Tyk2 Targeting in Immune-Mediated Inflammatory Diseases

Identification of small molecule activators targeting TYK2 pseudokinase domain

Tyrosine kinase 2 (TYK2) plays a crucial role in both adaptive and innate immune responses. The catalytic activity of the TYK2 JH1 kinase domain is controlled by the TYK2 JH2 pseudokinase domain and stabilized to maintain its inactive state until the upstream receptor activations. Here, we report the discovery of aminopyridine analogs as novel TYK2 activators through structural modification of a known JH2 binder. Compound 16b demonstrated a dose-dependent increase in TYK2 enzymatic activity.

Cold Storage Disrupts the Proteome and Phosphoproteome Landscape in Rat Kidney Transplants

BACKGROUND

Prolonged cold storage (CS) of kidneys results in poor long-term outcomes after transplantation (Tx). We reported previously that CS of rat kidneys for 18 h before transplant impaired proteasome function, disrupted protein homeostasis, and reduced graft function. The goal of the present study was to identify the renal proteins, including phosphoproteins, that are dysregulated by this CS injury.

METHODS

Isolated donor Lewis rat kidneys were subject to 18 h CS and transplanted into recipient Lewis rats (CS + Tx). Autotransplantation (transplant with 0 h CS) or Sham (right nephrectomy) surgeries served as controls. The proteome of kidney homogenates was analyzed with tandem mass-tag mass spectrometry to identify CS-induced abnormalities in kidney grafts.

RESULTS

CS injury disrupted the renal proteome/phosphoproteome landscape in kidney grafts and dysregulated numerous signaling pathways. We identified 3217 phosphopeptides (with 1398 novel phosphosites) that were significantly dysregulated in a CS-specific manner. In particular, proteins and pathways such as complement system and mitogen-activated protein kinases, including p38MAPK, were upregulated, whereas antioxidant/metabolic pathways, such as glutathione, were suppressed in CS + Tx groups compared with autotransplantation and sham controls.

CONCLUSIONS

This study provides deeper insight into the disruption of the renal proteome/phosphoproteome caused by CS injury and provides a novel set of pathways and molecules, including p38MAPK, that can be investigated to delineate their specific role in renal transplant outcomes, ultimately improving outcomes for patients with end-stage kidney disease.

ABBV-712-induced cardiac pathology in rats is related to off-target-driven acute vasodilation, tachycardia, and increased cardiac contractility

Following an observation of myocardial toxicity in rats with an experimental TYK2 inhibitor (ABBV-712), investigative studies were performed to identify the mechanism. Telemetry-instrumented rats were administered ABBV-712 with or without atenolol to investigate effects of co-dosing on hemodynamic parameters and cardiac pathology. In vitro studies included cytotoxicity assessment in human-induced pluripotent stem cell-derived cardiomyocytes and relaxation of isolated rat aorta. Off-target pharmacology was evaluated by binding and inhibition screening assays. Finally, TYK2 knockout mice were administered ABBV-712 to evaluate hemodynamics as compared with wild-type animals. ABBV-712 resulted in decreased mean arterial pressure and increased heart rate in rats that was prevented by pre-dosing atenolol. ABBV-712-induced myocardial necrosis was also prevented by atenolol, suggesting a mechanistic link between hemodynamic changes and cardiac pathology. The pathology was unrelated to direct cytotoxicity on cardiomyocytes as demonstrated in vitro and was shown to be a compound-related effect on vascular relaxation mediated by the endothelium. The toxicity was considered an off-target effect, as demonstrated by similar hemodynamic responses between TYK2 knockout and wild-type mice administered ABBV-712, as well as by the lack of hemodynamic alterations in the knockout mouse. Inhibition of identified off-targets was unlikely to be the cause of the hemodynamic changes. In conclusion. a novel TYK2 inhibitor was associated with decreased mean arterial pressure, increased heart rate, and secondary myocardial necrosis in rats. These effects were unrelated to TYK2 inhibition. This report is an example of a cross-functional mechanistic investigation into the pharmacologic cause of an identified cardiovascular toxicity.

Hyper IgE Syndrome: Bridging the Gap Between Immunodeficiency, Atopy, and Allergic Diseases

PURPOSE OF REVIEW

It seeks to answer key questions about the molecular and cellular mechanisms underlying Hyper IgE Syndrome (HIES), the genetic mutations responsible, and their contributions to both immunodeficiency and allergic manifestations. Additionally, it aims to explore diagnostic strategies and therapeutic approaches that address these overlapping domains, thereby improving disease management.

RECENT FINDINGS

Recent research has identified several pivotal genetic mutations, including those in STAT3, DOCK8, and PGM3, which play critical roles in disrupting immune pathways such as Th17 differentiation and IgE regulation. These molecular defects have been linked to the hallmark features of HIES, including recurrent infections and elevated serum IgE levels, as well as its overlap with atopic conditions like eczema, asthma, and food allergies. Advances in diagnostic tools, such as biomarker identification and genetic testing, have improved the differentiation of HIES from more common atopic disorders. Therapeutic advancements, including the use of targeted biologics and interventions addressing both immunodeficiency and allergic symptoms, have shown promise in enhancing patient outcomes. This review highlights the role of specific genetic mutations in shaping the clinical and immunological phenotype of HIES. Key takeaways include the necessity of integrating molecular insights with clinical observations for accurate diagnosis and the potential of emerging targeted therapies to address both immunological and allergic aspects of the syndrome.

