Pharmacogenetics and future therapeutic scenarios: what affects the prediction of response to treatment with etanercept?

TNF-α-1031T/C gene polymorphism as a predictor of malnutrition in patients with gastric cancer

Introduction

Malnutrition is a complex clinical syndrome, the exact mechanism of which is yet not fully understood. Studies have found that malnutrition is associated with anorexia and inadequate intake, tumor depletion, leptin, tumor-induced metabolic abnormalities in the body, and catabolic factors produced by the tumor in the circulation and cytokines produced by the host immune system. Among these, single nucleotide polymorphisms (SNPs) are present in the gene encoding the pro-inflammatory cytokine TNF-α.

Aim

The objective of this study was to investigate TNF-α -1,031 T/C gene polymorphism as an unfavorable predictor of malnutrition in patients with gastric cancer.

Methods

The study group consisted of 220 gastric cancer patients treated at Affiliated Jinhua Hospital, Zhejiang University School of Medicine. Malnutrition was mainly assessed by the Global Consensus on Malnutrition Diagnostic Criteria (GLIM). DNA was extracted from peripheral leukocytes of whole blood samples using an animal DNA extraction kit. DNA was amplified using a 1.1× T3 Super PCR mixture and genotyped using SNP1 software.

Results

There are three major genetic polymorphisms in TNF-α. Among the 220 patients with gastric cancer, there were 7 patients with the CC genotype, 61 with the CT genotype and 152 with the TT genotype. Compared to patients with the TT genotype, patients with the C allele had an approximately 2.5-fold higher risk of developing malnutrition (p = 0.003; OR = 0.406). On the basis of multivariate analysis, patients with the CC genotype had an approximately 20.1-fold higher risk of developing malnutrition (p = 0.013; OR = 20.114), while those with the CT genotype had an almost 3.7-fold higher risk of malnutrition (p = 0.002; OR = 3.218).

Conclusion

SNP (-1,031 T/C) of the TNF-α may be a useful marker in the assessment of the risk of nutritional deficiencies in gastric cancer patients. Patients with gastric cancer carrying the C allele should be supported by early nutritional intervention, but more research is still needed to explore confirmation.

Ixekizumab for the treatment of ankylosing spondylitis

INTRODUCTION

Ixekizumab (IXE) is a high affinity IgG4 approved for the treatment of ankylosing spondylitis (AS). Recently, two phase III randomized clinical trials (COAST-V, COAST-W) showed significant and sustained improvements in signs and symptoms of AS as evaluated by ASAS40 response. Areas covered: The authors performed a comprehensive literature search on this topic, by a review of published articles to date. The authors introduced the structure and the mechanism of action of IXE, and critically reviewed data from clinical trials, concerning its efficacy and safety in AS.Expert opinion: IXE proved dramatic efficacy and tolerable safety in patients with AS, in particular, patients with intolerance or insufficient response to TNFi, which provides an alternative and breakthrough for the treatment options of AS. IXE might not work in AS with IBD and uveitis involvement. Patients treated with IXE should be aware of candida infection in long term application.

Current Understanding of an Emerging Role of HLA-DRB1 Gene in Rheumatoid Arthritis-From Research to Clinical Practice

Rheumatoid arthritis (RA) is an autoimmune disease with an unclear pathogenic mechanism. However, it has been proven that the key underlying risk factor is a genetic predisposition. Association studies of the HLA-DRB1 gene clearly indicate its importance in RA morbidity. This review presents the current state of knowledge on the impact of HLA-DRB1 gene, functioning both as a component of the patient’s genome and as an environmental risk factor. The impact of known HLA-DRB1 risk variants on the specific structure of the polymorphic HLA-DR molecule, and epitope binding affinity, is presented. The issues of the potential influence of HLA-DRB1 on the occurrence of non-articular disease manifestations and response to treatment are also discussed. A deeper understanding of the role of the HLA-DRB1 gene is essential to explore the complex nature of RA, which is a result of multiple contributing factors, including genetic, epigenetic and environmental factors. It also creates new opportunities to develop modern and personalized forms of therapy.

What Is the Clinical Relevance of TNF Inhibitor Immunogenicity in the Management of Patients With Rheumatoid Arthritis?

