Janus kinase-targeting therapies in rheumatology: a mechanisms-based approach

Baricitinib as a treatment for myasthenia gravis: a case report

Myasthenia gravis (MG) is an autoimmune disease that targets neuromuscular junctions. While immunotherapy remains the cornerstone of treatment, the effects of Janus kinase (JAK) inhibitors on MG remain underexplored. In this report, we describe the case of a 58-year-old woman with ocular myasthenia gravis who received treatment with the JAK inhibitor, baricitinib for alopecia areata. The patient presented with left eyelid ptosis and an inadequate response to steroids and pyridostigmine, along with symptoms of alopecia areata. Following diagnosis, we initiated a treatment regimen consisting of baricitinib for six months. After initiation of baricitinib, we observed a complete resolution of the patient's MG symptoms, accompanied by hair regrowth, even when steroids were tapered and pyridostigmine was discontinued. Furthermore, the titer of the anti-acetylcholine receptor antibody was decreased. This report represents the first reported case of anti-acetylcholine receptor antibody-positive MG that was successfully treated through the inhibition of JAK activity.

Rheumatic adverse events of immune checkpoint inhibitors in cancer immunotherapy

INTRODUCTION

The advent of immune checkpoint inhibitors (ICIs) in cancer treatment has marked a transformative era, albeit tempered by immune-related adverse events (irAEs), including those impacting the musculoskeletal system. The lack of precise epidemiologic data on rheumatic irAEs is attributed to factors such as potential underrecognition, underreporting in clinical trials, and the tendency to overlook manifestations without immediate life-threatening implications, further complicating the determination of accurate incidence rates, while the complete understanding of the mechanisms driving rheumatic irAEs remains elusive.

AREAS COVERED

This literature review comprehensively examines rheumatic irAEs in cancer patients undergoing ICI therapy, encompassing epidemiology, risk factors, mechanisms, clinical manifestations, and current management guidance for prevalent conditions such as inflammatory arthritis, polymyalgia rheumatica, and myositis. Less frequent rheumatic and musculoskeletal irAEs are also explored, alongside insights into ongoing clinical trials testing therapeutic and preventive strategies for irAEs. A thorough literature search on Medline and the National Cancer Institute Clinical Trials Database was conducted up to October 2023 to compile relevant information.

EXPERT OPINION

In light of the evolving landscape of cancer immunotherapy, there is a compelling need for prospective longitudinal studies to enhance understanding and inform clinical management strategies for rheumatic irAEs.

A case report of systemic lupus erythematosus complicating interstitial lung disease and thickened pericardium treated with tofacitinib

RATIONALE

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that damages multiple organs and systems, including the lungs, kidneys, and heart. The respiratory system is commonly affected by SLE, leading to problems such as pleurisy, pleural effusion, and interstitial lung disease (ILD). In addition, SLE can involve the heart, with pericarditis being the most common manifestation. Notably, pericardial effusion frequently accompanies pericarditis involved by SLE, and aspects such as thickened pericardium (TP) can be challenging to detect early on. There are limited reports on TP and even fewer reports on the treatment of ILD with TP. This study investigates the clinical treatment of SLE complicating ILD and TP and reports on a successful case treated with tofacitinib, offering new strategies for managing such patients.

PATIENT CONCERNS

A 35-year-old female patient presented to the hospital with polyarticular swelling and pain that had been ongoing for over 4 years, as well as recurrent chest pain for 2 years that worsened over the course of 1 day.

DIAGNOSES

The patient was diagnosed with SLE complicating ILD and TP, with hematologic involvement.

INTERVENTIONS

Treatment involved the administration of tofacitinib in combination with low-dose methylprednisolone (MP) and mycophenolate mofetil (MMF).

OUTCOMES

The patient experienced recurrent chest pain and difficulty in reducing glucocorticoids (GCs), but the patient conditions were improved upon the addition of tofacitinib. The patient has been followed up for 16 months, and the patient MP dosage has been reduced to 6 mg once daily. The patient condition remains stable without recurrence, and the patient quality of life has improved.

LESSONS

In cases of SLE complicating ILD and TP, when tapering GCs is difficult, treatment with tofacitinib can be effective in achieving remission and maintaining stability.

Targeting cytokines in psoriatic arthritis

Psoriatic arthritis (PsA) is part of the psoriatic disease spectrum and is characterized by a chronic inflammatory process that affects entheses, tendons and joints. Cytokines produced by immune and non-immune cells play a central role in the pathogenesis of PsA by orchestrating key aspects of the inflammatory response. Pro-inflammatory cytokines such as TNF, IL-23 and IL-17 have been shown to regulate the initiation and progression of PsA, ultimately leading to the destruction of the architecture of the local tissues such as soft tissue, cartilage and bone. The important role of cytokines in PsA has been underscored by the clinical success of antibodies that neutralize their function. In addition to biologic agents targeting individual pro-inflammatory cytokines, signaling inhibitors that block multiple cytokines simultaneously such as JAK inhibitors have been approved for PsA therapy. In this review, we will focus on our current understanding of the role of cytokines in the disease process of PsA and discuss potential new treatment options based on modulation of cytokine function.

Real-world comparative study of drug retention of Janus kinase inhibitors in patients with rheumatoid arthritis

BACKGROUND

Janus kinase (JAK) inhibitors (JAKis) are effective therapeutic agents against rheumatoid arthritis (RA). However, patients having RA with particular risk factors may have a higher incidence of adverse effects (AEs), including major cardiovascular events (MACE) and infections. In this multicenter cohort study, we aimed to clarify the risk factors affecting the drug retention of JAKis in patients with RA.

METHODS

We retrospectively evaluated patients with RA who received their first JAKi (tofacitinib, baricitinib, upadacitinib, or filgotinib) at our institute. The clinical outcomes, including AEs, were recorded, particularly MACE and serious infections. The drug retention rates were analyzed using the Kaplan-Meier method, and risk factors affecting drug retention rates were determined using a multivariable Cox regression hazards model.

RESULTS

Overall 184 patients with RA receiving their first use of baricitinib (57.6%), tofacitinib (23.9%), upadacitinib (12.0%), or filgotinib (6.5%) were included in this study. Fifty-six (30.4%) patients discontinued JAKi treatment owing to ineffectiveness (9.2%) or AEs, including infections (21.2%). The overall drug retention rates were significantly lower in patients treated with pan-JAKi than in those treated with JAK1 inhibitors (p = 0.03). In the Cox regression model, the presence of baseline high RA disease activity, use of glucocorticoid and treatments with pan-JAKis were associated with reduced drug retention rates of JAKis (p < 0.001, p = 0.01 and 0.04, respectively). Pan-JAKi treated patients with high disease activity had significantly lower drug retention rates (p < 0.001).

CONCLUSIONS

In a real-world setting, the drug retention rates of JAKis were reduced mainly by treatment discontinuation owing to AEs. Treatment with pan-JAKis and high baseline RA disease activity were identified as predictive factors for the discontinuation of JAKis. Lower drug retention rates were found in patients receiving pan-JAKis with high disease activity than in those without high disease activity.

A Review of Myositis-Associated Interstitial Lung Disease

There is a well-established relationship between different subsets of idiopathic inflammatory myopathies (IIMs, myositis) and interstitial lung disease (ILD), with lung complications sometimes presenting prior to myopathic manifestations. The subtypes of myositis include those that are strongly associated with ILD, such as polymyositis (PM) and dermatomyositis (DM). Research has shown that in certain patients, these can then be further divided into subtypes using myositis-specific antibodies (MSAs), which are specific for myositis, and myositis-associated antibodies (MAAs), which can be found in myositis in overlap syndromes with other connective tissue diseases (CTDs). Notably, certain MSAs and MAAs are associated with ILD in patients with myositis. The clinical presentations of ILD in patients with myositis can vary widely and can be insidious in onset and difficult to diagnose. As ILD can progress rapidly in some cases, it is essential that clinicians are able to identify and diagnose ILD in patients with myositis. For this reason, the aim of this review is to highlight the clinical features, diagnostic criteria, important histopathologic, laboratory, and radiographic features, and treatment modalities for those patients with myositis-associated ILD.

