Immunogenicity of anti-TNF biologic therapies for rheumatoid arthritis. Nat Rev Rheumatol. 2013;9:164-172. [PMID: 23399692 DOI: 10.1038/nrrheum.2013.4]

Biosimilars in rheumatology: current perspectives and lessons learnt

Biosimilars, based on biopharmaceuticals approved by regulatory agencies that are no longer under patent protection, have efficacy and safety comparable to their reference products, and are a new therapeutic option to treat inflammatory diseases. Biosimilars must be distinguished from 'biomimics' or 'biocopies', which are marketed in some countries but have not been evaluated according to the stringent regulatory pathway used for biosimilars. CT-P13, based on infliximab, was the first biosimilar approved for the treatment of inflammatory diseases; however, some countries did not allow extrapolation of indications to all eight diseases for which the reference drug infliximab is approved. Antidrug antibodies can reduce drug levels and affect clinical efficacy, but although available data suggest that biosimilars and their reference products have comparable immunogenicity, this important property might differ between individual biopharmaceuticals. This Review discusses biosimilars already approved within the past 3 years to treat rheumatic diseases, as well as others that are currently under development. The main challenges posed by biosimilars are also addressed, such as the extrapolation of indications to diseases only studied for the reference drug, and the definition of strategies for adequate pharmacovigilance to monitor biosimilars after marketing approval.

Immunogenicity of biologic agents in rheumatoid arthritis patients: lessons for clinical practice

Anti-drug antibodies (ADAbs) develop in up to a third of patients treated with biologic agents, with such immunogenicity being one of the main reasons for the loss of efficacy observed in an important proportion of patients treated with such agents. The appearance of ADAbs has consequences in terms of efficacy and tolerance of the biodrug: the development of ADAbs is associated with a poorer clinical response and with an increased risk of adverse effects. Formation of ADAbs has been observed with all biologic DMARDs, but anti-TNF agent mAbs appear to be the largest contributors, independent of humanization of the antibody. ADAb identification is technically difficult and not standardized, partly explaining important variations between published studies. A variety of factors can influence the risk of ADAb appearance, some of which are linked to the treatment strategy, such as the combination with synthetic DMARDs or the rhythm of administration of the biodrug, whereas other factors are dependent on the patient, such as the level of inflammation at onset or body weight. The detection of these antibodies and/or the dosage of the biologic agent itself could have consequences for the bedside practice of clinicians and should be well understood. This review of the literature proposes an overview of the data published on the subject to help clinicians manage the biodrugs according to these new concepts.

Inflammatory Bowel Disease: An Overview of Immune Mechanisms and Biological Treatments

Inflammatory bowel diseases (IBD) are characterized by chronic inflammation of the intestinal tract associated with an imbalance of the intestinal microbiota. Crohn's disease (CD) and ulcerative colitis (UC) are the most widely known types of IBD and have been the focus of attention due to their increasing incidence. Recent studies have pointed out genes associated with IBD susceptibility that, together with environment factors, may contribute to the outcome of the disease. In ulcerative colitis, there are several therapies available, depending on the stage of the disease. Aminosalicylates, corticosteroids, and cyclosporine are used to treat mild, moderate, and severe disease, respectively. In Crohn's disease, drug choices are dependent on both location and behavior of the disease. Nowadays, advances in treatments for IBD have included biological therapies, based mainly on monoclonal antibodies or fusion proteins, such as anti-TNF drugs. Notwithstanding the high cost involved, these biological therapies show a high index of remission, enabling a significant reduction in cases of surgery and hospitalization. Furthermore, migration inhibitors and new cytokine blockers are also a promising alternative for treating patients with IBD. In this review, an analysis of literature data on biological treatments for IBD is approached, with the main focus on therapies based on emerging recombinant biomolecules.

Regulation of tumour necrosis factor signalling: live or let die

Tumour necrosis factor (TNF) is a pro-inflammatory cytokine that has important roles in mammalian immunity and cellular homeostasis. Deregulation of TNF receptor (TNFR) signalling is associated with many inflammatory disorders, including various types of arthritis and inflammatory bowel disease, and targeting TNF has been an effective therapeutic strategy in these diseases. This Review focuses on the recent advances that have been made in understanding TNFR signalling and the consequences of its deregulation for cellular survival, apoptosis and regulated necrosis. We discuss how TNF-induced survival signals are distinguished from those that lead to cell death. Finally, we provide a brief overview of the role of TNF in inflammatory and autoimmune diseases, and we discuss up-to-date and future treatment strategies for these disorders.

Systemic Lupus Erythematosus: Molecular Mimicry between Anti-dsDNA CDR3 Idiotype, Microbial and Self Peptides-As Antigens for Th Cells

Systemic lupus erythematosus (SLE) is marked by a T helper (Th) cell-dependent B cell hyperresponsiveness, with frequent germinal center reactions, and gammaglobulinemia. A feature of SLE is the finding of IgG autoantibodies specific for dsDNA. The specificity of the Th cells that drive the expansion of anti-dsDNA B cells is unresolved. However, anti-microbial, anti-histone, and anti-idiotype Th cell responses have been hypothesized to play a role. It has been entirely unclear if these seemingly disparate Th cell responses and hypotheses could be related or unified. Here, we describe that H chain CDR3 idiotypes from IgG⁺ B cells of lupus mice have sequence similarities with both microbial and self peptides. Matched sequences were more frequent within the mutated CDR3 repertoire and when sequences were derived from lupus mice with expanded anti-dsDNA B cells. Analyses of histone sequences showed that particular histone peptides were similar to VDJ junctions. Moreover, lupus mice had Th cell responses toward histone peptides similar to anti-dsDNA CDR3 sequences. The results suggest that Th cells in lupus may have multiple cross-reactive specificities linked to the IgVH CDR3 Id-peptide sequences as well as similar DNA-associated protein motifs.

