Cytokine Signalling Forum

Publications





November 17

Tofacitinib or Adalimumab versus Placebo for Psoriatic Arthritis

Mease P, Hall S, FitzGerald O, van der Heijde D, Merola J F, Avila-Zapata F, Cieslak D, Graham D, Wang C, Menon S, Hendrikx T, Kanik K S.
N Engl J Med 2017; 377:1537-50. DOI: 10.1056/NEJMoa1615975

In the Phase 3 OPAL Broaden trial of patients with active psoriatic arthritis (PsA) with inadequate response to ≥1 csDMARD, superior efficacy was observed in patients treated with tofacitinib (TOF) compared with those given placebo. Patients were randomised to: 5 mg TOF BID, 10 mg TOF BID, 40 mg adalimumab administered subcutaneously q2W, or placebo with a switch to 5 mg TOF at Month 3. Adalimumab was used as an active control in the study. A variety of primary and secondary endpoints wer...

Keywords: JAK, Tofacitinib, Clinical, Phase 3

Treatment Persistence and Healthcare Costs Among Patients with Rheumatoid Arthritis Changing Biologics in the USA

Chastek B, Chieh-I Chen, Proudfoot C, Shinde S, Kuznik A, Wei W.
Adv Ther. 2017 Nov;34(11):2422-2435. doi: 10.1007/s12325-017-0617-5

Updated treatment guidelines recommend the use of different mechanism of action (MOA) therapies earlier in the treatment course. Clinical studies have revealed that this approach may be better than TNFi cycling, and may be more cost effective. This study of Commercial and Medicare Advantage claims data showed that patients who switched MOA had higher treatment persistence and lower healthcare costs than TNFi cyclers. After the first TNFi claim, patients either cycled to another TNFi (n=935) or...

Keywords: JAK, Tofacitinib, Real World, Value

August 17

Treatment Persistence and Clinical Outcomes of Tumor Necrosis Factor Inhibitor Cycling or Switching to a New Mechanism of Action Therapy: Real-world Observational Study of Rheumatoid Arthritis Patients in the United States with Prior Tumor Necrosis Factor Inhibitor Therapy

Wei W, Knapp K, Wang L, Chen C-I, Craig GL, Ferguson K Schwartzman S.
Adv Ther. 2017 Aug;34(8):1936-1952. doi: 10.1007/s12325-017-0578-8

This retrospective, observational study used a real-world US clinical database to demonstrate greater effectiveness of switching to a therapy with an alternative mechanism of action (MOA) vs cycling between TNF inhibitors (TNFis) in patients in which TNFi therapy has failed. Between 1 April 2010 and 31 March 2015, a total of 613 of the observed patients failed a TNFi therapy and then either cycled to another TNFi therapy (54.2%) or switched to a therapy with an alternative MOA (45.8%). The most...

Keywords: JAK, Tofacitinib, Real World, Efficacy

July 17

Pathogenetic Insights from the Treatment of Rheumatoid Arthritis

McInnes I, Schett G.
Lancet 2017;389:2328–37 DOI 10.1016/S0140-6736(17)31472-1

This review paper examines the understanding gained from looking at the effects of specific immune interventions in the treatment of RA. The introduction of novel IL-6 agents has provided the ideal opportunity to explore the distinct effect of cytokine inhibition, as opposed to receptor inhibition, at the molecular level. Mechanistic insights into TNF could also be obtained in the future with advanced molecular and informatics approaches, and future biopsy studies will be important to explore t...

Keywords: Cytokine Signalling, Preclinical, MOA

June 17

Outcomes of Tumor Necrosis Factor Inhibitor Cycling versus Switching to a Disease-modifying Anti-rheumatic Drug with a New Mechanism of Action Among Patients with Rheumatoid Arthritis

Chastek B, Becker LK, Chen CI, Mahajan P and Curtis JR.
J Med Econ 2017;20:464–73

This retrospective study looked at claims-based datasets to establish whether it is preferable to switch to another TNF inhibitor (TNFi) or to a therapy with a different mechanism of action (MOA) when RA treatment failure occurs with an initial TNFi, due to inadequate response or lack of tolerability. Administrative claims data from a large US database were used to compare treatment patterns, treatment effectiveness (based on fulfillment of six criteria) and costs in in the 12 months after RA p...