Biologic and small-molecule therapy for treating moderate to severe atopic dermatitis: Mechanistic considerations

Atopic dermatitis (AD) is a complex and heterogeneous skin disease for which achieving complete clinical clearance for most patients has proven challenging through single cytokine inhibition. Current studies integrate biomarkers and evaluate their role in AD, aiming to advance our understanding of the diverse molecular profiles implicated. Although traditionally characterized as a TH2-driven disease, extensive research has recently revealed the involvement of TH1, TH17, and TH22 immune pathways as well as the interplay of pivotal immune molecules, such as OX40, OX40 ligand (OX40L), thymic stromal lymphopoietin, and IL-33. This review explores the mechanistic effects of treatments for AD, focusing on mAbs and Janus kinase inhibitors. It describes how these treatments modulate immune pathways and examines their impact on key inflammatory and barrier biomarkers.

Efficacy of Upadacitinib As a Second-line JAK Inhibitor in Ulcerative Colitis: A Case Series

Upadacitinib, a recently approved Janus kinase (JAK) inhibitor specific for JAK1, may be a promising candidate in patients with ulcerative colitis (UC) who present no response or intolerance to first-line JAK inhibitors. We assessed the therapeutic impact of upadacitinib on six UC patients who demonstrated an inadequate response or intolerance to tofacitinib or filgotinib. After 2 months of treatment, 5 patients (83.3%) achieved clinical remission, and all patients experienced decreased levels of C-reactive protein. One patient had coronavirus disease 2019 pneumonia and showed a mild increase in transaminase levels. This case series highlights the potential utility of a rotation strategy among JAK inhibitors.

Identifying the genetic association between common rheumatic diseases and vitiligo

BACKGROUND

Although observational studies have suggested a correlation between vitiligo and rheumatic diseases, conclusive evidence supporting a causal relationship is still lacking. Therefore, this study aims to explore the potential causal relationship between vitiligo and rheumatic diseases.

METHODS

Using genome-wide association studies, we performed a two-sample Mendelian randomization (MR) analysis. In our analysis, the random-effects inverse variance weighted (IVW) method was predominantly employed, followed by several sensitivity analyses, which include heterogeneity, horizontal pleiotropy, outliers, and "leave-one-out" analyses.

RESULTS

The genetically predicted vitiligo was associated with an increased risk of rheumatoid arthritis (RA) (OR, 1.47; 95% confidence interval [CI], 1.29-1.68; p < 0.001), and systemic lupus erythematosus (SLE) (OR, 1.22; 95% CI, 1.06-1.39; p = 0.005). The causal associations were supported by sensitivity analyses. In Sjögren's syndrome and ankylosing spondylitis, no causal relationship with vitiligo was found in the study.

CONCLUSION

Our MR results support the causal effect that vitiligo leads to a higher risk of RA and SLE. Individuals with vitiligo should be vigilant for the potential development of RA and SLE. Managing and addressing this potential requires regular monitoring.

A rare case of symptomatic creatine kinase elevation in a patient with rheumatoid arthritis treated with baricitinib

The safety profile of baricitinib (BARI), a Janus kinase inhibitor broadly used for the treatment of rheumatoid arthritis (RA), includes asymptomatic laboratory abnormalities, such as an increase in creatine kinase (CK). Data from randomized controlled trials suggest that concomitant myalgia is rare in RA and does not lead to drug discontinuation. We describe the case of a 68-year-old Caucasian female with longstanding, multi-failure RA who started BARI and achieved disease remission. However, she developed a symptomatic CK increase, as well as a parallel increase in total cholesterol, low-density lipoprotein, and triglycerides. Dechallenge-rechallenge demonstrated a plausible relationship between the clinical/laboratory abnormalities and BARI. In fact, when the drug was withdrawn, CK returned to normal and myalgia disappeared, whereas symptoms returned and CK levels increased when BARI was restarted. BARI may be rarely associated with symptomatic CK elevation, and this may pose clinical challenges, particularly for patients with multi-failure RA who achieved good disease control with BARI but required drug discontinuation due to intolerance.

JAK inhibition enhances checkpoint blockade immunotherapy in patients with Hodgkin lymphoma

Unleashing antitumor T cell activity by checkpoint inhibitor immunotherapy is effective in cancer patients, but clinical responses are limited. Cytokine signaling through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway correlates with checkpoint immunotherapy resistance. We report a phase I clinical trial of the JAK inhibitor ruxolitinib with anti-PD-1 antibody nivolumab in Hodgkin lymphoma patients relapsed or refractory following checkpoint inhibitor immunotherapy. The combination yielded a best overall response rate of 53% (10/19). Ruxolitinib significantly reduced neutrophil-to-lymphocyte ratios and percentages of myeloid suppressor cells but increased numbers of cytokine-producing T cells. Ruxolitinib rescued the function of exhausted T cells and enhanced the efficacy of immune checkpoint blockade in preclinical solid tumor and lymphoma models. This synergy was characterized by a switch from suppressive to immunostimulatory myeloid cells, which enhanced T cell division.

The Retention Rate and Safety of JAK Inhibitors in Rheumatoid Arthritis: Real Word Data from a Monocentric Cohort

Background/Objectives: To date, the literature concerning real-world data on the retention rate and safety of Janus kinase inhibitors (JAKis) is limited. To retrospectively evaluate the overall drug retention rate (DRR) of different JAKis in a monocentric cohort of patients with rheumatoid arthritis (RA). Methods: Patients diagnosed with RA and treated with JAKis who were evaluated at our outpatient clinic from March 2017 to December 2023 were included in the study. Demographic, clinical characteristics, and comorbidities were recorded. The DRR was evaluated as the time to drug discontinuation, and baseline predictors of drug discontinuation were investigated through Cox regression after adjusting for baseline confounders. Results: The global DRR for JAKis was 51.3%. The DRR was 37.5% for tofacitinib, 46.6% for baricitinib, 69.4% for upadacitinib, and 53.5% for filgotinib. Considering all JAKis, the only significant predictor of drug discontinuation was the use of JAKis as a first-line treatment (HR 95% CI [0.25 (0.13-0.46)]. When considering each JAKi individually, a longer disease duration predicted TOF discontinuation (HR95% CI [1.05 (1.01-1.09)], while seropositivity protected against TOF being withdrawn (HR95% CI [0.41 (0.17-0.97)]. No independent predictors emerged for other JAKis. Conclusions: the use of JAKis as a first-line treatment as well as disease duration and serology may impact the DRR of JAKis, which may inform tailored treatment strategies in clinical practice.

Modifying T cell phenotypes using TYK2 inhibitor and its implications for the treatment of systemic lupus erythematosus

OBJECTIVES

The tuning effects of JAK/TYK2 inhibitors on the imbalance between T follicular helper (Tfh) and T regulatory (Treg) cells, related to systemic lupus erythematosus (SLE) pathogenesis, were investigated using human peripheral blood samples.

METHODS

Peripheral blood mononuclear cells from untreated patients with SLE and healthy controls were analysed. Tfh1 cells were identified in nephritis tissue, and the effect of Tfh1 cells on B-cell differentiation was examined by coculturing naïve B cells with Tfh1 cells.