Therapeutic Drug Monitoring of Anti-tumor Necrosis Factor Agents in Patients with Inflammatory Bowel Diseases

Anti-tumor necrosis factor (TNF) agents have radically changed the treatment of inflammatory bowel diseases. Although a significant amount of patients respond to therapy, others experience only a partial response or do not benefit at all. Although, in some cases, the mechanistic action of the anti-TNF therapy may explain such findings, we have now learned that many patients may instead suffer from inadequate dosing and drug exposure. Such heterogeneity in how patients respond to therapy may be explained by multiple pharmacodynamic variables, such as factors that alter drug clearance, including the level of systemic inflammation, the presence of antidrug antibodies, and concomitant use of immunomodulators. Multiple studies have found that low-serum anti-TNF levels are associated with active disease and that adjusting the dose in these cases may offer a therapeutic benefit. In this review, we discuss the most recent evidence on therapeutic drug monitoring in patients with inflammatory bowel disease receiving anti-TNF biological therapies.

Potent anti-inflammatory effects of the narrow spectrum kinase inhibitor RV1088 on rheumatoid arthritis synovial membrane cells

Background and Purpose

To investigate whether a narrow spectrum kinase inhibitor RV1088, which simultaneously targets specific MAPKs, Src and spleen tyrosine kinase (Syk), is more effective at inhibiting inflammatory signalling in rheumatoid arthritis (RA) than single kinase inhibitors (SKIs).

Experimental Approach

elisas were used to determine the efficacy of RV1088, clinically relevant SKIs and the pharmaceutical Humira on pro-inflammatory cytokine production by activated RA synovial fibroblasts, primary human monocytes and macrophages, as well as spontaneous cytokine synthesis by synovial membrane cells from RA patients. In human macrophages, RNAi knockdown of individual kinases was used to reveal the effect of inhibition of kinase expression on cytokine synthesis.

Key Results

RV1088 reduced TNF-α, IL-6 and IL-8 production in all individual activated cell types with low, nM, IC₅₀s. SKIs, and combinations of SKIs, were significantly less effective than RV1088. RNAi of specific kinases in macrophages also caused only modest inhibition of pro-inflammatory cytokine production. RV1088 was also significantly more effective at inhibiting IL-6 and IL-8 production by monocytes and RA synovial fibroblasts compared with Humira. Finally, RV1088 was the only inhibitor that was effective in reducing TNF-α, IL-6 and IL-8 synthesis in RA synovial membrane cells with low nM IC₅₀s.

Conclusions and Implications

This study demonstrates potent anti-inflammatory effect of RV1088, highlighting that distinct signalling pathways drive TNF-α, IL-6 and IL-8 production in the different cell types found in RA joints. As such, targeting numerous signalling pathways simultaneously using RV1088 could offer a more powerful method of reducing inflammation in RA than targeting individual kinases.

A novel anti-TNF scFv constructed with human antibody frameworks and antagonistic peptides

The introduction of TNF inhibitors has revolutionized the treatment of some chronic inflammatory diseases, e.g., rheumatoid arthritis and Crohn's disease. However, immunogenicity is one of the important mechanisms behind treatment failure, and generally, switching to another TNF inhibitor will be the first choice for patients and doctors, which results in unmet need for novel anti-TNF agents. Small antibody molecules with less number of epitope may be valuable in less immunogenicity. In this study, with the help of computer-guided molecular design, single-chain variable fragment (scFv) TSA2 was designed using consensus frameworks of human antibody variable region as scaffold to display anti-TNF antagonistic peptides. TSA2 showed evidently improved bioactivity over TSA1 (anti-TNF scFv explored before) and almost similar activity as S-Remicade (the scFv form of Remicade, anti-TNF antibody approved by FDA), especially in inhibiting TNF-induced cytotoxicity and NF-κB activation. Human antibody consensus frameworks with less immunogenicity have been used in the designing of VH domain antibody, scFv TSA1 and TSA2. A serial of TNF-related works convinced us that the novel design strategy was feasible and could be used to design inhibitors targeting more other molecules than TNF-α. More importantly, these designed inhibitors derived from computer modeling may form a virtual antibody library whose size depends on the number of candidate antagonistic peptides. It will be molecular-targeted virtual antibody library because of the specific antagonistic peptides and the potential antibodies could be determined by virtual screening and then confirmed by biologic experiments.