The Expanding Therapeutic Potential of Deucravacitinib Beyond Psoriasis: A Narrative Review

Deucravacitinib is an allosteric, selective tyrosine kinase 2 (TYK2) inhibitor that has demonstrated significant efficacy in the treatment of psoriasis. TYK2, a member of the Janus kinase (JAK) family, plays a critical role in intracellular signaling pathways for pro-inflammatory cytokines. Unlike traditional JAK inhibitors, which target active domains, deucravacitinib selectively binds to the pseudokinase domain of TYK2. This binding induces a conformational change that locks the enzyme in an inactive state, ensuring superior selectivity for TYK2 over JAK 1/2/3. This unique mechanism specifically inhibits key pro-inflammatory cytokines, including IL-12, IL-23, and type I interferons, critical in the pathogenesis of psoriasis and other immune-mediated diseases. As a result, deucravacitinib represents a promising option for targeted therapy in immune-mediated diseases and may reduce adverse events commonly associated with broader immunosuppressive treatments. Furthermore, its oral administration offers a convenient alternative to injectable biologics, potentially improving patient adherence and treatment satisfaction. This review highlights recent studies suggesting that deucravacitinib may also have therapeutic benefits in psoriatic arthritis, palmoplantar pustulosis, systemic lupus erythematosus, Sjogren's disease, and inflammatory bowel disease. Given its expanding therapeutic potential, deucravacitinib may provide a safer and more effective alternative to current therapies, offering a tailored approach to treatment.

A systematic review of the efficacy of TYK2 inhibitors in patients with dermatological disease

This study systematically reviews existing data on the efficacy of Tyrosine Kinase 2 (TYK2) inhibitors in comparison to placebo or standard treatments for therapeutic benefit and improving quality of life in dermatological diseases. Seventeen records representing 13 clinical trials, one matching-adjusted indirect comparison, and one case study were included. Results indicate that Deucravacitinib is superior to placebo, Apremilast and Adalimumab in treating adult patients with moderate-to-severe plaque psoriasis and superior to placebo in the treatment of adults with systemic lupus erythematosus. Comparative investigations on Brepocitinib and Ropsacitinib were more limited. Oral Brepocitinib demonstrated superiority over placebo in managing alopecia areata, and hidradenitis suppurativa. Topical Brepocitinib exhibited superiority over placebo in treating atopic dermatitis, but not plaque psoriasis. Ropsacitinib demonstrated superiority over placebo in the management of plaque psoriasis. Brepocitinib and Ropsacitinib had more side effects than Deucravacitinib.

JAK inhibitors: a new choice for diabetes mellitus?

Altered tyrosine kinase signaling is associated with a variety of diseases. Tyrosine kinases can be classified into two groups: receptor type and nonreceptor type. Nonreceptor-type tyrosine kinases are subdivided into Janus kinases (JAKs), focal adhesion kinases (FAKs) and tec protein tyrosine kinases (TECs). The beneficial effects of receptor-type tyrosine kinase inhibitors (TKIs) for the treatment of diabetes mellitus (DM) and the mechanisms involved have been previously described. Recently, several clinical cases involving the reversal of type 1 diabetes mellitus (T1DM) during treatment with JAK inhibitors have been reported, and clinical studies have described the improvement of type 2 diabetes mellitus (T2DM) during treatment with JAK inhibitors. In vivo and in vitro experimental studies have elucidated some of the mechanisms behind this effect, which seem to be based mainly on the reduction in β-cell disruption and the improvement of insulin resistance. In this review, we briefly describe the beneficial effects of JAK inhibitors among nonreceptor tyrosine kinase inhibitors for the treatment of DM and attempt to analyze the mechanisms involved.

Association of tyrosine kinase 2 polymorphisms with susceptibility to microscopic polyangiitis in a Guangxi population

Background

Heredity and epigenetics affect the pathogenesis of microscopic polyangiitis (MPA). Tyrosine kinase 2 (TYK2) polymorphisms (rs2304256C > A, rs280519A > G, and rs12720270G > A) may be potential protective factors against anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Current research suggests that TYK2 is associated with various autoimmune diseases; however, no study has examined the relationship between TYK2 polymorphisms and AAV. This study assessed the effect of TYK2 polymorphisms on susceptibility to MPA.

Methods

Overall, 562 Chinese participants (265 patients with MPA and 297 healthy volunteers) were recruited. Polymerase chain reactions combined with high-throughput sequencing were used to analyze polymorphic loci, while logistic regression analysis was used to assess the relationship between polymorphism of the TYK2 gene and MPA susceptibility.

Results

In males, individuals with the CA genotype (rs2304256) in the overdominant model showed a significantly reduced risk of MPA (odds ratio (OR) = 0.52; 95% confidence interval (CI) [0.29-0.93]; p = 0.025). Regarding rs280519, male carriers of the AG genotype had a significantly lower risk of developing MPA in both the codominant (OR = 0.51; 95% CI [0.28-0.93]; p = 0.039) and overdominant (OR = 0.48; 95% CI [0.27-0.86]; p = 0.013) models. The GA genotype of rs12720270 was associated with low susceptibility to MPA in males (OR = 0.52; 95% CI [0.29-0.93]; p = 0.027).

