Efficacy and safety of tofacitinib in the treatment of rheumatoid arthritis: a systematic review and meta-analysis

Treatment with Janus kinase inhibitors in juvenile dermatomyositis: A review of the literature

BACKGROUND/OBJECTIVES

Janus kinase (JAK) inhibitors have been increasingly used in the treatment of juvenile dermatomyositis (JDM). This review aims to comprehensively analyze previous studies concerning the utilization of JAK inhibitors in JDM patients.

METHODS

We conducted a thorough review of MEDLINE and Scopus databases, spanning from their inception to September 1st, 2023, to identify articles involving JDM patients treated with JAK inhibitors.

RESULTS

Our literature search yielded 26 articles that encompassed 195 patients with JDM who received JAK inhibitors. The median (min-max) age of the patients was 4.9 (1-17) years (F/M:1.2). The most frequently used JAK inhibitor was tofacitinib (57.4 %), and improvement was achieved in 89.7 % of patients treated with tofacitinib. The improvement rate for ruxolitinib, which was the second most frequently used JAK inhibitor (27.2 %), was 69.2 %. For baricitinib (15.4 %), the improvement rate was 92.7 %. The most prevalent indication for JAK inhibitor use was resistant/recurrent skin involvement (34.7 %) followed by resistant/recurrent muscle involvement (28.6 %). Adverse events were reported in 72.1 % of the patients; an increase in infections (especially upper respiratory tract infections) was the most common side effect.

CONCLUSION

Our findings suggest that JAK inhibitors may be a good therapeutic option, particularly in the management of refractory JDM cases with an acceptable safety profile. However, further controlled studies are essential to establish a higher level of evidence for the optimal use of JAK inhibitors in JDM treatment.

Recalcitrant nodular scabies showing excellent response to tofacitinib: five case reports

Scabies is a contagious skin condition caused by Sarcoptes scabiei, and it is always associated with an intense, unbearable, nocturnal deteriorating itch. Its presentations include classic burrows, erythema, pruritic papules, pustules, vesicles, and inflammatory nodules, with diffuse or localized distribution on the finger webs, wrist flexors, elbows, axillae, buttocks, genitalia, and breasts. Nodular scabies is an uncommon clinical variant of scabies. Its management is still challenging for some patients up to date, although topical, intralesional or systemic corticosteroids, topical calcineurin inhibitors, and crotamiton as well as cryotherapy alone or in different combinations are used. We here report five male patients of nodular scabies, aged between 14 and 25 years, who had classical scabies that had been cured by sulfur ointment for at least 4 weeks except for their itching nodules, and their residual pruritic nodules also failed in previous treatments including antihistamines, topical applying and intralesional injection of steroids as well as topical tacrolimus in different combinations before being recruited to this study. The patients were administered tofacitinib 5 mg, twice a day, which led to excellent and rapid improvement for both lesions and symptoms after 1-4 weeks of treatment, respectively, without any associations. During 6 months of follow-up, only one had re-infection of scabies associated with nodules that were cured by sulfur ointment and tofacitinib again. No adverse reaction was observed. The present results suggested that tofacitinib might be a potential agent for nodular scabies with excellent response.

Network Approaches to Uncover Pathogenesis and Therapeutic Targets of Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are currently recognized to involve chronic intestinal inflammation in genetically susceptible individuals. Patients with IBD mainly develop gastrointestinal inflammation, but it is sometimes accompanied by extraintestinal manifestations such as arthritis, erythema nodosum, episcleritis, pyoderma gangrenosum, uveitis, and primary sclerosing cholangitis. These clinical aspects imply the importance of interorgan networks in IBD. In the gastrointestinal tract, immune cells are influenced by multiple local environmental factors including microbiota, dietary environment, and intercellular networks, which further alter molecular networks in immune cells. Therefore, deciphering networks at interorgan, intercellular, and intracellular levels should help to obtain a comprehensive understanding of IBD. This review focuses on the intestinal immune system, which governs the physiological and pathological functions of the digestive system in harmony with the other organs.

Breaking through the therapeutic ceiling of inflammatory bowel disease: Dual-targeted therapies

Emerging biologics and small-molecule drugs have changed the clinical status quo of inflammatory bowel disease (IBD). However, current treatments remain at a standstill in terms of response and remission in many cases. Accumulating evidence indicates that dual-targeted therapy (DTT) could be promising in overcoming the existing ceiling of IBD treatment. However, data on the efficacy and safety of DTT on Crohn's disease and ulcerative colitis are still limited or insufficient. Moreover, there is a lack of studies delineating the mechanisms of DTT. Given that various targeted drugs have different targets among the extensive redundant inflammatory networks, DTT could result in various outcomes. In this review, we have summarized the current data on the safety, effectiveness, and clinical development status of novel targeted drugs related to refractory IBD, and have explored the mechanism of action of therapy. We have categorized therapeutic agents into "Therapeutic Agents Targeting Cellular Signaling Pathways" and "Therapeutic Agents Targeting Leukocyte Trafficking" based on the different therapeutic targets, and also by classifying therapeutic agents targeting the cellular signaling pathways into "JAK-dependent" and "JAK-independent," and placed the existing drug combinations into 3 categories based on their mechanisms, namely, overlapping, synergistic, and complementary effects. Lastly, we have proposed the possible mechanisms of DTT to conceive a theoretical framework for clinical decision-making and further drug development and research from an IBD standpoint.

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.

Zingerone (4-(four-hydroxy-3-methylphenyl) butane-two-1) modulates adjuvant-induced rheumatoid arthritis by regulating inflammatory cytokines and antioxidants

OBJECTIVE

Ginger (Zingiber officinale Roscoe) is considered to be one of the most commonly consumed dietary condiments of the world. The present study was designed to explicate the protective role of zingerone; an active ingredient of ginger in complete Freund's adjuvant (FCA)-immunized arthritic rats.