Macrophage-derived tumor necrosis factor-α mediates diabetic renal injury

Monocyte/macrophage recruitment correlates strongly with the progression of diabetic nephropathy. Tumor necrosis factor-alpha (TNF-α) is produced by monocytes/macrophages but the direct role of TNF-α and/or macrophage-derived TNF-α in the progression of diabetic nephropathy remains unclear. Here we tested whether inhibition of TNF-α confers kidney protection in diabetic nephropathy via a macrophage-derived TNF-α dependent pathway. Compared to vehicle-treated mice, blockade of TNF-α with a murine anti-TNF-α antibody conferred kidney protection in Ins2Akita mice as indicated by reductions in albuminuria, plasma creatinine, histopathologic changes, kidney macrophage recruitment and plasma inflammatory cytokine levels at 18 weeks of age. To assess the direct role of macrophage-derived TNF-α in diabetic nephropathy, we generated macrophage specific TNF-α deficient mice (CD11bCre/TNF-α^Flox/Flox). Conditional ablation of TNF-α in macrophages significantly reduced albuminuria, the increase in plasma creatinine and BUN, histopathologic changes and kidney macrophage recruitment compared to diabetic TNF-α^Flox/Flox control mice after 12 weeks of streptozotocin-induced diabetes. Thus, production of TNF-α by macrophages plays a major role in diabetic renal injury. Hence, blocking TNF-α could be a novel therapeutic approach for treatment of diabetic nephropathy.

Etanercept: a review of its use in autoimmune inflammatory diseases

With its approval more than 15 years ago, subcutaneous etanercept (Enbrel(®)) was the first biological disease-modifying antirheumatic drug (bDMARD) and the first tumour necrosis factor inhibitor to be approved for use in rheumatic diseases. Etanercept remains an important cost-effective treatment option in adult patients with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis or plaque psoriasis, and in paediatric patients with juvenile idiopathic arthritis or plaque psoriasis. In all of these populations, etanercept (with or without methotrexate) effectively reduced signs and symptoms, disease activity and disability, and improved health-related quality of life, with these benefits sustained during long-term treatment. The safety profile of etanercept during short- and long-term treatment was consistent with the approved product labelling, with adverse events being of a predictable and manageable nature. The introduction of etanercept and other bDMARDs as therapeutic options for patients with autoimmune rheumatic diseases and spondyloarthropathies revolutionized disease management and these agents continue to have a central role in treatment strategies. This article reviews the extensive clinical experience with etanercept in these patient populations.

Pegylation of biological molecules and potential benefits: pharmacological properties of certolizumab pegol

PEGylation of biological proteins, defined as the covalent conjugation of proteins with polyethylene glycol (PEG), leads to a number of biopharmaceutical improvements, including increased half-life, increased solubility and reduced aggregation, and reduced immunogenicity. Since their introduction in 1990, PEGylated proteins have significantly improved the management of various chronic diseases, including rheumatoid arthritis (RA) and Crohn's disease. Certolizumab pegol is the only PEGylated anti-tumour necrosis factor (TNF)-α agent. It is a PEGylated, humanised, antigen-binding fragment of an anti-TNF monoclonal antibody. Unlike other anti-TNF agents, it has no crystallisable fragment (Fc) domain. Because of its novel structure, certolizumab pegol may have a different mechanism of action to the other anti-TNF agents, and also has different pharmacodynamic properties, which could possibly translate to a different safety profile. Pharmacodynamic studies have shown that certolizumab pegol binds to TNF with a higher affinity than adalimumab and infliximab. Certolizumab pegol is also more potent at neutralising soluble TNF-mediated signalling than adalimumab and infliximab, and has similar or lesser potency to etanercept. Certolizumab pegol does not cause detrimental in vitro effects such as degranulation, loss of cell integrity, apoptosis, complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. Certolizumab pegol may also penetrate more effectively into inflamed arthritic tissue than other anti-TNF agents, and is not actively transported across the placenta during pregnancy. Pharmacokinetic studies in healthy volunteers demonstrated that single intravenous and subcutaneous doses of certolizumab pegol had predictable pharmacokinetics. The pharmacokinetics of certolizumab pegol in patients with RA and Crohn's disease were consistent with pharmacokinetics in healthy volunteers.

Biologic monotherapy in the treatment of rheumatoid arthritis

Biologics, possibly in combination with a conventional disease-modifying antirheumatic drug (DMARD) - preferably methotrexate (MTX), are used in accordance with the recommendations of the international rheumatological societies. However, in clinical practice, this recommendation is often problematic, as many rheumatologists know from personal experience. The quality of life of the patient is affected mainly by drug-induced intolerances (eg, MTX). Thus, the acceptance of the patient to treatment is often so inadequate that a discontinuation of the drug is necessary. In daily practice, approximately 30% of patients with biological therapy receive no concomitant DMARD according to the register data.

Rheumatoid Arthritis - Anti-TNF

This review will focus on the recent information and strategies now informing best use of TNF inhibitor therapy in RA. These issues include the role of TNFi therapy in early RA management, anti-drug antibodies in TNFi therapy, updates on safety and optimal dosage regimens in long term management.

Prediction of clinical response after 1 year of infliximab therapy in rheumatoid arthritis based on disease activity at 3 months: posthoc analysis of the RISING study

OBJECTIVE

To investigate the probability of clinical remission (REM) or low disease activity (LDA) after 1 year of infliximab (IFX) therapy based on disease activity at 3 months in patients with rheumatoid arthritis (RA).

METHODS

Methotrexate-refractory patients with RA received 3 mg/kg of IFX at weeks 0, 2, and 6, followed by 3 mg/kg, 6 mg/kg, or 10 mg/kg every 8 weeks from Week 14 (W14) to Week 46. Correlation of disease activity at W14 with disease activity at W54 and probability of REM/LDA at W54 were analyzed in each dosing group.

