Upadacitinib for the treatment of rheumatoid arthritis

Structural optimizations on the 7H-pyrrolo[2,3-d]pyrimidine scaffold to develop highly selective, safe and potent JAK3 inhibitors for the treatment of Rheumatoid arthritis

Janus Kinase 3 (JAK3) is important for the signaling transduction of cytokines in immune cells and is identified as potential target for treatment of rheumatoid arthritis (RA). Recently, we designed and synthesized two JAK3 inhibitors J1b and J1f, which featured with high selectivity but mild bioactivity. Therefore, in present study the structure was optimized to increase the potency. As shown in the results, most of the compounds synthesized showed stronger inhibitory activities against JAK3 in contrast to the lead compounds, among which 9a was the most promising candidate because it had the most potent effect in ameliorating carrageenan-induced inflammation of mice and exhibited low acute in vivo toxicity (MTD > 2 g/kg). Further analysis revealed that 9a was highly selective to JAK3 (IC50 = 0.29 nM) with only minimal effect on other JAK members (>3300-fold) and those kinases bearing a thiol in a position analogous to that of Cys909 in JAK3 (>150-fold). Meanwhile, the selectivity of JAK3 was also confirmed by PBMC stimulation assay, in which 9a irreversibly bound to JAK3 and robustly inhibited the signaling transduction with mild suppression on other JAKs. Moreover, it was showed that 9a could remarkably inhibited the proliferation of lymphocytes in response to concanavalin A and significantly mitigate disease severity in collagen induced arthritis. Therefore, present data indicate that compound 9a is a selective JAK3 inhibitor and could be a promising candidate for clinical treatment of RA.

Treatment of rosacea with upadacitinib and abrocitinib: case report and review of evidence for Janus kinase inhibition in rosacea

Introduction

Conventional rosacea treatments are not uniformly pervasive, and the adverse reactions can potentially constrain their utility. The clinical use of JAK1 inhibitors upadacitinib and abrocitinib in the treatment of refractory rosacea has rarely been explored.

Case report

We presented two cases of patients who received the JAK1 inhibitor upadacitinib and four cases of patients who received the JAK1 inhibitor abrocitinib for the treatment of refractory rosacea.

Discussion

The JAK1 inhibitors upadacitinib and abrocitinib may be promising medical options for patients with refractory rosacea. However, the long-term safety and efficacy of upadacitinib and abrocitinib require prospective controlled studies to assess them more comprehensively.

Systematic Review with Meta-analysis: Efficacy and Safety of Upadacitinib in Managing Moderate-to-Severe Crohn's Disease and Ulcerative Colitis

BACKGROUND

In the panorama of therapeutic strategies for inflammatory bowel diseases, oral upadacitinib stands out for its potential to improve short-term and long-term patient outcomes.

OBJECTIVE

This meta-analysis aspires to collate and assess the available evidence regarding the efficacy and safety of upadacitinib in managing moderate-to-severe Crohn's disease and ulcerative colitis.

METHODS

A meta-analysis was conducted using studies sourced from MEDLINE/PubMed, Cochrane Library, Scopus, and Embase, published from January 2010 to March 2024. Peer-reviewed articles that reported data on the effects of upadacitinib in adult patients with Crohn's disease and ulcerative colitis were included based on established inclusion and exclusion criteria.

RESULTS

Eight studies, encompassing a total of 2818 patients treated with upadacitinib, were included. In primary outcomes, for patients with Crohn's disease who were using upadacitinib, the weighted pooled clinical remission rate was found to be 45.8% (95% confidence interval [CI] 0.39-0.52), while for patients with ulcerative colitis who were using upadacitinib, the rate was 25.4% (95% CI 0.17-0.36). The pooled clinical response rate for Crohn's disease was 53.6% (95% CI 0.50-0.57), and for ulcerative colitis it was 72.6% (95% CI 0.69-0.76). The pooled serious adverse event rate was 6.0% (95% CI 0.07-0.09).

CONCLUSIONS

Upadacitinib demonstrates significant efficacy in achieving clinical remission and response in patients with moderate-to-severe Crohn's disease and ulcerative colitis, as shown by clinical remission rates of 44.9% and 36.0%, respectively. The treatment also maintains a favorable safety profile with a serious adverse event rate of 7.8%, making it an effective option for those resistant or intolerant to traditional immunosuppressants or tumor necrosis factor antagonists.

FDA-Approved Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) Inhibitors for Managing Rheumatoid Arthritis: A Narrative Review of the Literature

Rheumatoid arthritis (RA) is a complex autoimmune disease causing chronic joint inflammation and, in more serious cases, organ involvement. RA typically affects people between the ages of 35 and 60; however, it can also afflict children younger than the age of 16 years and can also demonstrate a pattern of remission later in the disease course. Non-steroidal anti-inflammatory drugs, glucocorticoids, exercise, and patient education are all used in the management of RA, which is divided into symptomatic management and disease-modifying management (disease-modifying antirheumatic drugs) to reduce pain and inflammation, thereby preserving joint function. Janus kinase inhibitors (JAKis) have led to a substantial improvement in the management of RA. By specifically targeting the JAK-signal transducer and activator of transcription pathway, which is essential for immunological modulation, these inhibitors also demonstrate promise in treating various autoimmune illnesses, including inflammatory bowel diseases, giant cell arteritis, ankylosing spondylitis, and psoriatic arthritis. Tofacitinib, baricitinib, upadacitinib, peficitinib, delgocitinib, and filgotinib are examples of FDA-approved JAKis that have distinct properties and indications for treating a range of autoimmune illnesses. JAKis demonstrate a promising treatment approach for managing RA and other autoimmune diseases while enhancing patient outcomes and quality of life. However, due to major safety concerns and the need for long-term success, meticulous patient monitoring is essential.

Effect of P. corylifolia on the pharmacokinetic profile of tofacitinib and the underlying mechanism

This work aimed to explore the mechanisms underlying the interaction of the active furanocoumarins in P. corylifolia on tofacitinib both in vivo and in vitro. The concentration of tofacitinib and its metabolite M8 was determined using UPLC-MS/MS. The peak area ratio of M8 to tofacitinib was calculated to compare the inhibitory ability of furanocoumarin contained in the traditional Chinese medicine P. corylifolia in rat liver microsomes (RLMs), human liver microsomes (HLMs) and recombinant human CYP3A4 (rCYP3A4). We found that bergapten and isopsoralen exhibited more significant inhibitory activity in RLMs than other furanocoumarins. Bergapten and isopsoralen were selected to investigate tofacitinib drug interactions in vitro and in vivo. Thirty rats were randomly allocated into 5 groups (n = 6): control (0.5% CMC-Na), low-dose bergapten (20 mg/kg), high-dose bergapten (50 mg/kg), low-dose isopsoralen (20 mg/kg) and ketoconazole. 10 mg/kg of tofacitinib was orally intervented to each rat and the concentration level of tofacitinib in the rats were determined by UPLC-MS/MS. More imporrantly, the results showed that bergapten and isopsoralen significantly inhibited the metabolism of tofacitinib metabolism. The AUC(0-t), AUC(0-∞), MRT(0-t), MRT(0-∞) and Cmax of tofacitinib increased in varying degrees compared with the control group (all p < 0.05), but CLz/F decreased in varying degrees (p < 0.05) in the different dose bergapten group and isopsoralen group. Bergapten, isopsoralen and tofacitinib exhibit similar binding capacities with CYP3A4 by AutoDock 4.2 software, confirming that they compete for tofacitinib metabolism. P. corylifolia may considerably impact the metabolism of tofacitinib, which can provide essential information for the accurate therapeutic application of tofacitinib.