RESULTS

Tfh1 cell numbers were increased in the peripheral blood of patients, and activated Treg cell counts were decreased relative to Tfh1 cell counts. This imbalance in the Tfh to Treg ratio was remarkably pronounced in cases of lupus nephritis, especially in types III and IV active nephritis. Immunohistochemistry revealed Tfh1 cell infiltration in lupus nephritis tissues. Co-culture of Tfh1 cells (isolated from healthy individuals) with naïve B cells elicited greater induction of T-bet+ B cells than controls. In JAK/TYK2-dependent STAT phosphorylation assays using memory CD4+ T cells, IL-12-induced STAT1/4 phosphorylation and Tfh1 cell differentiation were inhibited by both JAK and TYK2 inhibitors. However, phosphorylation of STAT5 by IL-2 and induction of Treg cell differentiation by IL-2+TGFβ were inhibited by JAK inhibitors but not by TYK2 inhibitors, suggesting that TYK2 does not mediate the IL-2 signalling pathway.

CONCLUSIONS

Tfh1 cells can induce T-bet+ B cell production and may contribute to SLE pathogenesis-associated processes. TYK2 inhibitor may fine-tune the immune imbalance by suppressing Tfh1 differentiation and maintaining Treg cell differentiation, thereby preserving IL-2 signalling, unlike other JAK inhibitors.

Epigenetic targets of Janus kinase inhibitors are linked to genetic risks of rheumatoid arthritis

BACKGROUND

Current strategies that target cytokines (e.g., tumor necrosis factor (TNF)-α), or signaling molecules (e.g., Janus kinase (JAK)) have advanced the management for allergies and autoimmune diseases. Nevertheless, the molecular mechanism that underpins its clinical efficacy have largely remained elusive, especially in the local tissue environment. Here, we aimed to identify the genetic, epigenetic, and immunological targets of JAK inhibitors (JAKis), focusing on their effects on synovial fibroblasts (SFs), the major local effectors associated with destructive joint inflammation in rheumatoid arthritis (RA).

METHODS

SFs were activated by cytokines related to inflammation in RA, and were treated with three types of JAKis or a TNF-α inhibitor (TNFi). Dynamic changes in transcriptome and chromatin accessibility were profiled across samples to identify drug targets. Furthermore, the putative targets were validated using luciferase assays and clustered regularly interspaced short palindromic repeat (CRISPR)-based genome editing.

RESULTS

We found that both JAKis and the TNFi targeted the inflammatory module including IL6. Conversely, specific gene signatures that were preferentially inhibited by either of the drug classes were identified. Strikingly, RA risk enhancers for CD40 and TRAF1 were distinctively regulated by JAKis and the TNFi. We performed luciferase assays and CRISPR-based genome editing, and successfully fine-mapped the single causal variants in these loci, rs6074022-CD40 and rs7021049-TRAF1.

CONCLUSIONS

JAKis and the TNFi had a direct impact on different RA risk enhancers, and we identified nucleotide-resolution targets for both drugs. Distinctive targets of clinically effective drugs could be useful for tailoring the application of these drugs and future design of more efficient treatment strategies.

Covalent fragment-based drug discovery for target tractability

An important consideration in drug discovery is the prioritization of tractable protein targets that are not only amenable to binding small molecules, but also alter disease biology in response to small molecule binding. Covalent fragment-based drug discovery has emerged as a powerful approach to aid in the identification of such protein targets. The application of irreversible binding mechanisms enables the identification of fragment hits for challenging-to-target proteins, allows proteome-wide screening in a cellular context, and makes it possible to determine functional effects with modestly potent ligands without the requirement for extensive compound optimization. Here, we provide an overview of recent approaches to covalent fragment-based screening and discuss how these have been applied to establish the tractability of unexplored binding sites on protein targets.

Safety Profile of Upadacitinib up to 5 Years in Psoriatic Arthritis, Ankylosing Spondylitis, and Non-radiographic Axial Spondyloarthritis: An Integrated Analysis of Clinical Trials

INTRODUCTION

This integrated analysis of the phase 2/3 and phase 3 SELECT trials describes the safety profile of upadacitinib, an oral Janus kinase inhibitor, for up to 5 years of exposure across psoriatic arthritis (PsA), ankylosing spondylitis (AS), and non-radiographic axial spondyloarthritis (nr-axSpA) (including pooled axial spondyloarthritis [axSpA]).

METHODS

Safety data from five trials of upadacitinib in PsA (2 trials), AS (2 trials), and nr-axSpA (1 trial) were analyzed up to a data cut-off of August 15, 2022. One PsA study included adalimumab as an active comparator. Treatment-emergent adverse events (TEAEs) were summarized for PsA (pooled upadacitinib 15 mg once daily and adalimumab 40 mg biweekly), AS (pooled upadacitinib 15 mg), nr-axSpA (upadacitinib 15 mg), and pooled axSpA (pooled upadacitinib 15 mg from axSpA trials). TEAEs were reported as exposure-adjusted event rates per 100 patient-years (E/100 PY).

RESULTS

A total of 1789 patients (PsA, n = 907; AS, n = 596; nr-axSpA, n = 286) received ≥ 1 dose of upadacitinib 15 mg for 3689 PY of exposure or adalimumab (n = 429) for 1147 PY of exposure. Overall TEAEs and serious TEAEs were highest in PsA and numerically higher with upadacitinib versus adalimumab; rates were similar between AS and nr-axSpA. In PsA, higher rates of serious infection, herpes zoster (HZ), lymphopenia, and nonmelanoma skin cancer (NMSC) were observed with upadacitinib versus adalimumab. Rates of malignancy excluding NMSC, adjudicated major adverse cardiovascular events, and adjudicated venous thromboembolic events were comparable between upadacitinib and adalimumab in PsA and were similar across diseases.

CONCLUSION

Higher rates of serious infection, HZ, lymphopenia, and NMSC were observed with upadacitinib versus adalimumab in PsA; slightly elevated rates for most of these TEAEs were seen with upadacitinib in PsA versus axSpA. Upadacitinib 15 mg demonstrated a generally consistent safety profile across disease states with no new safety signals identified.

TRIAL REGISTRATION

SELECT-AXIS 1: NCT03178487; SELECT-AXIS 2: NCT04169373; SELECT-PsA 1: NCT03104400; SELECT-PsA 2: NCT03104374.

CXCR6+CD69+ CD8+ T cells in ascites are associated with disease severity in patients with cirrhosis

Background & Aims

Patients with advanced cirrhosis often develop hepatic decompensation, which is accompanied by systemic inflammation and may eventually lead to acute-on-chronic liver failure. One important cause of systemic hyperinflammation is a dysregulated overshooting immune response in ascites in the abdominal cavity. In this study, we analyzed the role of CD8+ T cells in the ascites immune compartment.

Methods

Peripheral blood and ascites fluid were collected from 50 patients with decompensated cirrhosis. Phenotype and functional responses of CD8+ T cells were analyzed, and obtained data were compared with each other as well as with healthy controls and patients with compensated cirrhosis.

Results

High-dimensional flow cytometry revealed that CD8+ T cells are abundant in the ascites of patients with cirrhosis and exhibit a chronically activated bystander phenotype with innate-like functions. Indeed, we identified distinct CXCR6+CD69+ clusters of late effector memory CD8+ T cells that were rarely found in blood and correlated with clinical parameters of disease severity. Moreover, this CD8+ T-cell population was hyperresponsive to innate cytokines and exhibited cytokine-mediated bystander activation. Interestingly, the Janus kinase (JAK) inhibitor tofacitinib was able to effectively block bystander-activated CXCR6+CD69+ CD8+ T cells and significantly suppress effector molecule production.

Conclusions

The results indicate that CXCR6+CD69+ CD8+ T cells in ascites are associated with disease severity and may contribute to inflammation in patients with decompensated cirrhosis, suggesting that targeted inhibition of this immune cell subset may be a viable therapeutic option.