Conclusions

This study indicates that mutations in the TYK2 gene (rs2304256, rs280519, and rs12720270) may be associated with a reduced risk of MPA in the male Chinese population in Guangxi. The A allele of single nucleotide polymorphism (SNP) rs2304256 may be a protective factor against MPA, while the G alleles of SNPs rs280519 and rs12720270 are protective factors against MPA.

Lack of TYK2 signaling enhances host resistance to Candida albicans skin infection

Candida albicans is the most common human fungal pathogen, causing diseases ranging from local to life-threating systemic infections. Tyrosine kinase 2 (TYK2), a crucial mediator in several cytokine signaling pathways, has been associated with protective functions in various microbial infections. However, its specific contribution in the immune response to fungal infections has remained elusive. In this study, we show that mice lacking TYK2 or its enzymatic activity exhibit enhanced resistance to C. albicans skin infections, limiting fungal spread and accelerating wound healing. Impaired TYK2-signaling prompted the formation of a distinctive layer of necrotic neutrophils around the fungal pathogens. Transcriptomic analysis revealed TYK2's pivotal role in regulating interferon-inducible genes in neutrophils, thereby impacting their antifungal capacity during infection. Furthermore, we show that TYK2-dependent interferon-gamma (IFNγ) production contributes to fungal dissemination from the skin to the kidneys. Our study uncovers a hitherto unrecognized detrimental role of TYK2 in cutaneous C. albicans infections.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of the oral allosteric TYK2 inhibitor ESK-001 using a randomized, double-blind, placebo-controlled study design

ESK-001 is a highly selective allosteric inhibitor of tyrosine kinase 2 (TYK2), which plays an essential role in mediating cytokine signaling in multiple immune-mediated diseases. In 2 phase I studies, a first-in-human single ascending dose (SAD) and multiple ascending dose (MAD) study and a multiple-dose (MD) study, we evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of orally administered ESK-001 in healthy participants using a randomized, double-blind, placebo-controlled study design. ESK-001 was rapidly absorbed with systemic exposures generally increasing dose-proportionally across all cohorts. The mean terminal half-life ranged from 8 to 13 h with no to minimal accumulation of ESK-001 following q.d. doses and ~2-fold accumulation following Q12 doses. Less than 1% of unchanged ESK-001 was eliminated in urine. ESK-001 inhibited the downstream TYK2 pathway as shown by inhibition of pSTAT1 expression. Transcriptomic analysis of unstimulated whole blood samples confirmed dose-dependent inhibition of Type I IFN-induced genes and SIGLEC1, a novel TYK2-responsive biomarker. By correlating PK exposure data with PD readouts, a strong PK/PD relationship was demonstrated. There were no deaths, serious treatment-emergent adverse events (TEAEs), nor severe TEAEs, and most TEAEs were mild in severity. In conclusion, ESK-001 was generally safe and well-tolerated in healthy participants, showed linear dose-dependent PK characteristics, and maximally inhibited TYK2-dependent pathways with a predictable concentration-dependent PK/PD relationship. These findings were used to select the dose range of ESK-001 for the STRIDE phase II trial in plaque psoriasis and to support further clinical development of ESK-001 in other TYK2-mediated diseases.

JAK 1-3 inhibitors and TYK-2 inhibitors in dermatology: Practical pearls for the primary care physician

Guidelines for primary care clinicians on monitoring and safety guidelines regarding Janus kinase and tyrosine kinase 2 inhibitors in the treatment of inflammatory skin conditions are often unclear. This review aims to provide the primary care physician with a review of clinically relevant and updated information regarding the monitoring and overall profile of these medications. To do so, a systematic review was conducted using the PubMed database and relevant Food and Drug Administration (FDA) approved drug inserts from manufacturers. Janus kinase and tyrosine kinase 2 inhibitors have recently gained FDA approval for the treatment of several inflammatory skin conditions including atopic dermatitis, plaque psoriasis, alopecia areata, and vitiligo. There is a known box warning associated with the Janus kinase inhibitors that create the need for monitoring and close follow-up while patients are undergoing these treatments. Although these medications are often prescribed by specialists, as their use becomes more prevalent and therapies continue to gain approval for the treatment of these commonly encountered conditions, it is important for the primary physician to be updated and aware of the current monitoring guidelines and safety profile for this class of medication. Both Janus kinase inhibitors and tyrosine kinase 2 inhibitors display significant efficacy in the treatment of their approved conditions and research continues to move forward with the approval of more medications from these classes.

The response to influenza vaccination is associated with DNA methylation-driven regulation of T cell innate antiviral pathways

BACKGROUND

The effect of vaccination on the epigenome remains poorly characterized. In previous research, we identified an association between seroprotection against influenza and DNA methylation at sites associated with the RIG-1 signaling pathway, which recognizes viral double-stranded RNA and leads to a type I interferon response. However, these studies did not fully account for confounding factors including age, gender, and BMI, along with changes in cell-type composition.

