Tofacitinib: A Review in Rheumatoid Arthritis

Crossing the barriers: Revisiting the gut feeling in rheumatoid arthritis

To avoid autoimmunity, it is essential to keep the balance between the defence against pathogens and the maintenance of tolerance to self-antigens. Mucosal inflammation may lead to breakdown of tolerance and activation of autoreactive cells. Growing evidence suggests a major contribution of gut microbiota to the onset of chronic, autoimmune inflammatory diseases including rheumatoid arthritis (RA). RA patients show significant differences in the composition of gut microbiota compared to healthy controls, and in murine arthritis models certain bacteria can induce inflammatory Th17 responses or autoantibody production. The gut microbiota plays an important role in regulating the balance between immunogenic and tolerogenic immune responses. The intestinal barrier is the site of the body where most host-microbiota interaction takes place. Certain microbiota or their metabolites can cause a break in homeostasis by affecting the intestinal barrier integrity and permeability. However, an intact intestinal barrier is essential to separate the intestinal epithelium from toxins, microorganisms, and antigens in the gut lumen. This review will focus on the correlation between a leaky gut and the onset of arthritis. Furthermore, it will be discussed how targeting the intestinal barrier function by dietary changes might provide an opportunity to modulate the development of RA.

Paroxetine-Overview of the Molecular Mechanisms of Action

In the 21st century and especially during a pandemic, the diagnosis and treatment of depression is an essential part of the daily practice of many family doctors. It mainly affects patients in the age category 15–44 years, regardless of gender. Anxiety disorders are often diagnosed in children and adolescents. Social phobias can account for up to 13% of these diagnoses. Social anxiety manifests itself in fear of negative social assessment and humiliation, which disrupts the quality of social functioning. Treatment of the above-mentioned disorders is based on psychotherapy and pharmacotherapy. Serious side effects or mortality from antidepressant drug overdose are currently rare. Recent studies indicate that paroxetine (ATC code: N06AB), belonging to the selective serotonin reuptake inhibitors, has promising therapeutic effects and is used off-label in children and adolescents. The purpose of this review is to describe the interaction of paroxetine with several molecular targets in various points of view including the basic chemical and pharmaceutical properties. The central point of the review is focused on the pharmacodynamic analysis based on the molecular mechanism of binding paroxetine to various therapeutic targets.

Identification of the metabolites of tofacitinib in liver microsomes by liquid chromatography combined with high resolution mass spectrometry

Tofacitinib is an orally available Janus kinase inhibitor. The aim of this study was to investigate the metabolism of tofacitinib in mouse, rat, monkey, and human liver microsomes fortified with β-nicotinamide adenine dinucleotide phosphate tetrasodium salt and uridine diphosphate glucuronic acid. The biotransformation was executed at a temperature of 37°C for 60 min, and the samples were analyzed by ultra-high performance liquid chromatography combined with high-resolution mass spectrometry (UHPLC-HRMS) operated in positive electrospray ionization mode. The structures of the metabolites were elucidated according to their retention times, accurate masses, and MS/MS spectra. Under the current conditions, a total of 13 metabolites, including 1 glucuronide conjugate, were detected and structurally proposed. Oxygenation of the pyrrolopyrimidine ring, oxygenation of piperidine ring, N-demethylation, oxygenation of piperidine ring side chain, and glucuronidation were the primary metabolic pathways of tofacitinib. Among the tested species, tofacitinib showed significant species difference. Compared with other species, rat showed similar metabolic profiles to those of humans. The present study provides some new information regarding the metabolism of tofacitinib in animals and humans, which would bring us considerable benefits for the subsequent studies focusing on the pharmacological effect and toxicity of this drug.

Endocannabinoid system: Role in blood cell development, neuroimmune interactions and associated disorders

The endocannabinoid system (ECS) is a complex physiological network involved in creating homeostasis and maintaining human health. Studies of the last 40 years have shown that endocannabinoids (ECs), a group of bioactive lipids, together with their set of receptors, function as one of the most important physiologic systems in human body. ECs and cannabinoid receptors (CBRs) are found throughout the body: in the brain tissues, immune cells, and in the peripheral organs and tissues as well. In recent years, ECs have emerged as key modulators of affect, neurotransmitter release, immune function, and several other physiological functions. This modulatory homoeostatic system operates in the regulation of brain activity and states of physical health and disease. In several research studies and patents the ECS has been recognised with neuro-protective properties thus it might be a target in neurodegenerative diseases. Most immune cells express these bioactive lipids and their receptors, recent data also highlight the immunomodulatory effects of endocannabinoids. Interplay of immune and nervous system has been recognized in past, recent studies suggest that ECS function as a bridge between neuronal and immune system. In several ongoing clinical trial studies, the ECS has also been placed in the anti-cancer drugs spotlight. This review summarizes the literature of cannabinoid ligands and their biosynthesis, cannabinoid receptors and their distribution, and the signaling pathways initiated by the binding of cannabinoid ligands to cannabinoid receptors. Further, this review highlights the functional role of cannabinoids and ECS in blood cell development, neuroimmune interactions and associated disorders. Moreover, we highlight the current state of knowledge of cannabinoid ligands as the mediators of neuroimmune interactions, which can be therapeutically effective for neuro-immune disorders and several diseases associated with neuroinflammation.

