Therapeutic Advantage of Tyk2 Inhibition for Treating Autoimmune and Chronic Inflammatory Diseases

Augmentative effects of leukemia inhibitory factor reveal a critical role for TYK2 signaling in vascular calcification

Medial vascular calcification in chronic kidney disease (CKD) involves pro-inflammatory pathways induced by hyperphosphatemia. Several interleukin 6 family members have been associated with pro-calcific effects in vascular smooth muscle cells (VSMCs) and are considered as therapeutic targets. Therefore, we investigated the role of leukemia inhibitory factor (LIF) during VSMC calcification. LIF expression was found to be increased following phosphate exposure of VSMCs. LIF supplementation aggravated, while silencing of endogenous LIF or LIF receptor (LIFR) ameliorated the pro-calcific effects of phosphate in VSMCs. The soluble LIFR mediated antagonistic effects towards LIF and reduced VSMC calcification. Mechanistically, LIF induced phosphorylation of the non-receptor tyrosine-protein kinase 2 (TYK2) and signal transducer and activator of transcription-3 (STAT3) in VSMCs. TYK2 inhibition by deucravacitinib, a selective, allosteric oral immunosuppressant used in psoriasis treatment, not only blunted the effects of LIF, but also interfered with the pro-calcific effects induced by phosphate. Conversely, TYK2 overexpression aggravated VSMC calcification. Ex vivo calcification of mouse aortic rings was ameliorated by Tyk2 pharmacological inhibition and genetic deficiency. Cholecalciferol-induced vascular calcification in mice was improved by Tyk2 inhibition and in the Tyk2-deficient mice. Similarly, calcification was ameliorated in Abcc6/Tyk2-deficient mice after adenine/high phosphorus-induced CKD. Thus, our observations indicate a role for LIF in CKD-associated vascular calcification. Hence, the effects of LIF identify a central pro-calcific role of TYK2 signaling, which may be a future target to reduce the burden of vascular calcification in CKD.

Efficacy and safety of deucravacitinib for the management of psoriasis: a drug safety evaluation

INTRODUCTION

Nowadays, despite the wide availability of biological drugs and apremilast for psoriasis management, there is always a need for new therapies to customize the therapeutic approach on the basis of the patient's clinical features and comorbidities, especially in order to achieve a prolonged therapeutic response. Thus, new treatment strategies are required to offer patients a personalized approach. In this scenario, major knowledge on psoriasis pathogenesis led to the development of deucravacitinib, an orally administered selective TYK2 inhibitor.

AREAS COVERED

The aim of this manuscript is to review the current literature on the effectiveness and safety of deucravacitinib in psoriasis to offer readers a wide perspective. The current English literature was analyzed using the PubMed, Google Scholar, Embase, Cochrane Skin, and clinicaltrials.gov databases, selecting the most relevant manuscripts.

EXPERT OPINION

Deucravacitinib appears to be an innovative weapon for the management of moderate to severe psoriasis. Despite its efficacy and safety profiles have been revealed by RCTs, real-life data are still scant. Certainly, deucravacitinib broadens the range of therapeutic alternatives for psoriasis patients, thus enhancing the holistic and personalized approaches required for the treatment of this disease.

TYK2 signaling promotes the development of autoreactive CD8+ cytotoxic T lymphocytes and type 1 diabetes

Tyrosine kinase 2 (TYK2), a member of the JAK family, has attracted attention as a potential therapeutic target for autoimmune diseases. However, the role of TYK2 in CD8+ T cells and autoimmune type 1 diabetes (T1D) is poorly understood. In this study, we generate Tyk2 gene knockout non-obese diabetes (NOD) mice and demonstrate that the loss of Tyk2 inhibits the development of autoreactive CD8+ T-BET+ cytotoxic T lymphocytes (CTLs) by impairing IL-12 signaling in CD8+ T cells and the CD8+ resident dendritic cell-driven cross-priming of CTLs in the pancreatic lymph node (PLN). Tyk2-deficient CTLs display reduced cytotoxicity. Increased inflammatory responses in β-cells with aging are dampened by Tyk2 deficiency. Furthermore, treatment with BMS-986165, a selective TYK2 inhibitor, inhibits the expansion of T-BET+ CTLs, inflammation in β-cells and the onset of autoimmune T1D in NOD mice. Thus, our study reveals the diverse roles of TYK2 in driving the pathogenesis of T1D.