RESULTS

Here, we studied the influenza vaccine response in a longitudinal cohort vaccinated over two consecutive years (2019-2020 and 2020-2021), using peripheral blood mononuclear cells and a targeted DNA methylation approach. To address the effects of multiple factors on the epigenome, we designed a multivariate multiple regression model that included seroprotection levels as quantified by the hemagglutination-inhibition (HAI) assay test.

CONCLUSIONS

Our findings indicate that 179 methylation sites can be combined as potential signatures to predict seroprotection. These sites were not only enriched for genes involved in the regulation of the RIG-I signaling pathway, as found previously, but also enriched for other genes associated with innate immunity to viruses and the transcription factor binding sites of BRD4, which is known to impact T cell memory. We propose a model to suggest that the RIG-I pathway and BRD4 could potentially be modulated to improve immunization strategies.

New and emerging oral therapies for psoriasis

Psoriasis is a chronic inflammatory skin disease affecting 2-3% of the global population. Traditional systemic treatments, such as methotrexate, cyclosporine, acitretin and fumaric acid esters, have limited efficacy and are associated with significant adverse effects, necessitating regular monitoring and posing risks of long-term toxicity. Recent advancements have introduced biologic drugs that offer improved efficacy and safety profiles. However, their high cost and the inconvenience of parenteral administration limit their accessibility. Consequently, there is a growing interest in developing new, targeted oral therapies. Small molecules, such as phosphodiesterase 4 inhibitors (e.g. apremilast) and TYK2 inhibitor (e.g. deucravacitinib), have shown promising results with favourable safety profiles. Additionally, other novel oral agents targeting specific pathways, including IL-17, IL-23, TNF, S1PR1 and A3AR, are under investigation. These treatments aim to combine the efficacy of biologics with the convenience and accessibility of oral administration, addressing the limitations of current therapies. This narrative review synthesizes the emerging oral therapeutic agents for psoriasis, focusing on their mechanisms of action, stages of development and clinical trial results.

JAK Inhibitors in Rheumatoid Arthritis: Immunomodulatory Properties and Clinical Efficacy

Rheumatoid arthritis (RA) is a highly prevalent autoimmune disorder. The pathogenesis of the disease is complex and involves various cellular populations, including fibroblast-like synoviocytes, macrophages, and T cells, among others. Identification of signalling pathways and molecules that actively contribute to the development of the disease is crucial to understanding the mechanisms involved in the chronic inflammatory environment present in affected joints. Recent studies have demonstrated that the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway regulates the behaviour of immune cells and contributes to the progression of RA. Several JAK inhibitors, such as tofacitinib, baricitinib, upadacitinib, and filgocitinib, have been developed, and their efficacy and safety in patients with RA have been comprehensively investigated in a number of clinical trials. Consequently, JAK inhibitors have been approved and registered as a treatment for patients with RA. In this review, we discuss the involvement of JAK/STAT signalling in the pathogenesis of RA and summarise the potential beneficial effects of JAK inhibitors in cells implicated in the pathogenesis of the disease. Moreover, we present the most important phase 3 clinical trials that evaluated the use of these agents in patients.

Biologics and Small Molecule Targeted Therapies for Pediatric Alopecia Areata, Psoriasis, Atopic Dermatitis, and Hidradenitis Suppurativa in the US: A Narrative Review

BACKGROUND

The management of pediatric dermatological conditions such as alopecia areata (AA), psoriasis, atopic dermatitis (AD), and hidradenitis suppurativa (HS) has significantly evolved with the introduction of biologics and small molecule targeted therapies. The advancement in understanding the immunopathogenesis of these chronic skin conditions has led to the development and approval of novel biologics and small molecule therapies. Initially approved by the United States Food and Drug Administration (FDA) for adults, most of these therapies are now being evaluated in clinical trials for safety and efficacy in adolescents and children, expanding new treatment options for pediatric patients. The role of the FDA in drug approval is multifaceted from drug inception, ensuring that research, data, and evidence show that the proposed drug is effective and safe for the intended use.

OBJECTIVE

The goal of this review article is to provide an overview of the recently FDA-approved and potential biologic and oral small molecule therapies in clinical trials for AA, psoriasis, AD, and HS in pediatric patients.

METHODS

The search for this review included keywords in ClinicalTrials.gov, PubMed, and Google Scholar for the latest research and clinical trials relevant to these conditions and treatments without the PRISMA methodology.

RESULTS

For pediatric AA, ritlecitinib is FDA-approved, while baricitinib and updacitinib are in phase 3 clinical trials for pediatric approval. The FDA-approved drugs for pediatric psoriasis include secukinumab, ustekinumab, ixekizumab, etanercept, and apremilast. Other phase 3 clinical trials for pediatric psoriasis include risankizumab, guselkumab, tildrakizumab, brodalumab, and deucravacitinib. For pediatric AD, the FDA-approved drugs are dupilumab, tralokinumab, abrocitinib, and upadacitinib, with many other drugs in phase 3 trials. Adalimumab is an FDA-approved biologic for pediatric HS, with various clinical trials ongoing for adults. The approved biologics and small molecule therapies had higher efficacy and improved safety profiles compared to traditional medications.

CONCLUSIONS

With numerous ongoing trials, the success of these clinical trials could lead to their inclusion in treatment guidelines for these chronic skin conditions. Biologics and small molecule therapies offer new avenues for effective disease management, enabling personalized therapeutic interventions and improving pediatric health outcomes.