METHODS

24 Wistar rats were divided into 4 groups with 6 rats each. Group I as control followed by group II, III and IV were treated with single intradermal injection of FCA (0.1 ml = 100 µg) to induce rheumatoid arthritis. Group III and IV were also administered with zingerone orally at 25 mg/kg b.w for 3 weeks at two different time points.

RESULTS

Adjuvant-treated rats exhibited a significant increase in lipid peroxidation and a reduction in the enzymatic antioxidants such as SOD, catalase and GPx, in the liver and joint tissues. Moreover, FCA inoculation resulted in the increase in levels of NF-κB, TGF-β, TNF-α, IL-1β, IL-6 and Hs-CRP and a decrease in IL-10 levels. Zingerone significantly reduced the levels of NF-κB, TGF-β, TNF-α, IL-1β, IL-6 and Hs-CRP and markedly increased IL-10 levels. Levels of antioxidant enzymes were also restored by zingerone treatment.

DISCUSSION

Oral administration of zingerone ameliorated inflammatory outburst and decreased oxidative stress, suggesting its role in the prevention of rheumatoid arthritis. Further mechanistic insights are necessary to study the exact mechanism involved.

Perioperative Management of Antirheumatic Medications in Patients with RA and SLE Undergoing Elective Foot and Ankle Surgery: A Critical Analysis Review

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Recent literature has shown that continued use rather than discontinuation of various antirheumatic agents throughout the perioperative period may present an opportunity to mitigate the risks of elective surgery.

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For patients with rheumatoid arthritis and systemic lupus erythematosus, perioperative management of medication weighs the risk of infection against the risk of disease flare when immunosuppressive medications are withheld.

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Broadly speaking, current evidence, although limited in quality, supports perioperative continuation of disease-modifying antirheumatic drugs, whereas biologic drugs should be withheld perioperatively, based on the dosing interval of the specific drug.

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For any withheld biologic drug, it is generally safe to restart these medications approximately 2 weeks after surgery, once the wound shows evidence of healing, all sutures and staples have been removed, and there is no clinical evidence of infection. The focus of this recommendation applies to the optimization of wound-healing, not bone-healing.

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In most cases, the usual daily dose of glucocorticoids is administered in the perioperative period rather than administering "stress-dose steroids" on the day of surgery.

JAK-inhibitors for dermatomyositis: A concise literature review

Refractory dermatomyositis (DM) is defined as cases that do not show improvement after initial treatment with two different immunosuppressives combined with corticosteroids with or without intravenous immunoglobulins. In recent years, few studies have reported a positive response to the use of Janus kinase inhibitors (JAK-inhibitors) for the treatment of refractory DM. A systematic literature review was performed for articles studying the use of JAK-inhibitors for the treatment of refractory DM. We identified 38 females and 15 males treated with JAK-inhibitors without serious side effects. Tofacitinib was the most frequently used JAK-inhibitor followed by ruxolitinib. Significant improvement in CDASI score, muscle strength, body weight, and skin lesions were reported in most of the studies. The duration of follow-up ranged from 1 to 15 months without relapse. Therefore, the use of JAK-inhibitors looks promising in the treatment of refractory DM and further high volume research may be required to validate the current concept. As only case reports and series were identified without direct comparison for review, there is a potential risk of bias. Despite these limitations, we believe that the result of this analysis allows a better understanding of treatment options for refractory DM and will help generate a hypothesis that can be further tested.

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.

Multidisciplinary Guidance Regarding the Use of Immunomodulatory Therapies for Acute Coronavirus Disease 2019 in Pediatric Patients

BACKGROUND

Immune-mediated lung injury and systemic hyperinflammation are characteristic of severe and critical coronavirus disease 2019 (COVID-19) in adults. Although the majority of severe acute respiratory syndrome coronavirus 2 infections in pediatric populations result in minimal or mild COVID-19 in the acute phase of infection, a small subset of children develop severe and even critical disease in this phase with concomitant inflammation that may benefit from immunomodulation. Therefore, guidance is needed regarding immunomodulatory therapies in the setting of acute pediatric COVID-19. This document does not provide guidance regarding the recently emergent multisystem inflammatory syndrome in children (MIS-C).

METHODS

A multidisciplinary panel of pediatric subspecialty physicians and pharmacists with expertise in infectious diseases, rheumatology, hematology/oncology, and critical care medicine was convened. Guidance statements were developed based on best available evidence and expert opinion.

RESULTS

The panel devised a framework for considering the use of immunomodulatory therapy based on an assessment of clinical disease severity and degree of multiorgan involvement combined with evidence of hyperinflammation. Additionally, the known rationale for consideration of each immunomodulatory approach and the associated risks and benefits was summarized.

CONCLUSIONS

Immunomodulatory therapy is not recommended for the majority of pediatric patients, who typically develop mild or moderate COVID-19. For children with severe or critical illness, the use of immunomodulatory agents may be beneficial. The risks and benefits of such therapies are variable and should be evaluated on a case-by-case basis with input from appropriate specialty services. When available, the panel strongly favors immunomodulatory agent use within the context of clinical trials. The framework presented herein offers an approach to decision-making regarding immunomodulatory therapy for severe or critical pediatric COVID-19 and is informed by currently available data, while awaiting results of placebo-controlled randomized clinical trials.

M-134, a novel HDAC6-selective inhibitor, markedly improved arthritic severity in a rodent model of rheumatoid arthritis when combined with tofacitinib

BACKGROUND

Although tofacitinib has shown highly significant efficacy for rheumatoid arthritis (RA), there are still a considerable number of patients that are non-responders owing to its limited effectiveness and various adverse effects. Thus, alternative options with better efficacy and lower toxicity are desired. Here, M-134, a recently developed HDAC6 inhibitor, was examined for its therapeutic potential when combined with tofacitinib in a rat model of RA.