Impact and Implications

Patients with advanced cirrhosis often develop hepatic decompensation, which is accompanied by systemic inflammation and eventually leads to acute-on-chronic liver failure. One important cause of systemic hyperinflammation is a dysregulated overshooting immune response in ascites in the abdominal cavity. In this study, we demonstrate that CXCR6+CD69+ CD8+ T cells are abundant in the ascites of patients with cirrhosis, exhibit a chronically activated bystander phenotype, and correlate with clinical parameters of disease severity. Moreover, we show that the Janus kinase (JAK) inhibitor tofacitinib can effectively block these bystander-activated CXCR6+CD69+ CD8+ T cells, suggesting that targeted inhibition of this immune cell subset may be a potential therapeutic strategy.

Clinical trial number

Prospective registry: INFEKTA (DRKS00010664).

Comprehensive insights into rheumatoid arthritis: Pathophysiology, current therapies and herbal alternatives for effective disease management

Rheumatoid arthritis is a chronic autoimmune inflammatory disease characterized by immune response overexpression, causing pain and swelling in the synovial joints. This condition is caused by auto-reactive antibodies that attack self-antigens due to their incapacity to distinguish between self and foreign molecules. Dysregulated activity within numerous signalling and immunological pathways supports the disease's development and progression, elevating its complexity. While current treatments provide some alleviation, their effectiveness is accompanied by a variety of adverse effects that are inherent in conventional medications. As a result, there is a deep-rooted necessity to investigate alternate therapeutic strategies capable of neutralizing these disadvantages. Medicinal herbs display a variety of potent bioactive phytochemicals that are effective in the complementary management of disease, thus generating an enormous potency for the researchers to delve deep into the development of novel phytomedicine against autoimmune diseases, although additional evidence and understanding are required in terms of their efficacy and pharmacodynamic mechanisms. This literature-based review highlights the dysregulation of immune tolerance in rheumatoid arthritis, analyses the pathophysiology, elucidates relevant signalling pathways involved, evaluates present and future therapy options and underscores the therapeutic attributes of a diverse array of medicinal herbs in addressing this severe disease.

Design and synthesis of highly selective Janus kinase 3 covalent inhibitors for the treatment of rheumatoid arthritis

Selective inhibition of Janus kinase 3 (JAK3) is a promising strategy for the treatment of autoimmune diseases. Based on the discovery of a hydrophobic pocket unutilized between the lead compound RB1 and the JAK3 protein, a series of covalent JAK3 inhibitors were prepared by introducing various aromatic fragments to RB1. Among them, J1b (JAK3 IC50 = 7.2 nM, other JAKs IC50 > 1000 nM) stood out because of its low toxicity (MTD > 2 g/kg) and superior anti-inflammatory activity in Institute of Cancer Research mice. Moreover, the acceptable bioavailability (F% = 31.69%) ensured that J1b displayed excellent immune regulation in collagen-induced arthritis mice, whose joints in the high-dose group were almost recovered to a normal state. Given its clear kinase selectivity (Bmx IC50 = 539.9 nM, other Cys909 kinases IC50 > 1000 nM), J1b was nominated as a highly selective JAK3 covalent inhibitor, which could be used to safely treat arthritis and other autoimmune diseases.

Leukemia inhibitory factor (LIF) receptor amplifies pathogenic activation of fibroblasts in lung fibrosis

Fibrosis drives end-organ damage in many diseases. However, clinical trials targeting individual upstream activators of fibroblasts, such as TGFβ, have largely failed. Here, we target the leukemia inhibitory factor receptor (LIFR) as a "master amplifier" of multiple upstream activators of lung fibroblasts. In idiopathic pulmonary fibrosis (IPF), the most common fibrotic lung disease, we found that lung myofibroblasts had high LIF expression. Further, TGFβ1, one of the key drivers of fibrosis, upregulated LIF expression in IPF fibroblasts. In vitro anti-LIFR antibody blocking on human IPF lung fibroblasts reduced induction of profibrotic genes downstream of TGFβ1, IL-4 and IL-13. Further, siRNA silencing of LIFR in IPF precision cut lung slices reduced expression of fibrotic proteins. Together, we find that LIFR drives an autocrine positive feedback loop that amplifies and sustains pathogenic activation of IPF fibroblasts downstream of multiple external stimuli, implicating LIFR as a therapeutic target in fibrosis.

Significance Statement

Fibroblasts have a central role in the pathogenesis of fibrotic diseases. However, due to in part to multiple profibrotic stimuli, targeting a single activator of fibroblasts, like TGFβ, has not yielded successful clinical treatments. We hypothesized that a more effective therapeutic strategy is identifying a downstream "master amplifier" of a range of upstream profibrotic stimuli. This study identifies the leukemia inhibitory factor receptor (LIFR) on fibrotic lung fibroblasts amplifies multiple profibrotic stimuli, such as IL-13 and TGFβ. Blocking LIFR reduced fibrosis in ex vivo lung tissue from patients with idiopathic pulmonary fibrosis (IPF). LIFR, acting as a master amplifier downstream of fibroblast activation, offers an alternative therapeutic strategy for fibrotic diseases.

VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic): clinical review in a rapidly emerging field

VEXAS syndrome is a recently described entity characterized by systemic inflammatory and hematologic manifestations. The disease was first characterized by Beck et al. in 2020 in a study characterizing 25 patients with undiagnosed adult-onset inflammatory syndromes. While the literature regarding VEXAS syndrome has grown exponentially since 2020, there is still much to be understood. This lack of information leads to challenges in both the diagnosis and treatment of patients with VEXAS syndrome. Patients will often have a variety of clinical symptoms that can lead to missed or delayed diagnoses. Additionally, awareness of VEXAS syndrome is still developing among clinicians. In this comprehensive review, we summarize the current literature regarding VEXAS syndrome, and explore clinical updates of this emerging disease state. Our aim of this review is to increase awareness regarding this new disease state and identify research areas to better understand future treatment approaches for patients with VEXAS syndrome.

Emerging biologic frontiers for Sjogren's syndrome: Unveiling novel approaches with emphasis on extra glandular pathology

Primary Sjögren's Syndrome (pSS) is a complex autoimmune disorder characterized by exocrine gland dysfunction, leading to dry eyes and mouth. Despite growing interest in biologic therapies for pSS, FDA approval has proven challenging due to trial complications. This review addresses the absence of a molecular-target-based approach to biologic therapy development and highlights novel research on drug targets and clinical trials. A literature search identified potential pSS treatment targets and recent advances in molecular understanding. Overlooking extraglandular symptoms like fatigue and depression is a notable gap in trials. Emerging biologic agents targeting cytokines, signal pathways, and immune responses have proven efficacy. These novel therapies could complement existing methods for symptom alleviation. Improved grading systems accounting for extraglandular symptoms are needed. The future of pSS treatment may involve gene, stem-cell, and tissue-engineering therapies. This narrative review offers insights into advancing pSS management through innovative biologic interventions.

What rheumatologists need to know about mRNA vaccines: current status and future of mRNA vaccines in autoimmune inflammatory rheumatic diseases

Messenger RNA (mRNA) vaccines as a novel vaccine platform offer new tools to effectively combat both emerging and existing pathogens which were previously not possible. The 'plug and play' feature of mRNA vaccines enables swift design and production of vaccines targeting complex antigens and rapid incorporation of new vaccine constituents as needed. This feature makes them likely to be adopted for widespread clinical use in the future.Currently approved mRNA vaccines include only those against SARS-CoV-2 virus. These vaccines demonstrate robust immunogenicity and offer substantial protection against severe disease. Numerous mRNA vaccines against viral pathogens are in the early to late phase of development. Several mRNA vaccines for influenza are tested in clinical trials, with some already in phase 3 studies. Other vaccines in the early and late phases of development include those targeting Cytomegalovirus, varicella zoster virus, respiratory syncytial virus and Epstein-Barr virus. Many of these vaccines will likely be indicated for immunosuppressed populations including those with autoimmune inflammatory rheumatic diseases (AIIRD). This review focuses on the mechanism, safety and efficacy of mRNA in general and summarises the status of mRNA vaccines in development for common infectious diseases of particular interest for patients with AIIRD.

