both the inflammatory and other dermatological aspects of psoriasis.

Biologics and Small Molecule Agents in Allergic and Immunologic Skin Diseases

PURPOSE OF REVIEW

Biologics and small molecules are key therapeutic options in the treatment of chronic immunologic and allergic skin conditions. By directly targeting innate and inflammatory responses within the skin, including pro-inflammatory cytokines and cellular signaling pathways, these new agents have the potential to counteract the inflammatory cascade responsible for various conditions, including psoriasis and atopic dermatitis. Over the past decade, groundbreaking research identifying key cytokines and receptors involved in the pathogenesis of these diseases has allowed for the development of highly efficacious biologics and small molecules that are associated with unprecedented rates of skin clearance and favorable adverse event profiles.

RECENT FINDINGS

This narrative review evaluates new and upcoming biologic and small molecule agents for the treatment of two allergic/immunologic skin diseases-atopic dermatitis and psoriasis. Numerous small molecules and biologics targeting TNF-α, IL-12/23, IL-17 and IL-17R, and IL-23 are commercially available for the treatment of psoriasis, and newer agents are in various stages of development. Currently, dupilumab, a monoclonal antibody that blocks IL-4R∝, is the only approved biologic for atopic dermatitis. Antibodies targeting IL-13 and IL-31 and small molecules that inhibit Janus kinase and pruritus-mediating receptors are currently being studied in clinical trials. Further investigations into the pathophysiology of atopic dermatitis will likely yield additional therapeutic options in the future. This article reviews recent literature on small molecules and biologics for the treatment of atopic dermatitis and psoriasis.

Evaluation of a Janus kinase 1 inhibitor, PF-04965842, in healthy subjects: A phase 1, randomized, placebo-controlled, dose-escalation study

AIMS

To determine the safety, tolerability, pharmacokinetics and pharmacodynamics of the Janus kinase 1-selective inhibitor, PF-04965842.

METHODS

This was a phase 1, first-in-human, randomized, double-blind, placebo-controlled, combination single- and multiple-dose escalation, parallel design study in healthy subjects (http://clinicaltrials.gov, NCT01835197). Subjects received a single dose of placebo or 3, 10, 30, 100, 200, 400 or 800 mg PF-04965842 (single ascending dose phase) and placebo or 30 mg once daily (QD), 100 mg QD, 200 mg QD, 400 mg QD, 100 mg twice daily (BID) or 200 mg BID PF-04965842 for 10 consecutive days (multiple ascending dose phase). The primary objective was to determine the safety and tolerability of PF-04965842.

RESULTS

Seventy-nine subjects were randomized and received study treatments. There were no deaths or serious adverse events. The most frequent treatment-emergent adverse events were headache (n = 13), diarrhoea (n = 11) and nausea (n = 11). PF-04965842 was absorbed rapidly (median time at which maximum plasma concentration occurred generally ≤1 h following either single- or multiple-dose administration) and eliminated rapidly (mean t_½ 2.8-5.2 h after 10 days of QD or BID administration in the multiple ascending dose phase). Increases in maximum plasma concentration and area under the concentration-time curve were dose proportional up to 200 mg (single or total daily doses) with an apparent trend towards greater than proportional increases with higher doses. Less than 4.4% of the dose was recovered unchanged in urine. Changes in pharmacodynamic biomarkers were consistent with the known effects of Janus kinase signalling inhibition.

CONCLUSIONS

These results support further evaluation of PF-04965842 for clinical use in patients with inflammatory diseases.