METHODS

The single or combined administration of M-134 and tofacitinib was examined in complete Freund's adjuvant-induced arthritis (AIA) or collagen-induced arthritis (CIA) rodent models. To evaluate the therapeutic and adverse effects, the following factors were observed: macroscopic or microscopic scoring of all four paws; the expression of ICAM-1, VCAM-1, and IP-10 in the joints and that of various cytokines and chemokines in the plasma; the weight of the thymus and the liver; and changes in hematological enzymes.

RESULTS

Combination treatment showed strong synergistic effects as measured by the clinical score and histological changes, without adverse effects such as weight loss in the thymus and increased liver enzymes (ALT and AST). Additionally, it also reduced ICAM-1, VCAM-1, and IP-10 expression in the joints, and M-134 increased the efficacy of tofacitinib by regulating various cytokines, such as interleukin (IL)-1β, IL-17, and TNF-α, in the serum of AIA rats. Differences in the cytokine expression for each drug were found in the CIA model.

CONCLUSIONS

M-134 and tofacitinib combination therapy is a potential option for the treatment of RA through the regulation of cytokines, chemokines, and adhesion molecules.

Efficacy and Safety of Tofacitinib, Baricitinib, and Upadacitinib for Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the efficacy and safety profiles of different dosing regimens of tofacitinib, baricitinib, and upadacitinib, novel selective oral Janus activated kinase inhibitors, in rheumatoid arthritis (RA).

METHODS

Randomized controlled trials of tofacitinib (5 and 10 mg twice daily) baricitinib (2 and 4 mg daily), and upadacitinib (15 and 30 mg daily) in RA were identified from MEDLINE, EMBASE, and Cochrane databases through December 11, 2019. Random-effects models were used to estimate pooled mean differences and relative risks (RRs). American College of Rheumatology 20%, Health Assessment Questionnaire-Disability Index, adverse events, risk for infection, venous thromboembolic events, and malignancy were calculated.

RESULTS

Twenty trials with an overall low risk of bias involving 8982 patients were identified. Tofacitinib, baricitinib, and upadacitinib improved RA control as determined by American College of Rheumatology 20% (RR, 2.03; 95% CI, 1.87 to 2.20) and Health Assessment Questionnaire-Disability Index scores (mean differences, -0.31; 95% CI, -0.34 to -0.28) compared with placebo. Adverse events were more frequent with upadacitinib, 30 mg, daily (RR, 1.15; 95% CI, 1.02 to 1.30); upadacitinib, 15 mg, daily (RR, 1.14; 95% CI, 1.02 to 1.27); and baricitinib, 4 mg, daily (RR, 1.13; 95% CI, 1.02 to 1.24). The risk for infection was highest with tofacitinib, 10 mg, twice daily (RR, 2.75; 95% CI, 1.72 to 4.41), followed by upadacitinib, 15 mg, daily (RR, 1.35; 95% CI, 1.14 to 1.60) and baricitinib, 4 mg, daily (RR, 1.28; 95% CI, 1.12 to 1.45). Data for venous thromboembolic events were not available for tofacitinib or baricitinib, but there was no increase in risk with upadacitinib (15 mg daily: RR, 2.34; 95% CI, 0.34 to 15.92).

CONCLUSION

Tofacitinib, baricitinib, and upadacitinib significantly improve RA control. Head-to-head Janus activated kinase inhibitor clinical trials are needed to further inform decision making.

JAK inhibitors and infections risk: focus on herpes zoster

Currently, there is a growing interest in Janus kinase (JAK) intracellular signalling since targeted inhibitors against these pathways are proving effective in the treatment of a range of immune-mediated diseases, such as rheumatoid arthritis (RA), psoriasis, psoriatic arthritis (PsA), inflammatory bowel disease and atopic dermatitis. In particular, post marketing experience and the increasing development of new pharmacological inhibitors of broad and increasingly selective JAK pathways provide new insights into the JAK pathway role in viral infections as well as their pathogenic role in immune-mediated inflammatory diseases. Herein we provide an overview of the biological role of JAK signalling and its role in immunity against viruses, with particular regard to herpes zoster reactivation. Thereafter, we will discuss the evidence currently available on the principal JAK inhibitors and their association with viral infections.

Metabolic Activation of Tofacitinib Mediated by Myeloperoxidase in Vitro

Tofacitinib (TFT) is used for the treatment of moderately and severely active rheumatoid arthritis. Unfortunately, TFT was reported to induce leukopenia, and the underlying mechanisms remain unclear. The present study demonstrated that TFT was oxidized to a chemically reactive nitrenium ion by myeloperoxidase (MPO) occurring in neutrophils. The electrophilic ion showed chemical reactivity toward N-acetyl-cysteine (NAC) to produce two TFT-NAC conjugates (M1 and M2) in incubation of TFT with leucocytes in the presence of NAC. The generation of the nitrenium ion was verified by HClO-mediated oxidation of TFT. In addition, the nitrenium ion was found to react with sulfhydryl groups of cysteine residues of cellular protein in leucocytes after exposure to TFT. The study facilitates the understanding of the mechanisms of TFT toxic action.