Tumor necrosis factor-α inhibitors (TNFis) have revolutionized the management of rheumatoid arthritis (RA), however despite considerable progress, only a small proportion of patients maintain long-term clinical response. Selection of, and switching between, biologics is mainly empirical, experiential, and not evidence-based. Most biopharmaceutical proteins (BP) can induce an immune response against the foreign protein component. Immunogenicity and the development of anti-drug antibodies (ADAs) is considered one of the main reasons for loss of therapeutic efficacy (secondary failure). ADAs may neutralize and/or promote clearance of circulating BP with resultant low serum drug levels, loss of clinical response, poor drug survival and adverse events, such as infusion reactions. ADA identification is technically difficult and not standardized, making interpretation of immunogenicity data from published clinical studies challenging. Trough TNFi drug levels correlate with clinical outcomes, exhibiting a "concentration-response" relationship. Measurement of ADA and drug levels may improve patient care and improve cost-effectiveness of BP use. However, in the absence of clinically-validated, reliable assays and consensus guidelines, therapeutic drug monitoring (TDM) and immunogenicity testing have not been widely adopted in routine clinical practice in Rheumatology. Here we discuss the utility and relevance of TDM and immunogenicity testing of TNFis in RA (focusing on the most widely used TNFis globally, with the most available data, i.e., infliximab, adalimumab, and etanercept), the limitations of currently available assays and potential future immunopharmacological strategies to personalize disease management.

Pharmacodynamics OF TNF α inhibitors for the treatment of psoriasis

Introduction: The treatment of psoriasis with conventional topical therapies and disease-modifying anti-rheumatic drugs (DMARDs) is often linked to unsatisfactory outcomes and the risk of serious adverse events. Over the last decades, research advances in understanding the role of tumor necrosis factor alpha (TNF α) and other cytokines in the pathogenesis of psoriasis have driven the introduction of biologic agents targeting specific immune mediators in everyday clinical practice. TNF α inhibitors are a consolidated treatment option for patients with moderate-to-severe disease with remarkable efficacy and a reassuring safety profile.Areas covered: The PubMed database was searched using combinations of the following keywords: psoriasis, TNF α inhibitors, biologic therapy, pharmacodynamics, adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, adverse effects. The aim of this review is to describe the pharmacodynamic profile of anti-TNF α inhibitors, currently approved by the European Medicines Agency (EMA) for the treatment of psoriasis, focusing on related clinical implications, also in comparison to the new generation biological therapies targeting the interleukin 23/interleukin 17 axis.Expert opinion: Pharmacodynamics of TNF α inhibitors should be fully considered in planning patient's therapy strategies, especially in case of secondary failures, poor adherence to treatment, instable psoriasis, high risk of infection, pregnant or lactating women, metabolic comorbidities, coexistence of other immune-mediated inflammatory diseases.

Update upon the infection risk in patients receiving TNF alpha inhibitors

INTRODUCTION

TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory drugs or DMARDs in the treatment of chronic immune-mediated diseases.

AREAS COVERED

Patients receiving TNF-α inhibitors are at high risk of infections. An update is made on the risk of infection in patients receiving TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

EXPERT OPINION

Infliximab than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis infection and the overall risk of opportunistic infections should be considered before beginning a course of TNF-α inhibitors. A careful medical history, Mantoux test/quantiferon-TB Gold In-tube Test and chest-X-ray should always be performed before starting TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitors treatment. Finally, appropriate vaccinations for influenza, S. pneumoniae, and HBV should be administered to decrease the risk of infection, and patients who are at high risk of herpes zoster reactivation would benefit from a second vaccination in adulthood.