Targeting TYK2 for Fighting Diseases: Recent Advance of TYK2 Inhibitors

TYK2 (tyrosine-protein kinase 2) is a non-receptor protein kinase belonging to the JAK family and is closely associated with various diseases, such as psoriasis, inflammatory bowel disease, systemic lupus erythematosus. TYK2 activates the downstream proteins STAT1-5 by participating in the signal transduction of immune factors such as IL-12, IL-23, and IL-10, resulting in immune expression. The activity of the inhibitor TYK2 can effectively block the transduction of excessive immune signals and treat diseases. TYK2 inhibitors are divided into two types of inhibitors according to the different binding sites. One is a TYK2 inhibitor that binds to JH2 and inhibits its activity through an allosteric mechanism. The representative inhibitor is BMS-986165, developed by Bristol-Myers Squibb. The other class binds to the JH1 adenosine triphosphate (ATP) site and prevents the catalytic activity of the kinase by blocking ATP and downstream phosphorylation. This paper mainly introduces the protein structure, signaling pathway, synthesis, structure-activity relationship and clinical research of TYK2 inhibitors.

Deucravacitinib in the treatment of psoriasis

PURPOSE OF THE ARTICLE

Psoriasis is a chronic, immune-mediated, skin disease with a significantly negative impact on patients' quality of life. Moderate-to-severe disease often requires systemic therapies and currently available ones still have numerous disadvantages or limitations. Tyrosine kinase 2 (TYK2) mediates immune signaling of IL-12, IL-23, and type I interferons, without interfering with other critical systemic functions. This article aims to review the current knowledge on deucravacitinib, a new oral drug which selectively inhibits TYK2, granting it a low risk of off-target effects.

MATERIALS AND METHODS

A review of the published literature was conducted using the PubMed database, published abstracts and virtual presentations from scientific meetings, data from industry press releases, and results published on ClinicalTrials.gov regarding the deucravacitinib for the treatment of psoriasis. Manuscripts with trial results, case series, clinical trial data from ClinicalTrials.gov, and articles highlighting expert perspectives on the topic of the article were selected.

RESULTS

Two phase 3, 52-week trials evaluated deucravacitinib 6 mg against placebo and apremilast - POETYK PSO-1 and PSO-2, enrolling 1688 patients with moderate-to-severe psoriasis. At week 16, over 50% of patients treated with deucravacitinib reached PASI75, significantly superior to placebo and apremilast. Symptomatic improvement was also reported, with greater impact on itch. Deucravacitinib was well tolerated and safe. There were no reports of serious infections, thromboembolic events, or laboratory abnormalities. Persistent efficacy and consistent safety profiles were reported for up to 2 years.

CONCLUSIONS

Deucravacitinib has the potential to become a safe, effective, and well-tolerated treatment for patients with moderate-to-severe disease. Future studies will be important to determine the exact role of this drug in the treatment of psoriasis.

JAK-STAT signaling in inflammation and stress-related diseases: implications for therapeutic interventions