RESULTS

Disease activities at W14 were significantly correlated with both disease activity at W54 and probability of REM/LDA at W54 in patients continuing 3 mg/kg as well as in those receiving 6 mg/kg or 10 mg/kg therapy from W14. Results showed that, if approximate REM or LDA had not been achieved by W14, > 50% of patients continuing 3 mg/kg therapy would not be able to achieve REM or LDA at W54. However, even in patients with high or moderate disease activity at W14, dose escalation to 6 mg/kg or 10 mg/kg enabled many to achieve REM/LDA.

CONCLUSION

Disease activity at W14 in standard-dose IFX therapy enabled the prediction of longterm clinical response at continued standard dose, as well as subsequent escalated-dose regimens. Disease activity at W14 was hypothesized to be an important index for IFX treatment strategy.

Systematic comparison of drug-tolerant assays for anti-drug antibodies in a cohort of adalimumab-treated rheumatoid arthritis patients

Drug interference complicates assessment of immunogenicity of biologicals and results in an underestimation of anti-drug antibody (ADA) formation. Drug-tolerant assays have the potential to overcome such limitations. However, to which extent drug-tolerant assays provide an unbiased picture of the antibody response to a biological is unknown. In this study, we compared the measurement of ADA to adalimumab in 94 consecutive adalimumab-treated rheumatoid arthritis patients using the traditional antigen binding test (ABT) and four different drug-tolerant assays, the Ph-shift anti-Idiotype Antigen binding test (PIA) and three newly developed assays for this study: an acid-dissociation radioimmunoassay (ARIA), a temperature-shift radioimmunoassay (TRIA) and an electrochemoluminescence-based assay (ECL). Our results indicate that drug-tolerant assays provide a fairly consistent view on the antibody formation: quantitatively, the results from all four assays correlate well (Spearman r > 0.9). However, the percentage of ADA-positive patients ranges from 51 to 66% between assays, with the ARIA identifying the highest number of patients as positive. These differences are largely due to patients making low amounts of ADA; if ADA levels were above ca. 100 AU/ml, a patient was identified as positive in all four assays. Adalimumab concentrations were significantly lower in ADA-positive samples. Taken together, the results indicate that these different drug-tolerant assays provide a similar and reasonably consistent view on ADA responses, which however, breaks down at the lower end of the detectable range, and highlight that ADA is best reported quantitatively. Furthermore, if an even more sensitive drug-tolerant assay could be developed, one would probably find additional positive samples that will predominantly contain very low levels of ADA.

Therapeutic vaccination with TNF-Kinoid in TNF antagonist-resistant rheumatoid arthritis: a phase II randomized, controlled clinical trial

Objectives

Active immunization, or vaccination, with tumor necrosis factor (TNF)-Kinoid (TNF-K) is a novel approach to induce polyclonal anti-TNF antibodies in immune-mediated inflammatory diseases. This study was performed to transfer the proof of concept obtained in mice model of rheumatoid arthritis (RA) into human. We designed a pilot study to demonstrate the feasibility of therapeutic vaccination in RA.

Methods

This was a phase IIa, placebo-controlled, multicenter study in adults with RA who previously experienced secondary failure of TNF antagonists. Patients were immunized intramuscularly with 2 or 3 doses of placebo (n = 10) or 90 (n = 6), 180 (n = 12), or 360 µg TNF-K (n = 12). The primary objective was to identify the best dose and schedule based on anti-TNF antibody titers. Clinical symptoms and safety were assessed during 12 months and solicited reactions for 7 days after each injection.

Results

The highest anti-TNF antibody response was detected in patients immunized with 360 µg TNF-K and with 3 injections, although this difference was not significant with all other groups. Similar proportions of patients receiving TNF-K and placebo reported adverse events up to month 12. Serious adverse events were reported by 4 patients treated with TNF-K (13.3%) and 3 treated with placebo (30.0%), all unrelated to treatment. At month 12, DAS28-CRP, tender and swollen joint counts, and HAQ scores decreased significantly more in patients who exhibited anti-TNF antibody response than in patients who did not.

Conclusions

TNF-K therapeutic vaccination induced dose- and schedule-dependent anti-TNF antibodies in RA patients and was well tolerated. Patients who developed anti-TNF antibodies showed a trend toward clinical improvement. Although the most aggressive dose and schedule, i.e. 360 mg dose administered 3 times, did show a strong trend of higher antibody response, further studies are warranted to examine even higher and more frequent doses in order to establish the best conditions for clinical improvement.

Trial Registration

ClinicalTrials.gov NCT01040715

Mononeuritis multiplex as the first presentation of refractory sarcoidosis responsive to etanercept

BACKGROUND

Several disorders may present with mononeuritis multiplex and the etiological diagnosis can be challenging.

CASE PRESENTATION

We report a 42 year-old female who presented with severe lower limb neuropathic pain, asymmetric weakness and sensory impairment and was diagnosed with mononeuritis multiplex. Biopsy showed a granulomatous vasculitic process with eosinophils, scarce granulomata and axonal neuropathy and granulomatosis with poliangiitis was assumed. Steroids, cyclophosphamide, alemtuzumab, azathioprine, mycophenolate mofetil and rituximab were used, all with transient and insufficient response. Skin biopsy performed in a further exacerbation allowed sarcoidosis diagnosis. Infliximab and, later, adalimumab induced good clinical and laboratorial response, but neutralizing antibodies developed to both drugs, so etanercept was tried with good clinical response.