Update upon efficacy and safety of etanercept for the treatment of spondyloarthritis and juvenile idiopathic arthritis

TNF-α inhibitors have demonstrated efficacy both as monotherapy and in combination with disease-modifying anti-rheumatic drugs (DMARDs) in the treatment of chronic inflammatory immune-mediated diseases such as rheumatoid arthritis, Crohn's disease, ulcerative colitis, ankylosing spondylitis (AS), psoriasis (Ps) and/or psoriatic arthritis (PsA) and may be administered off-label to treat disseminated granuloma annulare, systemic lupus erythematosus and systemic sclerosis. There are several TNF-α inhibitors available for clinical use including infliximab, adalimumab, golimumab, certolizumab pegol and etanercept. In this article, we discuss the efficacy and safety of etanercept in the treatment of spondyloarthritis and juvenile idiopathic arthritis (JIA). Etanercept is effective in the treatment of PsA, AS, JIA and uveitis. Independent predictors of achieving a sustained clinical improvement or MDA in children with JIA include shorter disease duration, no concurrent oral corticosteroid use, history of chronic anterior uveitis and age <9 years. IBD incidence was lower in patients receiving etanercept plus MTX. Intra-articular administration of etanercept seems to favor a prompt target joint improvement without serious adverse events. Etanercept improve endothelial function reducing the risk of acute cardiovascular and/or cerebrovascular events. The most commonly reported adverse events were nasopharyngitis, epidermal and dermal conditions, upper respiratory tract infection, cough, headache and fatigue.

Impact of pharmacogenomics upon the therapeutic response to etanercept in psoriasis and psoriatic arthritis

TNF-α inhibitors have demonstrated efficacy both as monotherapy and in combination with disease-modifying anti-rheumatic drugs (DMARDs) in the treatment of chronic inflammatory immune-mediated diseases. Etanercept is a decoy receptor" for TNF-α and it is composed of two p75 TNF-α receptors fused to human IgG1. Areas covered: We discuss the potential role of pharmacogenetics in predicting the response to etanercept in patients with Ps and PsA. Expert opinion: Pharmacogenetics represents the new frontier for the discovery of potential genetic markers of biological response to TNF-α inhibitors. Clinical studies showed that TNF-α -308 G/G, +489 GG and the +489 GA, TNF-α -857C (rs1799724), TNFRSF1B 676T (rs1061622), TNFAIP3 G SNP (rs610604), FcγRIIIA-V158F, HLA-C*06, IL-17 A (rs2275913 and rs10484879), IL-17F (rs763780) and IL17RA (rs4819554) SNPs favor the response to etanercept. However, most of these studies are often small and not sufficiently powered to detect an effect and markers tend to be more prognostic than predictive of therapeutic response. Furthermore, studies often examines only the effects of a single SNP, while it would be more useful to analyze more haplotypes in contemporary in the same patients. Appropriately designed clinical trials are needed before a pharmacogenetic approach may be applicable in daily clinical therapeutic practice.

Comparison of drug survival and clinical outcome in patients with ankylosing spondylitis treated with etanercept or adalimumab

OBJECTIVE

To compare rates of drug survival and clinical response during 2 years of follow-up in ankylosing spondylitis (AS) patients treated with etanercept or adalimumab in routine care.

METHOD

Biological-naïve consecutive AS patients treated with etanercept (n = 163) or adalimumab (n = 82) were followed. Treatment discontinuation was due to inefficacy, adverse events, loss to follow-up, planning a pregnancy, or uveitis. Disease activity was assessed by the Ankylosing Spondylitis Disease Activity Score using C-reactive protein (ASDAS-CRP). Moderate disease activity was defined as an ASDAS-CRP < 2.1.

RESULTS

Twenty-seven patients (32.9%) treated with adalimumab and 30 (18.4%) with etanercept discontinued treatment. Cox regression analysis demonstrated a significant difference in survival rate between discontinuation of the drug in adalimumab patients compared with etanercept patients [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.3-4.5, p = 0.005; corrected for confounding factors: HR 2.5, 95% CI 1.3-4.5, p = 0.006]. There was no significant difference at 2 years of follow-up between the adalimumab- and the etanercept-treated patients in mean ± sd ASDAS-CRP (1.9 ± 1.1 and 2.0 ± 0.9, respectively, p = 0.624), and 23 out of 34 (67.6%) compared to 71 out of 117 (60.7%) reached ASDAS-CRP moderate disease activity (odds ratio 0.738, 95% CI 0.329-1.657, p = 0.530).

CONCLUSION

No significant difference was found between AS patients treated with etanercept and those treated with adalimumab in mean ASDAS-CRP and reaching ASDAS-CRP minimal disease activity at 2 year follow-up. Drug survival rate was higher in etanercept- compared to adalimumab-treated patients. However, this should be interpreted cautiously as the risk of allocation bias cannot be excluded.