The Janus kinase-signal transducer and transcription activator pathway (JAK-STAT) serves as a cornerstone in cellular signaling, regulating physiological and pathological processes such as inflammation and stress. Dysregulation in this pathway can lead to severe immunodeficiencies and malignancies, and its role extends to neurotransduction and pro-inflammatory signaling mechanisms. Although JAK inhibitors (Jakinibs) have successfully treated immunological and inflammatory disorders, their application has generally been limited to diseases with similar pathogenic features. Despite the modest expression of JAK-STAT in the CNS, it is crucial for functions in the cortex, hippocampus, and cerebellum, making it relevant in conditions like Parkinson's disease and other neuroinflammatory disorders. Furthermore, the influence of the pathway on serotonin receptors and phospholipase C has implications for stress and mood disorders. This review expands the understanding of JAK-STAT, moving beyond traditional immunological contexts to explore its role in stress-related disorders and CNS function. Recent findings, such as the effectiveness of Jakinibs in chronic conditions such as rheumatoid arthritis, expand their therapeutic applicability. Advances in isoform-specific inhibitors, including filgotinib and upadacitinib, promise greater specificity with fewer off-target effects. Combination therapies, involving Jakinibs and monoclonal antibodies, aiming to enhance therapeutic specificity and efficacy also give great hope. Overall, this review bridges the gap between basic science and clinical application, elucidating the complex influence of the JAK-STAT pathway on human health and guiding future interventions.

Current and emerging prospects in the psoriatic treatment

Psoriasis is an autoimmune chronic disorder that causes inflammation and a scaly epidermis. The exact pathogenesis of the disease is not known yet. According to the studies, psoriasis is considered an immune-mediated disease. Until now it is believed that genetic and environmental factors are responsible for the disease. There are many comorbidities associated with psoriasis which increases difficulties as patients in some cases get addicted to drugs, alcohol, and smoking which reduces their quality of life. The patient may face social ignorance or suicidal thoughts which may arise in the patient's mind. Due to the undefined trigger of the disease, the treatment is not fully established but by considering the severe impact of the disease researchers are focusing on novel approaches for successful treatment. which has succeeded to a large extent. Here we review pathogenesis, problems faced by psoriatic patients, the need for the development of new treatments over conventional therapies, and the history of psoriatic treatments. We thoroughly focus on emerging treatments like biologics, biosimilars, and small molecules which are now showing more efficacy and safety than conventional treatments. Also, this review article discusses novel approaches which are now in research such as drug repurposing, treatment by stimulation of the vagus nerve, regulation of microbiota, and autophagy for improving disease conditions.

Clinical Utility of Deucravacitinib for the Management of Moderate to Severe Plaque Psoriasis

Introduction

Psoriasis is a chronic, immune-mediated skin condition with significant detriments to physical/mental health. While systemic therapies are available for the treatment of moderate-to-severe psoriasis, patients can experience therapeutic failure, loss of efficacy, or medical contraindications that require other therapeutic options.

Objective

With the recent approval of deucravacitinib, a first-in-class TYK2 small molecule inhibitor administered orally for psoriasis patients, we reviewed data from randomized controlled trials (RCTs) to synthesize its clinical utility. To our knowledge, this is the first systematic review and meta-analysis of deucravacitinib comparing its clinical efficacy to placebo in psoriasis.

Methods

A literature search was conducted in PubMed (MEDLINE), Embase, and the Cochrane Central Register of Controlled Trials to identify RCTs studying deucravacitinib in human patients with moderate-to-severe psoriasis.

Results

One placebo-controlled Phase II RCT and two placebo-controlled/active-comparator Phase III RCTs were included for review. Patients (N=1953) treated with deucravacitinib 6 mg daily showed marked improvement in disease severity (Psoriasis Area and Severity Index (PASI), static Physician Global Assessment (sPGA) and quality-of-life outcomes compared to patients administered comparator (apremilast) and placebo. Clinical improvement given deucravacitinib was noted for scalp psoriasis but not fingernail psoriasis. Meta-analysis (deucravacitinib, n=888; placebo, n=466) comparing rates of clearance (sPGA 0/1) demonstrated superior efficacy of deucravacitinib compared to placebo (odds ratio, 12.87; 95% confidence interval, 8.97-18.48; χ²=4.08, I²=51%). Deucravacitinib was well-tolerated, with similar rate of occurrence and type of adverse events reported among patients treated with placebo or apremilast at Week 12-16. No cardiovascular events, serious infections, or lab abnormalities were noted.