Abelmoschus manihot (L.) medik. seeds alleviate rheumatoid arthritis by modulating JAK2/STAT3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Abelmoschus manihot (L.) Medik. Seeds (AMS, སོ་མ་ར་ཛ།), a Tibetan classical herbal in China, are rich in flavonoids and phenolic glycosides compounds, such as quercetin and its derivatives. Moreover, it has been found to possess anti-rheumatoid arthritis (RA) effects. Nonetheless, its anti-RA mechanism is yet unknown.

AIM OF THE STUDY

This research aimed to examine the active ingredients of AMS as well as potential pharmacological mechanisms in AMS on RA.

MATERIALS AND METHODS

The ultra-performance liquid chromatography-electrospray ionization-tandem multistage mass spectrometry (UPLC-ESI-IT-MSn) technique was used to determine the primary chemical components of AMS that were responsible for the therapeutic effects on RA. In addition, 36 male Wistar rats weighing between 200 and 220 g were classified at random into six groups [normal control group, collagen-induced arthritis (CIA) group, methotrexate group (positive control, 1.05 mg/kg), AMS group (157.5 mg/kg, 315 mg/kg, 630 mg/kg)]. CIA rats were given AMS extract by intragastric administration for 28 days, and their ankles were photographed to observe the degree of swelling. Further, the arthritis score, paws swelling, and body weight changes of CIA rats were determined to observe whether AMS has any effect on RA, and synovial and cartilage tissue injuries were identified by histopathology. Besides, the levels of IL-10, TNF-α, IL-1β, INF-γ, etc. in serum were estimated by ELISA. Western blot experiments were implemented to identify the expression levels of protein involved in the JAK2/STAT3 signaling pathway in the CIA rats' synovial tissues. Moreover, the mechanisms and targets of active ingredient therapy of AMS for RA were predicted using network pharmacology and then verified using molecular docking.

RESULT

In the present study, 12 compounds were detected by UPLC-ESI-IT-MSn, such as quercetin and its derivative which could be potential active ingredients that contribute to the anti-RA properties of AMS. Our in vivo studies on CIA rats revealed that an AMS-H dose of 630 mg/kg significantly improved joint damage while decreasing the arthritic index and paw swelling. Furthermore, AMS inhibited the INF-γ, IL-6, IL-17, IL-1β, and TNF-α, levels while upregulating the expression of anti-inflammatory cytokines IL-10 and IL-4 in serum. Besides, AMS inhibited the protein Bcl-2/Bax, STAT3, and JAK2 levels, and promoted the expression of Caspase3, SOCS1, and SOCS3 in the JAK2/STAT3 pathway. Additionally, the JAK/STAT signaling pathway was found to perform a remarkable function in the AMS therapy of RA as evidenced by enrichment in GO terms and KEGG pathways. Meanwhile, data from molecular docking experiments indicated that the core targets of PIK3CA, JAK2, and SRC bound stably to the active ingredients of mimuone, 4'-methoxy-bavachromanol, and quercetin.

CONCLUSION

According to these findings, the AMS could improve joint inflammation in CIA rats, and its underlying mechanism could be linked to the regulation of the JAK2/STAT3 pathway. Therefore, AMS might become a promising agent for alleviating inflammation in RA patients.

The immunopathogenesis of sarcoidosis

Sarcoidosis is a granulomatous multiorgan disease, thought to result from exposure to yet unidentified antigens in genetically susceptible individuals. The exaggerated inflammatory response that leads to granuloma formation is highly complex and involves the innate and adaptive immune system. Consecutive immunological studies using advanced technology have increased our understanding of aberrantly activated immune cells, mediators and pathways that influence the formation, maintenance and resolution of granulomas. Over the years, it has become increasingly clear that disease immunopathogenesis can only be understood if the clinical heterogeneity of sarcoidosis is taken into consideration, along with the distribution of immune cells in peripheral blood and involved organs. Most studies offer an immunological snapshot during disease course, while the cellular composition of both the circulation and tissue microenvironment may change over time. Despite these challenges, novel insights on the role of the immune system are continuously published, thus bringing the field forward. This review highlights current knowledge on the innate and adaptive immune responses involved in sarcoidosis pathogenesis, as well as the pathways involved in non-resolving disease and fibrosis development. Additionally, we describe proposed immunological mechanisms responsible for drug-induced sarcoid like reactions. Although many aspects of disease immunopathogenesis remain to be unraveled, the identification of crucial immune reactions in sarcoidosis may help identify new treatment targets. We therefore also discuss potential therapies and future strategies based on the latest immunological findings.

Cardiovascular Risk Management in Patients Treated With Janus Kinase Inhibitors

ABSTRACT

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

Upadacitinib for the treatment of adult patients with active psoriatic arthritis

INTRODUCTION

Psoriatic arthritis (PsA) is a rheumatic disorder that may be responsible for relevant articular impairment. The recently licensed Janus Kinase (JaK) inhibitors represent a new opportunity to improve PsA treatment. This review deals with the clinical usefulness of the selective JaK-1 inhibitor upadacitinib (UPA) in patients with PsA.

COVERED AREAS

Two phase-III studies are available: SELECT-PsA 1, performed in patients with an inadequate response to non-biological therapies, and SELECT-PsA 2, conducted in biologic-experienced patients. Long-term extension results and post-hoc analysis data of these two trials are also available.

EXPERT OPINION

The results provided by the trials indicate that UPA may be used to treat all of the clinical manifestations of PsA. Venous thromboembolism, cardiovascular events, and malignancy, the most feared adverse events associated with JaK inhibitor use, were not increased in the trial populations, yet long-term observational studies are needed to make sure that UPA is safe in this respect.

Heterogeneity of macrophage activation syndrome and treatment progression

Macrophage activation syndrome (MAS) is a rare complication of autoimmune inflammatory rheumatic diseases (AIIRD) characterized by a progressive and life-threatening condition with features including cytokine storm and hemophagocytosis. Predisposing factors are typically associated with microbial infections, genetic factors (distinct from typical genetically related hemophagocytic lymphohistiocytosis (HLH)), and inappropriate immune system overactivation. Clinical features include unremitting fever, generalized rash, hepatosplenomegaly, lymphadenopathy, anemia, worsening liver function, and neurological involvement. MAS can occur in various AIIRDs, including but not limited to systemic juvenile idiopathic arthritis (sJIA), adult-onset Still's disease (AOSD), systemic lupus erythematosus (SLE), Kawasaki disease (KD), juvenile dermatomyositis (JDM), rheumatoid arthritis (RA), and Sjögren's syndrome (SS), etc. Although progress has been made in understanding the pathogenesis and treatment of MAS, it is important to recognize the differences between different diseases and the various treatment options available. This article summarizes the cell types and cytokines involved in MAS-related diseases, the heterogeneity, and treatment options, while also comparing it to genetically related HLH.

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

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

Drug survival and change of disease activity using a second janus kinase inhibitor in patients with difficult-to-treat rheumatoid arthritis who failed to a janus kinase inhibitor and subsequent biologics

BACKGROUND

To assess the drug survival and change of disease activity using a second Janus kinase inhibitor (JAKi) after failure to a JAKi and subsequent biologic disease-modifying anti-rheumatic drugs (bDMARDs) in patients with difficult-to-treat rheumatoid arthritis (RA).

METHODS

This retrospective cohort study included 32 patients with difficult-to-treat RA who failed to a JAKi and subsequently to one or more bDMARDs and then switched to a second JAKi. To assess drug survival, electronic medical records of each patient were reviewed. Data on whether the second JAKi was discontinued, and the reasons for discontinuation were collected. The change of disease activity was assessed by analyzing changes in tender joint count (TJC), swollen joint count (SJC), patient's global assessment of disease activity on a visual-analogue scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Disease Activity Score for 28 joints with ESR (DAS28-ESR), and DAS28-CRP from baseline to that at six months from initiation of the second JAKi.