CONCLUSIONS

To the best of our knowledge, this is the first report of sarcoidosis successfully treated with etanercept. This drug may be considered in refractory sarcoidosis after other TNF-α inhibitors failure, having the advantage of not being associated with neutralizing antibodies development.

Etanercept ameliorates inflammation and pain in a novel mono-arthritic multi-flare model of streptococcal cell wall induced arthritis

Background

The impact of anti-TNF, corticosteroid and analgesic therapy on inflammation and pain was evaluated in a novel mono-arthritic multi-flare rat Streptococcal Cell Wall (SCW) model using Etanercept, Dexamethasone and Buprenorphine.

Methods

Multiple flares of arthritis were induced with an intra-articular injection of SCW in the hind ankle on day 1, followed by intravenous challenges on days 21 and 42. Inflammation and pain were monitored in the hind paws. Cytokine profiling, cell phenotyping, bioluminescence imaging and histopathological evaluation were also performed.

Results

Local injection of SCW caused a rapid onset of inflammation and pain in the injected ankle which resolved within 4 days (Flare 1). Intravenous injection 20 days after sensitization resulted in an increase in ankle diameter and pain, which partially resolved in 8 days (Flare 2). The subsequent intra-venous injection in the same animals 14 days after resulted in a more chronic disease with inflammation and pain persisting over a period of 10 days (Flare 3). In Flare 2, therapeutic administration of Dexamethasone inhibited paw swelling (95%; P<0.001) and pain (55%; P<0.05). Therapeutic administration of Buprenorphine inhibited pain (80%; P<0.001) without affecting paw swelling (0%). Prophylactic administration of Etanercept in Flare 2 inhibited paw swelling (≥60%; P<0.001) and pain by ≥30%. Expression of IL-1β, IL-6, MCP-1 and CINC was reduced by >50% (P<0.001). Treatment with Etanercept in Flare 3 inhibited paw swelling by 60% (P<0.001) and pain by 25%. Prior treatment with Etanercept in Flare 2 followed by re-administration in Flare 3 led to a complete loss in the efficacy of Etanercept. Systemic exposure of Etanercept corroborated with lack of efficacy. Dexamethasone inhibited inflammation and pain in both Flares 2 and 3 (P<0.001).

Conclusions

We established a novel multi-flare SCW arthritis model enabling drug intervention in different stages of disease. We show for the first time the evaluation of inflammation and pain simultaneously in this model. Etanercept and Dexamethasone inhibited inflammation, pain and proinflammatory cytokines in this model. Taken together, this model facilitates the assessment of anti-rheumatic agents targeting inflammation and pain in the multiple flare paradigm and offers a powerful tool for drug discovery.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-409) contains supplementary material, which is available to authorized users.

Detection of drug specific circulating immune complexes from in vivo cynomolgus monkey serum samples

BACKGROUND

Administration of a biotherapeutic can result in the formation of anti-drug antibodies (ADAs). The resulting ADA can potentially form immune complexes (ICs) with the drug leading to altered pharmacokinetic (PK) profiles and/or adverse events. Furthermore the presence of such complexes may interfere with accurate PK assessment, and/or detection of ADA in immunogenicity assays. Here, we present two assays to detect the presence of drug-ADA immune complexes in cynomolgus monkeys.

RESULTS

Serum samples were analyzed for IC formation in vivo. 8/8 tested animals were positive for drug specific IC. Depending on the time point tested 4/8 or 7/8 animals tested positive for ADA during drug dosing. All 8 animals were confirmed positive for ADA during the washout phase, indicating drug interference in the bridging assay. Relative amount of IC over time was determined and its correlation with PK and ADA was then assessed. Multivariate data analysis demonstrates good correlation between signals obtained from the anti-drug and FcγRIIIa based capture assays, although due to its biological characteristic FcγRIIIa based assay captured only a subset of drug specific IC. In one animal IC remained in circulation even when the drug levels decreased below detection limit.

CONCLUSION

Results from this study indicate the presence of IC during administration of an immunogenic biotherapeutic. Potential application of these assays includes detection of ADA in an IC during high drug levels. The results on the kinetics of IC formation during ADA response can complement the understanding of PK and ADA profiles. Moreover, the presence of IC indicates possible ADA interference in standard PK assays and potential underestimation of total drug exposure in toxicology studies. In addition this study also highlights the need to understand downstream in vivo consequences of drug-ADA IC as no animals under investigation developed adverse events.

New biologics for glomerular disease on the horizon

The major advances achieved in immunology and cellular biology have led to the development of biotherapies that specifically target different mediators and pathways involved in the physiopathology of renal diseases. After the major breakthroughs obtained with B-cell depletion in autoantibody-mediated glomerulopathies, several other immunomodulation strategies are being tested in autoimmune glomerulonephritides, such as blockade of B-cell costimulation and activation, inhibition of complement pathways or modification of the T-B-lymphocyte crosstalk. Other drugs, inhibiting proinflammatory cytokines, are being developed in order to control the inflammatory response initiating and amplifying the kidney tissue injury observed in different systemic diseases. Finally, several promising therapeutic agents target specific renal cells such as podocytes or fibroblasts, blocking the common final steps of the deleterious pathological process underlying various types of nephropathy. Although several of these drugs are still under evaluation in phase 2/3 clinical trials, biotherapies have undoubtedly opened a new era in the treatment of glomerular disease.