Conclusion

Deucravacitinib possesses good efficacy, with no report of safety concerns associated with prior JAK inhibitors used for psoriasis. Meta-analysis demonstrated deucravacitinib's superiority compared to placebo, indicating its promising clinical utility. Further studies are needed to observe long-term safety and efficacy, and to compare deucravacitinib to existing treatments.

Design, synthesis and biological evaluation of novel N-(methyl-d3) pyridazine-3-carboxamide derivatives as TYK2 inhibitors

As a mediator of pro-inflammatory cytokines, TYK2 is an attractive target to treat autoimmunity diseases. Herein, we reported the design, synthesis, and structure-activity relationships (SARs) of N-(methyl-d₃) pyridazine-3-carboxamide derivatives as TYK2 inhibitors. Among them, compound 24 exhibited acceptable inhibition activity against STAT3 phosphorylation. Furthermore, 24 showed satisfactory selectivities toward other members of JAK family and performed a good stability profile in liver microsomal assay. Pharmacokinetics (PK) study indicated that compound 24 has reasonable PK exposures. In anti-CD40-induced colitis models, compound 24 was orally highly effective with no significant hERG and CYP isozymes inhibition. These results indicated that compound 24 was worthy of further investigation for the development of anti-autoimmunity diseases agents.

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.

Discovery of a potent and subtype-selective TYK2 degrader based on an allosteric TYK2 inhibitor

TYK2, a member of the JAK family of proximal membrane-bound tyrosine kinases, has emerged as an attractive target for the treatment of autoimmune diseases. Herein, we report the discovery of first-in-class potent and subtype-selective TYK2 degraders. By conjugating a TYK2 ligand from a known allosteric TYK2 inhibitor with a VHL ligand as the E3 ligase ligand via alkyl linkers of various lengths, we rapidly identified TYK2 degrader 5 with moderate TYK2 degradation activity. Degrader 5 induced TYK2 degradation without affecting the protein level of subtype kinases (JAK1, JAK2, and JAK3) in Jurkat cellular assays. Furthermore, modifying the TYK2 ligand moiety of degrader 5 yielded the more potent TYK2 degrader 37 with retained selectivity for JAKs. Our subtype-selective TYK2 degraders represent valuable chemical probes for investigating the biology of TYK2 degradation.

Genome-wide identification, immune response profile and functional characterization of IL-10 from spotted knifejaw (Oplegnathus punctatus) during host defense against bacterial and viral infection

Interleukin 10 (IL-10), a pleiotropic cytokine, plays an essential role in multiple immunity responses. In the current study, the sequences of IL-10 family were identified from spotted knifejaw (Oplegnathus punctatus) whole genome, and O. punctatus IL-10 (OpIL-10) was cloned and characterized. OpIL-10 encodes 187 amino acids with a typical IL-10 family signature motif and predicted α-helices. It shared high identities with Notolabrus celidotus IL-10 and Epinephelus Lanceolatus IL-10. OpIL-10 was widely detected in healthy tissues, with the abundant expression in liver and skin. It was significantly up-regulated in the six immune-related tissues (liver, spleen, kidney, intestine, gill and skin) after infection against Vibrio harveyi and spotted knifejaw iridovirus (SKIV). Dual-luciferase analysis showed that OpIL-10 overexpression could suppress the activity of NF-κB. Meanwhile, OpIL-10 knockdown caused the down-regulation of five immune-related genes in JAK2/STAT3 signaling pathway and NF-κB signaling pathway, including IL-10R2, TYK2, STAT3, NOD2, and IκB. In addition, LPS and poly I:C stimulated expression of pro-inflammatory cytokines, including IL-6, IL-1β, IL-8, and IL-12, were lower with recombinant OpIL-10 (rOp IL-10) than the control group, indicating the anti-inflammatory roles of rOpIL-10. Taken together, these results indicated OpIL-10 as a negative regulator in the inflammatory responses of spotted knifejaw against bacterial and viral infection, which would help us better understand the role of IL-10 in teleost immunity.