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.

Efficacy and safety of JAK inhibitors in rheumatoid arthritis: update for the practising clinician

Janus kinase (JAK) inhibitors, including tofacitinib, baricitinib, upadacitinib and filgotinib, are increasingly used in the treatment of rheumatoid arthritis (RA). There has been debate about their safety, particularly following the issuance of guidance by regulatory agencies advising caution in their use in certain patients. The registrational clinical trials and registry data of JAK inhibitors did not identify a difference in the risk of major adverse cardiovascular events (MACEs), venous thromboembolism, malignancies or infections (other than herpes zoster) with a JAK inhibitor versus a biologic DMARD. In the ORAL Surveillance trial, which enrolled patients >50 years of age with ≥1 cardiovascular risk factor, tofacitinib was statistically inferior to TNF inhibitors for the occurrence of MACEs and malignancy. Further post hoc analysis of the data revealed that an age of ≥65 years, a high baseline cardiovascular risk, a history of smoking, sustained inflammation, disease activity and suboptimal treatment of cardiovascular comorbidities all increase the risk of these outcomes. The guidance issued by regulatory agencies should be carefully considered to ensure appropriate and safe treatment of patients with RA without undertreatment of patients who might benefit from JAK inhibitor, as well as biologic, treatment. As always, the risks associated with the use of these agents, treatment goals, costs and patient preferences should be discussed with the patient.

JAK1 promotes HDV replication and is a potential target for antiviral therapy

BACKGROUND & AIMS

Chronic co-infection with HBV and HDV leads to the most aggressive form of chronic viral hepatitis. To date, no treatment induces efficient viral clearance, and a better characterization of virus-host interactions is required to develop new therapeutic strategies.

METHODS

Using loss-of-function strategies, we validated the unexpected proviral activity of Janus kinase 1 (JAK1) - a key player in innate immunity - in the HDV life cycle and determined its mechanism of action on HDV through various functional analyses including co-immunoprecipitation assays.

RESULTS

We confirmed the key role of JAK1 kinase activity in HDV infection. Moreover, our results suggest that JAK1 inhibition is associated with a modulation of ERK1/2 activation and S-HDAg phosphorylation, which is crucial for viral replication. Finally, we showed that FDA-approved JAK1-specific inhibitors are efficient antivirals in relevant in vitro models including primary human hepatocytes.

CONCLUSIONS

Taken together, we uncovered JAK1 as a key host factor for HDV replication and a potential target for new antiviral treatment.

IMPACT AND IMPLICATIONS

Chronic hepatitis D is the most aggressive form of chronic viral hepatitis. As no curative treatment is currently available, new therapeutic strategies based on host-targeting agents are urgently needed. Here, using loss-of-function strategies, we uncover an unexpected interaction between JAK1, a major player in the innate antiviral response, and HDV infection. We demonstrated that JAK1 kinase activity is crucial for both the phosphorylation of the delta antigen and the replication of the virus. By demonstrating the antiviral potential of several FDA-approved JAK1 inhibitors, our results could pave the way for the development of innovative therapeutic strategies to tackle this global health threat.

Janus Kinase Inhibitors and Adverse Events of Acne: A Systematic Review and Meta-Analysis

Importance

Janus kinase (JAK) inhibitors are increasingly used across a range of dermatologic conditions. Adverse events of acne have been noted in some studies in clinical practice, but the scope of this outcome across JAK inhibitors has not been established.

Objective

To systematically analyze all published phase 2 and 3 placebo-controlled randomized clinical trials (RCTs) of JAK inhibitors for the risk of acne as an adverse effect of these medications.

Data Sources

Comprehensive search of Ovid MEDLINE and PubMed databases through January 31, 2023.

Study Selection

Inclusion criteria were phase 2 and 3 placebo-controlled RCTs of JAK inhibitors published in English with reported adverse events of acne.

Data Extraction and Synthesis

Two reviewers independently reviewed and extracted information from all included studies.

Main Outcomes and Measures

The primary outcome of interest was the incidence of acne following JAK inhibitor use. A meta-analysis was conducted using random-effects models.

Results

A total of 25 unique studies (10 839 unique participants; 54% male and 46% female) were included in the final analysis. The pooled odds ratio (OR) was calculated to be 3.83 (95% CI, 2.76-5.32) with increased ORs for abrocitinib (13.47 [95% CI, 3.25-55.91]), baricitinib (4.96 [95% CI, 2.52-9.78]), upadacitinib (4.79 [95% CI, 3.61-6.37]), deucravacitinib (2.64 [95% CI, 1.44-4.86]), and deuruxolitinib (3.30 [95% CI, 1.22-8.93]). Estimated ORs were higher across studies investigating the use of JAK inhibitors for the management of dermatologic compared with nondermatologic conditions (4.67 [95% CI, 3.10-7.05]) as well as for JAK1-specific inhibitors (4.69 [95% CI, 3.56-6.18]), combined JAK1 and JAK2 inhibitors (3.43 [95% CI, 2.14-5.49]), and tyrosine kinase 2 inhibitors (2.64 [95% CI, 1.44-4.86]).

Conclusions and Relevance

In this systematic review and meta-analysis, JAK inhibitor use was associated with an elevated odds of acne. Patients should be properly counseled on this potential adverse effect of these medications before treatment initiation. Future studies are needed to further elucidate the pathophysiology of this association.