Tofacitinib Is a Mechanism-Based Inactivator of Cytochrome P450 3A4

Tofacitinib (TFT) is an oral JAK inhibitor which has been approved for the treatment of moderately and severely active rheumatoid arthritis. TFT was found to show concentration-, time-, and NADPH-dependent inhibition of CYP3A4, and irreversibility of the inactivation was also observed. Incubation (40 min, 37 °C) of recombinant CYP3A4 with TFT at 200 μM resulted in >70% loss of CYP3A4 activity. Estimated k_inact and K_I were 0.037 min^-1 and 93.2 μM, respectively. GSH and superoxide dismutase/catalase revealed minor or little protection against the CYP3A4 inactivation. Furthermore, ketoconazole attenuated TFT-mediated CYP3A4 inactivation. Epoxide and α-keto-aldehyde intermediates of TFT were trapped and characterized in microsomal incubations, respectively. The aldehyde intermediate is believed to be the key for the enzyme inactivation. Multiple P450 enzymes, including CYPs2C19, 3A4, 2D6, and 1A2, participated in the metabolism of TFT to the epoxide, while the formation of the aldehyde was mainly catalyzed by CYP3A4. In conclusion, TFT was proven to be a mechanism-based inactivator of CYP3A4.

Positioning biologics and new therapies in the management of inflammatory bowel disease

PURPOSE OF REVIEW

Since the advent of anti-tumour necrosis factor agents, knowledge of their optimal use and their pitfalls has grown exponentially. However, the range of therapeutic agents available to clinicians and patients is expanding, creating challenging decisions about which drugs to use at any given time point. The present review aims to provide a framework within which positioning decisions can be made in the context of limited comparative effectiveness data.

RECENT FINDINGS

The present review will summarize the current literature emphasizing how best to use biologic agents, and will provide suggestions as to how they should be positioned. Recent trials comparing efficacy and safety will be considered as will their strengths and weaknesses.

SUMMARY

On reading this review, clinicians should have an understanding of the optimal use of currently approved biologic agents and tofacitinib and how they might be positioned in relation to one another.

Questioning a publication bias between industry-funded and non-industry-funded randomized controlled trials on biological and small molecule therapy for rheumatoid arthritis

BACKGROUND

There has been a significant increase in financial support of clinical research by the pharmaceutical industry.

METHODS

We performed a comprehensive systematic literature review to determine whether there is publication bias for rheumatoid arthritis (RA) studies between industry-funded and non-industry funded randomized controlled trials (RCTs), and between RCTs with positive results (PRs) and those with negative results (NRs) of FDAapproved biological and small molecule drug therapy for RA. Each RCT was classified as having either a PR or a NR, and as having received commercial funding or not.

RESULTS

Most (297/349, 85.18%) of the RCTs were commercially funded. There was no significant difference in PRs or association with publication between commercially and noncommercially funded RCTs. Sample size was significantly larger in commercially funded RCTs and in those with PRs, and it was the only significant parameter that predicted publication in higher impact factor journals in the field of RA.

CONCLUSION

There is no significant association between commercial funding and the publication of positive results or the publication of an RCT in higher impact factor journals.

[New drugs for treatment of juvenile idiopathic arthritis]

The introduction of biologics 20 years ago has significantly changed the pharmacotherapy of juvenile idiopathic arthritis. Biologics are among the most successful innovations, not only in rheumatology. In addition to their strong efficacy the rapid onset of improvement , biologics offer an option for prevention of long-term damage and a realistic prospect of remission. This article discusses innovations in biologics and the importance of the latest group for targeted therapy with small molecules in pediatric rheumatology.

Update of the Mexican College of Rheumatology Guidelines for the Pharmacological Treatment of Rheumatoid Arthritis, 2018

Therapeutic advances in rheumatoid arthritis require periodic review of treatment guidelines.

OBJECTIVE

To update the Mexican College of Rheumatology guidelines on the pharmacological treatment of rheumatoid arthritis.

METHOD

Board certified rheumatologists from different health institutions and regions of the country participated. Work teams were formed that reviewed the previous guidelines, elaborated new questions, reviewed the literature, and scored the evidence that was presented and discussed in plenary session. The conclusions were presented to infectologists, gynaecologists and patients. Recommendations were based on levels of evidence according to GRADE methodology.

RESULTS

Updated recommendations on the use of available medications for rheumatoid arthritis treatment in Mexico up to 2017 are presented. The importance of adequate and sustained control of the disease is emphasized and relevant safety aspects are described. Bioethical conflicts are included, and government action is invited to strengthen correct treatment of the disease.

CONCLUSIONS

The updated recommendations of the Mexican College of Rheumatology on the pharmacological treatment of rheumatoid arthritis incorporate the best available information to be used in the Mexican health care system.

The Use of Janus Kinase Inhibitors in Vitiligo: A Review of the Literature

Vitiligo is a common acquired depigmenting disorder characterized by the development of white macules and patches due to the loss of melanocytes. Patients with vitiligo can be stigmatized by society, making the disease a source of psychological stress that can considerably affect quality of life. The goal of vitiligo treatment is to obtain skin repigmentation in the majority of cases, and less commonly to depigment the remaining normal skin. There is no consistent, long-term, durable therapy for vitiligo for all patients, highlighting the unmet need for new safe and effective therapies to control this disease. Recently, JAK inhibitors have been explored as a promising novel treatment option in vitiligo. The JAK and signal transducers and activators of transcription (STAT) pathway is an attractive therapeutic target because IFN-γ-dependent cytokines produced through this pathway have been implicated in the pathogenesis of disease. This literature review describes vitiligo pathophysiology, explains the usefulness of the JAK inhibitors for treatment, and summarizes published case reports, case series, and open-label studies. Research outlined here shows JAK inhibitors in patients with vitiligo have a favorable safety profile and effectively produce repigmentation of lesions, especially with concomitant ultraviolet exposure. Additional studies are required to confirm efficacy, establish safety, and investigate durability of repigmentation.

