October 2013

Inhibition of JAK/STAT signalling pathway in rheumatoid synovial fibroblasts using small molecule compounds

Clin Exp Immunol. 2013 Aug 23. doi: 10.1111/cei.12190

Current JAK inhibitors CP-690,550 and INCB020850 have inhibitory effects on multiple JAK pathways, therefore Migita et al. tested whether selective inhibition of JAK3, using PF-956980, would be enough to ameliorate the rheumatoid inflammatory process. The results indicated that the inhibition of JAK3 alone is does not achieve control of STAT3-dependent signalling, and while it is suggested that the targeting of singular JAK pathways should lead to fewer adverse events, it appears that this appro...

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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

Inhibitors of switch kinase ‘spleen tyrosine kinase’ in inflammation and immune-mediated disorders: A review

European Journal of Medicinal Chemistry 2013 67:434–446

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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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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Inhibition of spleen tyrosine kinase in the treatment of rheumatoid arthritis

Rheumatology 2013;52:1556–1562 doi:10.1093/rheumatology/ket225

Both the innate and adaptive immune responses are targeted by current RA treatments, but these treatments do not achieve consistent sustained disease remission. Protein kinase inhibitors represent a promising new therapeutic target, owing to their influence on downstream signalling and oral bioavailability. Fostamatinib (R788) has shown ACR20 responses of 67–72% in MTX inadequate responder patients at doses of 100mg bd and 150mg bd. However, the results in biologic non-responder patients were no...

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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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Targeting the SYK-BTK axis for the treatment of immunological and hematological disorders: recent progress and therapeutic perspectives

Pharmacol Ther. 2013 May; 138(2):294–309

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...

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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

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...

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Cytokines in the pathogenesis of rheumatoid arthritis

Nature Reviews Immunology 2007; 7:429-42

The imbalance between the activity of pro- and anti-inflammatory cytokines favouring induction of autoimmunity, chronic inflammation and joint damage is well known, but how cytokines are organised within a hierarchical regulatory network and which cytokines are the best targets for clinical intervention is uncertain. This review therefore examines the effector function of cytokines in the immunological processes central to the pathogenesis of rheumatoid arthritis (RA). The paper aims to try and ...

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