Intravenous tocilizumab: a review of its use in adults with rheumatoid arthritis

Tocilizumab (Actemra®, RoActemra®) is a humanized monoclonal antibody that acts as an interleukin-6 receptor antagonist. Intravenous tocilizumab as monotherapy or in combination with disease-modifying anti-rheumatic drugs (DMARDs) is indicated for the treatment of adult patients with moderate to severe active rheumatoid arthritis (RA) who had an inadequate response to one or more DMARDs or tumor necrosis factor (TNF) α antagonists (the specific indication varies between countries); it may also be used as monotherapy in patients for whom continued methotrexate use is inappropriate. This article reviews the efficacy and tolerability of tocilizumab in these patients and briefly summarizes its pharmacology. Several large well-designed clinical trials and routine clinical practice studies showed that tocilizumab was an effective and generally well tolerated biologic for the treatment of adults with RA, including those with an inadequate response to DMARDs or TNFα antagonists. In these studies, tocilizumab as monotherapy or in combination with DMARDs (including methotrexate) had beneficial effects on the signs and symptoms of disease, health-related quality of life/physical function, and/or radiologic disease progression. In addition, tocilizumab monotherapy was more effective than adalimumab monotherapy in improving the signs and symptoms of disease in patients for whom continued methotrexate use was inappropriate. As with other biologic DMARDS, infections were the most common adverse event associated with tocilizumab therapy. Pooled and meta-analyses demonstrated that the efficacy and tolerability profile of tocilizumab was sustained during long-term (up to 9 years) therapy. Although additional comparative data are needed to position tocilizumab more definitively with respect to other biologic DMARDs, current evidence indicates that tocilizumab is effective as a first- or subsequent-line biologic in patients with moderate to severe RA.

Small-molecule inhibitors for autoimmune arthritis: success, failure and the future

Treatment of patients with aggressive autoimmune arthritis, such as rheumatoid arthritis (RA), is a considerable challenge for physicians, particularly rheumatologists. Because of the nature of autoimmune arthritis, effective and complete suppression of disease activity has been the primary therapeutic goal. Although currently available disease-modifying antirheumatic drugs (DMARDs) can successfully control the disease progression in a large proportion of patients, the benefit/risk ratio is not very much satisfied. The introduction of biologic agents such as anti-tumor necrosis factor-α, anti-interleukin-6, and anti-CD20 brings significant help to those patients with an inadequate response to treatment with DMARDs. In considering the limitation of currently available DMARDs and biologics, the development of new DMARDs, small-molecule inhibitors (SMIs), has recently emerged. In the past few years, a great volume of knowledge has been revealed from the experience of examining the usefulness of several SMIs for therapeutics of autoimmune arthritis. This paper addresses the up-to-date knowledge regarding autoimmune arthritis, therapeutics, findings from recently developed SMIs and the benefits and drawbacks of the development of SMIs. In addition, perspectives on the future development of SMIs for autoimmune arthritis will be described and discussed.

Tocilizumab, a humanized anti-IL-6R antibody, as an emerging therapeutic option for rheumatoid arthritis: molecular and cellular mechanistic insights

Pro-inflammatory cytokines play a major role in the initiation and maintenance of joint inflammation and destruction in rheumatoid arthritis (RA). The therapeutic success of biologics targeting tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1) and interleukin (IL)-6 receptor (IL-6R) has broadened the treatment options for RA. These agents have potential overlapping and discriminating biologic effects, as well as different pharmacological features. Tocilizumab (TCZ) is a humanized monoclonal antibody that binds and neutralizes IL-6R, resulting in the inhibition of various IL-6-mediated biological activities, including inflammation-related, immunomodulatory and tissue/matrix remodelling effects. Randomized, double-blind, controlled phase III studies and a number of early clinical observational studies have shown that treatment with TCZ results in rapid and sustained improvement in the signs and symptoms of RA among different patient populations. These studies have established the efficacy and safety of TCZ. Here, we review the pleiotropic functions of IL-6 and how it impinges on many aspects of RA pathogenesis, and highlight the clinical experience to date with TCZ as an emerging new treatment option for RA.

TNF and TNF-receptors: From mediators of cell death and inflammation to therapeutic giants - past, present and future

Tumor Necrosis Factor (TNF), initially known for its tumor cytotoxicity, is a potent mediator of inflammation, as well as many normal physiological functions in homeostasis and health, and anti-microbial immunity. It also appears to have a central role in neurobiology, although this area of TNF biology is only recently emerging. Here, we review the basic biology of TNF and its normal effector functions, and discuss the advantages and disadvantages of therapeutic neutralization of TNF - now a commonplace practice in the treatment of a wide range of human inflammatory diseases. With over ten years of experience, and an emerging range of anti-TNF biologics now available, we also review their modes of action, which appear to be far more complex than had originally been anticipated. Finally, we highlight the current challenges for therapeutic intervention of TNF: (i) to discover and produce orally delivered small molecule TNF-inhibitors, (ii) to specifically target selected TNF producing cells or individual (diseased) tissue targets, and (iii) to pre-identify anti-TNF treatment responders. Although the future looks bright, the therapeutic modulation of TNF now moves into the era of personalized medicine with society's challenging expectations of durable treatment success and of achieving long-term disease remission.