Design of novel JAK3 Inhibitors towards Rheumatoid Arthritis using molecular docking analysis

Multiple cytokines play a pivotal role in the pathogenesis of Rheumatoid Arthritis by inducing intracellular signaling and it is known that the members of the Janus kinase (JAK) family are essential for such signal transduction. Janus kinase 3 is a tyrosine kinase that belongs to the Janus family of kinases. Drugs targeting JAK3 in the treatment of Rheumatoid arthritis is relevant. Therefore, it is of interest to design suitable inhibitors for JAK3 dimer using molecular docking with Molegro Virtual Docker. The compound possessing the highest affinity score is subjected to virtual screening to retrieve inhibitors. The compound SCHEMBL19100243 (PubChem CID- 76749591) displays a high affinity with the target protein. The affinity scores of this compound are more than known drugs. ADMET analysis and BOILED Egg plot provide insights into this compound as a potent inhibitor of JAK3.

JAK Inhibitors in Rheumatology: Implications for Paediatric Syndromes?

PURPOSE OF REVIEW

Given the recent increase in the profile and use of Janus kinase inhibitors (JAKinibs) in adult patients with rheumatic diseases, we aimed to review the current evidence accruing for use in paediatric rheumatology patients.

RECENT FINDINGS

Significant advances have been made in the management of rheumatic diseases in the past two decades. The introduction of biologic agents in both adults and children has provided significant improvements to patient outcomes and led to better quality of life. Moreover, responses to similar agents allude to common effector pathways operating across juvenile and adult synovitis especially. However, inefficacy and intolerance of these agents leads to a subset of children with limited treatment options. Since 2012, Janus kinase (JAK) inhibitors (JAKinibs), a novel group of oral small molecule inhibitors, have demonstrated their efficacy in several forms of adult inflammatory arthritis, such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). There are hopes that these successes will be transferable to the paediatric population. In the following review, we discuss the development and progress of JAKinibs in this regard.

Anti-rheumatoid activity of ethanolic extract of Sesamum indicum seed extract in Freund's complete adjuvant induced arthritis in Wistar albino rats

Sesamum indicum, one of the first recorded plants used for its seeds, is reported to have analgesic, antioxidant, anticancer, anti-obesity as well as hepato and nephro protective activities. The current study evaluated the effects of two doses (400 and 800 mg/kg) of ethanolic extract of S. indicum seeds in Freund's complete adjuvant induced arthritis in rats in comparison with diclofenac and methotrexate by the changes produced in body weight, body temperature, paw volume and spontaneous activity, hemoglobin, erythrocyte sedimentation rate, total white blood cells, red blood cells, Interleukin-6 and Tumor necrosis factor-α as well as joint changes in X-ray and histological changes in joint tissue. Unlike the untreated group, the groups treated with S. indicum showed significant decrease in paw volume, body weight, white blood cell count, erythrocyte sedimentation rate, Interleukin-6 and Tumor necrosis factor-α and an increase in body weight, spontaneous activity, hemoglobin level, and red blood cell count. Histopathological examination showed gross reduction in synovial inflammation and cartilage damage. X-ray revealed significant improvement in joint space. The effect of ethanolic extract of S. indicum was found to be equivalent to methotrexate and greater than diclofenac.

Chronic Pain in Inflammatory Arthritis: Mechanisms, Metrology, and Emerging Targets-A Focus on the JAK-STAT Pathway

Chronic pain is nowadays considered not only the mainstay symptom of rheumatic diseases but also "a disease itself." Pain is a multidimensional phenomenon, and in inflammatory arthritis, it derives from multiple mechanisms, involving both synovitis (release of a great number of cytokines) and peripheral and central pain-processing mechanisms (sensitization). In the last years, the JAK-STAT pathway has been recognized as a pivotal component both in the inflammatory process and in pain amplification in the central nervous system. This paper provides a summary on pain in inflammatory arthritis, from pathogenesis to clinimetric instruments and treatment, with a focus on the JAK-STAT pathway.

JAK inhibition as a therapeutic strategy for immune and inflammatory diseases

This corrects the article DOI: 10.1038/nrd.2017.201.

Management of the Rheumatoid Arthritis Patient with Interstitial Lung Disease

The treatment of rheumatoid arthritis (RA) has undergone considerable changes over the last 15–20 years. With an expansion in the armamentarium of therapies available for RA comes a wider choice in selecting the best treatment in terms of comparative safety in the presence of comorbidities. Clinicians frequently encounter patients with RA-associated interstitial lung disease with uncontrolled joint disease and have to make decisions about the safest treatments in this context with the eventual goal of joint remission. In this chapter, available evidence is reviewed on the comparative pulmonary safety of non-biologic disease-modifying antirheumatic drugs (nbDMARDs), biologic DMARDs, biosimilars and targeted synthetic DMARDs in RA-ILD. In addition, the potential role for additional immunosuppression in RA-ILD is reviewed as well as overarching recommendations proposed for patient assessment to guide treatment decisions and management.

JAK inhibition as a therapeutic strategy for immune and inflammatory diseases

The discovery of cytokines as key drivers of immune-mediated diseases has spurred efforts to target their associated signalling pathways. Janus kinases (JAKs) are essential signalling mediators downstream of many pro-inflammatory cytokines, and small-molecule inhibitors of JAKs (jakinibs) have gained traction as safe and efficacious options for the treatment of inflammation-driven pathologies such as rheumatoid arthritis, psoriasis and inflammatory bowel disease. Building on the clinical success of first-generation jakinibs, second-generation compounds that claim to be more selective are currently undergoing development and proceeding to clinical trials. However, important questions remain about the advantages and limitations of improved JAK selectivity, optimal routes and dosing regimens and how best to identify patients who will benefit from jakinibs. This Review discusses the biology of jakinibs from a translational perspective, focusing on recent insights from clinical trials, the development of novel agents and the use of jakinibs in a spectrum of immune and inflammatory diseases.