JAK-inhibitors and risk on serious viral infection, venous thromboembolism and cardiac events in patients with rheumatoid arthritis: A protocol for a prevalent new-user cohort study using the Danish nationwide DANBIO register

Janus Kinase inhibitors (JAKis) are targeted synthetic disease-modifying antirheumatic drugs and represent an important alternative to treat patients with moderate to high rheumatoid arthritis (RA) disease activity. Safety concerns associated with increased risk for venous thromboembolism (VTE), serious viral infection, and, more recently, major adverse cardiovascular events (MACE) in JAKi users have emerged worldwide. However, as the exact mechanisms to explain these safety concerns remain unclear, the increased risk of VTE, MACE, and serious viral infection in JAKi users is heavily debated. In light of the need to enrich the safety profile of JAKis in real-world data, we aim to quantify the incidence and risk of MACE, VTE, and serious viral infections in RA patients registered in the Danish DANBIO registry, a nationwide registry of biological therapies used in rheumatology. Therefore, we will conduct a population-based cohort study using a prevalent new-user design. We will identify all RA patients in the DANBIO, ≥ 18 years old, receiving a JAKi or a tumor necrosis factor α inhibitor (TNF-αi) from January 2017 to December 2022. Prevalent and new users of JAKis will be matched to TNF-αi comparators with similar exposure history using time-conditional propensity scores (TCPS). We will describe the cumulative incidence of the outcomes (VTE, MACE, serious viral infection) in each exposure group (JAKi users; TNF-αi users), stratified by outcome type. Additionally, the Aalen-Johansen method will be used to estimate the time-to-event survival function stratified by outcome type. We will also estimate the hazard ratio (HR) with 95% confidence interval (CI) of each outcome in both exposure groups using the time-dependent Cox proportional hazards model. Results will enrich the safety profile of JAKis in real-world data.

Engineered protein and Jakinib nanoplatform with extraordinary rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a relatively common inflammatory disease that affects the synovial tissue, eventually results in joints destruction and even long-term disability. Although Janus kinase inhibitors (Jakinibs) show a rapid efficacy and are becoming the most successful agents in RA therapy, high dosing at frequent interval and severe toxicities cannot be avoided. Here, we developed a new type of fully compatible nanocarriers based on recombinant chimeric proteins with outstanding controlled release of upadacitinib. In addition, the fluorescent protein component of the nanocarriers enabled noninvasive fluorescence imaging of RA lesions, thus allowing real-time detection of RA therapy. Using rat models, the nanotherapeutic is shown to be superior to free upadacitinib, as indicated by extended circulation time and sustained bioefficacy. Strikingly, this nanosystem possesses an ultralong half-life of 45 h and a bioavailability of 4-times higher than pristine upadacitinib, thus extending the dosing interval from one day to 2 weeks. Side effects such as over-immunosuppression and leukocyte levels reduction were significantly mitigated. This smart strategy boosts efficacy, safety and visuality of Jakinibs in RA therapy, and potently enables customized designs of nanoplatforms for other therapeutics.

Electronic Supplementary Material

Supplementary material (further details of DLS analysis, biocompatibility of PCP-UPA, CIA models construction, etc.) is available in the online version of this article at 10.1007/s12274-023-5838-0.

New Targets and Strategies for Rheumatoid Arthritis: From Signal Transduction to Epigenetic Aspect

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to joint damage and even permanent disability, seriously affecting patients' quality of life. At present, the complete cure for RA is not achievable, only to relieve the symptoms to reduce the pain of patients. Factors such as environment, genes, and sex can induce RA. Presently, non-steroidal anti-inflammatory drugs, DRMADs, and glucocorticoids are commonly used in treating RA. In recent years, some biological agents have also been applied in clinical practice, but most have side effects. Therefore, finding new mechanisms and targets for treating RA is necessary. This review summarizes some potential targets discovered from the perspective of epigenetics and RA mechanisms.

Docking and Selectivity Studies of Covalently Bound Janus Kinase 3 Inhibitors

The Janus kinases (JAKs) are a family of non-receptor cytosolic protein kinases critical for immune signaling. Many covalently bound ligands of JAK3 inhibitors have been reported. To help design selective JAK inhibitors, in this paper, we used five model proteins to study the subtype selectivity of and the mutational effects on inhibitor binding. We also compared the Covalent Dock programs from the Schrodinger software suite and the MOE software suite to determine which method to use for the drug design of covalent inhibitors. Our results showed that the docking affinity from 4Z16 (JAK3 wild-type model), 4E4N (JAK1), 4D1S (JAK2), and 7UYT (TYK2) from the Schrödinger software suite agreed well with the experimentally derived binding free energies with small predicted mean errors. However, the data from the mutant 5TTV model using the Schrödinger software suite yielded relatively large mean errors, whereas the MOE Covalent Dock program gave small mean errors in both the wild-type and mutant models for our model proteins. The docking data revealed that Leu905 of JAK3 and the hydrophobic residue at the same position in different subtypes (Leu959 of JAK1, Leu932 of JAK2, and Val981 of TYK2) is important for ligand binding to the JAK proteins. Arg911 and Asp912 of JAK3, Asp939 of JAK2, and Asp988 of TYK2 can be used for selective binding over JAK1, which contains Lys965 and Glu966 at the respective positions. Asp1021, Asp1039, and Asp1042 can be utilized for JAK1-selective ligand design, whereas Arg901 and Val981 may help guide TYK2-selective molecule design.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Erdheim-Chester disease with Rosai-Dorfman-like lesions: treatment with methotrexate, anakinra and upadacitinib

Erdheim-Chester disease (ECD) is a non-Langerhans cell histiocytosis characterised by clonal expansion of histiocytes in various organs. These induce an inflammatory environment, which leads to damage of the affected areas. Recently, a new disease entity was proposed encompassing key features of ECD but also of Rosai-Dorfman-Destombes disease, another histiocytosis. Mitogen-activated protein kinase kinase 1 (MAP2K1) mutations seem to present a specific genetic lesion for this subtype.Here, we describe a case of this new disease entity with clinical, radiological and genetic findings compatible with ECD but histological findings compatible with Rosai-Dorfman-Destombes disease. In particular, there were intraabdominal and retroperitoneal lesions, which tested positive for a (c.167A>C; p.Q56P) mutation of the MAP2K1 gene. On histological examination, S100-positive, giant histiocytes with focal emperipolesis of haematological cells in addition to infiltration by lymphocytes and granulocytes were seen.As described for this rare variant of ECD, there was also bilateral testicular infiltration. We also describe a manifestation of oligoarthritis in this patient with ECD.The patient was treated with methotrexate and prednisolone. While radiological response to this regime was excellent, arthritis persisted. We added anakinra, which induced a response of the arthritis for more than a year. Due to treatment failure therapy was switched to upadacitinib, which induced a remission of the arthritis as well.This case adds a rare phenotype to an already rare presentation of ECD. The patient responded to immunosuppressive therapy.