RESULTS

Overall, discontinuation of the second JAKi occurred in 20 (62.5%) patients. Primary failure, secondary failure, adverse events, and insurance coverage issues were the reasons for discontinuation in 9 (45.0%), 5 (25.0%), 2 (10.0%), and 4 (20.0%) patients, respectively. The estimated 2-year drug survival rate was 39.3%. In terms of change of disease activity, the second JAKi significantly improved TJC (p < 0.001), SJC (p < 0.001), VAS (p < 0.001), CRP (p = 0.026), DAS28-ESR (p < 0.001), and DAS28-CRP (p < 0.001) at 6-month compared with that at the baseline.

CONCLUSIONS

Second JAKi could be a therapeutic option in patients with difficult-to-treat RA who have failed to a JAKi and subsequent bDMARDs.

Janus kinase inhibitors and tumour necrosis factor inhibitors show a favourable safety profile and similar persistence in rheumatoid arthritis, psoriatic arthritis and spondyloarthritis: real-world data from the BIOBADASER registry

OBJECTIVES

To compare the safety of Janus kinase inhibitors (JAKi) with that of tumour necrosis factor inhibitors (TNFi) and determine drug persistence among patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA).

METHODS

We analysed data from patients included in BIOBADASER 3.0 and treated with JAKi or TNFi from 2015 to 2023 and estimated the incidence rate ratio (IRR) of adverse events and persistence.

RESULTS

A total of 6826 patients were included. Of these, 52% had RA, 25% psoriatic arthritis and 23% axial SpA. Treatment was with TNFi in 86%. The mean duration of treatment was 2.2±2.0 years with TNFi versus 1.8±1.5 with JAKi. JAKis were prescribed in older patients with longer term disease, greater comorbidity and later treatment lines and more frequently as monotherapy. The IRR of all infections and gastrointestinal events was higher among patients with RA treated with JAKi. Drug persistence at 1, 2 and 3 years was 69%, 55% and 45% for TNFi and 68%, 54% and 45% for JAKi. Multivariate regression models showed a lower probability of discontinuation for JAKi (HR=0.85; 95% CI 0.78-0.92) and concomitant conventional synthetic disease-modifying antirheumatic drugs (HR=0.90; 95% CI 0.84-0.96). The risk of discontinuation increased with glucocorticoids, comorbidities, greater disease activity and later treatment lines.

CONCLUSIONS

Infections, herpes zoster and gastrointestinal adverse events in patients with RA tended to be more frequent with JAKi. However, prognosis was poor in patients receiving JAKi. Persistence was similar for TNFi and JAKi, although factors associated with discontinuation differed by diagnostic group.

Discovery of the First-in-Class Inhibitors of Hypoxia Up-Regulated Protein 1 (HYOU1) Suppressing Pathogenic Fibroblast Activation

Fibroblasts are key regulators of inflammation, fibrosis, and cancer. Targeting their activation in these complex diseases has emerged as a novel strategy to restore tissue homeostasis. Here, we present a multidisciplinary lead discovery approach to identify and optimize small molecule inhibitors of pathogenic fibroblast activation. The study encompasses medicinal chemistry, molecular phenotyping assays, chemoproteomics, bulk RNA-sequencing analysis, target validation experiments, and chemical absorption, distribution, metabolism, excretion and toxicity (ADMET)/pharmacokinetic (PK)/in vivo evaluation. The parallel synthesis employed for the production of the new benzamide derivatives enabled us to a) pinpoint key structural elements of the scaffold that provide potent fibroblast-deactivating effects in cells, b) discriminate atoms or groups that favor or disfavor a desirable ADMET profile, and c) identify metabolic "hot spots". Furthermore, we report the discovery of the first-in-class inhibitor leads for hypoxia up-regulated protein 1 (HYOU1), a member of the heat shock protein 70 (HSP70) family often associated with cellular stress responses, particularly under hypoxic conditions. Targeting HYOU1 may therefore represent a potentially novel strategy to modulate fibroblast activation and treat chronic inflammatory and fibrotic disorders.

Rare SH2B3 coding variants in lupus patients impair B cell tolerance and predispose to autoimmunity

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease with a clear genetic component. While most SLE patients carry rare gene variants in lupus risk genes, little is known about their contribution to disease pathogenesis. Amongst them, SH2B3-a negative regulator of cytokine and growth factor receptor signaling-harbors rare coding variants in over 5% of SLE patients. Here, we show that unlike the variant found exclusively in healthy controls, SH2B3 rare variants found in lupus patients are predominantly hypomorphic alleles, failing to suppress IFNGR signaling via JAK2-STAT1. The generation of two mouse lines carrying patients' variants revealed that SH2B3 is important in limiting the number of immature and transitional B cells. Furthermore, hypomorphic SH2B3 was shown to impair the negative selection of immature/transitional self-reactive B cells and accelerate autoimmunity in sensitized mice, at least in part due to increased IL-4R signaling and BAFF-R expression. This work identifies a previously unappreciated role for SH2B3 in human B cell tolerance and lupus risk.

Emerging therapeutic targets in systemic sclerosis

Systemic sclerosis is an autoimmune connective tissue disease which is characterised by vascular perturbations, inflammation, and fibrosis. Although huge progress recently into the underlying molecular pathways that are perturbed in the disease, currently no therapy exists that targets the fibrosis element of the disease and consequently there is a huge unmet medical need. Emerging studies reveal new dimensions of complexity, and multiple aberrant pathways have been uncovered that have shed light on disturbed signalling in the disease, primarily in inflammatory pathways that can be targeted with repurposed drugs. Pre-clinical animal models using these inhibitors have yielded proof of concept for targeting these signalling systems and progressing to clinical trials. This review will examine the recent evidence of new perturbed pathways in SSc and how these can be targeted with new or repurposed drugs to target a currently intractable disease.

Post hoc analysis of patients with rheumatoid arthritis under clinical remission in two Japanese Phase 3 trials of peficitinib treatment (RAJ3 and RAJ4)

OBJECTIVE

We evaluated remission rates and their relationship with baseline characteristics in patients with rheumatoid arthritis treated with the oral Janus kinase inhibitor peficitinib.

METHODS

This post hoc analysis of data from two Phase 3 studies (RAJ3 and RAJ4) of peficitinib (100 and 150 mg/day) in Asian rheumatoid arthritis patients investigated clinical disease activity index (CDAI) remission and low disease activity rates from baseline to Week 52. CDAI, Health Assessment Questionnaire-Disability Index, and van der Heijde-modified total Sharp score remission/low disease activity rates at Week 52 were evaluated among patients achieving CDAI remission at Weeks 12/28. Logistic regression analyses explored the relationship between baseline characteristics and CDAI remission/low disease activity rates.

RESULTS

CDAI remission rates increased over time in a dose-dependent manner in both peficitinib-treated groups. Most patients achieving CDAI remission at Weeks 12/28 also achieved remission at Week 52. Following the multivariate analysis of demographic and baseline characteristics, factors associated with the achievement of CDAI remission at Week 28 included male sex, low baseline prednisone dose (RAJ3 only), and low baseline Disease Activity Score 28-C-reactive protein (RAJ4 only).

CONCLUSIONS

Peficitinib demonstrated persistent efficacy in clinical remission to Week 52. Baseline characteristics associated with CDAI remission were mostly consistent with previous studies using other disease-modifying antirheumatic drugs.