Keywords: JAK, Tofacitinib, Real World, Value

September 16

Treating Experimental Arthritis with the Innate Immune Inhibitor Interleukin-37 Reduces Joint and Systemic Inflammation

Cavalli G, Koenders M, Kalabokis V, Kim J, Tan AC, Garlanda C, Manovani A, Dagna L, Joosten LAB, Dinarello CA.
Rheumatology (Oxford) 2016; DOI 10.1093/rheumatology/kew325

IL-37, a member of the IL-1 family, has recently been characterised as a fundamental inhibitor of innate inflammation. This study examines the effects of recombinant IL-37 on joint inflammation and pathology in a mouse model of arthritis, and also explores its potential in the treatment of human joint inflammation. In this mouse model of experimental arthritis, short-term, low-dose treatment with IL-37 suppressed joint and systemic inflammation. Wild-type mice received three intraperitoneal dos...

Keywords: Cytokine Signalling, Preclinical, MOA

May 16

Baricitinib in Patients with Refractory Rheumatoid Arthritis

Genovese et al.
N Engl J Med. 2016 Mar 31;374(13):1243-52. doi: 10.1056/NEJMoa1507247

For patients who have an inadequate response or unacceptable side effects associated with biologic DMARDs, the options for treatment beyond conventional DMARDs are limited. This phase 3 trial of the JAK 1/2 inhibitor, baricitinib, studied its efficacy in bDMARD-IR patients. 527 patients were randomized to either baricitinib 2mg, 4mg or placebo for up to 24 weeks. At week 12 the primary endpoints were tested hierarchically to control type 1 error; these endpoints were ACR20, HAQ-DI score, DAS28...

Keywords: JAK, Baricitinib, Clinical, Phase 3

December 15

Incidence and complications of interstitial lung disease in users of tocilizumab, rituximab, abatacept and anti-tumor necrosis factor α agents, a retrospective cohort study

Curtis JR, Sarsour K, Napalkov P, Costa LA, and Schulman KL.
Arthritis Research & Therapy (2015) 17:319 DOI: 10.1186/s13075-015-0835-7

Interstitial lung disease (ILD) is a common extra-articular condition for RA patients. This retrospective cohort study of health insurance databases investigates the ILD incidence and exacerbation between ABA, TCZ, RTX, and anti-TNFα agents in adult RA patients with prior biologic therapy. Two definitions of ILD were used: one specific, one sensitive; descriptive results were produced for both. In patients with no history of ILD, the overall incidence rate of ILD ranged from 1.8% to 6.4%...

Keywords: IL-6, Tocilizumab, Real World, Infections

October 15

Tofacitinib regulates synovial inflammation in psoriatic arthritis, inhibiting STAT activation and induction of negative feedback inhibition

W Gao, T McGarry, C Orr, J McCormick, D J Veale, U Fearon.
Annals of the Rheumatic Diseases. 2015 Sep 9. doi:10.1136/annrheumdis-2014-207201

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis (Ps) and characterised by synovitis and progressive destruction of articular cartilage and bone. Recently developed agents for PsA target IL12p40, IL-6 and IL-17, several of which signal through the JAK family of receptor-associated tyrosine kinases. Tofacitinib is a drug of the JAK inhibitor class and is currently approved for the treatment of RA in 27 countries. This study evaluated the effect of tofacitini...

Keywords: JAK, Tofacitinib, Preclinical, MOA

Calprotectin more accurately discriminates the disease status of rheumatoid arthritis patients receiving tocilizumab than acute phase reactants

José Inciarte-Mundo, Virginia Ruiz-Esquide, Maria Victoria Hernández, Juan D Cañete, Sonia Raquel Cabrera-Villalba, Julio Ramirez, Jordi Yagüe and Raimon Sanmarti.
Rheumatology. 2015 Aug 4. doi:pii: kev251. [Epub ahead of print]

Calprotectin is a member of the S100 protein family that has strong pro-inflammatory effects that reflect local ongoing inflammation rather than systemic response, due to its release at local inflammation sites. High calprotectin levels have been found in SF and serum from RA patients and correlate with disease activity. This study analysed the accuracy of calprotectin compared to acute phase response in discriminating the clinical disease status of RA patients receiving TCZ. A clinical assessme...