Bioequivalence of the pharmacokinetics between tofacitinib aspartate and tofacitinib citrate in healthy subjects

Tofacitinib is an oral disease-modifying anti-rheumatic drug to selectively inhibit Janus kinases. Tofacitinib is a representative small molecule inhibitor that is used to treat many diseases including rheumatoid arthritis and various autoimmune conditions. Unlike biological agents, tofacitinib has several advantages, including the ability to be administered orally and a short half-life. This study aimed to evaluate the bioequivalence of the pharmacokinetics (PK) between tofacitinib aspartate 7.13 mg (test formulation) and tofacitinib citrate 8.08 mg (reference formulation; Xeljanz®) in healthy subjects. A randomized, open-label, single-dose, 2-sequence, 2-period, 2-treatment crossover trial was conducted in 41 healthy volunteers. A total of 5 mg of tofacitinib as the test or the reference formulation was administered, and serial blood samples were collected up to 14 hours after dosing for PK analyses. The plasma concentration of tofacitinib was determined by ultra-performance liquid chromatography-tandem mass spectrometry. A non-compartmental analysis was used to estimate the PK parameters. A total of 35 subjects completed the study and the study drug was well-tolerated. The mean maximum concentration (C_max) and area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUC_last) for the test formulation were 52.67 ng/mL and 133.86 ng∙h/mL, respectively, and 50.61 ng/mL and 133.49 h∙ng/mL for the reference formulation, respectively. The geometric mean ratios (90% confidence intervals) of the C_max and AUC_last between the 2 formulations were 1.041 (0.944-1.148) and 1.003 (0.968-1.039), respectively. Tofacitinib aspartate exhibited bioequivalent PK profiles to those of the reference formulation.

Trial Registration

ClinicalTrials.gov Identifier: NCT04278391.

Tofacitinib and Baricitinib Are Taken up by Different Uptake Mechanisms Determining the Efficacy of Both Drugs in RA

Background: Rheumatoid arthritis (RA) is a systemic autoimmune disease in which synovial fibroblasts (SF) play a key role. Baricitinib and Tofacitinib both act intracellularly, blocking the ATP-binding side of JAK proteins and thereby the downstream signalling pathway via STAT-3. Therefore, we investigated the role of organic cation transporters (OCTs) in Baricitinib and Tofacitinib cellular transport. Methods: OCT expression was analysed in SF isolated from RA and osteoarthritis (OA) patients, as well as peripheral blood mononuclear cells. The interaction of Baricitinib and Tofacitinib with OCTs was investigated using quenching experiments. The intracellular accumulation of both drugs was quantified using LC/MS. Target inhibition for both drugs was tested using Western blot for phosphorylated JAK1 and STAT3 upon stimulation with IL-6. Results: MATE-1 expression increased in OASF compared to RASF. The other OCTs were not differentially expressed. The transport of Baricitinib was not OCT dependent. Tofacitinib; however, was exported from RASF in a MATE-1 dependent way. Tofacitinib and Baricitinib showed comparable inhibition of downstream signalling pathways. Conclusion: We observed different cellular uptake strategies for Baricitinib and Tofacitinib. Tofacitinib was exported out of healthy cells due to the increased expression of MATE1. This might make Tofacitinib the favourable drug.

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.

IFN-γ enhances cell-mediated cytotoxicity against keratinocytes via JAK2/STAT1 in lichen planus

Lichen planus (LP) is a chronic debilitating inflammatory disease of unknown etiology affecting the skin, nails, and mucosa with no current FDA-approved treatments. It is histologically characterized by dense infiltration of T cells and epidermal keratinocyte apoptosis. Using global transcriptomic profiling of patient skin samples, we demonstrate that LP is characterized by a type II interferon (IFN) inflammatory response. The type II IFN, IFN-γ, is demonstrated to prime keratinocytes and increase their susceptibility to CD8⁺ T cell-mediated cytotoxic responses through MHC class I induction in a coculture model. We show that this process is dependent on Janus kinase 2 (JAK2) and signal transducer and activator of transcription 1 (STAT1), but not JAK1 or STAT2 signaling. Last, using drug prediction algorithms, we identify JAK inhibitors as promising therapeutic agents in LP and demonstrate that the JAK1/2 inhibitor baricitinib fully protects keratinocytes against cell-mediated cytotoxic responses in vitro. In summary, this work elucidates the role and mechanisms of IFN-γ in LP pathogenesis and provides evidence for the therapeutic use of JAK inhibitors to limit cell-mediated cytotoxicity in patients with LP.

Inhibition of colitis by ring-modified analogues of 6-acetamido-2,4,5-trimethylpyridin-3-ol

6-Aminopyridin-3-ol scaffold has shown an excellent anti-inflammatory bowel disease activity. Various analogues with the scaffold were synthesized in pursuit of the diversity of side chains tethering on the C(6)-position. Structure-activity relationship among the analogues was investigated to understand the effects of the side chains and their linkers on their anti-inflammatory activities. In this study, structural modification moved beyond side chains on the C(6)-position and reached to pyridine ring itself. It expedited us to synthesize diverse ring-modified analogues of a representative pyridine-3-ol, 6-acetamido-2,4,5-trimethylpyridin-3-ol (9). In the evaluation of compounds on their inhibitory actions against TNF-α-induced adhesion of monocytic cells to colonic epithelial cells, an in vitro model mimicking colon inflammation, the effects of compounds 9, 17, and 19 were greater than tofacitinib, an orally available anti-colitis drug, and compound 17 showed the greatest activity. In addition, TNF-α-induced angiogenesis, which permits more inflammatory cell migration into inflamed tissues, was significantly blocked by compounds 17 and 19 in a concentration-dependent manner. In the comparison of in vivo therapeutic effects of compounds 9, 17, and 19 on dextran sulfate sodium (DSS)-induced colitis in mice, compound 17 was the most potent and efficacious, and compound 19 was better than compound 9 which showed a similar degree of inhibitory effect to tofacitinib. Taken together, it seems that either the trimethyl system or the hydroxyl group on the pyridinol ring is essential to the activity. This finding might become a new milestone in the development of pyridinol-based anti-inflammatory bowel disease agents.