Inhibition of Inflammation-Associated Olfactory Loss by Etanercept in an Inducible Olfactory Inflammation Mouse Model

OBJECTIVE

To determine the effect of a soluble human tumor necrosis factor alpha (TNF-α) receptor blocker (etanercept) on an inducible olfactory inflammation (IOI) mouse model.

STUDY DESIGN

An in vivo study using a transgenic mouse model.

SETTING

Research laboratory.

SUBJECTS AND METHODS

To study the impact of chronic inflammation on the olfactory system, a transgenic mouse model of chronic rhinosinusitis-associated olfactory loss was utilized (IOI mouse), expressing TNF-α in a temporally controlled fashion within the olfactory epithelium. In one group of mice (n = 4), etanercept was injected intraperitoneally (100 μg/dose, 3 times/week) concurrent with a 2-week period of TNF-α expression. A second group of mice (n = 2) underwent induction of TNF-α expression for 8 weeks, with etanercept treatment administered during the final 2 weeks of inflammation. Olfactory function was assayed by elecro-olfactogram (EOG), and olfactory tissue was processed for histology and immunohistochemical staining. Each group was compared with an equal-number control group.

RESULTS

Compared with nontreated IOI mice, etanercept-treated IOI mice showed significantly improved EOG responses after 2 weeks (P < .001). After 8 weeks of induced inflammation, there was massive loss of olfactory epithelium and no EOG response in nontreated IOI mice. However, in etanercept-treated mice, regeneration of olfactory epithelium was observed.

CONCLUSION

Concomitant administration of etanercept in IOI mice results in interruption of TNF-α-induced olfactory loss and induction of neuroepithelial regeneration. This demonstrates that etanercept has potential utility as a tool for elucidating the role of TNF-α in other olfactory inflammation models.

Immunogenicity of infliximab and adalimumab: what is its role in hypersensitivity and modulation of therapeutic efficacy and safety?

INTRODUCTION

TNF-α inhibitors have demonstrated efficacy both as monotherapy and in combination with disease-modifying antirheumatic drugs (DMARDs) in the treatment of chronic inflammatory immune-mediated diseases such as rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, psoriasis and/or psoriatic arthritis, and may be administered off-label to treat disseminated granuloma annulare systemic lupus erythematosus and systemic sclerosis. There are several TNF-α inhibitors available for clinical use including infliximab, adalimumab, golimumab, certolizumab pegol and etanercept.

AREAS COVERED

infliximab and adalimumab can induce the development of anti-infliximab (anti-IFX) and anti-adalimumab (anti-ADA) monoclonal antibodies (mAbs). In this review, we discuss the impact of anti-IFX and anti-ADA mAbs upon efficacy and safety of these biological agents.

EXPERT OPINION

IgG/IgE neutralizing antibodies against infliximab and adalimumab decrease the possibility of achieving a minimal disease activity state or clinical remission, decrease drug survival, increase the need for doctors to prescribe a higher drug dosage and, finally, favor the occurrence of adverse events. Concomitant administration of DMARDs such as methotrexate or leflunomide prevents the development of neutralizing Abs against infliximab and adalimumab.

Infection risk associated with anti-TNF-α agents: a review

INTRODUCTION

TNF-α is a pro-inflammatory cytokine known to a have a key role in the pathogenesis of chronic immune-mediated diseases. TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory or disease-modifying anti-rheumatic drugs (DMARDs) to treat chronic immune-mediated diseases.

AREAS COVERED

Patients receiving TNF-α inhibitors are at high risk of infections. Based on our experience, in this paper, we discuss the risk of infections associated with the administration of TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

EXPERT OPINION

Infliximab more so than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis (LTB) infection and the overall risk of opportunistic infections should be considered before beginning TNF-α inhibitor therapy. A careful medical history, Mantoux test and chest-x-ray should always be performed before prescribing TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitor treatment. Finally, patients who are at high risk of herpes zoster (HZ) reactivation would benefit from a second vaccination in adulthood when receiving TNF-α inhibitors.