A Meta-Analysis Evaluating the Effectiveness and Safety of Upadacitinib in Treating Rheumatoid Arthritis in Patients With Inadequate Response to Disease-Modifying Anti-Rheumatic Drugs

Upadacitinib, an oral Janus kinase (JAK) inhibitor, is used to manage rheumatoid arthritis. The objective was to generate statistical evidence from the existing data for upadacitinib efficacy and safety in various treatment regimens with different dosages in active rheumatoid arthritis patients. We searched PubMed, Cochrane, and ClinicalTrials.gov using PRISMA guidelines, providing data on the efficacy and safety of upadacitinib versus placebo in rheumatoid arthritis. 20% improvement in the American College of Rheumatology (ACR20) score response at 12 weeks was the primary outcome measure. Safety in adverse events, infections, or hepatic dysfunction was considered. The Mantel-Haenszel formula with random effect was used for the pooled odds ratio (OR) at a 95% confidence interval (CI) for dichotomous data. Meta-analysis was performed using RevMan version 5.4. Statistical heterogeneity was reported using I2 statistics; I2 > 75% was considered significant heterogeneity. A P value of less than 0.05 was considered significant. Data from 3233 patients were included in the analysis. The use of upadacitinib was associated with increased rates of achieving an ACR20 response compared with placebo (pooled OR 3.71; 95% CI 3.26-4.23; p-value <0.00001). Compared to a placebo, a 12 mg twice daily dose had the greatest effect, followed by a 15 mg once daily dose. Compared to the placebo, the incidence of any adverse event (pooled OR 1.66; 95% CI 1.36-2.02; p-value 0.0001) and infection (pooled OR 1.46; 95% CI 1.23-1.74; p-value 0.001) was found to be significantly higher in upadacitinib. Other adverse events, such as hepatic disorders and herpes zoster infections, were not statistically significant (p-value> 0.05). Maximum adverse events were seen at 12 mg twice daily. Upadacitinib, 15 mg once daily in combination with Methotrexate, was the most efficacious treatment regimen and was not associated with a significant risk for treatment-related adverse events in rheumatoid arthritis patients.

JAK: Not Just Another Kinase

The JAK/STAT axis is implicated in cancer, inflammation, and immunity. Numerous cytokines/growth factors affect JAK/STAT signaling. JAKs (JAK1, JAK2, JAK3, and TYK2) noncovalently associate with cytokine receptors, mediate receptor tyrosine phosphorylation, and recruit ≥1 STAT proteins (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, and STAT6). Tyrosine-phosphorylated STATs dimerize and are then transported into the nucleus to function as transcription factors. Signaling is attenuated by specific suppressor of cytokine signaling proteins, creating a negative feedback loop. Both germline mutations and polymorphisms of JAK family members correlate with specific diseases: Systemic lupus erythematosus (TYK2 polymorphisms); severe combined immunodeficiency (JAK3 mutations); pediatric acute lymphoblastic leukemia (TYK2 mutations); and hereditary thrombocytosis (JAK2 mutations). Somatic gain-of-function JAK mutations mainly occur in hematologic malignancies, with the activating JAK2 V617F being a myeloproliferative disorder hallmark; it is also seen in clonal hematopoiesis of indeterminate potential. Several T-cell malignancies, as well as B-cell acute lymphoblastic leukemia, and acute megakaryoblastic leukemia also harbor JAK family somatic alterations. On the other hand, JAK2 copy-number loss is associated with immune checkpoint inhibitor resistance. JAK inhibitors (jakinibs) have been deployed in many conditions with JAK activation; they are approved in myeloproliferative disorders, rheumatoid and psoriatic arthritis, atopic dermatitis, ulcerative colitis, graft-versus-host disease, alopecia areata, ankylosing spondylitis, and in patients hospitalized for COVID-19. Clinical trials are investigating jakinibs in multiple other autoimmune/inflammatory conditions. Furthermore, dermatologic and neurologic improvements have been observed in children with Aicardi-Goutieres syndrome (a genetic interferonopathy) treated with JAK inhibitors.

Management of Axial Spondyloarthritis - Insights into Upadacitinib

Although the pathogenesis of spondyloarthritis (SpA) has still not been elucidated our options to treat SpA have definitely improved in the last decades. There are two main types of SpA: (i) axial spondyloarthritis (axSpA), also covering the classical ankylosing spondylitis (AS) which is largely equivalent to radiographic (r)-axSpA but different from non-radiographic (nr)-axSpA, and (ii) peripheral SpA (pSpA) also covering psoriatic arthritis (PsA) as the main subtype. The subtype nr-axSpA has historically developed because the approval of drugs for AS did not cover forms without structural changes in the sacroiliac joints which is mandatory in the 1984 New York criteria. The definitions for axSpA are based on the 2009 Assessments in AxSpA International Society (ASAS) classification criteria. Several biologic disease modifying anti-rheumatic drugs (bDMARDs) such as the tumor necrosis factor alpha inhibitors (TNFi) and the interleukin-17-inhibitors (IL-17i) are approved mostly for the whole spectrum of SpA including axSpA and PsA but L-17i does not work in inflammatory bowel disease (IBD). Targeted synthetic (ts) DMARDs cover mainly the janus kinase (JAK)-inhibitors which have recently been developed to inhibit inflammation in several rheumatic and other immune mediated diseases such as IBD. Indeed, the physiologic mechanism of JAK-mediated signal transduction has been recognized as an important target because the inhibition of its actions was shown to successfully work as a therapeutic mechanism. There are now 4 small molecule JAK inhibitors (JAKi) that currently play a role in rheumatology with variable selectivity for the four different JAK isoforms: tofacitinib, baricitinib, upadacitinib and filgotinib. In this review, we summarize current clinical trial data and evaluate the use of the JAK1 selective inhibitor upadacitinib in the treatment of axSpA, including nr-axSpA and r-axSpA. Even though the efficacy and safety of upadacitinib over shorter periods of time has been convincing to date, long-term trials are needed to fully establish its performance and also evaluate the safety at higher doses, and its use in PsA.

A Comprehensive Overview of Globally Approved JAK Inhibitors

Janus kinase (JAK) is a family of cytoplasmic non-receptor tyrosine kinases that includes four members, namely JAK1, JAK2, JAK3, and TYK2. The JAKs transduce cytokine signaling through the JAK-STAT pathway, which regulates the transcription of several genes involved in inflammatory, immune, and cancer conditions. Targeting the JAK family kinases with small-molecule inhibitors has proved to be effective in the treatment of different types of diseases. In the current review, eleven of the JAK inhibitors that received approval for clinical use have been discussed. These drugs are abrocitinib, baricitinib, delgocitinib, fedratinib, filgotinib, oclacitinib, pacritinib, peficitinib, ruxolitinib, tofacitinib, and upadacitinib. The aim of the current review was to provide an integrated overview of the chemical and pharmacological data of the globally approved JAK inhibitors. The synthetic routes of the eleven drugs were described. In addition, their inhibitory activities against different kinases and their pharmacological uses have also been explained. Moreover, their crystal structures with different kinases were summarized, with a primary focus on their binding modes and interactions. The proposed metabolic pathways and metabolites of these drugs were also illustrated. To sum up, the data in the current review could help in the design of new JAK inhibitors with potential therapeutic benefits in inflammatory and autoimmune diseases.

