A Comprehensive Overview of Globally Approved JAK Inhibitors

Exploring mimosamycin as a Janus kinase 2 inhibitor: A combined computational and experimental investigation

Janus kinases (JAKs) are a family of intracellular tyrosine kinases that play a crucial role in signal transduction pathways. JAK2 has been implicated in the pathogenesis of leukemia, making it a promising target for research aimed at reducing the risk of this disease. This study examined the potential of mimosamycin as a JAK2 inhibitor using both in vitro and in silico approaches. We performed a kinase assay to measure the IC50 of mimosamycin for JAK2 inhibition, which was found to be 22.52 ± 0.87 nM. Additionally, we utilized molecular docking, molecular dynamics simulations, and free energy calculations to investigate the inhibitory mechanism at the atomic level. Our findings revealed that mimosamycin interacts with JAK2 at several key regions: the hinge-conserved region (M929, Y931, L932, and G935), the G loop (L855 and V863), and the catalytic loop (L983). To enhance the binding affinity of mimosamycin toward JAK2, we designed derivatives with propanenitrile and cyclopentane substitutions on the naphthoquinone core structure. Notably, these newly designed analogs exhibited promising binding patterns against JAK2. These insights could aid in the rational development of novel JAK2 inhibitors, with potential applications in the treatment of leukemia and related diseases.

Pharmacotherapy of type 1 diabetes - part 3: tomorrow

INTRODUCTION

The last 100 years have seen type 1 diabetes, a previously fatal disease, transformed by the administration of exogenous insulin.

AREAS COVERED

A standard literature search using the Google and Microsoft search engines and PubMed was performed. The development of synthetic insulins with varying onsets and duration of action improved glucose control, essential to mitigate the microvascular and macrovascular consequences of diabetes. Today insulin pumps guided by continuous glucose monitors are approaching the objective of normalized glucose levels. The area of greatest development is now in attempting to suppress the immune process which results in progressive destruction of the beta cell. It is possible to identify family members of patients with type 1 diabetes who may eventually develop the disease by measuring several beta cell antibodies. Very recently teplizumab, a CD3 inhibitor, has been approved to delay the onset of hyperglycemia in these individuals.

EXPERT OPINION

The future will see progress in immunosuppression, possibly using specific CAR-Treg cells directed at the beta cell antigens which trigger the immune process. In parallel, stem cell-derived beta cells may eventually make it possible to replace lost beta cells, resulting in a true cure for type 1 diabetes.

Challenges, opportunities, and therapeutic potential of JAK inhibitors and their derived PROTACs (2022 - 2023)

INTRODUCTION

Since the approval of the first JAK inhibitor, ruxolitinib, in 2011, the development of JAK inhibitors has expanded significantly, with applications spanning autoimmune diseases, cancer, and inflammatory disorders. This review explores the challenges and therapeutic potential of JAK inhibitors and their evolution into proteolysis-targeting chimeras (PROTACs), which offer novel avenues for selective JAK modulation.

AREAS COVERED

This review examines recent advancements in JAK inhibitors, including their mechanism of action, structure activity relationships, clinical applications, and emerging safety concerns. Additionally, PROTAC-based strategies targeting JAK proteins are discussed, highlighting their potential advantages over traditional small-molecule inhibitors. A comprehensive patent literature search was conducted, focusing on publications and patents from 2022 to 2023. Key selection criteria included small-molecule JAK inhibitors and JAK-targeting PROTACs with associated preclinical data.

EXPERT OPINION

While JAK inhibitors have transformed the treatment of various diseases, safety concerns, including risks of venous thromboembolism and herpes zoster, pose challenges to their widespread use. The advent of JAK-targeting PROTACs represents a promising strategy to enhance selectivity and mitigate off-target effects. However, further research is needed to optimize their therapeutic potential and establish their clinical viability.

The small molecule ML233 is a direct inhibitor of tyrosinase function

Melanogenesis is the biological process regulating the synthesis of melanin pigments in melanocytes. Defective melanogenesis is associated with numerous human skin diseases, including, but not limited to, albinism, vitiligo, melasma, and hypo- and hyperpigmentation disorders. Tyrosinase is the rate-limiting enzyme controlling melanogenesis, and hence tremendous efforts have been made to identify potent and safe inhibitors of tyrosinase function. However, despite decades of research, currently there is no effective treatment that inhibits melanogenesis or tyrosinase activity with no adverse side effects. In this study, we report the characterization of the ML233 chemical as a potent inhibitor of tyrosinase activity in vivo and in vitro. We demonstrate that ML233 reduces melanin production in the zebrafish model with no observable significant toxic side effects, and in murine melanoma cells. We also predict that these effects are mediated through direct tyrosinase-ML233 interaction, i.e., binding of the ML233 molecule to the active site of the protein to inhibit its function. Together, our results reveal that ML233 plays roles in both healthy and pathological skin cells via inhibition of melanin production. ML233-mediated tyrosinase inhibition is a potentially safe and effective approach to alleviate the symptoms of melanocyte-associated diseases and thereby substantially improve human health.

Interindividual variability and its impact on the effectiveness of Janus kinase inhibitors in rheumatoid arthritis treatment

Introduction

Achieving the primary treat-to-target (T2T) goal in rheumatoid arthritis (RA) remains challenging for many patients, reflecting limitations in the effectiveness of existing treatments. Our study examines factors influencing Janus kinase (JAK) inhibitor effectiveness by analyzing interindividual variability in demographic and clinical characteristics of real-world RA patients.

Materials and methods

This observational retrospective study involves RA patients receiving tofacitinib, baricitinib, upadacitinib, or filgotinib between September 2017 and January 2025. Predictive factors of achieving the T2T goal at 6 months were identified through logistic regression analyses. Disparities in the treatment effectiveness retention based on predictive factors were assessed using the Kaplan-Meier estimate and compared with the log-rank test. The Cox model was applied to analyze whether the predictive factors identified could influence the retention of JAK inhibitor treatment effectiveness.

Results

One hundred fifty patients were included: 81 (54%) achievers and 69 (46%) non-achievers of remission or, at least, low disease activity at 6 months of treatment. High disease activity at baseline, with respect to moderate activity, was identified as an unfavorable factor for achieving the T2T goal (Odds ratio adjusted: 0.96; 95% confidence interval: 0.92-0.99; p = 0.028). In treatment effectiveness retention rates, no differences were observed between patients with high versus moderate disease activity (p = 0.103). RA disease activity at baseline was not found to impact the survival of JAK inhibitor effectiveness (p = 0.106).

Conclusion

In RA, high disease activity at the initiation of treatment with tofacitinib, baricitinib, upadacitinib, or filgotinib does not preclude an effective treatment response but is associated with an increased risk of therapeutic failure. Factors not related to the achievement of the T2T goal at 6 months of JAK inhibitor treatment include: age, female sex, body mass index, RA disease duration, seropositivity for rheumatoid factor, seropositivity for anti-cyclic citrullinated peptides, JAK inhibitor selectivity, type and number of prior biologic treatments, concomitant use and number of prior conventional synthetic disease-modifying antirheumatic drugs, and number of prior JAK inhibitors. These conclusions are derived from a retrospective real-world study and should be confirmed in prospective studies.

JAK inhibitors as a promising therapy for immune-mediated photodermatoses

Immune-mediated photodermatoses (IMPs) are skin diseases caused by altered immune responses triggered by sunlight, including polymorphous light eruption (PMLE), actinic prurigo (AP), solar urticaria (SU), chronic actinic dermatitis (CAD), and hydroa vacciniforme (HV). Managing IMPs is challenging because of the need for rigorous sun protection and the poor response to conventional therapies, particularly in moderate-to-severe patients. Researchers are exploring new targeted therapies for IMPs, including Janus kinase (JAK) inhibitors, a novel class of small molecules that block the JAK-STAT signaling pathway. Several case reports and series show promising results. This study reviews the evidence-based rationale for using JAK inhibitors in IMP treatment, assessing their efficacy and safety.