Inside Perspective of the Synthetic and Computational Toolbox of JAK Inhibitors: Recent Updates

The mechanisms of inflammation and cancer are intertwined by complex networks of signaling pathways. Dysregulations in the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway underlie several pathogenic conditions related to chronic inflammatory states, autoimmune diseases and cancer. Historically, the potential application of JAK inhibition has been thoroughly explored, thus triggering an escalation of favorable results in this field. So far, five JAK inhibitors have been approved by the Food and Drug Administration (FDA) for the treatment of different diseases. Considering the complexity of JAK-depending processes and their involvement in multiple disorders, JAK inhibitors are the perfect candidates for drug repurposing and for the assessment of multitarget strategies. Herein we reviewed the recent progress concerning JAK inhibition, including the innovations provided by the release of JAKs crystal structures and the improvement of synthetic strategies aimed to simplify of the industrial scale-up.

Targeting IFN/STAT1 Pathway as a Promising Strategy to Overcome Radioresistance

The interferon (IFN)-mediated activation of the Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) signaling is crucial for cell sensitivity to ionizing radiation. Several preclinical studies have reported that the IFN/STAT1 pathway mediates radioresistance in the tumor microenvironment by shielding the immune responses and activating survival signaling pathways. This review focuses on the oncogenic function of the IFN/STAT1 pathway, emphasizing the major signaling pathway in radiation sensitization. Furthermore, it highlights the possibility of mediatory roles of the IFN/STAT1 pathway as a prognostic therapeutic target in the modulation of resistance to radiotherapy and chemotherapy. MicroRNA involved in the regulation of the IFN/STAT1 pathway is also discussed. A better understanding of radiation-induced IFN/STAT1 signaling will open new opportunities for the development of novel therapeutic strategies, as well as define new approaches to enhance radio-immunotherapy efficacy in the treatment of various types of cancers.

The anti-viral facet of anti-rheumatic drugs: Lessons from COVID-19

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has posed the world at a pandemic risk. Coronavirus-19 disease (COVID-19) is an infectious disease caused by SARS-CoV-2, which causes pneumonia, requires intensive care unit hospitalization in about 10% of cases and can lead to a fatal outcome. Several efforts are currently made to find a treatment for COVID-19 patients. So far, several anti-viral and immunosuppressive or immunomodulating drugs have demonstrated some efficacy on COVID-19 both in vitro and in animal models as well as in cases series. In COVID-19 patients a pro-inflammatory status with high levels of interleukin (IL)-1B, IL-1 receptor (R)A and tumor necrosis factor (TNF)-α has been demonstrated. Moreover, high levels of IL-6 and TNF-α have been observed in patients requiring intensive-care-unit hospitalization. This provided rationale for the use of anti-rheumatic drugs as potential treatments for this severe viral infection. Other agents, such as hydroxychloroquine and chloroquine might have a direct anti-viral effect. The anti-viral aspect of immunosuppressants towards a variety of viruses has been known since long time and it is herein discussed in the view of searching for a potential treatment for SARS-CoV-2 infection.

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.

New therapies in development for the management of non-infectious uveitis: A review

Uveitis is a spectrum of inflammatory disorders characterized by ocular inflammation and is one of the leading causes of preventable visual loss. The main aim of the treatment of uveitis is to control the inflammation, prevent recurrences of the disease and preserve vision while minimizing the adverse effects associated with the therapeutic agents. Initial management of uveitis relies heavily on the use of corticosteroids. However, monotherapy with high-dose corticosteroids is associated with side effects and cannot be maintained long term. Therefore, steroid-sparing agents are needed to decrease the burden of steroid therapy. Currently, the therapeutic approach for non-infectious uveitis (NIU) consists of a step-ladder strategy with the first-line option being corticosteroids in various formulations followed by the use of first-, second- and third-line agents in cases with suboptimal steroid response. Unfortunately, the agents currently at our disposal have limitations such as having a narrow therapeutic window along with their own individual potential side-effect profiles. Therefore, research has been targeted to identify newer drugs as well as new uses for older drugs that target specific pathways in the inflammatory response. Such efforts are made in order to provide targeted and safer therapy with reduced side effects and greater efficacy. Several specially designed molecular antibodies are currently in various phases of investigations that can potentially halt the inflammation in patients with NIU. In the review, we have provided a comprehensive overview of the current and upcoming therapeutic options for patients with NIU.

Joints for joints: cannabinoids in the treatment of rheumatoid arthritis

PURPOSE OF REVIEW

An increasing number of patients with rheumatoid arthritis (RA) are using cannabis to treat their symptoms, although systematic studies regarding efficacy in RA are lacking. Within this review we will give an overview on the overall effects of cannabinoids in inflammation and why they might be useful in the treatment of RA.