IL-17 Control of Cutaneous Immune Homeostasis

IL-17 is widely recognized for its roles in host defense and inflammatory disorders. However, it has become clear that IL-17 is also an essential regulator of barrier tissue physiology. Steady-state microbe sensing at the skin surface induces low-level IL-17 expression that enhances epithelial integrity and resists pathogens without causing overt inflammation. Recent reports describe novel protective roles for IL-17 in wound healing and counteracting physiologic stress; however, chronic amplification of these beneficial responses contributes to skin pathologies as diverse as fibrosis, cancer, and autoinflammation. In this paper, we discuss the context-specific roles of IL-17 in skin health and disease and therapeutic opportunities.

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.

The response to influenza vaccination is associated with DNA methylation-driven regulation of T cell innate antiviral pathways

Background

The effect of vaccination on the epigenome remains poorly characterized. In previous research, we identified an association between seroprotection against influenza and DNA methylation at sites associated with the RIG-1 signaling pathway, which recognizes viral double-stranded RNA and leads to a type I interferon response. However, these studies did not fully account for confounding factors including age, gender, and BMI, along with changes in cell type composition.

Results

Here, we studied the influenza vaccine response in a longitudinal cohort vaccinated over two consecutive years (2019-2020 and 2020-2021), using peripheral blood mononuclear cells and a targeted DNA methylation approach. To address the effects of multiple factors on the epigenome, we designed a multivariate multiple regression model that included seroprotection levels as quantified by the hemagglutination-inhibition (HAI) assay test.

Conclusions

Our findings indicate that 179 methylation sites can be combined as potential signatures to predict seroprotection. These sites were not only enriched for genes involved in the regulation of the RIG-I signaling pathway, as found previously, but also enriched for other genes associated with innate immunity to viruses and the transcription factor binding sites of BRD4, which is known to impact T cell memory. We propose a model to suggest that the RIG-I pathway and BRD4 could potentially be modulated to improve immunization strategies.

Cardiovascular Risk Management in Patients Treated With Janus Kinase Inhibitors

ABSTRACT

The Janus kinase-signal transducer and activator of transcription pathway plays a critical role in the pathogenesis of many immune-mediated inflammatory diseases (IMIDs). Although Janus kinase inhibitors (JAKi) are an effective treatment for several IMIDs, they have come under scrutiny as a class because of a potential risk of venous thromboembolism and cardiovascular (CV) events, specifically noted with the oral JAKi, tofacitinib, as reported in the ORAL Surveillance Trial of a high CV risk rheumatoid arthritis population. This trial resulted in a black box warning from the Food and Drug Administration and European Medicines Agency regarding risk of venous thromboembolism and CV events that was extended across several types of JAKi (including topical ruxolitinib) when treating IMIDs, leading to considerable controversy. Included is an up-to-date review of the current and rapidly evolving literature on CV risk in patients with IMIDs on JAKi therapy, including identification of potential risk factors for future venous thromboembolism and CV events on JAKi therapy. We suggest a comprehensive, multimodal, and systematic approach for evaluation of CV risk in patients considering taking JAKi and emphasize that cardiologists play an important role in risk stratification and mitigation for patients with high CV risk factors or on long-term JAKi therapies.

Macrophage: Hidden Criminal in Therapy Resistance

BACKGROUND

Although substantial efforts have been made by researchers to develop drugs, a disappointing reality is that the emergence of drug resistance is an unavoidable reality for the majority of patients. In recent years, emerging evidence suggests a connection between drug resistance and immune dysregulation.

SUMMARY

As a ubiquitously distributed, versatile innate immune cell, macrophages play essential roles in maintaining tissue homeostasis in a steady state. Nevertheless, it is becoming aware that macrophages undermine the action of therapeutic drugs across various disease types. Reprogramming macrophage function has been proven to be effective in restoring patient responsiveness to treatment. Herein, we comprehensively reviewed how macrophages respond to drugs and the mechanisms by which they contribute to treatment unresponsiveness in cancer, inflammatory diseases, and metabolic diseases. In addition, future prospects in macrophage-based combination therapy were discussed.

KEY MESSAGES

Targeting macrophages is a promising strategy for overcoming drug resistance in immune disorders.

Innovative Therapeutic Strategies in TYK2-Targeted Treatments: From Cancer to Autoimmune Disorders

Recent advancements in therapeutic approaches targeting tyrosine kinase 2 (TYK2) have shown promising results across various medical fields, including oncology and immunology. TYK2, a Janus kinase (JAK) family member, plays a significant role in cytokine signaling and immune regulation. This Patent Highlight explores the latest developments in TYK2 inhibitors, highlighting their potential in treating diverse conditions such as cancer, alopecia areata, and psoriatic arthritis.