Janus Kinase Antagonists and Other Novel Small Molecules for the Treatment of Crohn's Disease

There is an ongoing, unmet need for effective therapies for Crohn's disease. Treatments for Crohn's disease continue to evolve from the traditional biologics to novel small molecules, with targeted mechanisms directed toward pathways that are dysregulated in Crohn's disease. There are multiple emerging mechanisms of action, including Janus kinase inhibition, Smad7 inhibition, and sphingosine-1-phosphate receptor modulators, that are administered as oral medications, and small molecules represent the next generation of therapies for Crohn's disease.

2017 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Antirheumatic Medication in Patients With Rheumatic Diseases Undergoing Elective Total Hip or Total Knee Arthroplasty

OBJECTIVE

This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence-based guideline for the perioperative management of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).

METHODS

A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi-step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.

RESULTS

The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease-modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low- or moderate-quality evidence.

CONCLUSION

This guideline should help decision-making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high-quality direct randomized controlled trial data.

2017 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Antirheumatic Medication in Patients With Rheumatic Diseases Undergoing Elective Total Hip or Total Knee Arthroplasty

OBJECTIVE

This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence-based guideline for the perioperative management of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).

METHODS

A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi-step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.

RESULTS

The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease-modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low- or moderate-quality evidence.

CONCLUSION

This guideline should help decision-making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high-quality direct randomized controlled trial data.

Improved efficacy of allergen-specific immunotherapy by JAK inhibition in a murine model of allergic asthma

Background

Allergen-specific immunotherapy (AIT) is the only curative treatment for type-1 allergies, but sometimes shows limited therapeutic response as well as local and systemic side effects. Limited control of local inflammation and patient symptoms hampers its widespread use in severe allergic asthma.

Objective

Our aim was to evaluate whether AIT is more effective in suppression of local inflammation if performed under the umbrella of short-term non-specific immunomodulation using a small molecule inhibitor of JAK pathways.

Methods

In C57BL/6J mice, a model of ovalbumin (OVA)-induced allergic airway inflammation and allergen-specific immunotherapy was combined with the administration of Tofacitinib (TOFA, a FDA-approved JAK inhibitor) from 48 hours prior to 48 hours after therapeutic OVA-injection. The effect of TOFA on human FOXP3⁺CD4⁺ T cells was studied in vitro.

Results

AIT combined with short-term TOFA administration was significantly more effective in suppressing total cell and eosinophil infiltration into the lung, local cytokine production including IL-1β and CXCL1 and showed a trend for the reduction of IL-4, IL-13, TNF-α and IL-6 compared to AIT alone. Furthermore, TOFA co-administration significantly reduced systemic IL-6, IL-1β and OVA-specific IgE levels and induced IgG1 to the same extent as AIT alone. Additionally, TOFA enhanced the induction of human FOXP3⁺CD4⁺ T cells.

Conclusions

This proof of concept study shows that JAK inhibition did not inhibit tolerance induction, but improved experimental AIT at the level of local inflammation. The improved control of local inflammation might extend the use of AIT in more severe conditions such as polyallergy, asthma and high-risk patients suffering from mastocytosis or anaphylaxis.

Identification of related substances in tofacitinib citrate by LC-MS techniques for synthetic process optimization

A specific LC-MS method was developed for separation, identification and characterization of the process-related substances and degradation products in tofacitinib citrate. The separation was achieved on a LiChrospher C18 column (250mm×4.6mm, 5μm) by linear gradient elution of 0.1% ammonium acetate solution (pH adjusted to 4.0 by formic acid) and acetonitrile at a flow rate of 1.0mL/min. Forced degradation studies were conducted under hydrolytic (acidic, basic), oxidative, photolytic and thermal stress conditions as described in ICH. It was found that tofacitinib was stable under photolytic condition, but degraded obviously in acidic, basic, thermal and oxidative conditions. The high resolution TOF-MS and MS/MS were used for determination and structural identification of the related substances. Eleven major related substances were detected and identified as five process-related substances and six degradation products, and three of them were further synthesized and characterized by NMR spectroscopy. The most plausible mechanisms involved in the formation of the related substances were also proposed. Since related substances have a significant impact on drug safety, quality and efficacy, the data obtained are valuable for process monitoring and quality assurance of tofacitinib citrate.

Tofacitinib attenuates arthritis manifestations and reduces the pathogenic CD4 T cells in adjuvant arthritis rats

Rheumatoid arthritis (RA) is an autoimmune disease characterized by pronounced inflammation and leukocyte infiltration in affected joints. Tofacitinib is new agent, a selective inhibitor of Janus kinase (JAK) signaling pathways mediated by JAK1 and JAK3 and inhibits the key transcription factors STAT1 and STAT3. We investigated the action mechanisms of tofacitinib in rats with adjuvant-induced-arthritis (AIA). AIA-rats were treated orally with tofacitinib or with methotrexate. Arthritis severity and serum C-reactive protein (CRP) levels were evaluated, splenic cells were examined by flow cytometry and cytokines were analyzed by real-time PCR. Tofacitinib markedly reduced the clinical status of treated rats in comparison to control group. Reduced joints inflammation and down-regulated serum CRP levels reflected the clinical manifestations of the treated rats. Tofacitinib down-regulated significantly the frequency of CD4⁺IFN-γ⁺ T cells and reduced IL-1β mRNA expression levels in the spleen of the treated rats. These results show that tofacitinib attenuated arthritis severity, modified splenic populations and cytokine imbalance.

