The JAK inhibitor tofacitinib suppresses synovial JAK1-STAT signalling in rheumatoid arthritis

Ann Rheum Dis. 2014 Nov 14. pii: annrheumdis-2014-206028. doi: 10.1136/annrheumdis-2014-206028. [Epub ahead of print]

Targeting intracellular pathways such as JAK/STAT represents a novel approach to the treatment of RA. Tofacitinib is an oral JAK inhibitor, proven to be effective in the treatment of RA, yet the pathways affected by tofacitinib and the effects on gene expression in situ are unknown. In this study, Boyle et al. tested the hypothesis that tofacitinib targets cytokine signalling critical to the pathogenesis of rheumatoid synovitis by investigating tofacitinib effects on synovial pathobiology.
Single cytokine inhibition, e.g. TNFα or IL-6, has fundamentally improved the therapeutic armamentarium for the treatment of RA; yet clinically meaningful responses are achieved in only about half of RA patients treated. In addition, it is now well established that the pathogenesis of RA involves multiple mechanisms of cell activation and cell recruitment. These two factors have led to the emergence of the concept of dual specificity, sparking interest in the biologic arena, with a focus o...

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September 2014

SYK is a core signalling protein that drives inflammatory responses and is fundamental to the propagation of signals via numerous immune receptors. While the clinical development of the first SYK inhibitor, fostamatinib, was stopped due to poor results in the phase 3 RA programme, there remain important questions of mechanism which may aid future developments of this target.

In these murine studies, investigators sought to gain an understanding of how the active metabolite of fostamatini...

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Secukinumab is a fully human monoclonal antibody that selectively binds to and neutralises interleukin-17A, a cytokine shown to play a crucial role in plaque psoriasis, as well as other immune-mediated diseases.

These two pivotal phase 3 studies in plaque psoriasis, FIXTURE and ERAUSRE, were sponsored by Novartis Pharmaceuticals. Secukinumab met all primary endpoints, PASI 75 response and the response of 0 or 1 on the modified investigator’s global assessment, as well as key secondary end...

August 2014

Despite preclinical and healthy volunteer studies of tofacitinib showing no evidence of nephrotoxicity, increases in mean serum creatinine levels have been observed in patients treated with the drug during the RA clinical development programme. This report explores the clinical significance of this change.

Serum creatinine values and renal adverse event data were pooled from patients who received =1 dose of tofacitinib either with background DMARDs or as monotherapy in five Phase 3 studie...
This study pools data from the global tofacitinib RA development programme (phase II, phase III and long-term extension studies) to determine the rate of infections and all-cause mortality with tofacitinib treatment. In total, 4,789 patients within these studies received tofacitinib, at varying doses and with varying duration.

The overall incidence rate of serious infections was 3.09 events/100 patient-years (95% CI 2.73–3.49), which was stable over time, with pneumonia and skin and soft...

July 2014

Herpes Zoster and Tofacitinib Therapy in Patients with Rheumatoid Arthritis

Arthritis Rheumatol. 2014 Jun 18. [Epub ahead of print]

It is well established that patients with RA are at an increased risk of herpes zoster (HZ). What is less well known is whether some of the newer therapies available for treatment of RA increase this risk. Tofacitinib has been reported to be associated with an increased risk of HZ and this study quantifies that risk and reviews potential factors that represent an increased risk. Using data from the tofacitinib RA development programme; phase 2, 3, and long-term extension clinical trials, over 20...
The abnormal activation of skin immune cells, such as dermal dendritic cells (DDCs) and interleukin (IL)-17-producing γδ T (γδT17) cells, by IL-23 is known to provoke psoriasis-type inflammation. What is less well known is how peripheral nerves regulate cutaneous immune responses. In this study, IL-23-dependent psoriasis-like inflammation was induced in mice to help determine the precise molecular mechanism of neuroimmune communication in the skin. Findings indicate nocic...

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Tofacitinib Versus Methotrexate In Rheumatoid Arthritis

N Engl J Med. 2014;370(25):2377–2386.

ORAL Start is the latest trial to be reported in the tofacitinib clinical development programme. It compares the use of tofacitinib monotherapy to MTX monotherapy, in RA patients who have had either no or a sub-therapeutic dose of MTX in the past. Nine hundred and fifty eight patients received either tofacitinib (5 mg or 10 mg) twice daily, or methotrexate at a dose that was incrementally increased to 20 mg per week over 8 weeks. The co primary efficacy endpoints were ACR 70 response, and mean c...

May 2014

A major clinical imperative among rheumatologists is the ability to class patients into risk categories for radiographic progression. Indeed, identification of new independent biomarkers predictive of RA disease progression is a key target from OMERACT. This study by Maksymowych et al. sought to clarify the role of 14-3-3? in RA and whether it provided any clinically and/or serologically important prognostic information. First described as being elevated in RA in 2007, 14-3-3? has a strong corre...

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