Deciphering the host genetic factors conferring susceptibility to severe COVID-19 using exome sequencing

The COVID-19 pandemic remains a significant public health concern despite the new vaccines and therapeutics. The clinical course of acute SARS-CoV-2 infection is highly variable and influenced by several factors related to the virus and the host. Numerous genetic studies, including candidate gene, exome, and genome sequencing studies, genome-wide association studies, and other omics efforts, have proposed various Mendelian and non-Mendelian associations with COVID-19 course. In this study, we conducted whole-exome sequencing on 90 unvaccinated patients from Turkey with no known comorbidities associated with severe COVID-19. Of these patients, 30 had severe, 30 had moderate, and 30 had mild/asymptomatic disease. We identified rare variants in genes associated with SARS-CoV-2 susceptibility and pathogenesis, with an emphasis on genes related to the regulation of inflammation, and discussed these in the context of the clinical course of the patients. In addition, we compared the frequencies of common variants between each group. Even though no variant remained statistically significant after correction for multiple testing, we observed that certain previously associated genes and variants showed significant associations before correction. Our study contributes to the existing literature regarding the genetic susceptibility to SARS-CoV-2. Future studies would be beneficial characterizing the host genetic properties in different populations.

Attenuated effects of topical vinpocetine in an imiquimod-induced mouse model of psoriasis

Psoriasis is an uncontrolled, long-lasting inflammatory dermatosis distinguished by thickened, erythematous, and flaky skin lesions. Massive amounts of inflammatory cytokines are produced when immune system imbalances are driven by genetic and environmental triggers. Vinpocetine (VNP), a man-made analogue of the compound vincamine found in the dwarf periwinkle herb, has robust anti-inflammatory, immunomodulatory, and anti-oxidative effects; alleviates the epidermal penetration of immune cells, such as eosinophils and neutrophils; and abolishes the generation of pro-inflammatory molecules.

Objective

This study was aimed at exploring the effects of long-term topical VNP, both alone and co-administered with clobetasol propionate, in an imiquimod-induced mouse model of psoriasiform dermatitis.

Methods

The study protocol consisted of 48 Swiss albino mice, randomly divided into six groups of eight mice each. In group I, petroleum jelly was administered daily for 8 days. In group II, imiquimod was administered topically at 62.5 mg daily for 8 days. In groups III, VI, V, and VI, 0.05% clobetasol propionate, 1% VNP, 3% VNP, and 3% VNP plus 0.05% clobetasol were administered topically for an additional 8 days after the induction, thus resulting in a total trial length of 16 days.

Results

Topical VNP at various doses alleviated the severity of imiquimod-induced psoriatic lesions-including erythema, silvery-white scaling, and thickening-and reversed the histopathological abnormalities. Moreover, imiquimod-exposed animals treated with VNP showed markedly diminished concentrations of inflammatory biomarkers, including tumour necrosis factor-α, interleukin (IL)-8, IL-17A, IL-23, IL-37, nuclear factor-kappa B (NF-κB), and transforming growth factor-β1.

Conclusion

This research provides new evidence that VNP, alone and in combination with clobetasol, may serve as a potential adjuvant for long-term management of autoimmune and autoinflammatory skin diseases, particularly psoriasis, by attenuating psoriatic lesion severity, suppressing cytokine generation, and limiting NF-κB-mediated inflammation.

Emerging Oral Therapies for the Treatment of Psoriasis: A Review of Pipeline Agents

The introduction of biologic agents for the treatment of psoriasis has revolutionized the current treatment landscape, targeting cytokines in the interleukin (IL)-23/IL-17 pathway and demonstrating strong efficacy and safety profiles in clinical trials. These agents however are costly, are associated with a risk of immunogenicity, and require administration by intravenous or subcutaneous injection, limiting their use among patients. Oral therapies, specifically small molecule and microbiome therapeutics, have the potential to be more convenient and cost-effective agents for patients and have been a focus of development in recent years, with few targeted oral medications available for the disease. In this manuscript, we review pipeline oral therapies for psoriasis identified through a search of ClinicalTrials.gov (30 June 2022-1 October 2023). Available preclinical and clinical trial data on each therapeutic agent are discussed. Small molecules under development include tumor necrosis factor inhibitors, IL-23 inhibitors, IL-17 inhibitors, phosphodiesterase-4 inhibitors, Janus kinase inhibitors, A3 adenosine receptor agonists, and sphingosine-1-phosphate receptor 1 agonists, several of which are entering phase III trials. Oral microbials have also demonstrated success in early phase studies. As new oral therapies emerge for the treatment of psoriasis, real-world data and comparative trials are needed to better inform their use among patients.

Genetic and observational associations of lung function with gastrointestinal tract diseases: pleiotropic and mendelian randomization analysis

BACKGROUND

The two-way communications along the gut-lung axis influence the immune function in both gut and lung. However, the shared genetic characteristics of lung function with gastrointestinal tract (GIT) diseases remain to be investigated.

METHODS

We first investigated the genetic correlations between three lung function traits and four GIT diseases. Second, we illustrated the genetic overlap by genome-wide pleiotropic analysis (PLACO) and further pinpointed the relevant tissue and cell types by partitioning heritability. Furthermore, we proposed pleiotropic genes as potential drug targets by drug database mining. Finally, we evaluated the causal relationships by epidemiologic observational study and Mendelian randomization (MR) analysis.