JAK inhibitors in dermatology: The promise of a new drug class

New molecularly targeted therapeutics are changing dermatologic therapy. Janus kinase-signal transducer and activator of transcription (JAK-STAT) is an intracellular signaling pathway upon which many different proinflammatory signaling pathways converge. Numerous inflammatory dermatoses are driven by soluble inflammatory mediators, which rely on JAK-STAT signaling, and inhibition of this pathway using JAK inhibitors might be a useful therapeutic strategy for these diseases. Growing evidence suggests that JAK inhibitors are efficacious in atopic dermatitis, alopecia areata, psoriasis, and vitiligo. Additional evidence suggests that JAK inhibition might be broadly useful in dermatology, with early reports of efficacy in several other conditions. JAK inhibitors can be administered orally or used topically and represent a promising new class of medications. The use of JAK inhibitors in dermatology is reviewed here.

Biological Therapies of Immunologic Diseases: Strategies for Immunologic Interventions

The immune system possesses a vast number of potential targets for therapeutic intervention. Although therapies for many pathways have been pursued, only few have yielded significant success. Hindrances in altering biologic pathways include the potential for unwanted downstream effects, ineffectiveness owing to biological redundancy, recognition of a therapeutic molecule as foreign by the body's innate immune system, and the risks of subsequent malignancy and/or autoimmunity. This article covers currently available biotherapeutic agent classes as well as potential direction for future therapy.

Janus kinase inhibitors for rheumatoid arthritis

Treatment of autoimmune diseases, such as rheumatoid arthritis (RA), has advanced substantially over the past decade with the development of biologics targeting inflammatory cytokines. Recent progress in treating RA has been achieved with janus kinase (JAK) inhibitors (Jakinibs), an orally available disease-modifying anti-rheumatic drug targeting the intracellular kinase JAK and with similar efficacy to biologics. The first Jakinib approved for RA was tofacitinib, which exerted superiority to methotrexate and non-inferiority to tumor necrosis factor (TNF) inhibitors. In recent years, the Jakinib baricitinib has demonstrated superiority to both methotrexate and a TNF inhibitor, adalimumab. Given these promising findings, Jakinibs are expected to represent the next generation compounds for treating RA, and a number of Jakinibs are currently in clinical trials. Jakinibs can differ substantially in their selectivity against JAKs; tofacitinib and baricitinib target multiple JAKs, whereas the most recently developed Jakinibs target only a single JAK. The influence of Jakinib selectivity on efficacy and side effects is of great interest, requiring further careful observation.

Impact of tofacitinib on patient outcomes in rheumatoid arthritis - review of clinical studies

Rheumatoid arthritis is a chronic, progressive autoimmune disease associated with inflammation and destruction of joints and systemic effects, which result in significant impact on patient's quality of life and function. Tofacitinib was approved for the treatment of rheumatoid arthritis in the USA in 2012 and subsequently in other countries, but not by the European Medicines Agency. The goal of this review was to evaluate the impact of tofacitinib on patient-reported and patient-specific outcomes from prior clinical studies, focusing on quality of life, functionality, pain, global disease assessment, major adverse consequences, and withdrawals. A total of 13 reports representing 11 clinical studies on tofacitinib in rheumatoid arthritis were identified through PubMed and reference lists in meta-analyses and other reviews. Data on improvements in patient-driven composite tools to measure disease activity in rheumatoid arthritis, such as the Health Assessment Questionnaire, served as a major outcome evaluated in this review and were extracted from each study. Additional data extracted from those clinical studies included patient assessment of pain (using a 0-100 mm visual analog scale), patient global assessment of disease (using a 0-100 mm visual analog scale), patient withdrawals, withdrawals due to adverse effects or lack of effect, and risk of serious adverse effects, serious infections, and deaths. Tofacitinib 5 mg bid appears to have a favorable impact on patient outcomes related to efficacy and safety when compared with baseline values and with comparator disease-modifying antirheumatic drugs and placebo. Improvements were seen in the composite and individual measures of disease activity. Serious adverse effects, other adverse consequences, overall withdrawals, and withdrawals due to adverse effects and lack of efficacy are similar or more favorable for tofacitinib versus comparator disease-modifying antirheumatic drugs and placebo. At this point, tofacitinib appears to have an important role in the treatment of rheumatoid arthritis through improvement in these patient outcomes. However, it may require years of additional clinical studies and postmarketing surveillance to fully characterize the benefit-to-risk ratio of tofacitinib in a larger and diverse patient population.

Type I/II cytokines, JAKs, and new strategies for treating autoimmune diseases

Cytokines are major drivers of autoimmunity, and biologic agents targeting cytokines have revolutionized the treatment of immune-mediated diseases. Despite the effectiveness of these drugs, they do not induce complete remission in all patients, prompting the development of alternative strategies - including targeting of intracellular signal transduction pathways downstream of cytokines. Many cytokines that bind type I and type II cytokine receptors are critical regulators of immune-mediated diseases and employ the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway to exert their effect. Pharmacological inhibition of JAKs blocks the actions of type I/II cytokines, and within the past 3 years therapeutic JAK inhibitors, or Jakinibs, have become available to rheumatologists. Jakinibs have proven effective for the treatment of rheumatoid arthritis and other inflammatory diseases. Adverse effects of these agents are largely related to their mode of action and include infections and hyperlipidemia. Jakinibs are currently being investigated for a number of new indications, and second-generation selective Jakinibs are being developed and tested. Targeting STATs could be a future avenue for the treatment of rheumatologic diseases, although substantial challenges remain. Nonetheless, the ability to therapeutically target intracellular signalling pathways has already created a new paradigm for the treatment of rheumatologic disease.

