Therapeutic drug monitoring of anti-TNF drugs: an overview of applicability in daily clinical practice in the era of treatment with biologics in juvenile idiopathic arthritis (JIA).

BACKGROUND: Anti-tumor necrosis factor (TNF) drugs have improved the prognosis for juvenile idiopathic arthritis (JIA) significantly. However, evidence for individual treatment decisions based on serum anti-TNF drug levels and the presence of anti-drug antibodies (ADAbs) in children is scarce. We aimed to assess if anti-TNF drug levels and/or ADAbs influenced physician's treatment decisions in children with JIA. METHODS: Patients' records in our center were retrospectively screened for measurements of anti-TNF drug levels and ADAbs in children with JIA using etanercept, adalimumab or infliximab. Clinical characteristics and disease activity were retrieved from patient charts. RESULTS: We analyzed 142 measurements of anti-TNF drug levels in 65 children with JIA. Of these, ninety-seven (68.3%) were trough concentrations. N = 14/97 (14.4%) of these showed trough concentrations within the therapeutic drug range known for adults with RA and IBD. ADAbs against adalimumab were detected in seven patients and against infliximab in one patient. Seven (87,5%) of these ADAb-positive patients had non-detectable drug levels. A flowchart was made on decisions including rational dose escalation, stopping treatment in the presence of ADAbs and undetectable drug levels, showing that 45% of measurements influenced treatment decisions, which concerned 65% of patients (n = 42/65). CONCLUSIONS: In the majority of patients, measurement of anti-TNF drug levels led to changes in treatment. A wide variation of anti-TNF drug levels was found possibly due to differences in drug clearance in different age groups. There is need for determination of therapeutic drug ranges and pharmacokinetic curves for anti-TNF and other biologics in children with JIA.

Presence of anti-nuclear antibodies is a risk factor for the appearance of anti-drug antibodies during infliximab or adalimumab therapy in patients with rheumatoid arthritis.

This study aimed to directly analyze the potential relationship of anti-nuclear antibodies (ANA) before and after the administration of TNF-α inhibitors (TNFi) with the appearance of anti-drug antibodies (ADrA) in patients with rheumatoid arthritis (RA). A total of 121 cases, viz., 38, 53, and 30 cases treated with infliximab (IFX), adalimumab (ADA), and etanercept (ETN), respectively, were enrolled. The ANA titers were measured using indirect immunefluorescence assay (IF-ANA) and multiplex flow immunoassay (ANA Screen) before and serially during the therapy. The anti-IFX antibodies (HACA) and anti-ADA antibodies (AAA) were measured with a radioimmunoassay. ADrA turned positive in 14 (36.8%) among 38 patients treated with IFX, and 16 (30.2%) among 53 treated with ADA. All of them were positive for IF-ANA before TNFi administration, while ADrA never appeared in any of the 15 patients negative for IF-ANA (< 40). IF-ANA of high titers (≥ 320 and ≥ 640) before IFX treatment showed a significant association with the appearance of HACA 52 weeks after IFX (P = 0.040 and 0.017, respectively), whereas AAA appearance was not related to IF-ANA titers before treatment. Moreover, IF-ANA of high titers before IFX treatment was significantly associated with inefficacy and discontinuation of the treatment. The positivity of anti-SS-A antibodies before therapy might be a risk factor for ADrA appearance in patients treated with IFX or ADA. The percentage of patients whose IF-ANA titers increased was significantly higher with IFX than with ADA or ETN treatments (P = 0.026 and 0.022, respectively). High ANA titers and positive ANA Screen after IFX therapy showed a significant association with HACA appearance and possibly led to treatment failure. Among the three TNFi, only IFX showed a close relationship with IF-ANA and ADrA appearance, suggesting the interaction of immunogenicity with autoimmunity as well as the advantage of ANA measurement before TNFi therapy.

Drug-neutralizing Antibodies against TNF-α blockers as Biomarkers of Therapy Effect Evaluation.