Macrophage re-programming by JAK inhibitors relies on MAFB

Monocyte-derived macrophages play a key pathogenic role in inflammatory diseases. In the case of rheumatoid arthritis (RA), the presence of specific synovial tissue-infiltrating macrophage subsets is associated with either active disease or inflammation resolution. JAK inhibitors (JAKi) are the first targeted synthetic disease-modifying antirheumatic drugs (tsDMARD) approved for treatment of RA with comparable efficacy to biologics. However, the effects of JAKi on macrophage specification and differentiation are currently unknown. We have analyzed the transcriptional and functional effects of JAKi on human peripheral blood monocyte subsets from RA patients and on the differentiation of monocyte-derived macrophages promoted by granulocyte-macrophage colony-stimulating factor (GM-CSF), a factor that drives the development and pathogenesis of RA. We now report that JAKi Upadacitinib restores the balance of peripheral blood monocyte subsets in RA patients and skewed macrophages towards the acquisition of an anti-inflammatory transcriptional and functional profile in a dose-dependent manner. Upadacitinib-treated macrophages showed a strong positive enrichment of the genes that define synovial macrophages associated to homeostasis/inflammation resolution. Specifically, Upadacitinib-treated macrophages exhibited significantly elevated expression of MAFB and MAFB-regulated genes, elevated inhibitory phosphorylation of GSK3β, and higher phagocytic activity and showed an anti-inflammatory cytokine profile upon activation by pathogenic stimuli. These outcomes were also shared by macrophages exposed to other JAKi (baricitinib, tofacitinib), but not in the presence of the TYK2 inhibitor deucravacitinib. As a whole, our results indicate that JAKi promote macrophage re-programming towards the acquisition of a more anti-inflammatory/pro-resolution profile, an effect that correlates with the ability of JAKi to enhance MAFB expression.

Baricitinib for refractory Takayasu arteritis: a prospective cohort study in a tertiary referral centre

OBJECTIVE

To investigate the treatment efficacy and safety of baricitinib in patients with refractory Takayasu arteritis (TAK).

METHODS

We performed a prospective cohort study in which baricitinib 4 mg daily was prescribed to patients with refractory TAK, combined with oral glucocorticoids (GCs).

RESULTS

10 patients with refractory TAK were enrolled with a median age of 28 (IQR=22-37) years, median disease duration of 50 (IQR=24-65) months. The median dose of GCs was 10 (IQR=8.1-22.5) mg prednisone or equivalence dosage at baseline. At 6 months of baricitinib treatment, 6/10 (60%) patients had an overall treatment response. During an average follow-up of 15.3 (range 4-31) months, 4/10 (40%) patients maintained overall treatment response. 8/10 (80%) patients tapered or maintained the same dose of GCs with no change of the combined classical synthetic disease-modifying antirheumatic drugs. Two patients discontinued GCs at 18 and 24 months and were in continuous remission till the end of the study. One patient withdrew baricitinib due to liver dysfunction.

CONCLUSION

Baricitinib 4 mg daily is effective for refractory TAK and is well tolerated.

Abideen M, Monopoli KR, Blanchard C, Bouix-Peter C, Portal T, Harris JE, Khvorova A, Alterman JF. Multispecies-targeting siRNAs for the modulation of JAK1 in the skin

Identifying therapeutic oligonucleotides that are cross-reactive to experimental animal species can dramatically accelerate the process of preclinical development and clinical translation. Here, we identify fully chemically-modified small interfering RNAs (siRNAs) that are cross-reactive to Janus kinase 1 (JAK1) in humans and a large variety of other species. We validated the identified siRNAs in silencing JAK1 in cell lines and skin tissues of multiple species. JAK1 is one of the four members of the JAK family of tyrosine kinases that mediate the signaling transduction of many inflammatory cytokine pathways. Dysregulation of these pathways is often involved in the pathogenesis of various immune disorders, and modulation of JAK family enzymes is an effective strategy in the clinic. Thus, this work may open up unprecedented opportunities for evaluating the modulation of JAK1 in many animal models of human inflammatory skin diseases. Further chemical engineering of the optimized JAK1 siRNAs may expand the utility of these compounds for treating immune disorders in additional tissues.

The complex relationship between large granular lymphocyte leukemia and rheumatic disease

INTRODUCTION

Large granular lymphocytic (LGL) leukemia is a rare lymphoproliferative disorder characterized by an expansion of clonal T or NK lymphocytes. Neutropenia-related infections represent the main clinical manifestation. Even if the disease follows an indolent course, most patients will ultimately need treatment in their lifetime. Interestingly, LGL leukemia is characterized by a high frequency of autoimmune disorders with rheumatoid arthritis being the most frequent.

AREAS COVERED

This review covers the pathophysiology, clinic-biological features and the advances made in the treatment of LGL leukemia. A special focus will be made on the similarities in the pathophysiology of LGL leukemia and the frequently associated rheumatic disorders.

EXPERT OPINION

Recent advances in the phenotypic and molecular characterization of LGL clones have uncovered the key role of JAK-STAT signaling in the pathophysiology linking leukemic cells expansion and autoimmunity. The description of the molecular landscape of T- and NK-LGL leukemia and the improved understanding of the associated rheumatic disorders open the way to the development of new targeted therapies effective on both conditions.

Emerging Roles of Macrophage Polarization in Osteoarthritis: Mechanisms and Therapeutic Strategies

Osteoarthritis (OA) is the most common chronic degenerative joint disease in middle-aged and elderly people, characterized by joint pain and dysfunction. Macrophages are key players in OA pathology, and their activation state has been studied extensively. Various studies have suggested that macrophages might respond to stimuli in their microenvironment by changing their phenotypes to pro-inflammatory or anti-inflammatory phenotypes, which is called macrophage polarization. Macrophages accumulate and become polarized (M1 or M2) in many tissues, such as synovium, adipose tissue, bone marrow, and bone mesenchymal tissues in joints, while resident macrophages as well as other stromal cells, including fibroblasts, chondrocytes, and osteoblasts, form the joint and function as an integrated unit. In this study, we focus exclusively on synovial macrophages, adipose tissue macrophages, and osteoclasts, to investigate their roles in the development of OA. We review recent key findings related to macrophage polarization and OA, including pathogenesis, molecular pathways, and therapeutics. We summarize several signaling pathways in macrophage reprogramming related to OA, including NF-κB, MAPK, TGF-β, JAK/STAT, PI3K/Akt/mTOR, and NLRP3. Of note, despite the increasing availability of treatments for osteoarthritis, like intra-articular injections, surgery, and cellular therapy, the demand for more effective clinical therapies has remained steady. Therefore, we also describe the current prospective therapeutic methods that deem macrophage polarization to be a therapeutic target, including physical stimulus, chemical compounds, and biological molecules, to enhance cartilage repair and alleviate the progression of OA.

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

Importance

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

Objective

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

Data Sources

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

Study Selection

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

Data Extraction and Synthesis

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Rheumatoid arthritis: pathogenesis and therapeutic advances

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the unresolved synovial inflammation for tissues-destructive consequence, which remains one of significant causes of disability and labor loss, affecting about 0.2-1% global population. Although treatments with disease-modifying antirheumatic drugs (DMARDs) are effective to control inflammation and decrease bone destruction, the overall remission rates of RA still stay at a low level. Therefore, uncovering the pathogenesis of RA and expediting clinical transformation are imminently in need. Here, we summarize the immunological basis, inflammatory pathways, genetic and epigenetic alterations, and metabolic disorders in RA, with highlights on the abnormality of immune cells atlas, epigenetics, and immunometabolism. Besides an overview of first-line medications including conventional DMARDs, biologics, and small molecule agents, we discuss in depth promising targeted therapies under clinical or preclinical trials, especially epigenetic and metabolic regulators. Additionally, prospects on precision medicine based on synovial biopsy or RNA-sequencing and cell therapies of mesenchymal stem cells or chimeric antigen receptor T-cell are also looked forward. The advancements of pathogenesis and innovations of therapies in RA accelerates the progress of RA treatments.

The Effect of JAK Inhibitors on Patient-Reported Outcomes in Psoriatic Arthritis

Objective

Psoriatic arthritis (PsA) is a chronic inflammatory disease that affects the joints and skin of patients with psoriasis. In this review we aimed to summarise the available evidence regarding the effect of Janus kinase inhibitors (JAKi) on patient-reported outcomes (PROs) when used for the management of PsA.