Hijacking JAKis: JAK inhibitors as potential antiviral molecules, a mini review

Janus kinases (JAKs) are key players in the innate immune response and inflammation, catalysing the phosphorylation of STAT proteins, which ultimately leads to the expression of pro-inflammatory and antimicrobial genes. In this context, specific inhibitors of JAK kinases, or JAKis, have been extensively developed, with some already in clinical use for the treatment of chronic inflammatory diseases. However, the interactions between JAK kinases and viral replication appear to be far more complex than initially expected, with some JAKis showing unexpected antiviral properties against different classes of viruses. This mini review summarizes current knowledge about the interactions between JAK proteins and viral infections and discusses the antiviral potential of JAK inhibitors in the development of innovative therapeutic strategies.

AhR and STAT3: A Dangerous Duo in Chemical Carcinogenesis

Human chemical carcinogenesis is a multistage process where chemicals or their metabolites cause irreversible changes in normal cell physiology, eventually leading to uncontrolled proliferation, transforming a normal cell into a cancerous one. Signal transducer and activator of transcription 3 (STAT3) is a cytoplasmic transcription factor that regulates cell proliferation, differentiation, apoptosis, angiogenesis, inflammation, and immune responses. Its aberrant activation triggers tumor progression by promoting the expression of oncogenic genes; thus, STAT3 is classified as an oncoprotein. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that responds to a wide variety of chemicals, including carcinogens like dioxins, inducing genes associated with detoxification, proliferation, and immune regulation. Recent reports show that AhR plays a critical role in cancer development and maintenance. AhR may interact with signaling pathways, like the STAT3 pathway, which mediates the carcinogenic effects of several pollutants. Various chemical agents, such as industrial waste and hydrocarbon compounds, can alter the expression or signaling activity of AhR and STAT3 pathways, leading to different types of cancers. Understanding the complex STAT3-AhR network in the regulation of chemical carcinogenesis could open new avenues for cancer prevention or treatment, particularly in personalized medicine, aiming to improve life expectancy and achieving a complete cure.

Immune Memory: A New Frontier in Treating Recurrent Inflammatory Skin Diseases

The recurrence of inflammatory skin diseases represents a significant challenge in clinical practice, primarily mediated by immune memory. In inflammatory skin diseases, immune memory encompasses adaptive immune memory, trained immunity, and inflammatory memory, which are conducted by adaptive immune cells, innate immune cells, and structural cells, respectively. Adaptive immune memory is established through gene rearrangement, leading to antigen-specific immune memory. In contrast, trained immunity and inflammatory memory are formed through epigenetic and metabolic reprogramming, resulting in non-specific immune memory. Different types of immune memory work synergistically to aggravate localized inflammation in recurrent inflammatory skin diseases. However, immune memory in specific cells, such as macrophages, may also play an immunoregulatory role under certain conditions. We reviewed the immune memory mechanisms in different inflammatory skin diseases and discussed future strategies for targeted regulation of the molecular mechanisms underlying immune memory, such as targeted biological agents and epigenetic modifications. Additionally, we explored the potential for precise regulation of immune memory and its application in personalized treatment for recurrent inflammatory skin diseases.

Mitigating cyclophosphamide-induced hepatorenal toxicity: Linalool's role in modulating oxidative stress, inflammation, and apoptosis

Cyclophosphamide (CP) is associated with detrimental side effect including hepatic and renal toxicities. Linalool (LIN), acyclic monoterpene alcohol, is acquired from several plants' essential oils. Rats were disseminated into four groups. Group 1: Normal and Cyclophosphamide (CP) groups in which rats were given normal saline or CP intraperitoneally (200 mg/kg, ip on 12nd). Group 3 and 4 (LIN 50 + CP and LIN 100 + CP) groups in which rats were administered LIN (50 or 100 mg/kg) orally for 14 days and CP (200 mg/kg, ip on 12nd). Assessment of hepatic and renal function tests and histopathological examination were performed. Oxidative stress indicators, inflammatory mediators, and apoptosis markers in hepatic and renal homogenates were assessed. JAK2/STAT3/NFκB gene expression was measured. The network pharmacology study suggests JAK2 as one the targets so molecular docking of LIN against JAK2 was accomplished. LIN administration with CP resulted in a significant reduction in liver function test including ALT, AST, LDL, bilirubin, and γGTT1 and in renal function markers including BUN, creatinine, uric acid, Kim-1, NGAL, and CysC. Also, LIN increases in antioxidant ability via enhancing GST, GSH-Px, GSH-R, SOD, and catalase as well as a declining NO, MDA levels. Furthermore, LIN significantly diminished JAK2/STAT3/NFκB gene expressions with subsequent reduction in the inflammatory markers including TNF-α, MPO, ICAM-1, IL-6, and IL-1β levels and the apoptotic markers Bax and cleavage caspase-3 and 9. LIN protected the hepatic and renal tissues from ROS damage and mitigated JAK2/STAT3/NFκB with subsequent anti-inflammatory and anti-apoptotic properties.

Exploring the Efficacy, Safety, and Clinical Implications of Deucravacitinib in East Asians with Psoriasis: A Narrative Review

Deucravacitinib, a selective oral tyrosine kinase 2 (TYK2) inhibitor, has demonstrated strong efficacy in the treatment of moderate-to-severe psoriasis. It works through an allosteric mechanism to selectively inhibit TYK2, leading to the suppression of the IL-23/Th17/IL-17 axis and a reduction in key pro-inflammatory cytokines such as IL-17A, IL-17F, IL-22, and IL-23. This review focuses on the clinical implications of deucravacitinib in East Asian patients, highlighting its efficacy, safety, and differences in treatment outcomes compared to other populations. Data from pivotal trials such as POETYK PSO-3 and PSO-4, which included East Asian populations, demonstrated robust efficacy and safety profiles, often surpassing results observed in global trials like POETYK PSO-1 and PSO-2. Subgroup analyses and network meta-analyses further corroborate these findings, providing a comprehensive understanding of its therapeutic potential in this demographic. Factors such as lower body mass index, genetic predispositions, and environmental influences may contribute to these differences in response. The safety profile of deucravacitinib is favorable, with low rates of serious adverse events and stable laboratory parameters. This review underscores the need for further research to investigate the genetic, metabolic, and environmental factors that may influence treatment outcomes, aiming to optimize personalized treatment strategies for East Asian patients with psoriasis.

Review of Janus Kinase Inhibitors as Therapies for Noninfectious Uveitis

Uveitis remains one of the leading causes of blindness worldwide, with different etiologies requiring separate approaches to treatment. For over a decade, oral, topical, and local injection of corticosteroids as well as systemic conventional disease-modifying antirheumatic drugs (DMARDs) have remained the most effective treatment for noninfectious uveitis (NIU). Systemic administration of antitumor necrosis factor-α and other biological DMARDs have been used for treating cases that responded inadequately to conventional treatments. Unfortunately, some refractory patients still suffer from frequent attacks despite the combination of multiple treatments. Recently, there has been promising evidence for Janus kinase (JAK) inhibitors as the next-generation therapy for NIU. The JAK/signal transducers and activators of the transcription (STAT) signaling pathway mediate the downstream events involved in immune fitness, tissue repair, inflammation, apoptosis, and adipogenesis by binding various ligands, such as cytokines, growth hormones, and growth factors. The mutation or loss of JAK/STAT components is implicated in autoimmune diseases, thus inhibition of such pathways has been an important area of research in therapeutic development.1 In this review, we provide a comprehensive overview of the efficacy and safety of JAK inhibitors for the management of NIU, with evidence from current trials and case reports.

Primary and Acquired Resistance to Immunotherapy with Checkpoint Inhibitors in NSCLC: From Bedside to Bench and Back

Immunotherapy with checkpoint inhibitors has become the cornerstone of systemic treatment for non-oncogene addicted non-small-cell lung cancer. Despite its pivotal role, a significant proportion of patients-approximately 70-85%-either exhibit primary resistance to PD-1 blockade or develop acquired resistance following an initial benefit, even in combination with chemotherapy and/or anti-CTLA-4 agents. The phenomenon of primary and acquired resistance to immunotherapy represents a critical clinical challenge, largely based on our incomplete understanding of the mechanisms of action of immunotherapy, and the resulting lack of accurate predictive biomarkers. Here, we review the definitions and explore the proposed mechanisms of primary and acquired resistance, including those related to the tumor microenvironment, systemic factors, and intrinsic tumor characteristics. We also discuss translational data on adaptive changes within tumor cells and the immune infiltrate following exposure to checkpoint inhibitors. Lastly, we offer a comprehensive overview of current and emerging therapeutic strategies designed to prevent primary resistance and counteract acquired resistance.