Rheumatoid Arthritis and JAK-STAT Inhibitors: Prospects of Topical Delivery

Abstract:

Rheumatoid arthritis (RA) is the most common musculoskeletal disease in the world. The clinical prospects have increased tremendously since the advent of biological agents as therapy options. NSAIDs such as indomethacin, celecoxib, and etoricoxib are used often in the treatment of RA but off-target effects decreased their use. DMARDs such as methotrexate and etanercept were also effective in the treatment of RA, but tolerance to methotrexate developed in many cases. Janus kinase inhibitors (JAKi) have also gained popularity as a treatment option for rheumatoid arthritis. Tofacitinib is the foremost JAK inhibitor that is used to treat RA as an individual agent or in combination with other DMARDs. The most frequently used route of administration for JAKi is oral. Since oral formulations of JAK inhibitors have a number of health hazards, such as systemic toxicity and patient noncompliance, topical formulations of JAK inhibitors have emerged as a preferable alternative for administering JAK inhibitors. Tofacitinib delivered topically, seems to have the potential to eliminate or reduce the occurrences of negative effects when compared to tofacitinib taken orally. Given the scarcity of knowledge on the techniques for topical distribution of JAKi, more effort will be required to develop a stable topical formulation of JAKi to address the limitations of oral route. The current review looks at JAK inhibitors and the ways that have been used to generate topical formulations of them.

Janus kinase inhibitors for the therapy of atopic dermatitis

The JAK-STAT pathway is involved in the signaling of multiple cytokines driving cutaneous inflammation in atopic dermatitis (AD). Janus kinase (JAK) inhibitors target individual receptor-associated kinases, thereby preventing the mediation of inflammatory signals. Several JAK inhibitors with varying mechanism of action, potency, and safety represent potential therapeutic options for AD in both topical and systemic application. The JAK1/2 selective JAK inhibitor baricitinib was the first substance from this class of drugs approved by the EMA for the systemic oral treatment of AD. The clinical development program of the JAK1 selective inhibitors upadacitinib and abrocitinib is finalized with positive results for AD. The PAN-JAK inhibitor delgocitinib was the first substance being approved for the treatment of AD (in Japan). This review article covers the rising data on investigational and approved JAK inhibitors in the context of the treatment of AD.

Genome-wide association study of liver enzyme elevation in rheumatoid arthritis patients starting methotrexate

Aim: To identify novel genetic variants predisposing to elevation of Alanine aminotransferase (ALT) in rheumatoid arthritis (RA) patients after initiation of methotrexate (MTX) treatment. Patients & methods: We performed genome-wide association studies in 198 RA patients starting MTX. Outcomes were maximum level of ALT and ALT >1.5-times the upper level of normal within the first 6 months of treatment. Results: RAVER2 (rs72675408) was significantly associated with maximum level of ALT (p = 4.36 × 10^-8). This variant is in linkage disequilibrium with rs72675451, which is associated with differential expression of JAK1 and RAVER2. Conclusion: We found an association between ALT elevation and genetic variants that may regulate the expression of JAK1 and RAVER2. JAK1 encodes a janus kinase involved in the pathogenesis of RA.

Recent advances on signaling pathways and their inhibitors in rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by systemic synovitis leading to joint destruction in which imbalances in pro-inflammatory and anti-inflammatory cytokines promote the induction of autoimmunity. Some pro-inflammatory cytokines can trigger the signaling pathways which responsible for immune-mediated inflammation in RA, and the activated signaling pathways produce pro-inflammatory cytokines, resulting in aggravation of RA. Hence, understanding of the signaling pathways and their inhibitors might be advantageous in the development of therapeutic targets and new drugs for RA. In the current review, we summarize the signaling pathways involved in the pathogenesis of RA as well as the potential role of specific inhibitors in its management. We hope this paper may serve a reference for future studies on signaling pathways implicated in the pathogenesis of RA and benefit the treatment of RA.

Cardiovascular effects of approved drugs for rheumatoid arthritis

The risk of cardiovascular disease is increased in patients with rheumatoid arthritis compared with the general population owing to the influence of traditional and non-traditional risk factors. Inflammation has a pivotal contribution and can accelerate the atherosclerotic process. Although dampening inflammation with DMARDs should theoretically abrogate this process, evidence suggests that these drugs can also promote atherosclerosis directly and indirectly, hence adding to an increased cardiovascular burden. However, the extent and direction of the effects largely differ across drugs. Understanding how these drugs influence endothelial damage and vascular repair mechanisms is key to understanding these outcomes. NSAIDs and glucocorticoids can increase the cardiovascular risk. Conversely, conventional, biologic and targeted DMARDs control inflammation and reduce this risk, although some of these drugs can also aggravate traditional factors or thrombotic events. Given these data, the fundamental objective for clinicians should be disease control, in an individualized approach that considers the most appropriate drug for each patient, taking into account joint and cardiovascular outcomes. This Review provides a comprehensive analysis of the effects of DMARDs and other approved drugs on cardiovascular involvement in rheumatoid arthritis, from a clinical and mechanistic perspective, with a roadmap to inform the research agenda.

JAK Inhibitors and Modulation of B Cell Immune Responses in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic immune-mediated inflammatory disease that can lead to joint destruction, functional disability and substantial comorbidity due to the involvement of multiple organs and systems. B cells have several important roles in RA pathogenesis, namely through autoantibody production, antigen presentation, T cell activation, cytokine release and ectopic lymphoid neogenesis. The success of B cell depletion therapy with rituximab, a monoclonal antibody directed against CD20 expressed by B cells, has further supported B cell intervention in RA development. Despite the efficacy of synthetic and biologic disease modifying anti-rheumatic drugs (DMARDs) in the treatment of RA, few patients reach sustained remission and refractory disease is a concern that needs critical evaluation and close monitoring. Janus kinase (JAK) inhibitors or JAKi are a new class of oral medications recently approved for the treatment of RA. JAK inhibitors suppress the activity of one or more of the JAK family of tyrosine kinases, thus interfering with the JAK-Signal Transducer and Activator of Transcription (STAT) signaling pathway. To date, there are five JAK inhibitors (tofacitinib, baricitinib, upadacitinib, peficitinib and filgotinib) approved in the USA, Europe and/ or Japan for RA treatment. Evidence from the literature indicates that JAK inhibitors interfere with B cell functions. In this review, the main results obtained in clinical trials, pharmacokinetic, in vitro and in vivo studies concerning the effects of JAK inhibitors on B cell immune responses in RA are summarized.