RECENT FINDINGS

Peripherally, cannabinoids show anti-inflammatory effects by activating cannabinoid type 2 receptors (CB2) which decrease cytokine production and immune cell mobilization. In contrast, cannabinoid type 1 receptor (CB1) activation on immune cells is proinflammatory while CB1 antagonism provides anti-inflammatory effects by increasing β2-adrenergic signaling in the joint and secondary lymphoid organs. In addition, the nonpsychotropic cannabinoid, cannabidiol (CBD) demonstrated antiarthritic effects independent of cannabinoid receptors. In addition to controlling inflammation, cannabinoids reduce pain by activating central and peripheral CB1, peripheral CB2 receptors and CBD-sensitive noncannabinoid receptor targets.

SUMMARY

Cannabinoids might be a suitable treatment for RA, but it is important to target the right receptors in the right place. For clinical studies, we propose a combination of a CB2 agonist to decrease cytokine production, a peripheral CB1 antagonist to prevent detrimental CB1 signaling and to support anti-inflammatory effects of CB2 via activation of β2-adrenergic receptors and CBD to induce cannabinoid-receptor-independent anti-inflammatory effects.

Real-world evaluation of effectiveness, persistence, and usage patterns of tofacitinib in treatment of rheumatoid arthritis in Australia

INTRODUCTION

The aim of this study was to describe the real-world evidence for effectiveness, treatment persistence, and treatment patterns among patients in the community with rheumatoid arthritis treated with the JAK inhibitor tofacitinib.

METHODS

This was a retrospective, non-interventional cohort study that extracted data for new users of tofacitinib or biologic disease-modifying antirheumatic drugs (bDMARDs) from the Australian Optimizing Patient outcomes in Australian RheumatoLogy (OPAL) dataset between March 2015 and September 2018. Patients were propensity score matched at a 1:2 tofacitinib to bDMARD ratio based on age, sex, and selected baseline treatment combinations. Treatment effectiveness was evaluated using disease status measures. Treatment persistence was calculated and the percentage of patients receiving monotherapy or combination therapy at treatment initiation was evaluated.

RESULTS

Data from 2810 patients were extracted and 1950 patients were included in the matched population (1300 bDMARD initiators and 650 tofacitinib initiators). Patients were predominantly aged 55 to 74 years (57.8%) and female (81.2%). After 18 months of treatment, 52.4% and 57.8% of patients had achieved disease activity score (DAS) remission in the bDMARD and tofacitinib groups, respectively. The median treatment persistence for tofacitinib was similar to that for bDMARDs: 34.2 months (95% CI 32.2 to not reached) and 33.8 months (95% CI 28.8 to 40.4), respectively. In the overall population, more patients were prescribed tofacitinib as monotherapy (43.4%) compared with bDMARD monotherapy (33.4%).

CONCLUSIONS

Tofacitinib demonstrated treatment effectiveness and persistence similar to bDMARDs. Overall, there was a trend for more use of tofacitinib as monotherapy than bDMARDs. Key Points • This study provides real-world evidence regarding effectiveness, treatment persistence, and treatment patterns, among patients with rheumatoid arthritis (RA) in the community being treated with tofacitinib. • The study suggests that tofacitinib is an effective and enduring intervention in RA with tofacitinib persistence and effectiveness comparable to bDMARDs.

Tofacitinib inhibits ox-LDL-induced adhesion of THP-1 monocytes to endothelial cells

Atherosclerosis is a chronic inflammatory disease of the blood vasculature. Endothelial dysfunction is an early event in the development of atherosclerosis and the endothelium plays an important role in the innate immune defense in the pathology of cardiovascular diseases. New therapies are being developed based on the involvement of the immune system in atherosclerosis. In this study, we demonstrate that a commonly used anti-rheumatic drug, tofacitinib, possesses vascular protective properties in cultured primary human aortic endothelial cells (HAECs). Tofacitinib ameliorates oxidized low-density lipoprotein (ox-LDL)-induced adhesion of THP-1 cells to HAECs, suppresses the expression of vascular adhesion molecules and production of cytokines, including vascular cell adhesion molecule 1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Moreover, tofacitinib inhibits elevation of endothelial lectin-like ox-LDL receptor-1 (LOX-1) and production of reactive oxygen species (ROS) triggered by ox-LDL. As a result, the presence of tofacitinib reduces ox-LDL-induced cytotoxicity and improves endothelial viability. Mechanistically, we demonstrate that tofacitinib suppresses ox-LDL-mediated activation of NF-κB inhibitor α (IκB-α), accumulation of nuclear p65 and activation of nuclear factor κB (NF-κB) promoter, indicating that tofacitinib inhibits NF-κB activation. Collectively, our data support that tofacitinib possesses a novel protective function in endothelial cells, implying that tofacitinib could have the therapeutic potential to modulate inflammation in cardiovascular diseases.