Peficitinib suppresses diffuse-type tenosynovial giant cell tumor by targeting TYK2 and JAK/STAT signaling

Diffuse-type tenosynovial giant cell tumor (dTGCT) is a destructive but rare benign proliferative synovial neoplasm. Although surgery is currently the main treatment modality for dTGCT, the recurrence risk is up to 50%. Therefore, there is a great need for effective drugs against dTGCT with minor side effects. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling plays a central role in rheumatoid arthritis (RA), a disease with similar characteristics as dTGCT, but its function in dTGCT remains unknown. dTGCT fibroblast-like synoviocytes (FLS) and macrophages were isolated from 10 synovial tissue samples from dTGCT patients for the screening and validation of the five clinically approved JAK inhibitors to treat RA against dTGCT. Cell viability, cell death, inflammation and the activity of the JAK family members of cultured dTGCT FLS (both 2-D and 3-D) and macrophages were investigated for the efficacy of the JAK inhibitors. Here, we found that similar to RA, JAK/STAT signaling was markedly activated in the dTGCT synovium. Of the 5 JAK inhibitors, peficitinib was shown to have the most potency in addressing some of the pathological responses of dTGCT FLS and macrophages. The potency of peficitinib was much higher than pexidartinib, which is the only FDA-approved drug for dTGCT. Mechanistically, peficitinib inhibited tyrosine kinase 2 (TYK2), a JAK family member necessary for the pathological progression of dTGCT FLS and macrophages. In summary, we not only revealed JAK/STAT (especially TYK2) signaling as the major mechanism underlying dTGCT, but also identified peficitinib as a promising drug against dTGCT.

Janus-kinase inhibitor use in immune-mediated inflammatory diseases beyond licensed indications: A scoping review

INTRODUCTION

The use of Janus kinase inhibitors (JAKis) in immune-mediated inflammatory diseases (IMIDs) beyond licence is expanding rapidly. The aim of this scoping review was to identify and present the available evidence on the efficacy of JAKis in all conditions without marketing authorisation.

METHODS

Through a systematic literature search we identified studies including 5 or more patients that assessed the use of any JAKi for any efficacy outcome. Quantitative analyses in the form of pairwise meta-analyses were performed for eligible data from randomised controlled trials (RCTs) only.

RESULTS

Eighty-three (n = 83) studies in total were included in our review, assessing efficacy of JAKis in 34 IMIDs. In most conditions, JAKis exhibited generally positive effects, though the majority of evidence came from observational, non-comparative studies. Pairwise meta-analyses were possible for hidradenitis suppurativa and systemic lupus erythematosus (SLE). For hidradenitis suppurativa, we found a clear benefit of treatment with JAKis compared with placebo in achieving clinical response [OR 2.35, 95 % CI (1.24 to 4.46)]. For treatment-resistant SLE, the results were equivocal; JAKi showed some benefit over placebo but statistical significance was only reached for one of the two meta-analysed outcome measures [SLE Responder Index 4, OR 1.41, 95 % CI (1.01 to 1.98); SLE Disease Activity Index 2000; OR 1.36, 95 % CI (0.99 to 1.88)].

CONCLUSIONS

There is a rapidly increasing use of JAKis beyond current licencing in most IMIDs. Large comparative trials are necessary to confirm efficacy and guide future licencing decisions.

The small molecule ML233 is a direct inhibitor of tyrosinase function

Melanogenesis is the biological process regulating the synthesis of melanin pigments in melanocytes. Defective melanogenesis is associated with numerous human skin diseases, including, but not limited to, albinism, vitiligo, melasma, and hypo- and hyperpigmentation disorders. Tyrosinase is the rate-limiting enzyme controlling melanogenesis, and hence tremendous efforts have been made to identify potent and safe inhibitors of tyrosinase function. However, despite decades of research, currently there is no effective treatment that inhibits melanogenesis or tyrosinase activity with no adverse side effects. In this study, we report characterization of the ML233 chemical as a potent inhibitor of tyrosinase activity in vivo and in vitro. We demonstrate that ML233 reduces melanin production in the zebrafish model with no observable significant toxic side effects, and in murine melanoma cells. We also predict that these effects are mediated through direct tyrosinase-ML233 interaction, i.e., binding of the ML233 molecule to the active site of the protein to inhibit its function. Together, our results reveal that ML233 plays roles in both healthy and pathological skin cells via inhibition of melanin production. ML233-mediated tyrosinase inhibition is a potentially safe and effective approach to alleviate the symptoms of melanocyte-associated diseases and thereby substantially improve human health.

Therapeutic Advancements in Psoriasis and Psoriatic Arthritis

Background: Within the past few years, many new therapies have emerged for psoriasis and psoriatic arthritis (PsA). Current topical therapies-including corticosteroids, vitamin D analogs, tapinarof, and roflumilast-remain the mainstay for mild disease, while oral systemic and biologic options are for moderate to severe cases. Biologics-such as Tumor necrosis factor-alpha (TNF-alpha), Interleukin 12/23 (IL-12/23), Interleukin-17 (IL-17), and Interleukin-23 (IL-23)-have revolutionized care by providing highly effective and safer alternatives. Oral small molecules, including Janus kinase (JAK) and tyrosine kinase 2 (TYK2) inhibitors, further expand the therapeutic options. Objectives: The goal for this review article was to examine current and latest treatments for psoriasis and PsA and discuss whether these emerging therapeutic options address the unmet needs of current treatments. Methods: The search for this review article included PubMed, Google Scholar, and ClinicalTrials.gov for relevant articles and current clinical trials using keywords. Results: A wide range of novel psoriatic and PsA therapies are currently undergoing clinical trials. These include selective JAK inhibitors, TYK2 inhibitors, retinoic acid-related orphan receptor (RORγT) inhibitors, oral IL-23 receptor inhibitors, oral IL-17A inhibitors, nanobody products, sphingosine-1-phosphate (S1P1R) antagonists, A3 adenosine receptor (A3AR) agonists, heat shock protein (HSP) 90 inhibitors, and rho-associated protein kinases (ROCK-2) inhibitors. Conclusions: These different mechanisms of action not only expand treatment options but may offer potential solutions for patients who do not achieve adequate response with existing therapies. However, the safety and contraindications of these newer agents remain an important consideration to ensure appropriate patient selection and minimize potential risks. Certain mechanisms may pose increased risks for infection, cardiovascular manifestations, malignancy, or other immune-related adverse events, necessitating careful monitoring and individualized treatment decisions. Ongoing clinical research aims to address unmet needs for patients who do not respond to previous agents to achieve sustained remission, monitor long-term safety outcomes, and assess patient preferences for delivery, including a preference for oral delivery. Oral IL-23 inhibitors hold potential due to their robust safety profiles. In contrast, oral IL-17 inhibitors and TYK-2 inhibitors are effective but may present side effects that could impact their acceptability. It is essential to balance efficacy, safety, and patient preferences to guide the selection of appropriate therapies.

Matrix mechano-sensing at the invasive front induces a cytoskeletal and transcriptional memory supporting metastasis

The extracellular matrix (ECM) controls tumour dissemination. We characterise ECM organization in human and mouse tumours, identifying three regions: tumour body, proximal invasive front and distal invasive front. Invasive areas show increased matrix density, fibre thickness, length, and alignment, with unique radial fibre orientation at the distal invasive front correlating with amoeboid invasive features. Using patient samples and murine models, we find that metastases recapitulate ECM features of the primary tumour. Ex vivo culture of murine cancer cells isolated from the different tumour regions reveals a spatial cytoskeletal and transcriptional memory. Several in vitro models recapitulate the in vivo ECM organisation showing that increased matrix induces 3D confinement supporting Rho-ROCK-Myosin II activity, while radial orientation enhances directional invasion. Spatial transcriptomics identifies a mechano-inflammatory program associated with worse prognosis across multiple tumour types. These findings provide mechanistic insights into how ECM organization shapes local invasion and distant metastasis.