Efficacy and safety of upadacitinib in Japanese patients with rheumatoid arthritis (SELECT-SUNRISE): a placebo-controlled phase IIb/III study

Objective

To evaluate upadacitinib efficacy and safety dose response in Japanese patients with active RA and an inadequate response to conventional synthetic DMARDs (csDMARDs).

Methods

This was a multicentre, phase IIb/III, dose-ranging study conducted in Japan, in which patients on previously stable csDMARDs were randomized to receive upadacitinib 7.5, 15 or 30 mg once daily or matching placebo for a 12-week double-blind period. The primary endpoint was a 20% improvement in ACR criteria (ACR20) response at week 12 using non-responder imputation. Key secondary endpoints included ACR50, ACR70 and 28-joint DAS with CRP (DAS28-CRP) remission and low disease activity. Adverse events were also assessed.

Results

Of 197 patients treated, 187 completed the double-blind period. At week 12, more patients receiving upadacitinib 7.5, 15 or 30 mg vs placebo met the ACR20 response (75.5%, 83.7%, 80.0% vs 42.9%; P < 0.001), with significant differences observed as early as week 1. Stringent responses, including ACR50, ACR70 and DAS28-CRP <2.6, were achieved by significantly higher proportions of patients on upadacitinib than placebo and by numerically higher proportions on upadacitinib 15 or 30 mg vs upadacitinib 7.5 mg. Adverse events and infections (serious infections, opportunistic infections and herpes zoster) were more common with upadacitinib vs placebo and numerically highest with upadacitinib 30 mg. There were no venous thromboembolic events reported.

Conclusion

Efficacy of upadacitinib was demonstrated in this population of Japanese patients with RA and an inadequate response to csDMARDs. Safety and tolerability were consistent with other upadacitinib RA studies. The 15 mg dose of upadacitinib showed the most favourable benefit–risk profile.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT02720523.

[Pain in rheumatic diseases : What can biologics and JAK inhibitors offer?]

Persistent pain despite adequate inflammation control poses a big challenge in many rheumatic diseases for patients as well as physicians. The focus of drug development over the past years was on anti-inflammatory therapies. Enormous progress has been made and several treatment options have been added. It has been observed that pain triggered by inflammation can be effectively treated by inflammation control; however, the chronic pain component remains a problem, is little studied and specific treatment options are missing. Pain is influenced by inflammatory mediators, such as cytokines, which act on peripheral nociceptors and lead to peripheral sensitization. If inflammation continues, this can potentially lead to central sensitization and chronification of pain via immigration of immune cells and/or local activation of e.g. microglia. This leads to increasing autonomization and uncoupling of pain from the actual inflammatory process. The present review deals with the question if bDMARD or tsDMARD also show benefits concerning pain processes in addition to the profound inhibitory effects on inflammation. There are preclinical data that show an influence on sensitization following the use of cytokine inhibitors. On the other hand, so far clinical data show that bDMARDs as well as tsDMARDs consistently rapidly and reliably reduce nociceptive inflammatory pain across disease entities. An effect especially on the process of central sensitization and therefore on chronification of pain cannot be finally evaluated based on the currently available data.

Risk of infections and cardiovascular and venous thromboembolic events associated with JAK inhibitors in rheumatoid arthritis: protocols of two systematic reviews and network meta-analyses

INTRODUCTION

Janus kinases (JAK) inhibitors demonstrated to be effective in the treatment of adult patients with moderate-to-severe active rheumatoid arthritis (RA) but have been associated with serious cardiovascular and serious events. Two systematic reviews and network meta-analyses will be carried aiming to compare the relative safety of the different JAK inhibitors with regard to the risk of (1) cardiovascular and thromboembolic events and (2) serious infections in patients with RA.

METHODS AND ANALYSIS

PUBMED, Embase, Cochrane Controlled Register of Trials and ClinicalTrials.gov will be searched in order to identify randomised controlled trials evaluating the efficacy and safety of JAK inhibitors in patients with RA. The following events will be assessed: (1) any cardiovascular event; major adverse cardiovascular events and venous thromboembolism and (2) any infection; serious infections; herpes zoster infection and tuberculosis. Search terms will comprise RA and drugs names, including the thesaurus terms and the International Nonproprietary Names. The assessment of the methodological quality of the included studies will be performed through the RoB 2 tool: a revised Cochrane risk of bias tool for randomised trials. Network meta-analyses will be performed using STATA V.13.0. For each outcome, treatments will be ranked according to the probability of being the safest (best) alternative using the surface under the cumulative ranking curve.

ETHICS AND DISSEMINATION

Ethical approval is not required as no primary data are collected. This systematic review will be disseminated through peer-reviewed publications and at conference meetings.

Preclinical discovery and development of adalimumab for the treatment of rheumatoid arthritis

Introduction: Rheumatoid arthritis (RA) is an autoimmune disease that is characterized by progressive joint disorders with significant pain and stiffness. In the past, RA was a difficult -to-treat ailment, but nowadays with the advent of biologics and better treatment strategies, disease remission is an achievable goal. Tumor necrosis factor α (TNFα) inhibitors were the first category of biologics to emerge with adalimumab being the first fully human TNFα.Areas covered: the authors provide an overview of the historical events that led to the discovery of TNFα inhibitors and more specifically the drug adalimumab. Several key trials are presented regarding the safety of the drug as well as its successful journey, but there is also a narrative description of the drug's future after patent expiration.Expert opinion: Adalimumab is a fully human TNFα inhibitor with a fairly rapid onset of action. It has a generally good safety and efficacy profile. Clinicians must be aware of the possible side effects and treat them in a timely manner or discontinue the drug where appropriate. Due to the success of the bio-originator adalimumab, a multitude of biosimilars have emerged but not, thus far, for all of the indications of the bio-originator.

Efficacy and Safety of Upadacitinib Monotherapy in Methotrexate-Naive Patients With Moderately-to-Severely Active Rheumatoid Arthritis (SELECT-EARLY): A Multicenter, Multi-Country, Randomized, Double-Blind, Active Comparator-Controlled Trial

OBJECTIVE

The SELECT-EARLY trial was undertaken to study the effect of upadacitinib, an oral, reversible Janus kinase 1-selective inhibitor, as monotherapy in patients with predominantly early rheumatoid arthritis who were naive for or had limited exposure to methotrexate (MTX).

METHODS

Patients (n = 947) were randomized 1:1:1 to receive once-daily doses of upadacitinib 15 mg or 30 mg or weekly MTX (7.5-20 mg/week) for 24 weeks. The primary end points were the proportion of patients who met the American College of Rheumatology 50% (ACR50) improvement criteria at week 12, and the proportion in whom a Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP) of <2.6 was achieved at week 24. Data are presented through week 24.