Keywords: IL-6, Tocilizumab, Preclinical, MOA

June 15

TNF-α and IL-6 differentially regulate Dkk-1 in the inflamed arthritic joint

Yeremenko N, Zwerina K, Rigter G, Pots D, Fonseca J, Zwerina J, Schett G, Baeten D.
Arthritis Rheumatol. 2015 May 4. doi: 10.1002/art.39183. [Epub ahead of print]

Different inflammatory joint diseases have distinct patterns of bone damage, but the molecular pathways determining each one remains poorly defined. This study investigates the wingless (Wnt)-signalling pathway, by analysing the expression of Dkk-1 (an inhibitor of the Wnt pathway) and its regulation by the pro-inflammatory cytokines TNF-α and IL-6 in SpA versus RA inflamed peripheral joints. Findings from the study show an inverse correlation of Dkk-1 with IL-6 in vivo and a differential...

Keywords: IL-6, Preclinical, MOA

May 15

Evaluation of the effect of tofacitinib on measured glomerular filtration rate in patients with active rheumatoid arthritis: results from a randomised controlled trial

Kremer JM, Kivitz AJ, Simon-Campos JA, Nasonov EL, Tony HP, Lee SK, Vlahos B, Hammond C, Bukowski J, Li H, Schulman SL, Raber S, Zuckerman A, Isaacs JD.
Arthritis Res Ther. 2015 Apr 6;17(1):95.

Mean increases from baseline in patient serum creatinine (SCr) levels have been observed in the clinical development programme for the JAK inhibitor tofacitinib. These increases predominantly occurred within the first three months, and reversed with tofacitinib withdrawal. This phase 1, randomised, placebo-controlled, parallel-group, 2-period study assessed changes in measured glomerular filtration rate (mGFR) with tofacitinib, relative to placebo, in 148 patients with active RA. Results sh...

Keywords: JAK, Tofacitinib, Preclinical, MOA

April 15

Super-enhancers delineate disease-associated regulatory nodes in T cells

Vahedi G, Kanno Y, Furumoto Y, Jiang K, Parker SC, Erdos MR, Davis SR, Roychoudhuri R, Restifo NP, Gadina M, Tang Z, Ruan Y, Collins FS, Sartorelli V, O'Shea JJ.
Nature. 2015 Feb 16. doi: 10.1038/nature14154. [Epub ahead of print]

Transcription machinery (proteins responsible for activating or ‘switching off’ genes) is not distributed in the genome in a symmetrical (or even) manner. Some parts of the genome, so called super-enhancers (SEs), accumulate an exceptionally high level of proteins relevant to the regulation of transcription (i.e. the machinery is concentrated in particular parts of the genome). In this paper, the investigators asked about the locale of these regions in the genome of T cells. Then th...

Keywords: Cytokine Signalling, Preclinical, MOA

March 15

A small-molecule inhibitor of the NLRP3 inflammasome for the treatment of inflammatory diseases

Coll RC, Robertson AA, Chae JJ, et al.
Nat Med. 2015 Feb 16. doi: 10.1038/nm.3806. [Epub ahead of print]

A team of scientists at Trinity College Dublin and the University of Queensland Australia, led by Professor Luke O'Neill, have identified a key molecule that may result in the development of new anti-inflammatory therapies for diseases such as: cryopyrin-associated periodic syndrome (CAPS), multiple sclerosis, type 2 diabetes, Alzheimer’s disease and atherosclerosis. Professor O'Neill and his team have identified MCC950 as a potent, selective, small-molecule inhibitor of the ...

Keywords: Cytokine Signalling, Preclinical, MOA

January 15

Potential Mechanisms Leading to the Abnormal Lipid Profile in Patients With Rheumatoid Arthritis Versus Healthy Volunteers and Reversal by Tofacitinib

Charles-Schoeman C, Fleischmann R, Davignon J, Schwartz H, Turner S, Beysen C, Milad M, Hellerstein M, Luo Z, Kaplan I, Riese R, Zuckerman A, McInnes IB.
Arthritis Rheumatol. 2015;67(3):616-25.

Active RA is associated with changes in both high- and low-density lipoprotein cholesterol as well as changes in the level and function of several HDL-associated proteins, yet the pathways and mechanisms involved with systemic inflammation altered lipid metabolism have not been determined. In addition, treatments for active RA are known to modify lipid metabolism, such as increasing circulating cholesterol levels. In the clinical development programme, a proportion of tofacitinib-treated patien...