Methods

We utilised a narrative review approach as we searched the available literature for articles to be included in our study.

Results

JAKi have been found to be effective in inducing better PRO responses compared to placebo. These findings have been consistent across various patient populations, including those with active PsA, those with an inadequate response to conventional therapies, and those with comorbidities. The evidence supporting the benefits of JAKi on PROs in PsA is compelling, demonstrating consistent improvements in pain, physical function, fatigue, and quality of life.

Conclusion

Numerous studies have demonstrated the the efficacy of JAKi in improving PROs in patients with PsA.

Comorbidity Between Inflammatory Bowel Disease and Asthma and Allergic Diseases: A Genetically Informed Study

BACKGROUND

Little is known about shared origins between inflammatory bowel disease (IBD) and allergic diseases (asthma, allergic rhinitis, and eczema). We aimed to expand current knowledge on the etiological sources of comorbidities between these disorders using a range of genetically informed methods.

METHODS

Within-individual and familial co-aggregation analysis was applied to 2 873 445 individuals born in Sweden from 1987 to 2014 and their first- and second-degree relatives. Quantitative genetic modeling was applied to 38 723 twin pairs to decompose the genetic and environmental sources for comorbidity. Polygenic risk score analysis between IBD and allergic diseases was conducted in 48 186 genotyped twins, and linkage disequilibrium score regression was applied using publicly available data to explore the genetic overlap.

RESULTS

IBD was associated with asthma (adjusted odds ratio [aOR], 1.35; 95% confidence interval [CI], 1.30 to 1.40), allergic rhinitis (aOR, 1.27; 95% CI, 1.20 to 1.34), and eczema (aOR, 1.47; 95% CI, 1.38 to 1.56), with similar estimates for ulcerative colitis or Crohn's disease. The ORs for familial co-aggregation decreased with decreasing genetic relatedness. Quantitative genetic modeling revealed little evidence of common genetic factors between IBD and allergic diseases (eg, IBD and allergic rhinitis; genetic correlation ra = 0.06; 95% CI, -0.03 to 0.15) but did reveal some evidence of unique environmental factors between IBD and eczema (re = 0.16; 95% CI, 0.00 to 0.32). Molecular genetic analyses were similarly null for IBD and allergic diseases, except for a slight association between Crohn's disease polygenic risk score and eczema (OR, 1.09; 95% CI, 1.06 to 1.12).

CONCLUSIONS

We found little evidence to support a shared origin between IBD and any allergic disease but weak evidence for shared genetic and unique environmental components for IBD and eczema.

Periplogenin inhibits pathologic synovial proliferation and infiltration in rheumatoid arthritis by regulating the JAK2/3-STAT3 pathway

Rheumatoid arthritis (RA) is an autoimmune disease that affects joints, causing inflammation, synovitis, and erosion of cartilage and bone. Periplogenin is an active ingredient in the anti-rheumatic and anti-inflammatory herb, cortex periplocae. We conducted a study using a CIA model and an in vitro model of fibroblast-like synoviocytes (FLS) induced by Tumor Necrosis Factor-alpha (TNF-α) stimulation. We evaluated cell activity, proliferation, and migration using the CCK8 test, EDU kit, and transwell assays, as well as network pharmacokinetic analysis of periplogenin targets and RA-related effects. Furthermore, we measured inflammatory factors and matrix metalloproteinases (MMPs) expression using ELISA and qRT-PCR assays. We also evaluated joint destruction using HE and Safranin O-Fast Green Staining and examined the changes in the JAK2/3-STAT3 pathway using western blot. The results indicated that periplogenin can effectively inhibit the secretion of inflammatory factors, suppress the JAK2/3-STAT3 pathway, and impede the proliferation and migration of RA FLS. Thus, periplogenin alleviated the Synovial inflammatory infiltration of RA.

Current and emerging pharmacotherapies for cytokine release syndrome, neurotoxicity, and hemophagocytic lymphohistiocytosis-like syndrome due to CAR T cell therapy

INTRODUCTION

Chimeric antigen receptor (CAR) T cells have revolutionized the treatment of multiple hematologic malignancies. Engineered cellular therapies now offer similar hope to transform the management of solid tumors and autoimmune diseases. However, toxicities can be serious and often require hospitalization.

AREAS COVERED

We review the two chief toxicities of CAR T therapy, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), and the rarer immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome. We discuss treatment paradigms and promising future pharmacologic strategies. Literature and therapies reviewed were identified by PubMed search, cited references therein, and review of registered trials.

EXPERT OPINION

Management of CRS and ICANS has improved, aided by consensus definitions and guidelines that facilitate recognition and timely intervention. Further data will define optimal timing of tocilizumab and corticosteroids, current foundations of management. Pathophysiologic understanding has inspired off-label use of IL-1 receptor antagonism, IFNγ and IL-6 neutralizing antibodies, and janus kinase inhibitors, with data emerging from ongoing clinical trials. Further strategies to reduce toxicities include novel pharmacologic targets and safety features engineered into CAR T cells themselves. As these potentially curative therapies are used earlier in oncologic therapy and even in non-oncologic indications, effective accessible strategies to manage toxicities are critical.

Upadacitinib for the treatment of adults with active non-radiographic axial spondyloarthritis (nr-axSpA)

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) is a chronic inflammatory condition with axial and peripheral musculoskeletal involvement, fulfilling criteria of axSpA in the absence of advanced radiographic sacroiliitis. While appropriate treatment is required for chronic pain and disability resulting from disease progression, the limited availability of treatment options becomes evident. Upadacitinib, an oral selective Janus kinase 1 inhibitor, was approved in Europe, the United States, and other countries for management of nr-axSpA with inadequate response to existing therapies.

AREA COVERED

This review summarizes essential drug profiles, efficacy, and safety of upadacitinib for nr-axSpA in conjunction with data pertaining to radiographic axSpA.

EXPERT OPINION

In a phase 3 trial, upadacitinib exhibited efficacy for patients with nr-axSpA, irrespective of prior exposures to biological disease-modifying antirheumatic drugs (bDMARDs). The safety profiles of upadacitinib in nr-axSpA mirrored those in other indications, underscoring its potential as a promising treatment option for nr-axSpA. Concurrently, physicians should be aware of the absence of real-world data, longitudinal efficacy and safety, direct comparative studies between upadacitinib and bDMARDs in nr-axSpA, and evidence for precision medicine to identify patients who may optimally benefit from upadacitinib over bDMARDs. Future research is imperative to facilitate the effective utilization of upadacitinib in daily clinical practice.

Varicella-Zoster Meningitis and Myelitis After Herpes Zoster Dermatitis Treatment With Amenamevir: A Case Series and Literature Review

Varicella-zoster virus (VZV), known for causing chickenpox, establishes latent infections in neural tissues. Reactivation of VZV can lead to herpes zoster (HZ) and various neurological complications. In this report, we present four cases of VZV meningitis and myelitis following amenamevir treatment for HZ dermatitis with positive VZV DNA in cerebrospinal fluid (CSF) revealed by polymerase chain reaction (PCR). Three of them were considered immunocompromised hosts given the fact that two of these patients were taking immunosuppressive drugs for rheumatoid arthritis, and one patient had a history of sigmoid colon cancer (four months after resection). After HZ onset, amenamevir, which has poor CSF transfer, was prescribed for all the patients, and all of them developed central nervous complications by VZV (meningitis in three cases and myelitis in one case) confirmed by PCR. All the patients were treated with acyclovir, which has a higher CSF transfer, and fully recovered. We speculate that amenamevir might have failed to prevent VZV infection in the central nervous system (CNS) and think that consideration should be given to administering acyclovir in preference to amenamevir for ΗΖ patients at high risk of CNS VZV infection, such as immunocompromised hosts.