[Role of janus kinase inhibitors in the treatment of rheumatic diseases]

Janus kinases inhibitors (JAKI) are new orally administrable disease-modifying antirheumatic drugs (DMARD) for the treatment of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), representing a treatment alternative equally effective as biological DMARD that is also classified equivalent in the guidelines. JAKI reversibly inhibit intracellular signal transduction from the cytokine receptor to the nucleus. Tofacitinib and baricitinib, two JAKI already approved for RA treatment, are taken once or twice a day, respectively, and two more are expected to receive approval next year. Tofacitinib is also approved for PsA. Generally, JAKI are initially used in combination with methotrexate (MTX) but are equally effective as monotherapeutic treatment if MTX is contraindicated. In terms of therapy safety, JAKI and bDMARD are generally comparable with one exception: JAKI are associated with an increased risk of herpes zoster infection. JAKI treatment requires laboratory blood tests, especially blood count, transaminases and creatinine. Due to hepatic metabolization, tofacitinib is associated with certain drug interactions. Altogether JAKI enhance treatment possibilities for diseases such as RA and PsA combining the same effectiveness and safety as bDMARD with the option of oral administration.

Tofacitinib in Pediatric Psoriasis: An Open-Label Trial to Study Its Safety and Efficacy in Children

Introduction: Psoriasis is a chronic, multifactorial, inflammatory disorder, with an estimated prevalence of 0.71% in children. The commonly used therapeutic agents target the underlying inflammation. Tofacitinib has demonstrated efficacy in adult psoriasis. Aim: To study the efficacy, safety, and tolerability of tofacitinib in pediatric patients with moderate to severe chronic plaque psoriasis. Methods: The study included children aged between 8 and 17 years, with moderate to severe psoriasis, given tofacitinib 5 mg orally twice daily for at least 36 weeks. The clinical response was estimated using the Psoriasis Area and Severity Index (PASI) score, Physician’s Global Assessment (PGA), and the Children’s Dermatology Life Quality Index (CDLQI). The incidence and severity of adverse events (AEs) were meticulously recorded in each case. Results: A total of 47 patients, with a median age of 12.3 years, completed the study. At week 12, 55.32% achieved PASI 75, and 70.21% at week 36. PGA of clear or almost clear responses at week 12 were 59.57 and 65.96%, ­respectfully, at week 36. Relatively few and mostly minor ­adverse effects were noted. No severe AEs were reported. ­Conclusion: The treatment with tofacitinib was safe and well tolerated, and led to significant improvement of their disease and quality of life as reflected in CDLQI scores. However, the results need to be validated in larger multicenter trials.

Clinical significance of Janus kinase inhibitors in the therapy of rheumatoid arthritis: achievements and prospects

Significant successes in the use of biological agents (BA) have been achieved in the treatment of rheumatoid arthritis (RA); nonetheless, about 36% of patients cannot respond to therapy or achieve the expected effect. A new area in the treatment of RA is the use of Janus kinase (JAK) inhibitors, targeted synthetic disease-modifying anti-rheumatic drugs (chemical molecules with a molecular weight <1 kDa for oral administration) that inhibit the activity of intracellular signaling systems. The authors consider the clinical achievements and prospects, which open the use of JAK inhibitors in the treatment of RA.

The JAK inhibitor tofacitinib ameliorates immune‑mediated liver injury in mice

The prevalence of immune-mediated liver diseases such as autoimmune liver disease or viral hepatitis has increased in recent years, and the side effects of pre-existing treatments are a worldwide problem. Regulatory T cells (Tregs) and T helper 17 (Th17) cells play important roles in the development of immune-mediated hepatitis and may serve as potential therapeutic targets. Tofacitinib, a new Janus kinase (JAK) inhibitor, is under investigation for the treatment of rheumatoid arthritis; it is also helpful in treating ulcerative colitis and psoriasis. The roles of tofacitinib were investigated in conferring protection against immune-mediated liver injury in mice. T cell-mediated hepatitis was induced by concanavalin A (ConA). The mice in the treatment groups were administered with tofacitinib intragastrically before the ConA injection. Histopathological examination was performed by hematoxylin and eosin (H&E) staining, and the serum transaminase and inflammatory cytokine levels were determined using an automatic biochemistry analysis apparatus or cytometric bead array (CBA) kits. Flow cytometric analysis was used to detect Tregs and Th17 cells. Tofacitinib significantly decreased the hepatic injury induced by ConA and prominently decreased the liver transaminase level. The secretion of several anti-inflammatory cytokines such as interleukin (IL)-10 was upregulated in mice from the treatment group, compared to that in mice treated with ConA alone, while the expression of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) decreased. Tofacitinib treatment increased the number of Tregs and reduced the number of Th17 cells. Furthermore, tofacitinib could relieve liver fibrosis under conditions of autoimmune hepatitis (AIH). The present results indicated that tofacitinib improved immune-mediated hepatitis and restored the impaired Treg/Th17 cell ratio, which suggests that it may serve as a novel treatment approach for immune-mediated liver diseases.