Adverse event profile of ocular injury associated with JAK inhibitors in patients with rheumatoid arthritis: a disproportionality analysis

BACKGROUND

Janus kinase inhibitors (JAKIs) have been approved for the treatment of rheumatoid arthritis (RA) for several years. A recent real-world study has shown the possibility of a relationship between the occurrence of ocular adverse events (OEs) and the use of JAKIs but failed to rule out whether those OEs are related to RA.

RESEARCH DESIGN AND METHODS

A retrospective, pharmacovigilance study using the FDA Adverse Event Reporting System to evaluate OE reports following treatment with JAK inhibitors in patients with RA from Q1 2004 to Q1 2024.

RESULTS

We identified 3226 cases associated with JAKIs and 24,158 cases associated with TNFIs. Most of the OEs are serious cases, the age distribution was similar but the sex distribution was not balanced. The OEs with top 10 ROR values in TNFIs had no detectable signal in JAKIs, and the time of onset of OEs also shows difference. Besides, far fewer OE were reported for baricitinib than for the other JAKIs.

CONCLUSIONS

Different types of JAKIs are associated with special types of OEs and differ in time of onset compared with TNF inhibitors. More rigorous trials should be conducted to better understand the risk factors in JAKIs-related OEs.

Therapeutic Targeting of the Janus Kinase/Signal Transducer and Activator of Transcription Pathway in Cutaneous T-Cell Lymphoma

Background/Objectives: Cutaneous T-cell lymphoma (CTCL) is a rare group of non-Hodgkin lymphomas characterized by the clonal expansion of malignant T cells. While current treatments can alleviate symptoms and significant progress has been made in treating leukemic CTCL, a definitive cure remains elusive. Dysregulation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway is a key driver of CTCL pathogenesis. As a result, therapeutic strategies targeting JAK/STAT signaling have gained momentum, with the increasing use of JAK inhibitors and other agents that effectively suppress this pathway. These immune-modulating therapies have broad effects on physiological processes, inflammation, and the pathological changes associated with both inflammatory diseases and cancers. Several JAK inhibitors, originally FDA-approved for inflammatory conditions, are now being investigated for cancer treatment. Methods: In this paper, a brief review of the literature on JAK/STAT pathway dysregulation in CTCL is provided, highlighting both clinical and preclinical studies involving JAK inhibitors and other agents that target this pathway. Results: Specifically, we focus on six JAK inhibitors currently under clinical investigation-golidocitinib, ruxolitinib, cerdulatinib, tofacitinib, upadacitinib, and abrocitinib. Additionally, we discuss preclinical studies that explore the mechanisms underlying JAK/STAT pathway inhibition in CTCL. Furthermore, we review reported cases in which CTCL relapsed or emerged following JAK inhibitor treatment. Conclusions: Collectively, these findings support the potential clinical utility of targeting the JAK/STAT pathway in CTCL. However, further research is needed to evaluate safety risks, minimize adverse effects, and optimize these therapeutic strategies.

3,6-Anhydro-L-galactose suppresses mouse lymphocyte proliferation by attenuating JAK-STAT growth factor signal transduction and G1-S cell cycle progression

Recombinant GH16B β-agarase-catalyzed liquefaction of 5-7 %(w/v) melted agarose at 50 °C completely hydrolyzed agarose into neoagarohexaose (NA6) and neoagarotetraose (NA4). Subsequent saccharification by recombinant GH50A β-agarase or recombinant GH50A β-agarase/recombinant GH117A α-neoagarobiose hydrolase at 35 °C converted NA6/NA4 into neoagarobiose (NA2) or 3,6-anhydro-L-galactose (L-AHG)/D-galactose, respectively. Purification of NA6/NA4 and NA2 was achieved by Sephadex G-15 column chromatography, while L-AHG was purified by Sephadex G-10, achieving ≥ 98 % purity. L-AHG (25-200 μg/mL), but not NA2, NA4, or NA6, inhibited the proliferation of immobilized anti-CD3/anti-CD28-activated T cells and immobilized anti-CD40 + soluble anti-IgM + interleukin (IL)-4-activated B cells. This inhibition impacted the G1-S traverse in the cell cycle without influencing CD69 expression and p27Kip1 down-regulation, markers of the exit from G0 into G1 phase in activated lymphocytes. L-AHG impeded cyclin-dependent kinases (CDKs)-driven retinoblastoma phosphorylation, necessary for the G1-S traverse, by reducing the activating phosphorylation of CDKs (CDK4, CDK2, and CDK1) and lowering cyclin D3, cyclin A2 and cyclin B1 levels. Furthermore, L-AHG diminished the production of growth factors, including IL-2 in activated T cells and IL-6 in activated B cells. The antiproliferative effect of L-AHG on T cells was partially restored by exogenous IL-2 but was unaffected by exogenous IL-6 on B cells. L-AHG inhibited the activating phosphorylation of Janus kinase 1 (JAK1), affecting signal transducer and activator of transcription 1 (STAT1) and STAT3 signaling. These results demonstrate that L-AHG may serve as a novel immunosuppressant by impairing JAK-STAT growth factor signaling and G1-S cell cycle progression in T and B lymphocytes.

JAK inhibitors (JAKi): Mechanisms of action and perspectives in systemic and autoimmune diseases

Janus kinase (JAK) molecules are involved in important cellular activation pathways. Over the past decade, many targeted therapies have emerged, including the increasingly promising role of JAK inhibitors (JAKi) in the treatment of inflammatory and autoimmune diseases. The spectrum of use of these small molecules is increasingly broader. JAKi have been approved in several autoimmune diseases. Currently, four molecules (tofacitinib, baricitinib, upadacitinib and filgotinib) have been labeled for moderate to severe rheumatoid arthritis (RA) with failure or poor tolerance of one or more conventional disease-modifying antirheumatic drug (csDMARDS), or biologics (bDMARDS). JAKi are now also commonly used in other diseases such as psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis. They have also shown promising results in clinical trials for the treatment of other autoimmune conditions. We present here their mechanisms of action, and the main data about JAKi use on systemic and autoimmune diseases.

Fracture-Related Safety Reporting of JAK Inhibitors: An Analysis from the WHO Global VigiBase

INTRODUCTION

The Janus kinase (JAK) inhibitors are treatment options for autoimmune diseases. Numerous safety concerns have been raised. The European Medicines Agency updated the product information of tofacitinib to include the risk of fractures-but not for other JAK inhibitors. We conducted a global pharmacovigilance analysis of previously investigated JAK inhibitors to investigate a potential class effect.

METHODS

Individual case safety reports (ICSRs) for all licensed JAK inhibitors were identified from the global WHO pharmacovigilance database. The primary outcome of interest was a bone fracture. Disproportionality analyses using reporting odds ratios (RORs) were conducted.

RESULTS

We identified 122,037 ICSRs for tofacitinib, 27,786 ICSRs for upadacitinib, 14,616 ICSRs for baricitinib, 830 for filgotinib, and 350 for abrocitinib. Among the ICSRs, we identified 2198 (1.8%), 634 (2.3%), and 144 (1.0%) reports, where a bone fracture was reported for tofacitinib, upadacitinib, and baricitinib, respectively. Few reports were available for the newest drugs filgotinib (10) and abrocitinib (1). JAK inhibitors were associated with increased reporting for fracture: tofacitinib (ROR 3.34, 95% confidence interval [CI] 3.20-3.48), upadacitinib (ROR 4.23, 95% CI 3.80-4.48), baricitinib (ROR 1.80, 95% CI 1.52-2.11) and filgotinib (ROR 2.24, 95% CI 1.11-3.94). Patients with bone fractures were more often female, older and had a higher number of co-reported medications. They were more likely to use glucocorticoids, opioids, and bisphosphonates.

CONCLUSION

The results from this pharmacovigilance analysis, based on a spontaneous reporting database associated with inherent limitations, suggest a potential risk of fractures with JAK inhibitors, indicating that a class effect cannot be ruled out.

Post-COVID-19 Inflammatory Arthritis Treated With Upadacitinib: A Case Report

Two patients who developed inflammatory arthritis following COVID-19 infection are presented, characterized by arthralgias, arthritis, and elevated markers of inflammation (C-reactive protein). Both patients had clinically meaningful responses to treatment with upadacitinib, a Janus Kinase inhibitor (JAKi). This case report highlights the efficacy and safety of upadacitinib in the treatment of post-COVID-19 inflammatory arthritis.