Keywords: Cytokine Signalling, Preclinical, MOA

IL-6 stimulates intestinal epithelial proliferation and repair after injury

Kuhn KA, Manieri NA, Liu TC, Stappenbeck TS.
PLoS One. 2014 Dec 5;9(12):e114195. doi: 10.1371/journal.pone.0114195. eCollection 2014.

IL-6 is an inflammatory cytokine known to contribute to a number of autoimmune diseases such as RA. Therapies targeting the soluble IL-6 receptor have now become effective treatments for RA. However, one unforeseen, yet rare, potential complication of anti-IL-6 therapy is bowel perforation. Yet within the intestine, IL-6 protects intestinal epithelial cells from apoptosis during prolonged inflammation. The authors hypothesized that IL-6 may have beneficial properties in wound response/repair, s...

Keywords: IL-6, Preclinical, MOA

December 14

The activity of JAK-STAT pathways in rheumatoid arthritis: constitutive activation of STAT3 correlates with interleukin 6 levels

Isomäki P, Junttila I, Vidqvist KL, Korpela M, Silvennoinen O.
Rheumatology (Oxford). 2014 Nov 17. pii: keu430. [Epub ahead of print]

Non-response, parenteral administration and cost to produce are all aspects associated with the currently available anti-cytokine agents for RA. These related factors mean that alternative drugs are now being developed. Recent developments in therapeutic drugs to treat RA have focused on Janus kinases (JAKs) and signal transducer and activator of transcription (STATs) transcription pathways. Several cytokines that regulate immune responses in RA, such as IFN-g, IL-6 and IL-10, activate JAK-STAT ...

Keywords: JAK, Preclinical, MOA

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

Boyle DL, Soma K, Hodge J, Kavanaugh A, Mandel D, Mease P, Shurmur R, Singhal AK, Wei N, Rosengren S, Kaplan I, Krishnaswami S, Luo Z, Bradley J, Firestein GS.
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. A...

Keywords: JAK, Tofacitinib, Preclinical, MOA

Combined inhibition of TNFα and IL-17 as therapeutic opportunity for treatment in rheumatoid arthritis: Development and characterization of a novel bispecific antibody

Fischer JA, Hueber AJ, Wilson S, Galm M, Baum W, Kitson C, Auer J, Lorenz S, Moelleken J, Bader M, Tissot AC, Tan SL, Seeber S, Schett G.
Arthritis Rheumatol. 2015;67(1):51–62

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 foc...

Keywords: Cytokine Signalling, Preclinical, MOA

September 14

The active metabolite of spleen tyrosine kinase inhibitor fostamatinib abrogates the CD4+T cell-priming capacity of dendritic cells

Platt AM, Benson RA, McQueenie R, et al.
Rheumatology (Oxford). 2015;54(1):169–177

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 fostamatinib, ...

Keywords: Cytokine Signalling, Preclinical, MOA

August 14

Changes in serum creatinine in patients with active rheumatoid arthritis treated with tofacitinib: results from clinical trials

Isaacs JD, Zuckerman A, Krishnaswami S, et al.
Arthritis Res Ther. 2014;16(4):R158

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 studies a...

Keywords: JAK, Tofacitinib, Preclinical, MOA

July 14

Nociceptive sensory neurons drive interleukin-23-mediated psoriasiform skin inflammation

Riol-Blanco L, Ordovas-Montanes J, Perro M, et al.
Nature. 2014;510(7503):157–161.

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. Finding...

Keywords: Cytokine Signalling, Preclinical, MOA

June 14

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

Hammaker D, Boyle DL, Topolewski K et al.
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 eff...

Keywords: Cytokine Signalling, Preclinical, MOA

Alternative p38 MAPKs Are Essential for Collagen-Induced Arthritis

Criado G, Risco A, Alsina-Beauchamp D et al.
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 p38&delt...