Defining response to TNF-inhibitors in rheumatoid arthritis: the negative impact of anti-TNF cycling and the need for a personalized medicine approach to identify primary non-responders

Current guidelines recommend treating rheumatoid arthritis (RA) patients to reach low disease activity or remission, however, most biologic-naive RA patients fail to reach treatment targets on their first biologic therapy. Approximately 90% of biologic-naive RA patients receive a tumor necrosis factor alpha inhibitor (anti-TNF) as their first biologic treatment, even though several alternative mechanism of action (MOA) therapies are approved as first-line options. After 3 months of therapy, patients may remain on anti-TNF therapy even if they fail to achieve the treatment target, mainly due to formulary structures. This means patients have to endure a second and even a third ineffective anti-TNF-called anti-TNF cycling-before changing MOA. This significantly delays patients from reaching their treatment targets. All anti-TNF drugs target the same molecular and inflammatory pathways; thus, it is not surprising that most patients who are primary non-responders to their initial anti-TNF therapy fail to achieve their treatment targets when cycled through alternative anti-TNFs. This suggests that primary non-responders should be switched to an alternative MOA therapy rather than enduring anti-TNF cycling. Avoiding anti-TNF cycling would prevent disease progression and improve quality of life for RA patients who are primary non-responders to anti-TNFs. The development of a personalized medicine approach to identify primary non-responders to anti-TNFs prior to treatment would allow significantly more patients to reach their treatment target by treating them with alternative MOA therapies as first-line therapies.

[New directions of pharmacotherapy of immune - inflammatory rheumatic diseases]

Deciphering immunopathogenesis, expanding the scope of diagnostics and developing new methods for treating human autoimmune diseases are among the priority areas of XXI century medicine. Particularly widely autoimmune pathology is presented in immunoinflammatory rheumatic diseases (IIRD), such as rheumatoid arthritis, systemic lupus erythematosus, systemic scleroderma, systemic vasculitis associated with the synthesis of antineutrophilic cytoplasmic antibodies, Sjogren's syndrome, idiopathic inflammatory myopathies and other other types of others. Deciphering the pathogenesis mechanisms of IIRD created the prerequisites for improving pharmacotherapy, which in the future should lead to a dramatic improvement in the prognosis for these diseases. The review discusses new approaches to IIRD pharmacotherapy associated with the inhibition of tumor necrosis factor-α, interleukin-6 (IL-6), IL-1β, IL-17, IL-23, and the prospects for using Janus kinase inhibitors, depending on the prevailing pathogenesis mechanisms - autoimmunity or autoinflammation.

JAK inhibitors in 2019, synthetic review in 10 points

JAK inhibitors are recent treatments. Many publications have appeared in recent years, exposing treatment efficiencies in phases 2 and 3 studies, or their tolerance profile in various rheumatological diseases. We propose here a systematic review of JAK inhibitors, from their mechanism of physiological action up to the estimation of their current risk benefit balance, and their possible future applications. In order to better synthesize the data, we organized this review into 10 essential points. 1- What is the role of JAK/Stat pathway? 2- How can a single signaling pathway regulate as many different signals? 3- What are the commercialized JAK inhibitors and their validated indications in humans today? 4- What is the level of efficiency of JAK inhibitors in inflammatory diseases? 5- What is the delay of efficiency of JAK inhibitors? 6- Where is the place of JAK inhibitors in the therapeutic strategy today? 7- What is the infectious tolerance profile of JAK inhibitors? 8- What is the non-infectious safety profile of JAK inhibitors? 9- What is the cost of JAK inhibitors compared to other DMARDs? 10- What future prospects for JAK inhibitors?

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.

A systematic review of the association of obesity with the outcomes of inflammatory rheumatic diseases

This was a systematic review of the literature on the association between obesity and the outcome of inflammatory rheumatic diseases. We conducted a literature search using PubMed®, Embase and PsycINFO®. Articles were classified into three categories based on the effects of obesity on the outcomes of inflammatory rheumatic diseases. The subject population, country, type of studies, number of patients, measurement of obesity and outcomes assessed were presented. Quality was appraised using Kmet et al's criteria. 4,331 articles were screened and 60 were relevant to the objective. Obesity had a negative, positive and neutral association with outcomes of inflammatory rheumatic diseases in 38 (63.3%) studies with 57,612 subjects, 11 (18.3%) studies with 3,866 subjects, and 11 (18.3%) studies with 3,834 subjects, respectively. In most studies, the disease population had been diagnosed with rheumatoid arthritis (RA). Tumour necrosis factor-α inhibitors were mostly associated with negative outcomes. More studies examining subjects outside Europe and North America and diseases other than RA are warranted.

Estimation of Fraction Dissolved After Intratracheal Delivery of a Potent Janus Kinase Inhibitor, iJAK-001, with Low Solubility in Rat and Sheep: Impact of Preclinical PKPD on Inhaled Human Dose Projection

Background: A highly potent pan-Janus kinase (JAK) inhibitor with excellent kinome selectivity was developed for topical delivery to treat severe asthma. This poorly soluble drug discovery candidate, iJAK-001, is expected to exhibit long duration of JAK/STAT pathway inhibition at low doses in asthmatics because of depot effect after dry powder inhalation. Human dose projection for inhaled molecules with low aqueous solubility remains to be a daunting challenge because of several limitations: (1) bioanalytical measurement of dissolved fraction after inhalation of solid particles is uncertain; (2) distribution of these particles is not homogenous in the lung; (3) in vitro solubility measurements to estimate fraction dissolved may not be a reflection of local surface lung concentration; (4) lack of a surrogate biomarker of lung target engagement, and (5) invasive procedure needed to sample human lung tissue in the clinic. Methods: We leveraged in silico, in vitro, and in vivo tools preclinically and found significant differences in lung to plasma partition ratio when iJAK-001 was given intravenously (IV) or intratracheally in a solution-based formulation versus that in suspension, as well as pharmacodynamic response in preclinical asthma models when delivered systemically via IV infusion versus inhaled. Results and Conclusion: The combined results from above suggest that caution must be exercised using either lung or plasma exposure for human dose projection. Instead, using the local inhibitor concentration estimate based on delivery efficiency, dose, fraction absorbed, and rate of absorption normalized by lung (cardiac) blood flow may be more appropriate for dose projection.