RESULTS

At baseline, the median disease duration was 0.5 years (range 0-44 years). A total of 840 patients (89%) completed 24 weeks of treatment. The study met both primary end points for upadacitinib 15 mg and 30 mg versus MTX (ACR50 was achieved at week 12 in 52% and 56% of patients, respectively, versus 28% [P < 0.001], and DAS28-CRP <2.6 was achieved at week 24 in 48% and 50% of patients, respectively, versus 19% [P < 0.001]). Statistically significant and clinically meaningful improvements in multiple patient-reported outcomes (PROs) were recorded for both upadacitinib doses versus MTX. Overall, 88% of patients receiving upadacitinib 15 mg and 89% of patients receiving 30 mg, respectively, had no radiographic progression (modified total Sharp score ≤0) compared to 78% of those receiving MTX (P < 0.01). Through week 24, the frequency of treatment-emergent adverse events was similar between the MTX arm (65%) and upadacitinib 15 mg arm (64%), but was slightly higher in the upadacitinib 30 mg arm (71%). Six deaths were reported (2 in the upadacitinib 15 mg arm, 3 in the upadacitinib 30 mg arm, and 1 in the MTX arm).

CONCLUSION

Our findings indicate that patients receiving either dose of upadacitinib monotherapy experienced significant improvements in clinical, radiographic, and PROs compared to patients receiving MTX.

New era of therapy for endocrine autoimmune disorders

The new era of immune and reconstitution therapy of autoimmune disorders is ongoing. However, endocrine autoimmune diseases comprise a group of elaborating pathologies where the development of new treatment strategies remains slow. Substitution of the missing hormones is still standard practice, taking care of the devastating symptoms but not the cause of disease. As our knowledge of the genetic contribution to the aetiology of endocrine disorders increases and early diagnostic tools are available, it is now possible to identify persons at risk before they acquire full-blown disease. This review summarizes current knowledge and treatment of endocrine autoimmune disorders, focusing on type 1 diabetes, Addison's disease, autoimmune thyroid diseases and primary ovarian insufficiency. We explore which new therapies might be used in the different stages of the disease, focus on legalized therapy and elaborate on the ongoing clinical studies for these diseases and the research front, before hypothesizing on the way ahead.

BARICITINIB: NEW PHARMACOTHERAPY OPTIONS FOR RHEUMATOID ARTHRITIS AND OTHER IMMUNE-MEDIATED INFLAMMATORY RHEUMATIC DISEASES

Deciphering the mechanisms of the pathogenesis of immune-mediated inflammatory rheumatic diseases (IMIRDs) in conjunction with designing a wide range of biological agents is one of the major medical advances in the 21st century. A new promising area of pharmacotherapy for IMIRDs is associated with the design of the so-called targeted oral medications that primarily include Janus kinase (JAK) inhibitors. The review presents new data on the efficacy and safety of the new JAK inhibitor baricitinib in treating rheumatoid arthritis and other IMIRDs.

JAK-STAT inhibitors: Immersing therapeutic approach for management of rheumatoid arthritis

Rheumatoid arthritis is a world leading cause of musculoskeletal disease. With the introduction of biological agents as treatment alternatives the clinical possibilities have grown exponentially. Currently most common Disease-modifying anti-rheumatic drugs (DMARDs) treatment option involves intravenous or subcutaneous injection, and some patients struggle to respond to DMARDs or lose their primary reaction. An oral drug formulation with lowered costs of manufacturing and flexibility for healthcare workers to preferably perform treatment will result in decreased healthcare expenditures and increased medication compliance. The JAK-STAT inhibitors, a new class of small molecules drugs, fulfills these criteria and has recently shown efficacy in rheumatoid arthritis. Here we give a summary of how JAK-STAT inhibitors function and a detailed review of current clinical trials. Convincing clinical results suggest that therapeutic inhibition of the JAK proteins can effectively modulate a complex cytokine-driven inflammation.

Hi-JAKi-ng Synovial Fibroblasts in Inflammatory Arthritis With JAK Inhibitors

The Janus kinase (JAK)-Signal transducer and activator of transcription (STAT) pathway is one of the central signaling hubs in inflammatory, immune and cancer cells. Inhibiting the JAK-STAT pathway with JAK inhibitors (jakinibs) constitutes an important therapeutic strategy in cancer and chronic inflammatory diseases like rheumatoid arthritis (RA). FDA has approved different jakinibs for the treatment of RA, including tofacitinib, baricitinib and upadacitinib, and several jakinibs are being tested in clinical trials. Here, we reviewed published studies of jakinib effects on resolving synovial pathology in inflammatory arthritis. We discussed the results of jakinibs on structural joint damage in clinical trials and explored the effects of jakinibs across different in vitro, ex vivo, and in vivo synovial experimental models. We delved rigorously into experimental designs of in vitro fibroblast studies, deconvoluted jakinib efficacy in synovial fibroblasts across diverse experimental conditions and discussed their translatability in vivo. Synovial fibroblasts can readily activate the JAK-STAT signaling pathway in response to cytokine stimulation. We highlighted rather limited effects of jakinibs on the in vitro cultured synovial fibroblasts and inferred that direct and indirect (immune cell-dependent) actions of jakinibs are required to curb the fibroblast pathology in vivo. These actions have not been mimicked optimally in current in vitro experimental designs, where inflammatory stimuli do not naturally clear out with treatment as they do in vivo. While summarizing the broad knowledge of synovial jakinib effects, our review uniquely challenges future study designs to better mimick the jakinib actions in broader cell communities, as occurring in vivo in the inflamed synovium. This can deepen our understanding of collective synovial activities of jakinibs and their therapeutic limitations, thereby fostering jakinib development in arthritis.

A novel treatment for psoriatic arthritis: Janus kinase inhibitors

Psoriatic arthritis (PsA) is a type of chronic inflammatory arthritis which is associated with psoriasis. The early recognition and treatment for PsA are of critical importance. Janus kinase (JAK) inhibitors, as a kind of orally small molecules, have emerged as an encouraging class of drug in PsA treatment. This review provides a discussion of the role and current status of JAK inhibitors in the control of PsA. There are three JAK inhibitors approved for use in autoimmune diseases, for example, tofacitinib, baricitinib, and upadacitinib, and only tofacitinib has been approved in PsA treatment. The clinical trials of upadacitinib and filgotinib in PsA patients are undergoing. The efficacy and safety of these agents were briefly discussed. Although there are still issues in terms of their efficacy and safety currently, JAK inhibitors are expected to benefit more PsA patients in future.

