June 2014

Differential regulation of anti-inflammatory genes by p38 MAP kinase kinase 6

Journal of Inflammation 2014, 11:14

Several p38α inhibitors have been developed and evaluated in RA. However, despite pre-clinical data showing promise, the compounds have been shown to have little therapeutic efficacy. Previous studies have suggested this may be a result of inhibitors blocking the role of p38 in limiting inflammation. Previous studies by the same authors have shown that the targeting of MKK3 or MKK 6, which are the upstream activators of p38, may be superior to p38 blockade as the anti-inflammatory effects ...

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Alternative p38 MAPKs Are Essential for Collagen-Induced Arthritis

Arthritis and Rheumatology Vol66, No. 5, May2014 pp 1208-1217

MAPK family proteins are regulatory proteins, affecting processes such as synthesis and release of proinflammatory molecules which contribute to the pathogenesis of RA. In particular, the p38 MAPK protein family is central to proinflammatory cytokine production. There are four member of the p38 group; p38α, p38β, p38γ and p38δ. This study sought to evaluate p38γ and p38δ deficiency in mice CIA model. In p38γ-/- or p38δ-/- mice, the percentage of mic...

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May 2014

Safety and Efficacy of Tofacitinib, an Oral Janus Kinse Inhibitor, for the Treatment of Rheumatoid Arthritis, in Open-Label Longterm Extension Studies

J Rheumatol 2014;41;837-852

This study pooled data from two LTE studies involving patients who had previously participated in qualifying phase I, II and III studies. Data up to 60 months was included for safety aspects and efficacy data up to 48 months. However data for 10 mg BID and tofacitinib monotherapy was limited after 24 and 36 months respectively. Over the two studies, 4102 patients were treated for a total of 5963 patient years.Herpes zoster, both serious and non-serious, had a higher incidence rate in tofacitinib...

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Btk inhibition suppresses agonist-induced human macrophage activation and inflammatory gene expression in RA synovial tissue explants

Ann Rheum Dis Published Online First 24 April 2014 doi:10.1136/annrheumdis-2013-204143

Bruton’s tyrosine kinase, a downstream target of PI3K signalling, has been shown to be crucial in the B lymphocyte and myeloid cell contribution to murine models of arthritis. Synovial tissue samples were taken from biologically naïve RA (n=16) and PsA (n=12) patients in order to assess the expression of BTK. Separate RA synovial explants (n=8) were used to assess the effects of the specific BTK inhibitor RN486. BTK was expressed at equivalent levels in both RA and PsA synovial tissue, however e...

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April 2014

Molecular pathways: Molecular basis for sensitivity and resistance to JAK inhibitors

Clin Cancer Research doi:10.1158/1078-0432.CCR-13-0279

Janus kinases (JAKs) mediate the regulation of a variety of cytokine signals with alterations in JAK1, JAK2, JAK3 and Tyk2 signalling contributing to many disease states including autoimmune diseases and haematological malignancies. Recently tofacitinib and ruxolitinib have been approved for treatment for rheumatoid arthritis and myelofibrosis respectively. Several JAK2 inhibitors, such as momelotinib and pacritinib, currently in development for myelofibrosis and the JAK1/2 inhibitor baricitinib...

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February 2014

Safety of synthetic and biological DMARDs: a systematic literature review informing the 2013 update of the EULAR recommendations for the management of rheumatoid arthritis

Ann Rheum Dis doi:10.1136/annrheumdis-2013-204575

Two systematic literature reviews were undertaken to update the safety findings on synthetic and biological DMARDs in order to inform the updates to the EULAR recommendations to the treatment of RA. Of 10,559 articles screened, 49 were included for review covering a diverse range of outcomes. In the main these showed the patients on bDMARDs had a significantly greater risk of serious infections and tuberculosis compared with csDMARDs, while differences in data between studies mean a slight incre...

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January 2014

The orally available Btk inhibitor ibrutinib (PCI-32765) protects against osteoclast-mediated bone loss

Bone 2014;60:8-15

Ibrutinib is a first-in-class, orally available Btk (Bruton’s tyrosine kinase) inhibitor which has been shown to be effective in the treatment against certain types of leukemia and autoimmune disorders. Btk regulates the expression of genes involved in the differentiation and function of osteoclasts, and therefore inhibiting Btk suppresses osteoclastic bone resorption. Results from in vitro testing showed the suppressive effects on osteoclasts and murine models of RA showed ibrutinib treatment p...

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November 2013

Therapeutic Targeting of the JAK/STAT Pathway

Basic Clin Pharmacol Toxicol. 2013 Oct 24. doi: 10.1111/bcpt.12164

The inhibition of the JAK/STAT pathway has proven to be a powerful therapeutic tool in the treatment of autoimmune diseases. The authors review the role of the JAK/STAT pathway in human disease, including the role of mutations in defective function of this pathway. They discuss the rationale behind JAK inhibition and review the two JAK inhibitors currently approved by the FDA for clinical use; tofacitinib, for the treatment of RA, and ruxolitinib, for the treatment of polycythaemia vera and myel...

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EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2013 update

Ann Rheum Dis. 2013 doi: 10.1136/annrheumdis-2013-204573

The 2010 EULAR recommendations represented a significant step forward in the management of rheumatoid arthritis, and they have been widely adopted across the world. However, in the rapidly evolving world of rheumatology, it was recognised that a substantial amount of new evidence has accumulated, both on agents approved at that time as well as data on new compounds that have become available over the last 3–4 years. This motivated EULAR to form an international task force to update their recomme...

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October 2013

A meta-analysis of p38 mitogen-activated protein kinase inhibitors in patients with active rheumatoid arthritis

Clinical Rheumatology 2013 doi 10.1007/s10067-013-2340-1

The role of p38-MAPK inhibitors in treating RA is the subject of some debate. Li et al. therefore performed the first meta-analysis of the current data to evaluate the efficacy and safety of these compounds. The authors identified 3 papers, covering 4 RCTs, for analysis and the results showed that p38-MAPK inhibition achieves a better level of ACR20 improvement vs. placebo, but showed no meaningful difference in ACR50, DAS28 or CRP levels past week 12. Due to the inadequate number and quality of...

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