Keywords: Cytokine Signalling, Preclinical, MOA

Mechanism of Activation of Protein Kinase JAK2 by the Growth Hormone Receptor

Brooks AJ, Dai W, O’Mara ML et al.
Science 344, 2014; doi: 10.1126/science.1249783

Class I cytokine receptors are key regulators of many processes within the body. The receptors use the JAK-STAT signalling pathway, the deregulation of which causes it to become an important pathway in oncogenesis. Despite this, the processes responsible for JAK2 activation by class I receptors remains elusive. Previous studies using growth hormone and its receptor have led to a model of receptor activation where hormone induced receptor dimerization resulted in close proximity of the receptor ...

Keywords: JAK, Preclinical, MOA

Structure of the pseudokinase-kinase domains from protein kinase TYK2 reveals a mechanism for Janus kinase (JAK) autoinhibition

Lupardus PJ, Ultsch M, Wallweber H et al.
Proc Natl Acad Sci U S A. 2014 May 19. pii: 201401180. [Epub ahead of print]

The JAK family of kinases (JAK1, JAK2, JAK3 and TYK2) are receptor-associated tyrosine kinases that act downstream of many cytokines and interferons. Recent studies have provided structural information about the kinase and pseudokinase domains of JAKs however the molecular mechanism by which JAK activity is regulated by the pseudokinase domain is poorly understood. This study builds on a recent finding that the N terminus of the JAK1 pseudokinase group may act as a switch for kinase activation ...

Keywords: JAK, Preclinical, MOA

Structural basis for the recognition of interferon-α receptor by tyrosine kinase 2

Wallweber HJA, Tam C, Franke Y et al.
Nat Struct Mol Biol. 2014 May;21(5):443-8. doi: 10.1038/nsmb.2807. Epub 2014 Apr 6

Janus kinases, JAKs, are essential in the mediation of cytokine and interferon signalling whilst also being crucial to body processes such as immune function, hematopoeises, metabolism and cellular growth. However, it is not known is how the four members of the JAK family interact with and are activated by over 30 cytokine receptors with near perfect affinity and specificity. Currently, there are no crystal structures available for any JAK bound to a cytokine receptor. This study sought address...

Keywords: Cytokine Signalling, Preclinical, MOA

May 14

JAK2-STAT3 Blockade by AG490 Suppresses Autoimmune Arthritis in Mice via Reciprocal Regulation of Regulatory T cells and Th17 cells

Park JS, Lee J, Lim MA et al.
J Immunol 2014; 192:4417-4424

In this study, Park et al sought to investigate the effects of the JAK2 inhibitor, AG490 in RA. Using murine CIA models, both preventative and therapeutic models were investigated. In the preventative model, CIA mice treated with AG490 showed a significantly lower incidence rate of arthritis and arthritic scores when compared to mice injected with vehicle. In the therapeutic model, as in the preventative, AG490 treated mice exhibited less severe arthritis. Through further experiments, it was de...

Keywords: JAK, Preclinical, MOA

Blocking the janus-activated kinase pathway reduces tumor necrosis factor alpha-induced interlukin-18 bioactivity by caspase-1 inhibition

Marotte H, Tsou PS, Fedorova T et al.
Arthritis Research and Therapy 2014,16:R102

IL-18, a member of the IL-1 family, has been shown to play an important role in immune response and is involved in the pathogenesis of RA. The study objective was to examine the role of the JAK pathway in modulating TNFa-induced-IL18 bioactivity by reducing caspase-1 function. Caspase-1 is the protease that cleaves pro-IL-18 to IL-18, thereby activating it. In testing it was noted that by blocking the JAK pathway significantly decreased caspase-1 transcription, expression and activity showing th...

Keywords: JAK, Preclinical, MOA

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

Hartkamp LM, Fine JS, van Es IE et al.
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 tissu...

Keywords: BTK, Preclinical, MOA

14-3-3eta is a novel mediator associated with the pathogenesis of rheumatoid arthritis and joint damage

Maksymowych WP, van der Heijde D, Allaart CF et al.
Arthritis Research and Therapy 2014, 16:R99

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...

Keywords: Cytokine Signalling, Preclinical, MOA

April 14

Effects of Janus Kinase Inhibitor tofacitinib on circulating serum amyloid A and interlukin-6 during treatment for rheumatoid arthritis

Migita K, Izumi Y, Jiuchi Y et al.
Clinical and Experimental Immunology doi.10.1111/cei.12234

Tofacitinib is a JAK inhibitor currently approved for the treatment of RA in some parts of the world. In this paper, Migita et al tested the effects of tofacitinib on circulating serum amyloid A (SAA). SAA is a major acute-phase reactant in RA and studies have shown it may be a better marker for the assessment of inflammatory joint disease compared with C-reactive protein. SAA is induced by the binding of IL-6 and the activation of the JAK/STAT pathway, which is inhibited by tofacitinib. Results...