Relationship Between Janus Kinase Inhibitor Use and Development of Retinal Vein Occlusion

BACKGROUND AND OBJECTIVE

Janus kinase (Jak) inhibitors may have increased risk of thromboembolism compared to tumor necrosis factor (TNF) inhibitors. This study investigates the association between Jak inhibitor use and retinal vein occlusion.

PATIENTS AND METHODS

This retrospective, non-randomized cohort study used a federated health research network. Propensity-score matched risk ratios with 95% CI were calculated for central and branch retinal vein occlusion (CRVO, BRVO) in patients with immune-mediated inflammatory diseases (IMIDs) treated with Jak inhibitors versus TNF inhibitors.

RESULTS

Jak and TNF inhibitor cohorts each had 5,249 patients. Risk ratio for CRVO with Jak inhibitors (n = 11) versus TNF inhibitors (n = 18) was 0.61 [CI (0.29,1.29)]. Risk ratio for BRVO with Jak inhibitors (n = 17) compared to TNF inhibitors (n = 19) was 0.89 [CI (0.47,1.72)].

CONCLUSION

This study did not find evidence of increased risk of RVO with the use of Jak inhibitors compared to TNF inhibitors among patients with IMIDs, contributing to literature on Jak inhibitor safety. [Ophthalmic Surg Lasers Imaging Retina 2025;56:72-78.].

Selective JAK1 inhibitors and the therapeutic applications thereof: a patent review (2016-2023)

INTRODUCTION

The family of Janus kinases (JAKs) consists of four intracellular non-receptor tyrosine kinases: JAK1, JAK2, JAK3, and tyrosine kinase 2 (TYK2). Among these four subtypes, JAK1 is the only isoform that can form heterodimers with all three JAKs, and JAK1 dysfunction can lead to inflammation and severe autoimmune diseases. Interest in JAK1 inhibitors has grown tremendously, and the number of inhibitors targeting JAK1 continues to rise annually.

AREAS COVERED

This paper reviews JAK1 small molecule inhibitors that were reported in patent literature from January 2016 to December 2023. Web of Science, SciFinder, PubMed, WIPO, EPO, USPTO, and CNIPA databases were used for searching the literature and patents for JAK1 inhibitors.

EXPERT OPINION

JAK1 inhibitors show great promise in treating cytokine dysregulated disorders; nevertheless, nonselective JAK1 inhibitors have more severe side effects, which restricts the therapy's safety and use. Therefore, developing highly selective JAK1 inhibitors can mitigate potential risks and lead to next-generation therapies with improved efficacy and safety profiles.

Baricitinib in the Treatment of Severe Atopic Dermatitis Resistant to Cyclosporine: A Case Report Involving Two Cases

Atopic dermatitis (AD) is a chronic inflammatory skin disorder that profoundly affects quality of life, particularly in patients with moderate-to-severe disease that is refractory to conventional treatments. Cyclosporine is a cornerstone of systemic therapy for severe AD; however, its long-term use is hindered by toxicity, and effective alternatives are often unavailable or insufficient. Janus kinase inhibitors, including baricitinib, have emerged as promising therapeutic options by modulating key inflammatory pathways involved in AD pathogenesis. This report describes two cases of severe cyclosporine-refractory AD that were successfully managed with baricitinib. Both patients showed substantial clinical improvement, including significant reductions in affected body surface area, disease severity scores, pruritus, and sleep disturbances within four weeks of initiating treatment. No serious adverse effects were observed, and the treatment was well tolerated. These findings highlight the potential of baricitinib as a viable therapeutic alternative for severe AD, particularly in settings where biologics such as dupilumab or abrocitinib may be limited. While baricitinib demonstrates both rapid and sustained efficacy, further studies are warranted to confirm its long-term safety and define its optimal role in AD management.

The Cell-Specific Effects of JAK1 Inhibitors in Ulcerative Colitis

JAK1 inhibitors have become an important addition to the therapeutic options for ulcerative colitis (UC), targeting key inflammatory pathways mediated by cytokines such as the IL-6 family, interferons, IL-2 family, IL-10 family, and G-CSF. However, not all patients respond equally, and chronic inflammation persists in a subset of individuals. The variability in treatment response may reflect the heterogeneity of UC. Immune cells, epithelial cells, and stromal cells may have distinct contributions to disease pathogenesis. While JAK inhibitors were originally designed to target immune cells, their impact on non-immune cell types, such as epithelial and stromal cells, remains poorly understood. Investigating the mechanisms through which JAK1 inhibitors affect these diverse cellular populations and identifying the factors underlying differential responses is crucial to optimizing outcomes. This review explores the roles of immune, epithelial, and stromal cells in response to JAK1 inhibition and discusses potential strategies to improve treatment precision, such as predicting responders and identifying complementary therapeutic targets.

Targeting Cytokine-Mediated Inflammation in Brain Disorders: Developing New Treatment Strategies

Cytokine-mediated inflammation is increasingly recognized for playing a vital role in the pathophysiology of a wide range of brain disorders, including neurodegenerative, psychiatric, and neurodevelopmental problems. Pro-inflammatory cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) cause neuroinflammation, alter brain function, and accelerate disease development. Despite progress in understanding these pathways, effective medicines targeting brain inflammation are still limited. Traditional anti-inflammatory and immunomodulatory drugs are effective in peripheral inflammatory illnesses. Still, they face substantial hurdles when applied to the central nervous system (CNS), such as the blood-brain barrier (BBB) and unwanted systemic effects. This review highlights the developing treatment techniques for modifying cytokine-driven neuroinflammation, focusing on advances that selectively target critical cytokines involved in brain pathology. Novel approaches, including cytokine-specific inhibitors, antibody-based therapeutics, gene- and RNA-based interventions, and sophisticated drug delivery systems like nanoparticles, show promise with respect to lowering neuroinflammation with greater specificity and safety. Furthermore, developments in biomarker discoveries and neuroimaging techniques are improving our ability to monitor inflammatory responses, allowing for more accurate and personalized treatment regimens. Preclinical and clinical trial data demonstrate the therapeutic potential of these tailored techniques. However, significant challenges remain, such as improving delivery across the BBB and reducing off-target effects. As research advances, the creation of personalized, cytokine-centered therapeutics has the potential to alter the therapy landscape for brain illnesses, giving patients hope for better results and a higher quality of life.

Evaluation of Real-World Evidence to Assess Effectiveness Outcomes of Janus Kinase Inhibitors for Rheumatoid Arthritis: A Systematic Review of US Studies

Objective

This review summarized the real-world effectiveness outcomes of Janus kinase inhibitors (JAKi) for rheumatoid arthritis (RA) based on observational studies.

Methods

A systematic review followed PRISMA guidelines, with searches conducted in PubMed, Embase, and CINAHL from each database's inception to June 2, 2023. Studies were included if they evaluated real-world effectiveness outcomes of JAKi for US RA patients. Search terms included "RA", "JAKi", and "real-world". All citations were imported into COVIDENCE platform. Two reviewers independently performed title/abstract screening and full-text eligibility. For each article, study characteristics and effectiveness measures focusing on treatment pattern, clinical response, and patient-reported outcomes (PROs) of JAKi were extracted. Newcastle-Ottawa Scale (NOS) was utilized to assess the quality of the included articles.

Results

In total, 35 studies representing 252-30,556 patients were included. A majority used the administrative claims datasets (n=23, 65.71%), followed by 9 studies using electronic medical record (EMR) data and 3 studies using patient registry databases. Across claims-based studies, adherence, persistence, and effectiveness of JAKi were common outcomes. Adherence rates varied, with a proportion of days covered (PDC) ranging from 0.53 to 0.83 across 11 studies. Persistence of JAKi in RA patients was reported in 14 studies, where the median persistence time in treatment was reported to be between 121-516 days. Six studies applied effectiveness algorithms, with 14.8-26% of patients meeting effective treatment criteria. In addition, the most common measure of clinical response throughout the studies was Clinical Disease Activity Index (CDAI), with 10 articles reporting mean CDAI changes between -4.7 and 5.1. Across 12 studies that measured the PROs, the most prevalent PRO was pain, with the mean change in pain ranging from -9.3 to 8.9 across these studies.