Development of antirituximab antibodies in children with nephrotic syndrome

BACKGROUND

Rituximab is actively used as a rescue therapy for nephrotic syndrome (NS). The development of antidrug antibodies, including antirituximab antibodies (ARA) and human antichimeric antibodies (HACA), is reported with rituximab treatment in various diseases. Here we report two pediatric patients with NS who developed ARA.

CASE DIAGNOSIS AND TREATMENT

Rituximab was given as a rescue therapy for two patients with steroid-dependent NS. Both patients had been treated orally with glucocorticosteroid, methylprednisolone, and calcineurin inhibitors but experienced frequent relapses. With rituximab treatment, the patients remained in remission for several months. After the B-cell count recovered, the patients received a second course of rituximab administration and experienced a hypersensitivity reaction during drug infusion. CD19 cell counts rose despite treatment with rituximab. ARA titers were monitored before and after rituximab treatment, and the development of ARA after the second course of rituximab administration was confirmed.

CONCLUSIONS

We report the development of HACA in two patients with NS who did not achieve B-cell depletion after repeated administration of rituximab. This report suggests that additional studies are needed to determine the incidence of ARA in patients with NS, and its clinical significance.

Disease-regulated local IL-10 gene therapy diminishes synovitis and cartilage proteoglycan depletion in experimental arthritis

OBJECTIVES

Rheumatoid arthritis is a chronic destructive autoimmune disease, but the course is unpredictable in individual patients. An attractive treatment would provide a disease-regulated therapy that offers personalised drug delivery. Therefore, we expressed the anti-inflammatory interleukin-10 (IL-10) gene under the control of inflammation-dependent promoters in a mouse model of arthritis.

METHODS

Proximal promoters of S100a8, Cxcl1, Mmp13, Saa3, IL-1b and Tsg6 were selected by whole-genome expression analysis of inflamed synovial tissues from arthritic mice. Mice were injected intraarticularly in knee joints with lentiviral vectors expressing a luciferase reporter or the therapeutic protein IL-10 under control of the Saa3 or Mmp13 promoter. After 4 days, arthritis was induced by intraarticular injection of streptococcal cell walls (SCW). At different time points after arthritis induction, in vivo bioluminescent imaging was performed and knee joints were dissected for histological and RNA analysis.

RESULTS

The disease-regulated promoter-luciferase reporter constructs showed different activation profiles during the course of the disease. The Saa3 and Mmp13 promoters were significantly induced at day 1 or day 4 after arthritis induction respectively and selected for further research. Overexpression of IL-10 using these two disease-inducible promoters resulted in less synovitis and markedly diminished cartilage proteoglycan depletion and in upregulation of IL-1Ra and SOCS3 gene expression.

CONCLUSIONS

Our study shows that promoters of genes that are expressed locally during arthritis can be candidates for disease-regulated overexpression of biologics into arthritic joints, as shown for IL-10 in SCW arthritis. The disease-inducible approach might be promising for future tailor-made local gene therapy in arthritis.

Etanercept biosimilars

Etanercept was the first tumour necrosis factor alpha antagonist approved in the USA for the treatment of rheumatoid arthritis, in 1998, and then for other diseases. With the etanercept patent set to expire in the EU in 2015, a number of etanercept copies have reached the production phase and are undergoing clinical trials, with the promise of being cheaper alternatives to the reference product. In a global scenario that is favourable to the entry of biosimilars, this article discusses the stage of development, manufacture, clinical trials and the regulatory process involved in the approval of etanercept biosimilars, compiling the literature data. Reducing treatment cost is the principal attraction for biosimilars to emerge in the global market. It is essential for the doctors’ decision on the prescription of these medications, as well as for payers, to have clearly defined studies of clinical equivalence, quality, and safety in order to better evaluate the various copies of etanercept. The authors discuss the need to harmonize different national regulations and the introduction of effective pharmacosurveillance systems for prompt recognition of adverse effects in copies of biopharmaceuticals that differ from those found in the reference products.

Prolactin increases tumor necrosis factor alpha expression in peripheral CD14 monocytes of patients with rheumatoid arthritis

Tumor necrosis factor (TNF)-α is one of the major proinflammatory mediators of rheumatic arthritis (RA); the regulatory factors for TNF-α release is not fully understood. This study aims to investigate the role of prolactin receptor (PRLR) activation in regulating the expression and release of TNF-α from CD14(+) monocytes. The results showed that the expression of PRLR was detectable in CD14(+) monocytes of healthy subjects, which was markedly increased in RA patients. Exposure to PRL in the culture increased the expression and release of TNF-α from CD14(+) monocytes, which was abolished by the PRLR gene silencing or blocking the mitogen activated protein (MAPK) pathway. We conclude that exposure to PRL increases TNF-α release from CD14(+) monocytes of RA patients, which can be abolished by PRLR gene silencing or treating with MAPK inhibitor.

anti-TNF agents as therapeutic choice in immune-mediated inflammatory diseases: focus on adalimumab