Keywords: JAK, Tofacitinib, Preclinical, MOA

Hypoxia and STAT3 signalling interactions regulate pro-inflammatory pathways in rheumatoid arthritis

Gao W, McCormick J, Connolly M et al.
. ARD published online first 13 Feb 2014. Doi: 10.1136/annrheumdis-2013-204105

Hypoxia is a key driving force in joint inflammation, however little is known about the effect it can have on JAK/STAT signalling in rheumatoid arthritis. Due to the development of JAK inhibitors as therapeutics it is important to understand any links there may be. Previous studies have shown that HIF1a, a protein associated with hypoxia, facilitates the binding of STAT3 to haptoglobin promoter in HepG2 human hepatoma cells. HIF1a also requires interaction of Notch signalling pathways with STAT3...

Keywords: Cytokine Signalling, Preclinical, MOA

March 14

Features of the synovium of individuals at risk of developing rheumatoid arthritis

de Hair MJH, van de Sande MGH, Ramwadhdoebe TH et al.
Arthritis and Rheumatology March 2014:66;513-522

This study expands on previous findings that synovial inflammation does not coincide with the appearance of rheumatoid arthritis. This was a markedly larger study compared to previous, with 55 individuals assessed. All 55 subjects were positive for IgM rheumatoid factor and/or anti-citrillinated protein antibody as well as possessing no physical evidence of arthritis. 15 of the individuals tested developed arthritis after a median time of 13 months. In these patients the presence of inflammatory...

Keywords: Preclinical, MOA

Emergence of proinflammaotry autoreactive T-cell responses in preclinical rheumatoid arthritis

Aslam A, Nam J, Hunt L et al.
The Lancet, Volume 383, Page S22, 26 February 2014

Before the onset of clinically apparent disease, the pathogenesis of RA goes through a number of sequential phases. The presence of autoimmunity through RF and ACPAs can be detected up to 13 years before the onset of clinical synovitis. An important component of the immune system is Treg cells which limit damage caused by excessive immune activity. These cells have been found to be dysfunctional in RA. This study aimed to identify autoreactive T cells to a known RA-associated antigen and determi...

Keywords: Preclinical, MOA

Inhibition of TAK1 and/or JAK can rescue impaired chondrogenic differentiation of human mesenchymal stem cells in osteoarthritis-like conditions

Van Beuningen HM, de Vries-van Melle ML, Vitters El et al.
Tissue Engineering Part A doi:10/1089/ten.TEA.2013.0553

As it is nonvascularized and noninnervated, articular cartilage has a limited capacity to repair which presents a major clinical problem. In order to circumvent this inability to repair, stem cells can be placed into the joint or stimulated within the bone marrow. However, as the cartilage requiring repair is often in diseased joints, the factors involved in the disease state are potentially non-beneficial to the chondrogenesis of mesenchymal stem cells. In this study van Beuningen et al. invest...

Keywords: Cytokine Signalling, Preclinical, MOA

February 14

Effects of tofacitinib on lymphocytes in rheumatoid arthritis: relation to efficacy and infectious adverse events

Sonomoto K, Yamaoka K, Kubo S et al.
Rheumatology doi:10.1093/rheumatology/ket466

Due to its function as a JAK1/3 inhibitor, tofacitinib has effects on a wide ranging variety of cells. The authors of this paper have previously reported a suppression in cytokine production by CD4+ T lymphocytes caused by tofacitinib, while others have reported reduced chemokine production from fibroblast-like synoviocytes. The effects of tofacitinib on other cells however remain largely unknown. This study focused on tofacitinib’s effects on CD4+ T lymphocyte proliferation and on subsets...

