October 2013

Involvement of JAK/STAT signalling in the pathogenesis of inflammatory bowel disease

Pharmacological Research 2013; 76:1–8

The JAK/STAT signalling pathway has been implicated in the pathogenesis of several inflammatory diseases including inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). In this review, Coskun et al. provide an excellent background overview of the JAK/STAT cascade. They also highlight recent study findings investigating the mechanisms of the JAK/STAT pathway and the anti-inflammatory effects of novel JAK inhibitors in development and in clinical trials, particularly in IBD. In one study...

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The JAK inhibitor, tofacitinib, reduces the t cell stimulatory capacity of human monocyte-derived dendritic cells

Ann Rheum Dis 2013. doi: 10.1136/annrheumdis-2013-203756

The role of JAKs is highly important in lymphocyte differentiation, but their function in dendritic cells in unknown. In this study, the authors used tofacitinib, a JAK inhibitor, to assess the function of these kinases in dendritic cell activity. The results show that tofacitinib reduced the expression of CD80/CD86 by suppressing the activation of interferon regulatory factor (IRF)-7 and production of type 1 interferon (IFN), and also decreased T cell stimulatory capability. This suggests a nov...

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Proposal for a new nomenclature of disease-modifying antirheumatic drugs

Ann Rheum Dis 2013. doi: 10.1136/annrhuemdis-2013-204317

With the recent emergence of new therapeutics for rheumatoid arthritis, new nomenclature for disease-modifying antirheumatic drugs (DMARDs) may be needed to more accurately describe the new agents. Currently, DMARDs are divided into two broad groups: synthetic DMARDs (sDMARDs) and biological DMARDs (bDMARDs). The authors propose dividing synthetic DMARDs into conventional synthetic DMARDs (csDMARDs) which would encompass traditional DMARDs (e.g. methotrexate, leflunomide), and targeted synthetic...

Tofacitinib in combination with nonbiologic disease-modifying antirheumatic drugs in patients with active rheumatoid arthritis

Ann Intern Med. 2013;159;253-261

Many patients with active RA have an inadequate response to biologic and nonbiologic DMARDs. Kremer et al carried out a one year, randomized trial studying the efficacy of tofacitinib in conjunction with background nonbiologic DMARDs (primarily methotrexate) in these patients. The results showed that using tofacitinib in combination with nonbiologic DMARDs rapidly improved physical function and reduced signs and symptoms of RA versus placebo, measured by ACR20 rates, DAS28 and HAQ-DI. The data f...

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September 2013

Kinase Inhibitors: A new tool for the treatment of rheumatoid arthritis

Clinical Immunology 2013;148:66–78

Chakravaty et al. provide a comprehensive review of the scientific basis for kinase inhibitor use, and summarise experience from clinical trials in tofacitinib and fostamatinib, plus promising clinical data for p38-MAPK inhibitors and P13K? and P13Kd. The authors highlight potential future directions and challenges in kinase inhibitor research, including the emergence of kinases upstream of p38, such as MKK-3 and MKK-6, and the potential of BTK inhibition. One of the challenges of kinase inhibit...

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August 2013

Safety profile of protein kinase inhibitors in rheumatoid arthritis: a systematic review and meta-analysis

Ann Rheum Dis April 2013; doi:10.1136/annrheumdis-2012-203116

Salgado and colleagues conducted a systematic literature review of the safety profiles of protein kinase inhibitors (PKis) used for the treatment of rheumatoid arthritis (RA). Additionally, the study aims included identification of any class and molecule-related target and off-target adverse events. Data from 11,858 patients across 41 publications (phase 2 and 3 studies and two pooled analyses) were analysed. As well as published trials of PKi in RA, studies on healthy individuals and patients w...

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The JAK inhibitor tofacitinib for active rheumatoid arthritis: results from phase III trials

International Journal of Clinical Rheumatology June 2013; 8(3):311–13

The tofacitinib ORAL research program involves six phase 3 trials (Standard, Solo, Step, Scan, Sync and Start) to assess the safety and efficacy of tofacitinib 5 and 10 mg twice daily as monotherapy, or with either background MTX or traditional DMARD therapy. This report by Salgado et al. provides an overall analysis of the each of the study designs and the clinical results to date. The results show that tofacitinib effectively controlled the signs and symptoms of RA across a range of patient po...

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June 2013

Cytokine receptor signaling through the Jak–Stat–Socs pathway in disease

Molecular Immunology 2007; 44:2497-506

This review from 2007 provides an overview of the largest cytokine receptor family, the haematopoietin receptors, as well as other key components involved in one of the major cytokine signalling pathways implicated in autoimmune and inflammatory diseases. This includes the Janus kinases (Jaks), signal transducers and activators of transcription (Stats) and suppressors of cytokine signalling genes (Socs). Essentially, when a cytokine binds to a receptor from this group a functional cytokine recep...

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Janus kinases in immune cell signaling

Immunological Reviews 2009; 228:273-87

This review from 2009 describes the Janus Kinases (JAK) that includes JAK1, JAK2, and JAK3, a subgroup of non-receptor protein tyrosine kinases. This protein family has a diverse range of functions including roles in cell growth, survival, development, and differentiation of a variety of cells, and especially immune and haematopoietic cells. Current knowledge of protein structure, regulatory mechanisms, signalling pathways and intracellular interactions for the JAK family is reviewed. The paper ...

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Inhibition of JAK kinases in patients with rheumatoid arthritis: scientific rationale and clinical outcomes

Best Practice & Research Clinical Rheumatology 2010; 24:513-26

This article reviews data from animal and phase 2 clinical studies assessing the immunomodulatory effects and pharmacokinetics of CP-690,550 (now known as tofacitinib), as well as its efficacy and safety in patients with rheumatoid arthritis (RA). In two rodent models of arthritis, CP-690,550 produced dose-dependent decreases in signs of disease activity compared with untreated controls, reductions in histologically assessed inflammation and articular cartilage damage, and statistically signific...

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