The complex pathogenesis of immune-mediated inflammatory diseases (IMIDs) has been extensively investigated and dysregulation of cytokines, such as tumour necrosis factor (TNF) has been shown to play a dominant role in the pathogenesis of various IMIDs, such as rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, ulcerative colitis, psoriasis and psoriatic arthritis. The subsequent development of biological agents capable of blocking TNF has led to important advances in the pharmacotherapy of such diseases and confirmed the concept of a common pathophysiology among IMIDs with TNF having a predominant role. Five TNF inhibitors have currently been approved for treatment of one or more IMIDs; these include infliximab, etanercept, adalimumab, golimumab and certolizumab pegol. Given the similarities in the pathogenic background of IMIDs, one could expect that anti-TNF agents be similarly effective and with comparable tolerability profiles; however, this may not be the case. Structural and pharmacological differences among the anti-TNF drugs are likely to result in differences in efficacy and tolerability among the agents in the different IMIDs, together with differences in potency, therapeutic dose ranges, dosing regimens, administration routes, and propensity for immunogenicity. Among the five TNF inhibitors approved for treatment of IMIDs, adalimumab has the widest range of indications. Data from controlled clinical trials of adalimumab, showing its excellent efficacy and tolerability in a wide range of indications, are supported by real-world long-term data from observational studies, which confirm the value of adalimumab as a suitable choice in the management of IMIDs.

Infliximab in Pediatric Rheumatology Patients: A Retrospective Analysis of Infusion Reactions and Severe Adverse Events During 2246 Infusions over 12 Years

Objective.

To describe infusion reactions (IR) and severe adverse events (SAE) associated with infliximab (IFX) in pediatric patients with rheumatologic and ocular inflammatory diseases in a real-world setting.

Methods.

This is a retrospective chart review of all patients treated with IFX at the pediatric rheumatology division of a university hospital between October 2000 and December 2012.

Results.

A total of 2446 IFX infusions were given to 82 patients (72% female). IR occurred in 46 infusions (2%) of 14 patients (17%) after a mean IFX treatment time of 340 days (range 41–780); 9/14 patients (64%) experienced repeated IR. IR were classified as mild (26%), moderate (74%), or severe (0%). Indications for IFX were arthritis (60%), uveitis (20%), arthritis and uveitis (13%), and other inflammatory diseases (5%). The most common clinical symptoms were respiratory signs (72%), cutaneous manifestations (69%), and malaise (61%). In 6/14 patients (43%) with IR, IFX was discontinued: 4 patients because of repeated IR and 2 patients wished to stop treatment immediately following a mild IR. The other 8/14 patients (57%) received premedication with high-dose antihistamine (100%), corticosteroids (75%), and IFX dose increase (75%) and continued IFX treatment for a mean followup period of 146 weeks (range 26–537) after the first IR. We observed severe infections in 5/82 patients (6%); other SAE were rare.

Conclusion.

Mild and moderate IR occurred in 17% of our patients. Treatment with antihistamines and methylprednisolone, and increasing the IFX dose, allowed continued treatment despite IR in > 50% of patients. Other SAE were infrequent.

Current immunotherapy in rheumatoid arthritis

Rheumatoid arthritis is a common autoimmune disease primarily manifesting as chronic synovitis, subsequently leading to a change in joint integrity. Progressive disability and systemic complications are strongly associated with a decreased quality of life. To maintain function and health in patients with rheumatoid arthritis, early, aggressive and guided immunosuppressive therapy is required to induce clinical remission. Antirheumatic drugs are capable of controlling synovial inflammation and are therefore named 'disease-modifying antirheumatic drugs' (DMARDs). This article aims to bridge the beginning of DMARD therapy with agents such as methotrexate, leflunomide, sulfasalazine, injectable gold and (hydroxy)chloroquine with biological therapies, and with the new era of kinase inhibitors. Mechanisms of action, as well as advantages and disadvantages of DMARDs, are discussed with respect to the current literature and current recommendations.

Significant associations of antidrug antibody levels with serum drug trough levels and therapeutic response of adalimumab and etanercept treatment in rheumatoid arthritis

OBJECTIVE

To evaluate the associations between (1) antidrug antibody (ADAb) and therapeutic response, (2) ADAb and serum drug trough levels and (3) serum drug levels and therapeutic responses in rheumatoid arthritis (RA) patients receiving adalimumab or etanercept. Secondarily, we aim (1) to evaluate the concordance between radioimmunoassay and bridging ELISA for ADAb assessment and to evaluate the correlation between two different ELISA methods for detecting drug levels, and (2) to determine the optimal cut-off drug levels for good European League Against Rheumatism (EULAR) response.

METHODS

ADAb levels were determined by bridging ELISA and radioimmunoassay, and drug levels evaluated using sandwich ELISA among 36 adalimumab-treated patients and 34 etanercept-treated patients at the 6th and 12th month. The optimal cut-off drug levels for EULAR responses were determined by receiver-operating characteristic curve analysis.

RESULTS

ADAb was detected in 10 (27.8%) and 13 (36.1%) of adalimumab-treated patients after 12-month therapy using bridging ELISA and radioimmunoassay respectively, but not detected in any of etanercept-treated patients. The presence of ADAb was associated with lower EULAR response and lower drug levels compared with those without ADAb (both p<0.001). Drug trough levels were positively associated with DAS28 decrement (ΔDAS28) (all p<0.001). The optimal cut-off trough levels for adalimumab were 1.274 μg/mL and 1.046 μg/mL, and those for etanercept were 1.242 μg/mL and 0.800 μg/mL for good EULAR response assessed at the 6th and 12th month, respectively.

CONCLUSIONS

ADAb levels were inversely correlated with therapeutic response and drug levels. The positive correlation between drug levels and ΔDAS28 indicates that drug monitoring would be useful to evaluate therapeutic response of TNF-α inhibitors.