RESULTS

We found lung function and GIT diseases were genetically correlated. We identified 258 pleiotropic loci, which were enriched in gut- and lung-specific regions marked by H3K4me1. Among these, 16 pleiotropic genes were targets of drugs, such as tofacitinib and baricitinib targeting TYK2 for the treatment of ulcer colitis and COVID-19, respectively. We identified a missense variant in TYK2, exhibiting a shared causal effect on FEV1/FVC and inflammatory bowel disease (rs12720356, PPLACO=1.38 × 10- 8). These findings suggested TYK2 as a promising drug target. Although the epidemiologic observational study suggested the protective role of lung function in the development of GIT diseases, no causalities were found by MR analysis.

CONCLUSIONS

Our study suggested the shared genetic characteristics between lung function and GIT diseases. The pleiotropic variants could exert their effects by modulating gene expression marked by histone modifications. Finally, we highlighted the potential of pleiotropic analyses in drug repurposing.

Novel Janus Kinase Inhibitors in the Treatment of Dermatologic Conditions

Janus kinase inhibitors, also known as JAK inhibitors, JAKinibs or JAKi, are a new group of disease-modifying drugs. They work by inhibiting enzymes involved in the transmission of information from receptors located in the cell membrane to the cell interior, specifically to the cell nucleus, thus disrupting the JAK-STAT pathway. This pathway plays a role in key cellular processes such as the immune response and cell growth. This feature is used in the treatment of patients with rheumatological, gastroenterological and hematological diseases. Recently, it has been discovered that JAK-STAT pathway inhibitors also show therapeutic potential against dermatological diseases such as atopic dermatitis, psoriasis, alopecia areata and acquired vitiligo. Studies are underway to use them in the treatment of several other dermatoses. Janus kinase inhibitors represent a promising class of drugs for the treatment of skin diseases refractory to conventional therapy. The purpose of this review is to summarize the latest knowledge on the use of JAKi in dermatological treatment.

Inhibition of T-cell activity in alopecia areata: recent developments and new directions

Alopecia areata (AA) is an autoimmune disease that has a complex underlying immunopathogenesis characterized by nonscarring hair loss ranging from small bald patches to complete loss of scalp, face, and/or body hair. Although the etiopathogenesis of AA has not yet been fully characterized, immune privilege collapse at the hair follicle (HF) followed by T-cell receptor recognition of exposed HF autoantigens by autoreactive cytotoxic CD8+ T cells is now understood to play a central role. Few treatment options are available, with the Janus kinase (JAK) 1/2 inhibitor baricitinib (2022) and the selective JAK3/tyrosine kinase expressed in hepatocellular carcinoma (TEC) inhibitor ritlecitinib (2023) being the only US Food and Drug Administration-approved systemic medications thus far for severe AA. Several other treatments are used off-label with limited efficacy and/or suboptimal safety and tolerability. With an increased understanding of the T-cell-mediated autoimmune and inflammatory pathogenesis of AA, additional therapeutic pathways beyond JAK inhibition are currently under investigation for the development of AA therapies. This narrative review presents a detailed overview about the role of T cells and T-cell-signaling pathways in the pathogenesis of AA, with a focus on those pathways targeted by drugs in clinical development for the treatment of AA. A detailed summary of new drugs targeting these pathways with expert commentary on future directions for AA drug development and the importance of targeting multiple T-cell-signaling pathways is also provided in this review.

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.

The Relationship between COVID-19 Severity in Children and Immunoregulatory Gene Polymorphism

Coronavirus disease (COVID-19) and its outcomes remain one of the most challenging problems today. COVID-19 in children could be asymptomatic, but can result in a fatal outcome; therefore, predictions of the disease severity are important. The goal was to investigate the human genetic factors that could be associated with COVID-19 severity in children. Single-nucleotide polymorphisms of the following genes were studied: ACE2 (rs2074192), IFNAR2 (rs2236757), TYK2 (rs2304256), OAS1 (rs10774671), OAS3 (rs10735079), CD40 (rs4813003), FCGR2A (rs1801274) and CASP3 (rs113420705). In the case-control study were 30 children with mild or moderate course of the disease; 30 with severe COVID-19 symptoms and multisystem inflammatory syndrome in children (MIS-C) and 15 who were healthy, and who did not have SARS-CoV-2 (PCR negative, Ig G negative). The study revealed that ACE2 rs2074192 (allele T), IFNAR2 rs2236757 (allele A), OAS1 rs10774671 (allele A), CD40 rs4813003 (allele C), CASP3 rs113420705 (allele C) and male sex contribute to severe COVID-19 course and MIS-C in 85.6% of cases. The World Health Organization reported that new SARS-CoV-2 variants may cause previously unseen symptoms in children. Although the study has limitations due to cohort size, the findings can help provide a better understanding of SARS-CoV-2 infection and proactive pediatric patient management.