Tofacitinib for the treatment of rheumatoid arthritis: an update

INTRODUCTION

Tofacitinib inhibits the Janus kinases, tyrosine kinases that are activated by cytokines involved in the pathophysiology of rheumatoid arthritis. Areas covered: Clinical trials have revealed an anti-rheumatic effect of monotherapy and combination therapy with methotrexate (MTX). Post-hoc analysis of those clinical trials and real-world experiences will be reviewed to explore efficacy and safety. Expert commentary: The efficacy of tofacitinib monotherapy has garnered much attention and has been initiated in large number of patients. However, combination therapy with MTX is necessary in order to achieve the maximum effect. Combination therapy can be transferred to monotherapy by tapering and/or discontinuing MTX. The discontinuation of tofacitinib should be avoided and tapering should be investigated. There has been no new safety signal although venous thrombotic events (VTEs) have been raised and would require long-term follow-up. Increased events of Herpes zoster were observed and the use of a subunit vaccination is expected to become an effective tool for prevention. Post-hoc analysis of the clinical trials and real-world experience is revealing further usefulness of tofacitinib not only in rheumatoid arthritis but also other diseases. Additional experience and data from the real world are required to help improve the use of tofacitinib..

Tofacitinib: A Review in Psoriatic Arthritis

Tofacitinib (Xeljanz^®) is the first Janus kinase (JAK) inhibitor approved at a dosage of 5 mg twice daily (BID) in the EU and the USA for the treatment of active psoriatic arthritis (PsA), where it is indicated in combination with methotrexate for patients who have had an inadequate response or who have been intolerant to a prior therapy with a disease-modifying antirheumatic drug (DMARD). Two well-designed phase III trials (OPAL Broaden and OPAL Beyond) in patients with PsA with or without prior tumour necrosis factor inhibitor (TNFi) therapy showed that tofacitinib 5 mg BID (co-administered with methotrexate or another approved conventional synthetic DMARD) significantly improved the key clinical signs/symptoms and disability associated with PsA after 3 months of treatment, while also improving skin psoriasis, enthesitis, dactylitis, physical function and fatigue. According to interim data, the improvements in clinical signs/symptoms were maintained for up to 30 months in the ongoing long-term extension study OPAL Balance, with minimal radiographic progression seen after 12 months' therapy in the OPAL Broaden study. Tofacitinib 5 mg BID had an acceptable tolerability profile, with low incidences of serious infections, malignancies, cardiovascular events and gastrointestinal perforations over 36 months. Changes in laboratory parameters generally remained stable over 36 months of treatment. Although further studies are required to more definitively establish its efficacy and safety, currently available evidence indicates that tofacitinib expands the treatment options available for the treatment of PsA in patients who have had an inadequate response or who have been intolerant to a prior DMARD therapy.

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.

Tuberculosis, hepatitis B and herpes zoster in tofacitinib-treated patients with rheumatoid arthritis

There is currently interest in the risk of infections during treatment with new targeted synthetic disease-modifying antirheumatic drugs (DMARDs), specifically the Janus kinase inhibitor tofacitinib. Tofacitinib has been studied extensively in patients with rheumatoid arthritis and has been shown to be effective and generally safe. East Asian countries have a high background rate of tuberculosis (TB) and hepatitis B virus (HBV) infection and the risk of recurrence or reactivation of infections such as TB, HBV and herpes zoster during DMARD therapy is of particular interest in the region. This paper reviews available data on the risk of TB, HBV and herpes zoster infections, including recurrence/reactivation of infections, during treatment with tofacitinib, with a focus on east Asia.

A benzoxazole derivative PO-296 inhibits T lymphocyte proliferation by the JAK3/STAT5 signal pathway

Immunosuppressants have shown striking achievements in treating autoimmune diseases in recent years. It is urgent to develop more immunosuppressants to provide more options for patients. PO-296 [2-(6-chlorobenzo[d]oxazol-2-yl)-4,5,6,7-tetrahydro-2H-indazol-3-ol] was identified as a novel benzoxazole derivative. We observed that it exhibits an obvious immunosuppressive activity to T lymphocytes. PO-296 significantly inhibited the proliferation of activated human T lymphocyte without cytotoxicity. Moreover, PO-296 did not affect the expression of cluster of differentiation (CD)-25 or CD69 but induced T lymphocyte cycle arrest in the G0/G1 phase. Furthermore, PO-296 inhibited interleukin (IL)-6, IL-17, and interferon gamma expression but had no effect on IL-2, IL-4, or IL-10. Yet, importantly, PO-296 inhibited the phosphorylation of signal transducer and activator of transcription 5 (STAT5), increased the phosphorylation of p70S6K, but did not affect the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mitogen-activated protein kinase pathway. In conclusion, these findings indicate that PO-296 inhibits human activated T-lymphocyte proliferation by affecting the janus kinase 3 (JAK3)/STAT5 pathway. PO-296 possesses a potential lead compound for the design and development of new immunosuppressants for the treatment of autoimmune diseases.