Conclusion

Real-world studies on JAKi for RA reflect a range of effectiveness measures, illustrating the expanding role of JAKi in clinical practice.

Serum Lipids Alterations in Patients Under Systemic JAK Inhibitors Treatments in Dermatology: Clinical Aspects and Management

Background and Objectives: Janus kinase inhibitors (JAKi) have significantly advanced the treatment of various dermatological conditions by modulating the JAK-STAT signalling pathway. While these inhibitors have proven effective, they also pose challenges due to associated increase in serum lipid levels and relative potential cardiovascular risks. This perspective work aims to discuss the implications of these lipid alterations proposing management strategies for patients with dermatological disorders under JAKi treatments. Materials and Methods: This manuscript reviews existing and recent literature on the metabolic effects of JAKi, particularly focusing on their impact on lipid profiles in patients treated for dermatological diseases. Results: JAK inhibitors are consistently associated with an increase in both LDL and HDL levels shortly after treatment initiation, which tend to stabilise over time. Despite these changes, there is no clear evidence linking these alterations to an increased risk of major adverse cardiovascular events (MACE), indicating a complex interaction between lipid metabolism and JAK-STAT signalling. Conclusions: Although JAKi may induce lipid changes in patients, raising concerns, especially in ones with existing cardiovascular risks, currently there is no proven link to increased MACE in this population. Monitoring lipid levels, alongside lifestyle modifications and possible statin use, can manage these effects without the need to stopping treatment.

JAK inhibition decreases the autoimmune burden in Down syndrome

Background

Individuals with Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), display clear signs of immune dysregulation, including high rates of autoimmunity and severe complications from infections. Although it is well established that T21 causes increased interferon responses and JAK/STAT signaling, elevated autoantibodies, global immune remodeling, and hypercytokinemia, the interplay between these processes, the clinical manifestations of DS, and potential therapeutic interventions remain ill defined.

Methods

We report a comprehensive analysis of immune dysregulation at the clinical, cellular, and molecular level in hundreds of individuals with DS, including autoantibody profiling, cytokine analysis, and deep immune mapping. We also report the interim analysis of a Phase II clinical trial investigating the safety and efficacy of the JAK inhibitor tofacitinib through multiple clinical and molecular endpoints.

Results

We demonstrate multi-organ autoimmunity of pediatric onset concurrent with unexpected autoantibody-phenotype associations in DS. Importantly, constitutive immune remodeling and hypercytokinemia occur from an early age prior to autoimmune diagnoses or autoantibody production. Analysis of the first 10 participants to complete 16 weeks of tofacitinib treatment shows a good safety profile and no serious adverse events. Treatment reduced skin pathology in alopecia areata, psoriasis, and atopic dermatitis, while decreasing interferon scores, cytokine scores, and levels of pathogenic autoantibodies without overt immune suppression.

Conclusions

JAK inhibition is a valid strategy to treat autoimmune conditions in DS. Additional research is needed to define the effects of JAK inhibition on the broader developmental and clinical hallmarks of DS.

Funding

NIAMS, Global Down Syndrome Foundation.

Clinical trial number

NCT04246372.

Exploring emerging JAK inhibitors in the treatment of Aicardi-Goutières syndrome

INTRODUCTION

Aicardi-Goutières syndrome (AGS) is a genetically heterogeneous monogenic autoinflammatory disorder classified as an 'interferonopathy'. Nine genes have been implicated in AGS, encoding proteins involved in nucleic acid clearance, repair, sensing, or histone pre-mRNA processing. Dysregulation in these pathways leads to excessive type I interferon production, the primary driver of the disease. AGS typically presents with early-life neurological regression, followed by stabilization with varying degrees of neurological impairment and common extra-neurological features, such as chilblains. Advances in understanding AGS pathogenesis have enabled the development of new therapies, with JAK inhibitors emerging as the most studied option for reducing interferon-mediated effects.

AREAS COVERED

This review discusses the clinical features, genetic basis, and molecular pathways of AGS while tracing the evolution of its therapeutic strategies. Particular emphasis is placed on JAK inhibitors, which target proteins activated by type I interferons, providing a novel direction in treatment.

EXPERT OPINION

Inhibitors effectively reduce extra-neurological symptoms in AGS, though their impact on neurological outcomes remains unclear. The unknown natural history of AGS limits treatment evaluation. Despite growing insights, key aspects of pathogenesis and treatment optimization - including timing, administration, and long-term effects - remain unresolved, highlighting the need for further research.

Targeting inerleukin-6 for renoprotection

Sterile inflammation has been increasingly recognized as a hallmark of non-infectious kidney diseases. Induction of pro-inflammatory cytokines in injured kidney tissue promotes infiltration of immune cells serving to clear cell debris and facilitate tissue repair. However, excessive or prolonged inflammatory response has been associated with immune-mediated tissue damage, nephron loss, and development of renal fibrosis. Interleukin 6 (IL-6) is a cytokine with pleiotropic effects including a major role in inflammation. IL-6 signals either via membrane-bound (classic signaling) or soluble receptor forms (trans-signaling) thus affecting distinct cell types and eliciting various metabolic, cytoprotective, or pro-inflammatory reactions. Antibodies neutralizing IL-6 or its receptor have been developed for therapy of autoimmune and chronic non-renal inflammatory diseases. Small molecule inhibitors of Janus kinases acting downstream of the IL-6 receptor, as well as recombinant soluble glycoprotein 130 variants suppressing the IL-6 trans-signaling add to the available therapeutic options. Animal data and accumulating clinical experience strongly suggest that suppression of IL-6 signaling pathways bears therapeutic potential in acute and chronic kidney diseases. The present work analyses the renoprotective potential of clinically relevant IL-6 signaling inhibitors in acute kidney injury, chronic kidney disease, and kidney transplantation with focus on current achievements and future prospects.

Modulation of the JAK2-STAT3 pathway promotes expansion and maturation of human iPSCs-derived myogenic progenitor cells

Generation of in vitro induced pluripotent cells (hiPSCs)-derived skeletal muscle progenitor cells (SMPCs) holds great promise for regenerative medicine for skeletal muscle wasting diseases, as for example Duchenne Muscular Dystrophy (DMD). Multiple approaches, involving ectopic expression of key regulatory myogenic genes or small molecules cocktails, have been described by different groups to obtain SMPC towards cell-transplantation in vivo as a therapeutic approach to skeletal muscle diseases. However, hiPSCs-derived SMPC generated using transgene-free protocols are usually obtained in a low amount and resemble a more embryonal/fetal stage of differentiation. Here we demonstrate that modulation of the JAK2/STAT3 signaling pathway during an in vitro skeletal muscle differentiation protocol, increases the yield of PAX7+ and CD54+ SMPCs and drive them to a postnatal maturation stage, in both human ES and patient-derived iPSCs. Importantly, upon removal of the inhibition from the cultures, the obtained SMPCs are able to differentiate into multinucleated myotubes in vitro. These findings reveal that modulation of the JAK2/STAT3 signaling pathway is a potential therapeutic avenue to generate SMPCs in vitro with increase potential for cell-therapy approaches.

Recent Advances in the Management of Acute Severe Ulcerative Colitis

Acute severe ulcerative colitis is a medical emergency requiring inpatient treatment with intravenous steroids. Approximately one-third of patients do not respond to steroids sufficiently and require medical rescue therapy. Infliximab and cyclosporine are equally effective rescue agents, though infliximab is often preferred by clinicians for ease of use and greater familiarity. The use of cyclosporine is becoming more frequent, however, in patients previously exposed to infliximab. Those patients not exhibiting an adequate response to rescue therapy require colectomy. There is increasing interest in modified medical treatment to rescue the need for surgery. Janus kinase inhibitors may provide benefits when used alongside steroids from admission or as a rescue agent, but further randomised trials are needed to clearly establish their role. Intensified dosing of infliximab when used as a rescue therapy has shown mixed results but seems sensible in patients with low albumin and high disease burden. In this review, we describe the current established treatment pathways and report newer developments and evolving concepts that may in the future improve the care of patients with acute severe ulcerative colitis.