Localization and Quantification of Post-Translational Modifications of Proteins Using Electron Activated Dissociation Fragmentation on a Fast-Acquisition Time-of-Flight Mass Spectrometer

Protein post-translational modifications (PTMs) are crucial and dynamic players in a large variety of cellular processes and signaling. Proteomic technologies have emerged as the method of choice to profile PTMs. However, these analyses remain challenging due to potential low PTM stoichiometry, the presence of multiple PTMs per proteolytic peptide, PTM site localization of isobaric peptides, and neutral losses. Collision-induced dissociation (CID) is commonly used to characterize PTMs, but the application of collision energy can lead to neutral losses and incomplete peptide sequencing for labile PTM groups. In this study, we assessed the performance of an alternative fragmentation, electron activated dissociation (EAD), to characterize, site localize, and quantify peptides with labile modifications in comparison to CID, both operated on a recently introduced fast-scanning quadrupole-time-of-flight (QqTOF) mass spectrometer. We analyzed biologically relevant phosphorylated, succinylated, malonylated, and acetylated synthetic peptides using targeted parallel reaction monitoring (PRM or MRMHR) assays. We report that electron-based fragmentation preserves the malonyl group from neutral losses. The novel tunable EAD kinetic energy maintained labile modification integrity and provided better peptide sequence coverage with strong PTM-site localization fragment ions. Activation of a novel trap-and-release technology significantly improves the duty cycle and provided significant MS/MS sensitivity gains by an average of 6-11-fold for EAD analyses. Evaluation of the quantitative EAD PRM workflows revealed high reproducibility with coefficients of variation of ∼2-7%, as well as very good linearity and quantification accuracy. This novel workflow combining EAD and trap-and-release technology provides high sensitivity, alternative fragmentation information to achieve confident PTM characterization and quantification.

Risk of herpes zoster associated with JAK inhibitors in immune-mediated inflammatory diseases: a systematic review and network meta-analysis

Objective: Janus kinase (JAK) inhibitors are a novel class of drugs that have shown efficacy in treating immune-mediated inflammatory diseases (IMIDs). However, their safety profile in terms of herpes zoster infection remains unclear. We aimed to evaluate the risk of herpes zoster associated with JAK inhibitors in patients with IMIDs. Methods: A systematic search of electronic databases was conducted to identify randomized controlled trials (RCTs) that evaluated the safety of JAK inhibitors in patients with IMIDs including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), spondyloarthritis (SpA), psoriasis (PsO), and psoriatic arthritis (PsA). The primary outcome of interest was the incidence of herpes zoster infection. Network meta-analysis was performed to compare the risk of herpes zoster among different JAK inhibitors and placebo. Results: A network meta-analysis was conducted using data from 47 RCTs including 24,142 patients. In patients with IMIDs, peficitinib 100 mg QD was associated with the highest risk of herpes zoster infection in patients with IMIDs, followed by baricitinib 4 mg QD and upadacitinib 30 mg QD. No difference in herpes zoster risk was found for other JAK inhibitors compared with placebo. Subgroup analysis indicated that higher incidence of herpes zoster was found in patients treated by baricitinib 4 mg QD, peficitinib 100 mg QD, and upadacitinib 30 mg QD only in patients with RA. Conclusion: Our study suggests that some JAK inhibitors, particularly peficitinib, baricitinib, and tofacitinib, are associated with a higher risk of herpes zoster infection in patients with IMIDs.

The preclinical discovery and development of deucravacitinib for the treatment of psoriasis

INTRODUCTION

Psoriasis is a chronic inflammatory skin disease that most commonly presents as plaque psoriasis. The understanding of the pivotal pathogenetic role of the IL-23/IL-17 axis has dramatically changed the therapeutic approach to the disease. The identification of intracellular signaling pathways mediating IL-23 activity provided the rationale for targeting TYK2.

AREAS COVERED

This review assesses the underlying rationale that led to development of deucravacitinib, a novel oral TYK2 inhibitor, as a therapeutic option for the treatment of moderate-to-severe psoriasis, primarily focusing on pre-clinical and early phase clinical studies.

EXPERT OPINION

Innovative therapies used in patients with moderate-to-severe psoriasis include biologic agents and small molecules, which are associated with less adverse events than traditional systemic agents. Deucravacitinib, which selectively targets TYK2, has demonstrated to be effective in treating psoriasis, preserving a more favorable safety profile compared to other JAK inhibitors approved for the treatment of other immune diseases that block the ATP-binding site. Because of its oral administration, deucravacitinib represents an intriguing option in the therapeutic armamentarium of psoriasis, though the evaluation of long-term efficacy and safety is necessary to establish its place-in-therapy.

Evolving cognition of the JAK-STAT signaling pathway: autoimmune disorders and cancer

The Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathway is an evolutionarily conserved mechanism of transmembrane signal transduction that enables cells to communicate with the exterior environment. Various cytokines, interferons, growth factors, and other specific molecules activate JAK-STAT signaling to drive a series of physiological and pathological processes, including proliferation, metabolism, immune response, inflammation, and malignancy. Dysregulated JAK-STAT signaling and related genetic mutations are strongly associated with immune activation and cancer progression. Insights into the structures and functions of the JAK-STAT pathway have led to the development and approval of diverse drugs for the clinical treatment of diseases. Currently, drugs have been developed to mainly target the JAK-STAT pathway and are commonly divided into three subtypes: cytokine or receptor antibodies, JAK inhibitors, and STAT inhibitors. And novel agents also continue to be developed and tested in preclinical and clinical studies. The effectiveness and safety of each kind of drug also warrant further scientific trials before put into being clinical applications. Here, we review the current understanding of the fundamental composition and function of the JAK-STAT signaling pathway. We also discuss advancements in the understanding of JAK-STAT-related pathogenic mechanisms; targeted JAK-STAT therapies for various diseases, especially immune disorders, and cancers; newly developed JAK inhibitors; and current challenges and directions in the field.