Targeting cytokines to treat autoinflammatory diseases

Autoinflammatory diseases are rare group of conditions manifested by recurrent fevers, systemic inflammation, and dysfunctions of the innate immune system. These conditions are characterized by overproduction or lack of inhibition of various cytokines, and the advent of biologic drugs that block specific cytokines involved in these conditions has revolutionized their treatment. In this review, I will discuss the most common autoinflammatory conditions of adulthood including familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), mevalonate kinase deficiency/hyperimmunoglobulinemia D Syndrome (MKD/HIDS), TNF receptor-associated autoinflammatory syndrome (TRAPS), and systemic juvenile idiopathic arthritis/adult-onset Still's disease (SJIA/AOSD). I will discuss how IL-1, IL-6, IL-18, and TNF play pathogenic roles in these conditions and will review the evidence behind cytokine blockade for these diseases. Throughout the paper, I will reflect on gaps in knowledge of autoinflammatory diseases and will highlight the latest advances and newest drugs in development.

Safety concerns when using novel medications to treat alopecia

INTRODUCTION

Alopecia is often a cause of great concern to patients for cosmetic and psychologic reasons. The aim of treating non-scarring alopecias is to reduce hair loss and, to some extent, enhance hair regrowth. However, therapies for scarring alopecias are limited and aiming to halt disease progression. Nonetheless, available modalities of treatment come with numerous side effects. Areas covered: Many new treatments for non-scarring alopecias have been introduced in recent years. This review summarizes the safety concerns when using novel therapeutic modalities such as JAK inhibitors, hair transplantation, mesotherapy, oral minoxidil, platelet-rich plasma, microneedling, and 5α-reductase inhibitors for treating hair loss. A broad literature search was performed using PubMed and Google Scholar in April 2018 to compile published articles that reported the adverse effects of new therapeutic modalities for alopecia. Expert opinion: Although emerging therapeutic modalities for alopecia have demonstrated efficacy in hair regrowth and treating established disease, their safety profiles vary widely. When considering the new treatments for alopecia, physicians should weigh the potential benefits and risks of each treatment or combination treatment to ensure safe and successful outcomes.

Autophagy: A new concept in autoimmunity regulation and a novel therapeutic option

Nowadays, pharmacologic treatments of autoinflammatory diseases are largely palliative rather than curative. Most of them result in non-specific immunosuppression, which can be associated with broad disruption of natural and induced immunity with significant and sometimes serious unwanted injuries. Among the novel strategies that are under development, tools that modulate the immune system to restore normal tolerance mechanisms are central. In these approaches, peptide therapeutics constitute a class of agents that display many physicochemical advantages. Within this class of potent drugs, the phosphopeptide P140 is very promising for treating patients with lupus, and likely also patients with other chronic inflammatory diseases. We discovered that P140 targets autophagy, a finely orchestrated catabolic process, involved in the regulation of inflammation and in the biology of immune cells. In vitro, P140 acts directly on a particular form of autophagy called chaperone-mediated autophagy, which seems to be hyperactivated in certain subsets of lymphocytes in lupus and in other autoinflammatory settings. In lupus, the "correcting" effect of P140 on autophagy results in a weaker signaling of autoreactive T cells, leading to a significant improvement of pathophysiological status of treated mice. These findings also demonstrated ex vivo in human cells, open novel avenues of therapeutic intervention in pathological conditions, in which specific and not general targeting is highly pursued in the context of the new action plans for personalized medicines.

Role of janus kinase inhibitors in the treatment of alopecia areata

Alopecia areata (AA) is a common hair loss disorder worldwide with characteristic exclamation mark hairs. Although AA is self-limited, it can last for several months or even years in some patients. Currently, there is no US Food and Drug Administration-approved treatment for AA. Many off-label treatments are available but with limited efficacy. Through a better understanding of molecular biology, many targeted therapies have emerged as new alternatives for various autoimmune diseases. Various janus kinase (JAK) and signal transducer and activator of transcription (STAT) proteins form signaling pathways, which transmit extracellular cytokine signals to the nucleus and induce DNA transcriptions. By inhibiting JAK, T-cell-mediated inflammatory responses are suppressed. Increasing evidence suggests that JAK inhibitors (JAKis) are effective in the treatment of many autoimmune diseases, including AA. Among these, several studies on tofacitinib, ruxolitinib, and baricitinib in AA had been published, demonstrating promising outcomes of these agents. Unlike oral formulations, efficacy of topical forms of tofacitinib and ruxolitinib reported in these studies is still unsatisfactory and requires improvement. This review aims to summarize evidence of the efficacy and safety of JAKis in the treatment of AA.

A New Perspective: Mitochondrial Stat3 as a Regulator for Lymphocyte Function

Stat3 as a transcription factor regulating gene expression in lymphocytes during the immune response is well known. However, since the pioneering studies discovering the presence of Stat3 in mitochondria and its role in regulating mitochondrial metabolism, only a few studies have investigated this non-conventional function of Stat3 in lymphocytes. From this perspective, we review what is known about Stat3 as a transcription factor and what is known and unknown about mitochondrial Stat3 (mitoStat3) in lymphocytes. We also provide a framework to consider how some of the functions previously assigned to Stat3 as regulator of gene transcription could be mediated by mitoStat3 in lymphocytes. The goal of this review is to stimulate interest for future studies investigating mitoStat3 in the immune response that could lead to the generation of alternative pharmacological inhibitors of mitoStat3 for the treatment of chronic inflammatory diseases.