Demethylzeylasteral alleviates inflammation and colitis via dual suppression of NF-κB and STAT3/5 by targeting IKKα/β and JAK2

BACKGROUND

Ulcerative colitis (UC) is a common inflammatory bowel disease and a risk factor of colorectal cancer. Demethylzeylasteral (DZT), a bioactive component mainly isolated from Tripterygium wilfordii, has been shown to inhibit inflammation and cancer. However, its anti-UC function and molecular mechanisms have not been well characterized. This study aims to explore the therapeutic effect and functional targets of demethylzeylasteral against UC.

METHODS

RT-qPCR, Western blot and ELISA were used to detect the generation of pro-inflammatory cytokines and chemokines in murine macrophage cells. Luciferase reporter gene, Western blot, pull-down, CETSA, DARTS, and virtual docking were employed to detect the anti-inflammatory targets and molecular mechanisms of demethylzeylasteral. The anti-inflammatory and anti-colitis effects of demethylzeylasteral were further determined in DSS-challenged mice.

RESULTS

In vitro, demethylzeylasteral inhibited NO and PGE2 production by suppressing the mRNA and protein expression of iNOS and COX-2, and suppressed the mRNA expression of TNF-α, IL-1β, IL-6, MCP-1, CXCL9, and CXCL10 in RAW264.7 macrophages stimulated by LPS/IFNγ. Furthermore, demethylzeylasteral was not only capable of inhibiting IKKα/β-NF-κB activation, but also able to block JAKs-STAT3/5 activation in LPS/INFγ-incubated RAW264.7 cells or DSS-exposed colon tissues of mice. Mechanistically, demethylzeylasteral was found to directly bind to IKKα/β and JAK2 kinases, leading to inactivation of pro-inflammatory signaling cascades and reduced generation of cytokines and chemokines. In vivo, oral administration of demethylzeylasteral significantly attenuated DSS-induced colitis, which was mainly manifested as mitigated symptoms of colitis, colonic mucosal barrier damage, and colonic inflammation.

CONCLUSION

We demonstrated that demethylzeylasteral alleviated UC pathology by blocking NF-κB and STAT3/5 pathways via targeting IKKα/β and JAK2 kinases, raising the possibility that demethylzeylasteral could act as a candidate for the treatment of UC.

Future Directions in Therapies for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is caused by a complex interplay among hyperinflammation, endothelial dysfunction, and alveolar epithelial injury. Targeted treatments toward the underlying pathways have been unsuccessful in unselected patient populations. The first reliable biological subphenotypes reflective of these biological disease states have been identified in the past decade. Subphenotype targeted intervention studies are needed to advance the pharmacologic treatment of ARDS.

Therapeutic JAK1 Inhibition Reverses Lupus Nephritis in a Mouse Model and Demonstrates Transcriptional Changes Consistent With Human Disease

OBJECTIVE

Janus kinase family members are essential for signaling by multiple cytokines, including many implicated in systemic lupus erythematosus (SLE) pathogenesis. To test whether inhibition of JAK1 signaling can be efficacious in SLE, we used a JAK1-selective inhibitor (ABT-317) and evaluated its ability to ameliorate disease in murine SLE.

METHODS

Efficacy of ABT-317 was evaluated using NZB/W-F1 mice treated prophylactically and therapeutically. Primary endpoints were proteinuria, survival, and saliva production. Other endpoints included histological analysis of kidneys and salivary glands, flow cytometric analysis of splenic cell populations, and gene expression analysis by RNA sequencing in the kidneys, salivary glands, and blood. Publicly available human kidney gene transcription data were used to assess the translatability of the mouse findings.

RESULTS

ABT-317 was efficacious when dosed prophylactically and prevented disease for up to two months after treatment cessation. When dosed therapeutically, ABT-317 quickly reversed severe proteinuria and restored saliva production, as well as diminished kidney and salivary gland inflammation. ABT-317-induced changes in glomerular morphology coincided with normalization of a human nephrotic gene signature, suggesting translatability to human lupus nephritis (LN).

CONCLUSION

JAK1 inhibition prevented and reversed kidney and salivary gland manifestations of murine lupus with long-lasting effects after treatment cessation. These data, along with the presence of JAK1 and nephrotic gene signatures in human LN glomeruli, suggest that a JAK1-selective inhibitor may be an effective therapeutic in the treatment of human SLE and LN.

Medicinal chemistry perspective of JAK inhibitors: synthesis, biological profile, selectivity, and structure activity relationship

JAK-STAT signalling pathway was discovered more than quarter century ago. The JAK-STAT pathway protein is considered as one of the crucial hubs for cytokine secretion which mediates activation of different inflammatory, cellular responses and hence involved in different etiological factors. The various etiological factors involved are haematopoiesis, immune fitness, tissue repair, inflammation, apoptosis, and adipogenesis. The presence of the active mutation V617K plays a significant role in the progression of the JAK-STAT pathway-related disease. Consequently, targeting the JAK-STAT pathway could be a promising therapeutic approach for addressing a range of causative factors. In this current review, we provided a comprehensive discussion for the in-detail study of anatomy and physiology of the JAK-STAT pathway which contributes structural domain rearrangement, activation, and negative regulation associated with the downstream signaling pathway, relationship between different cytokines and diseases. This review also discussed the recent development of clinical trial entities. Additionally, this review also provides updates on FDA-approved drugs. In the current investigation, we have classified recently developed small molecule inhibitors of JAK-STAT pathway according to different chemical classes and we emphasized their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

Janus kinase inhibitors and adverse events of acne in dermatologic indications: a systematic review and network meta-analysis

Background: The occurrence of acne in patients treated with Janus kinase (JAK) inhibitors for skin diseases is a potential issue, which may reduce treatment adherence.

Purpose: To systematically analyzes randomized clinical trials (RCTs) of JAK inhibitors in dermatological indications for the risk of acne as an adverse event.

Methods: A meta-analysis of odds ratios (ORs) for acne incidence was conducted. Data were quantitatively synthesized using random-effects meta-analysis. Surface under the cumulative ranking curve (SUCRA) values representing the relative ranking probabilities of treatments were obtained. Analyses were performed using R statistical software version 4.4.0.

Results: A total of 11,396 patients were included from 24 studies. The incidence of acne for JAK inhibitors was ranked according to the SUCRA as follows: JAK1 inhibitors > TYK2 inhibitors > combined JAK1 and JAK2 inhibitors > combined JAK1 and TYK2 inhibitors > JAK3 + TEC inhibitors > pan-JAK inhibitors. ORs were higher for longer durations of drug use and larger dosages. Subgroup analyses by disease indication revealed increased ORs for psoriasis (5.52 [95% CI, 1.39-21.88]), vitiligo (4.15 [95% CI, 1.27-13.58]), alopecia areata (3.86 [95% CI, 1.58-9.42]), and atopic dermatitis (2.82 [95% CI, 1.75-4.54]). The use of JAK inhibitors in patients with systemic lupus erythematosus (SLE) may not significantly increase the incidence of acne.

Conclusions: There are higher rates of acne following treatment with JAK inhibitors for dermatologic indications, particularly with longer durations and larger dosages. Pan-JAK inhibitors exhibit the lowest incidence of acne.

Autoimmune hepatitis: Towards a personalized treatment

Autoimmune hepatitis is an uncommon condition that affects both adults and children and is characterized by chronic and recurrent inflammatory activity in the liver. This inflammation is accompanied by elevated IgG and autoantibody levels. Historically, treatment consists of steroids with the addition of azathioprine, which results in remission in approximately 80% of patients. Despite significant advancements in our understanding of the immune system over the past two decades, few modifications have been made to treatment algorithms, which have remained largely unchanged since they were first proposed more than 40 years ago. This review summarized the various treatment options currently available as well as our experiences using them. Although steroids are the standard treatment for induction therapy, other medications may be considered. Cyclosporin A, a calcineurin inhibitor that decreases T cell activation, has proven effective for induction of remission, but its long-term side effects limit its appeal for maintenance. Tacrolimus, a drug belonging to the same family, has been used in patients with refractory diseases with fewer side effects. Sirolimus and everolimus have interesting effects on regulatory T cell populations and may become viable options in the future. Mycophenolate mofetil is not effective for induction but is a valid alternative for patients who are intolerant to azathioprine. B cell-depleting drugs, such as rituximab and belimumab, have been successfully used in refractory cases and are useful in both the short and long term. Other promising treatments include anti-tumor necrosis factors, Janus kinases inhibitors, and chimeric antigen receptor T cell therapy. This growing armamentarium allows us to imagine a more tailored approach to the treatment of autoimmune hepatitis in the near future.