Keywords: JAK, Tofacitinib, Preclinical, MOA

January 14

PI3K-δ and PI3K-γ inhibition by IPI-145 abrogates immune responses and suppresses activity in autoimmune and inflammatory disease models

Winkler DG, Faia KL, DiNitto JP et al.
Chemistry and Biology Nov 13 20, 1364-1374

Phosphoinositide-3 kinases (PI3K) are cell signalling proteins that act as a central node for relaying signals from cell surface receptors and downstream mediators. Specifically they phosphorylate phosphatidylinositol to phosphatidylinositol-3,4,5-trisphosphate (PIP3). This acts a docking site for signalling proteins, leading to the activation of downstream effectors such as BTK. Therefore, inhibition of the PI3K-d and PI3K-? isoforms (PI3K-a and PI3K-ß demonstrated embryonic lethality in ...

Keywords: Cytokine Signalling, Preclinical, MOA

STA-21, a promising STAT3 inhibitor that reciprocally regulates Th17 and Treg, inhibits osteoclastgenesis and alleviates autoimmune inflammation

Park JS, Kwok SK, Lim MA et al.
Arthritis and Rheumatism doi: 10.1002/art.38305

STAT3 (signal transducer and activator of transcription 3) is the major transcription factor in the differentiation of Th17 cells, which along with IL-17 are significant in the development of RA. STA-21 is a new small molecule with significant inhibitory effects on STAT3, impeding DNA binding activity, dimerization and STAT3-dependent luciferase activity. While the effect of STA-21 in RA has not been fully determined, it has been hypothesised that STA-21 will suppress arthritis in animal models ...

Keywords: Cytokine Signalling, Preclinical, MOA

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

Shinohara M, Chang BY, Buggy JJ et al.
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 treat...

Keywords: BTK, Preclinical, MOA

October 13

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

Kubo S, Yamaoka K, Kondo M, et al.
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...

Keywords: JAK, Tofacitinib, Preclinical, MOA

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

Migita K, Izumi Y, Torigoshi T et al.
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...

Keywords: JAK, Preclinical, MOA

September 13

Inhibition of spleen tyrosine kinase in the treatment of rheumatoid arthritis

Nijjar JS, Tindell A, McInnes ID and Siebert S.
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 w...

Keywords: Cytokine Signalling, Preclinical, MOA

June 13

Inflammation and bone erosion are suppressed in models of rheumatoid arthritis following treatment with a novel Syk inhibitor

Pine PR, Chang B, Schoettler N, et al.
Clinical Immunology 2007; 124:244-57

This study investigated the capacity of the novel oral spleen tyrosine kinase (Syk) inhibitor R406, and its prodrug R788 (fostamatinib), to suppress the reversed passive Arthrus reaction (RPA) and collagen-induced arthritis (CIA) in rats. R406 (0.1, 1, 5 and 10 mg/kg) and R788 (10 and 30 mg/kg) reduced the cutaneous RPA reaction and inflammatory oedema in a dose-dependent manner, with statistically significant reductions in extravascular leakage and tissue swelling (72% reduction with R406 10 mg...

Keywords: Cytokine Signalling, Preclinical, MOA

Modulation of innate and adaptive immune responses by tofacitinib (CP-690,550)

Ghoreschi K, Jesson MI, Li X, et al.
Journal of Immunology 2011; 186(7):4234-43

This study investigated the effects of the novel Janus kinase (JAK) inhibitor CP-690,550 (now known as tofacitinib) on adaptive and innate immune responses, in order to establish the mode of action of JAK inhibitors in the setting of inflammatory diseases. The inhibition of specific JAK/STAT-dependent pathways by CP-690,550 was determined through analysis of cytokine stimulation of mouse and human T cells in vitro.The effects of CP-690,550 on Th-cell differentiation of naive...

Keywords: JAK, Tofacitinib, Preclinical, MOA

The JAK inhibitor CP-690,550 (tofacitinib) inhibits TNF-induced chemokine expression in fibroblast-like synoviocytes: autocrine role of type 1 interferon

Rosengren S, Corr M, Firestein GS, et al.
Annals of Rheumatic Diseases 2012; 71:440-47

This study investigated the effect of the novel Janus kinase (JAK) inhibitor CP-690,550 [tofacitinib] in fibroblast-like synoviocytes (FLSs) collected from patients with rheumatoid arthritis (RA). Human FLSs were cultured from the synovial tissue of patients with RA who were undergoing arthroplastic surgery, cultured and then serum-starved 48 hours prior to stimulation. Quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) or multiplex bead assay were used to...

Keywords: JAK, Tofacitinib, Preclinical, MOA