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...

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...
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

SYK plays a significant role in the immune cell signalling of B cells, mast cells, macrophages and neutrophils. Kaur et al. provide a comprehensive review of the molecule, its role in autoimmune disease and clinical data on its inhibition. The paper covers the basic chemistry of SYK including structure, mechanism of action, synthetic derivatives and function, and the relevance of SYK as a therapeutic target for many autoimmune diseases is discussed. The SYK inhibitors currently in clinical trial...

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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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Fostamatinib (R778) is a prodrug designed to deliver the active metabolite R406 which is an inhibitor of SYK and is currently under investigation for treatment of RA. The three clinical trials, conducted in healthy subjects, included two ascending dose studies and a formulation study. The first was a single ascending dose of R406, from 80-600mg, the second was a single and multiple dose study of fostamatinib in aqueous solution with single doses from 80-400mg and multiple doses of 160mg twice da...

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August 2013

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...
This review focuses on targeting spleen tyrosine kinase (SYK) and Bruton’s tyrosine kinase (BTK) inhibitors as potential immunomodulatory agents for the treatment of autoimmune and inflammatory disorders with SYK inhibition showing encouraging efficacy in patients with RA. The paper describes the role of SYK and BTK in several therapy areas including autoimmune diseases, allergic inflammatory disorders and haematological cancers as well as their role in innate immunity and regulators of adaptive...

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...

June 2013

Physiology of cytokine pathways in rheumatoid arthritis

Arthritis Care & Research 2001; 45(1):101-6

This review from 2001 describes the main cytokines involved in the pathophysiology of rheumatoid synovitis, and the redundant and synergistic nature of cytokine pathways in rheumatoid arthritis (RA). The self-regulating nature of cytokines are explained through the actions of anti-inflammatory cytokines, opposing cytokines, cytokine receptor antagonists, and naturally occurring antibodies. The paper explains that as disease often results when an imbalance develops in the cytokine network, therap...