Design of a potent and selective dual JAK1/TYK2 inhibitor

Janus kinase (JAK) inhibitors have gathered interest as treatments for several inflammatory and autoimmune diseases. The four first marketed inhibitors target JAK1, with varying selectivity towards other JAK family members, but none inhibit tyrosine kinase-2 (TYK2) at clinically relevant doses. TYK2 is required for the signaling of the interleukin (IL)-12 and IL-23 cytokines, which are key to the polarization of TH1 and TH17 cells, respectively; two cell subtypes that play major roles in inflammatory diseases. Herein, we report our effort towards the optimization of a potent and selective dual JAK1/TYK2 inhibitor series starting from a HTS hit. Structural information revealed vectors required to improve both JAK1 and TYK2 potency as well as selectivity towards JAK2. The potent inhibition of both JAK1 (3.5 nM) and TYK2 (5.7 nM) in biochemical assays by our optimized lead compound, as well as its notable selectivity against JAK2, were confirmed in cellular and whole blood assays. Inhibition of TYK2 by the lead compound was demonstrated by dose-dependent efficacy in an IL-23-induced psoriasis-like inflammation mouse model.

Covalent small-molecule inhibitors of SARS-CoV-2 Mpro: Insights into their design, classification, biological activity, and binding interactions

Since 2020, many compounds have been investigated for their potential use in the treatment of SARS-CoV-2 infection. Among these agents, a huge number of natural products and FDA-approved drugs have been evaluated as potential therapeutics for SARS-CoV-2 using virtual screening and docking studies. However, the identification of the molecular targets involved in viral replication led to the development of rationally designed anti-SARS-CoV-2 agents. Among these targets, the main protease (Mpro) is one of the key enzymes needed in the replication of the virus. The data gleaned from the crystal structures of SARS-CoV-2 Mpro complexes with small-molecule covalent inhibitors has been used in the design and discovery of many highly potent and broad-spectrum Mpro inhibitors. The current review focuses mainly on the covalent type of SARS-CoV-2 Mpro inhibitors. The design, chemistry, and classification of these inhibitors were also in focus. The biological activity of these inhibitors, including their inhibitory activities against Mpro, their antiviral activities, and the SAR studies, were discussed. The review also describes the potential mechanism of the interaction between these inhibitors and the catalytic Cys145 residue in Mpro. Moreover, the binding modes and key binding interactions of these covalent inhibitors were also illustrated. The covalent inhibitors discussed in this review were of diverse chemical nature and origin. Their antiviral activity was mediated mainly by the inhibition of SARS-CoV-2 Mpro, with IC50 values in the micromolar to the nanomolar range. Many of these inhibitors exhibited broad-spectrum inhibitory activity against the Mpro enzymes of other coronaviruses (SARS-CoV-1 and MERS-CoV). The dual inhibition of the Mpro and PLpro enzymes of SARS-CoV-2 could also provide higher therapeutic benefits than Mpro inhibition. Despite the approval of nirmatrelvir by the FDA, many mutations in the Mpro enzyme of SARS-CoV-2 have been reported. Although some of these mutations did not affect the potency of nirmatrelvir, there is an urgent need to develop a second generation of Mpro inhibitors. We hope that the data summarized in this review could help researchers in the design of a new potent generation of SARS-CoV-2 Mpro inhibitors.

Therapeutic potential of anticancer activity of nitrogen-containing heterocyclic scaffolds as Janus kinase (JAK) inhibitor: Biological activity, selectivity, and structure-activity relationship

The JAK-STAT signalling pathway is primarily involved in cytokine signalling and induces various factors namely, erythropoietin, thrombopoietin, interferons, interleukins, and granulocyte colony-stimulating factors. These factors tremendously influenced understanding human health and illness, specifically cancer. Inhibiting the JAK/STAT pathway offers enormous therapeutic promises against cancer. Many JAK inhibitors are now being studied due to their efficacy in various cancer treatments. Further, the Nitrogen-heterocyclic (N-heterocyclic) scaffold has always shown to be a powerful tool for designing and discovering synthetic compounds with diverse pharmacological characteristics. The review focuses on several FDA-approved JAK inhibitors and their systematic categorization. The medicinal chemistry perspective is highlighted and classified review on the basis of N-heterocyclic molecules. Several examples of designing strategies of N-heterocyclic rings including pyrrolo-azepine, purine, 1H-pyrazolo[3,4-d]pyrimidine, 1H-pyrrolo[2,3-b]pyridine, pyrazole, thieno[3,2-d] pyrimidine, and, pyrimidine-based derivatives and their structure-activity relationships (SAR) are discussed. Among the various N-heterocyclic-based JAK inhibitors pyrimidine-containing compound 1 exhibited excellent inhibition activity against JAK2WT and mutated-JAK2V617F with IC50 of 2.01 and 18.84 nM respectively. Amino pyrimidine-containing compound 6 and thiopheno[3,2-d]pyrimidine-containing compound 13 expressed admirable JAK3 inhibition activity with IC50 of 1.7 nM and 1.38 nM respectively. Our review will support the medicinal chemists in refining and directing the development of novel N-heterocyclic-based JAK inhibitors.

Review article: Novel therapies in inflammatory bowel disease - An update for clinicians

BACKGROUND

Several new treatments including small molecules and biologics have been approved for the treatment of inflammatory bowel diseases in recent years. Clinicians and patients now have a wide variety of therapeutic options to choose from and these novel therapies provide several advantages including oral administration, lower immunogenicity, better selectivity and arguably better safety profiles. An increase in treatment options has increased the complexity of decision-making. Both patients and clinicians have had to become rapidly familiar with efficacy of new medications balanced against a range of pre-initiation requirements, dosing schedules and adverse event profiles.

AIMS

To provide a simple guide to practising clinicians on recently approved and emerging therapies and address key challenges around treatment strategies such as optimal sequencing and timing of treatment.

METHODS

We comprehensively searched the published literature and major conference abstracts to identify phase III placebo-controlled and active comparator trials for Crohn's disease and ulcerative colitis.

RESULTS

Data for recently approved therapies including selective Janus kinase inhibitors, sphingosine-1 receptor modulators and p19 interleukin (IL)-23 inhibitors have demonstrated improved patient outcomes in both Crohn's disease and ulcerative colitis. Further comparative head-to-head studies have improved our understanding of when and how to optimally use newer therapies, specifically for IL-23 inhibitors. Data for emerging treatment options and novel treatment strategies such as early effective treatment, combinations of treatments and implications for sequencing are continuing to transform IBD care continually.

CONCLUSIONS

Recently approved novel therapies have expanded the range of medical options available to treat IBD. However, further data from long-term extension studies, real-world studies and head-to-head trials are warranted to better inform the long-term safety and optimal sequencing of treatments for patients living with IBD.

JAK inhibition decreases the autoimmune burden in Down syndrome

Individuals with Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), display clear signs of immune dysregulation, including high rates of autoimmune disorders and severe complications from infections. Although it is well established that T21 causes increased interferon responses and JAK/STAT signaling, elevated autoantibodies, global immune remodeling, and hypercytokinemia, the interplay between these processes, the clinical manifestations of DS, and potential therapeutic interventions remain ill defined. Here, we report a comprehensive analysis of immune dysregulation at the clinical, cellular, and molecular level in hundreds of individuals with DS. We demonstrate multi-organ autoimmunity of pediatric onset concurrent with unexpected autoantibody-phenotype associations. Importantly, constitutive immune remodeling and hypercytokinemia occur from an early age prior to autoimmune diagnoses or autoantibody production. We then report the interim analysis of a Phase II clinical trial investigating the safety and efficacy of the JAK inhibitor tofacitinib through multiple clinical and molecular endpoints. Analysis of the first 10 participants to complete the 16-week study shows a good safety profile and no serious adverse events. Treatment reduced skin pathology in alopecia areata, psoriasis, and atopic dermatitis, while decreasing interferon scores, cytokine scores, and levels of pathogenic autoantibodies without overt immune suppression. Additional research is needed to define the effects of JAK inhibition on the broader developmental and clinical hallmarks of DS. ClinicalTrials.gov identifier: NCT04246372.