Update on the 2012 Brazilian Society of Rheumatology Guidelines for the treatment of rheumatoid arthritis: position on the use of tofacitinib

In 2014, tofacitinib, a target-specific, synthetic disease modifying anti rheumatic drug (DMARD) and a selective inhibitor of Janus kinase (JAK) was approved for use in Brazil. This position paper aims to update the recommendations of the Brazilian Society of Rheumatology (SBR) on the treatment of rheumatoid arthritis (RA) in Brazil, specifically regarding the use of target-specific synthetic DMARDs. The method of this recommendation consisted of a literature review of scientific papers held on the Medline database. After this review, a text was produced, answering questions in Pico structure, considering efficacy and safety issues of tofacitinib use for RA treatment in different scenarios (such as first-line treatment after failure with methotrexate [MTX] or other conventional synthetic DMARDs after failure with biological therapy). Based on existing evidence, and considering the available data on efficacy, safety and cost of medications available to treat the disease in Brazil, the RA Commission of SBR, after a process of discussion and voting on proposals, established the following position on the use of tofacitinib for treatment of RA in Brazil: "Tofacitinib, alone or in combination with MTX, is an alternative for RA patients with moderate or high activity after failure of at least two different synthetic DMARDs and one biological DMARD." The level of agreement with this recommendation was 7.5. This position may be reviewed in the coming years, in the face of a greater experience with the use of this medication.

Comparative efficacy and safety of tofacitinib, with or without methotrexate, in patients with active rheumatoid arthritis: a Bayesian network meta-analysis of randomized controlled trials

This study aimed to assess the relative efficacy and safety of tofacitinib 5 and 10 mg twice daily, or in combination with methotrexate (MTX), in patients with active RA. Randomized controlled trials (RCTs) examining the efficacy and safety of tofacitinib in patients with active RA were included in this network meta-analysis. We performed a Bayesian network meta-analysis to combine the direct and indirect evidence from the RCTs. Ten RCTs including 4867 patients met the inclusion criteria. There were 21 pairwise comparisons including 11 direct comparisons of seven interventions. The ACR20 response rate was significantly higher in the tofacitinib 10 mg + MTX group than in the placebo and MTX groups (OR 7.56, 95 % credible interval (CrI) 3.07-21.16; OR 3.67, 95 % CrI 2.60-5.71, respectively). Ranking probabilities based on the surface under the cumulative ranking curve (SUCRA) indicated that tofacitinib 10 mg + MTX had the highest probability of being the best treatment for achieving the ACR20 response rate (SUCRA = 0.9254), followed by tofacitinib 5 mg + MTX (SUCRA = 0.7156), adalimumab 40 mg + MTX (SUCRA = 0.6097), tofacitinib 10 mg (SUCRA = 0.5984), tofacitinib 5 mg (SUCRA = 0.4749), MTX (SUCRA = 0.1674), and placebo (SUCRA = 0.0086). In contrast, the safety based on the number of withdrawals due to adverse events did not differ significantly among the seven interventions. Tofacitinib, at dosages 5 and 10 mg twice daily, in combination with MTX, was the most efficacious intervention for active RA and was not associated with a significant risk for withdrawals due to adverse events.

The JAK-STAT pathway: impact on human disease and therapeutic intervention

The Janus kinase (JAK)-signal transducer of activators of transcription (STAT) pathway is now recognized as an evolutionarily conserved signaling pathway employed by diverse cytokines, interferons, growth factors, and related molecules. This pathway provides an elegant and remarkably straightforward mechanism whereby extracellular factors control gene expression. It thus serves as a fundamental paradigm for how cells sense environmental cues and interpret these signals to regulate cell growth and differentiation. Genetic mutations and polymorphisms are functionally relevant to a variety of human diseases, especially cancer and immune-related conditions. The clinical relevance of the pathway has been confirmed by the emergence of a new class of therapeutics that targets JAKs.

Efficacy and safety of tofacitinib for treatment of rheumatoid arthritis

Tofacitinib is the first in a new class of nonbiologic disease-modifying antirheumatic drugs (DMARDs), a targeted, synthetic DMARD, approved for the treatment of rheumatoid arthritis (RA) as monotherapy or in combination with methotrexate or other non-biologic DMARD. Tofacitinib, an orally administered Janus kinase (JAK) inhibitor, decreases T-cell activation, pro-inflammatory cytokine production, and cytokine signaling by inhibiting binding of type I cytokine receptors family and γ-chain cytokines to paired JAK1/JAK3 receptors. The net effect of tofacitinb’s mechanism of action is decreased synovial inflammation and structural joint damage in RA patients. To date, six phase 3 trials have been conducted to evaluate the safety and efficacy of tofacitinib under the oral rheumatoid arthritis triaLs (ORAL) series. This review describes the pharmacology of the novel agent, tofacitinib, and details the safety and efficacy data of the ORAL trials.

Evaluation of the potential interaction between tofacitinib and drugs that undergo renal tubular secretion using metformin, an in vivo marker of renal organic cation transporter 2

Tofacitinib is a novel, oral Janus kinase inhibitor. The potential for drug-drug interactions (DDIs) between tofacitinib and drugs that undergo renal tubular secretion was evaluated using metformin as a probe transporter substrate, and genotyping for organic cation transporter (OCT) 1, OCT2 and multidrug and toxin extrusion 1 polymorphisms. Twenty-four healthy male subjects completed this open-label, fixed-sequence study. Subjects were administered a single oral metformin 500 mg dose on Days 1 and 4, and multiple oral tofacitinib 30 mg twice daily doses on Days 2, 3, and 4. Subjects underwent serial blood and urine samplings (Days 1 and 4) to estimate metformin pharmacokinetics. A single blood sample for tofacitinib was collected 2 hours after the morning dose (Day 4). The 90% confidence intervals for the ratios of maximum plasma concentration, area under the curve and renal clearance of metformin, with and without tofacitinib, were contained within the 80-125% acceptance range commonly used to establish a lack of DDI. No deaths, serious adverse events (AEs), severe AEs or discontinuations due to AEs were reported. The study confirms tofacitinib is unlikely to impact the pharmacokinetics of drugs that undergo renal tubular secretion, and concurs with its weak in vitro OCT2 inhibitory profile.