Janus Kinase Inhibition for Graft-Versus-Host Disease: Current Status and Future Prospects

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is a curative treatment for many hematological malignant and non-malignant diseases. A major complication of the procedure is the donor T-cell-mediated graft-versus-host disease (GvHD). GvHD accounts for about 10% of early mortality after transplantation. GVHD is also the major cause of morbidity and disability in the late follow-up phase of transplanted patients, mainly because of the low response to first-line steroids, and the lack of efficient second-line standard treatments. The increasing knowledge regarding GVHD pathogenesis provides new pharmacological targets, potentially exploitable in clinical practice, in order to prevent and treat this complication. This review provides a description of GVHD pathogenesis, with a focus on the central role of the Janus kinase-related mechanisms. The first inflammatory innate-immunity response is triggered by a JAK/STAT dependent pathway, and JAK inhibition impairs antigen-presenting cell differentiation and activation and downregulates the expression of signals for T-cell triggering. The chronic evolution of alloreactivity, characterized by the long-term maintenance of inflammation and fibrosis, is also dependent on JAK/STAT activation. Based on preclinical data, we reviewed the rationale behind the clinical use of JAK-inhibitors in GVHD, presenting available results of clinical trials and reports, and looked at future implementation of this new promising treatment approach.

Novel Gain-of-Function Mutation in Stat1 Sumoylation Site Leads to CMC/CID Phenotype Responsive to Ruxolitinib

Mutations in the coiled-coil and DNA-binding domains of STAT1 lead to delayed STAT1 dephosphorylation and subsequently gain-of-function. The associated clinical phenotype is broad and can include chronic mucocutaneous candidiasis (CMC) and/or combined immunodeficiency (CID). We report a case of CMC/CID in a 10-year-old boy due to a novel mutation in the small ubiquitin molecule (SUMO) consensus site at the C-terminal region of STAT1 leading to gain-of-function by impaired sumoylation. Immunodysregulatory features of disease improved after Janus kinase inhibitor (jakinib) treatment. Functional testing after treatment confirmed reversal of the STAT1 hyper-phosphorylation and downstream transcriptional activity. IL-17 and IL-22 production was, however, not restored with jakinib therapy (ruxolitinib), and the patient remained susceptible to opportunistic infection. In conclusion, a mutation in the SUMO consensus site of STAT1 can lead to gain-of-function that is reversible with jakinib treatment. However, full immunocompetence was not restored, suggesting that this treatment strategy might serve well as a bridge to definitive therapy such as hematopoietic stem cell transplant rather than a long-term treatment option.

Current Therapeutic Options in the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the joints. Untreated RA leads to a destruction of joints through the erosion of cartilage and bone. The loss of physical function is the consequence. Early treatment is important to control disease activity and to prevent joint destruction. Nowadays, different classes of drugs with different modes of action are available to control the inflammation and to achieve remission. In this review, we want to discuss differences and similarities of these different drugs.

Impact of Janus kinase inhibitors on risk of cardiovascular events in patients with rheumatoid arthritis: systematic review and meta-analysis of randomised controlled trials

Objectives

To investigate the effect of Janus kinase inhibitors (Jakinibs) on cardiovascular risk in adult patients with rheumatoid arthritis (RA) via a meta-analysis of randomised controlled trials (RCTs).

Methods

PubMed, Embase and Cochrane library were thoroughly searched for RCTs reporting safety issues in patients with RA receiving Jakinibs, from inception to October 2018. The primary and secondary outcomes were all cardiovascular events (CVEs) and major adverse cardiovascular events (MACEs)/venous thromboembolism events (VTEs). OR and 95% CI were calculated using the Mantel-Haenszel fixed-effect method.

Results

26 RCTs randomising 11 799 patients were included. No significant difference was observed regarding all CVEs risk following Jakinibs usage in general (OR 1.04 (0.61 to 1.76), p = 0.89), tofacitinib (OR 0.63 (0.26 to 1.54), p = 0.31), baricitinib (OR 1.21 (0.51 to 2.83), p = 0.66), upadacitinib (OR 3.29 (0.59 to 18.44), p = 0.18), peficitinib (OR 0.43 (0.07 to 2.54), p = 0.35) or decernotinib (OR 1.12 (0.13 to 10.11), p = 0.92). Likewise, there was no significant difference for Jakinibs treatment overall regarding occurrence of MACEs (OR 0.80 (0.36 to 1.75), p = 0.57) or VTEs (OR 1.16 (0.48 to 2.81), p = 0.74). Dose-dependent impact of Jakinibs on the risks of all CVEs, MACEs and VTEs was not observed in tofacitinib (5 mg vs 10 mg), upadacitinib (15 mg vs 30 mg), whereas baricitinib at 2 mg was found to be safer than 4 mg in all CVEs incidence (OR 0.19 (0.04 to 0.88), p = 0.03).

Conclusion

The existing evidence from RCTs indicated no significant change in cardiovascular risk for Jakinib-treated patients with RA in a short-term perspective, but postmarketing data are sorely needed to ascertain their cardiovascular safety, especially at the higher dose, due to increased risk of thromboembolism events for both tofacitinib and baricitinib at higher dosage.

Janus kinase inhibitors in immuno-inflammatory rheumatic diseases: new opportunities and prospects

Despite the great success in the diagnosis and treatment of immuno-inflammatory rheumatic diseases (IIRD), which led to a significant improvement in the prognosis in many patients, the fundamental medical problems of this pathology – the restoration of quality of life and reduction of mortality to the population level – are far from solution. This served as a powerful impetus to the study of new approaches to pharmacotherapy of IIRD, one of which is associated with the use of low-molecular synthetic drugs that inhibit intracellular "signal" molecules-Janus kinase (JAK), the socalled Jakinibs. The current achievements and trends concerning the use of JAK inhibitors in the treatment of IIRD are considered.

Discovery of a JAK1/3 Inhibitor and Use of a Prodrug To Demonstrate Efficacy in a Model of Rheumatoid Arthritis

The four members of the Janus family of nonreceptor tyrosine kinases play a significant role in immune function. The JAK family kinase inhibitor, tofacitinib 1, has been approved in the United States for use in rheumatoid arthritis (RA) patients. A number of JAK inhibitors with a variety of JAK family selectivity profiles are currently in clinical trials. Our goal was to identify inhibitors that were functionally selective for JAK1 and JAK3. Compound 22 was prepared with the desired functional selectivity profile, but it suffered from poor absorption related to physical properties. Use of the phosphate prodrug 32 enabled progression to a murine collagen induced arthritis (CIA) model. The demonstration of a robust efficacy in the CIA model suggests that use of phosphate prodrugs may resolve issues with progressing this chemotype for the treatment of autoimmune diseases such as RA.