INTRODUCTION: TNF-α blocker therapy is part of the treatment with biologics used in the management of inflammatory joint diseases. In recent years, drug-induced neutralizing antibodies have been shown to have a negative effect on the course of the disease process. AIM: To investigate drug-induced neutralizing antibodies against TNF-α blocking drugs used in patients with inflammatory joint diseases and their effect on the clinical course of the disease. MATERIALS AND METHODS: The study included 121 (56.8%) patients with rheumatoid arthritis, 50 (23.5%) patients with ankylosing spondylitis, 42 (19.7%) patients with psoriatic arthritis, and 31 sex and age-matched healthy controls. The patients were monitored at 0, 6, 12, and 24 months after initiation of TNF-α blocker treatment. The demographic data, vital signs and the parameters of inflammatory activity (C-reactive protein, erythrocyte sedimentation rate, and disease activity indices) were analyzed in all patients. Drug-induced anti-TNF-α blockers antibodies (adalimumab and etanercept) were analyzed using ELISA. Statistical analysis was performed with SPSS v. 24. RESULTS: Drug-induced neutralizing antibodies against adalimumab were obtained in 11.57% of patients at 6 month, in 17.64% at 12 month, and in 24.8% at 24 month. Drug-induced neutralizing antibodies to etanercept were not demonstrated in patients followed up at 6 months, at 7.77% at 12 months, and at 9.63% at 24 months. Between the presence of neutralizing antibodies to blockers of TNF-α and indices available for disease activity, there is a strong positive correlation and Pearson Correlation = 0.701, p=0.001. Patients with poor clinical response and available antibodies against adalimumab at 12 months were 82.36% and patients treated with etanercept 71.42%. The difference between the two groups was non-significant (U = 0.527, p> 0.05). Patients with poor clinical response and available anti-adalimumab antibodies at 24 month were 75%, and in patients treated with etanercept - 87.50%, the difference between the two groups not being able to reach significance (U = 0.623, p> 0.05). CONCLUSION: Drug-induced neutralizing antibodies against TNF-α blockers (adalimumab and etanercept) have a negative effect on the course of inflammatory joint disease and can be used as reliable biomarker to assess the effect of the treatment with these drugs.

In vitro human helper T-cell assay to screen antibody drug candidates for immunogenicity.

Monoclonal antibody (mAb) drugs offer a number of valuable treatments. Many newly developed mAb drugs include artificial modification of amino acid sequences from human origin, which may cause higher immunogenicity to induce anti-drug antibodies (ADA). If the immunogenicity of a new candidate can be understood in the nonclinical phase, clinical studies will be safer and the success rate of development improved. Empirically, in vitro immunogenicity assays with human cells have proved to be sufficiently sensitive to nonhuman proteins, but not to human/humanized mAb. To detect the weaker immunogenicity of human-based mAb, a more sensitive biomarker for in vitro assays is needed. The in vitro study here developed a proliferation assay (TH cell assay) using flow cytometry analysis that can detect a slight increase in proliferating TH cells. Samples from 218 donors treated with a low-immunogenic drug (etanercept) were measured to determine a positive threshold level. With this threshold, positive donor percentages among PBMC after treatment with higher-immunogenicity mAb drugs were noted, that is, 39.5% with humanized anti-human A33 antibody (hA33), 27.3% with abciximab, 25.9% with adalimumab, and 14.8% with infliximab. Biotherapeutics with low immunogenicity yielded values of 0% for basiliximab and 3.7% for etanercept. These data showed a good comparability with previously reported incidences of clinical ADA with the evaluated drugs. Calculations based on the data here showed that a TH cell assay with 40 donors could provide statistically significant differences when comparing low- (etanercept) versus highly immunogenic mAb (except for infliximab). Based on the outcomes here, for screening purposes, a practical cutoff point of 3/20 positives with 20 donors was proposed to alert immunogenicity of mAb drug candidates.

Etanercept concentration and immunogenicity do not influence the response to Etanercept in patients with juvenile idiopathic arthritis.

OBJECTIVE: To investigate the relationship of clinical response of Juvenile Idiopathic Arthritis (JIA) to etanercept (ETN) with ETN levels, and the presence of anti-drug antibodies to ETN (ADAb). METHODS: Prospective study of JIA patients under 18 years old. Clinical and pharmacological data were collected at two visits. JIA clinical inactivity and activity were assessed according to the Wallace criteria and to the Juvenile Arthritis Disease Activity Score (JADAS). ETN and ADAb serum levels assessments were determined using ELISA-based assays. RESULTS: 126 patients were enrolled. The median duration of ETN treatment at inclusion was 569 days (range 53-2340). ADAb were undetectable (<10 ng/ml) in 171/218 (78%) samples and were > 25 ng/mL in 2/218 samples. No significant relationship between ETN concentration and the clinical inactivity status and JIA activity was found using either univariate logistic regression or multiple logistic regression analysis, adjusted on one individual descriptors, time since diagnosis, time of sampling, use of corticosteroids or methotrexate and classification of JIA. No correlation was found between the remission status and the detection of ADAb. CONCLUSION: This study did not demonstrate any correlation between JIA activity and circulating ETN levels in a large population of patients with JIA previously treated with ETN for at least 1.5 months. As described for adults, our study confirms that ETN is marginally immunogenic in pediatric patients. These results do not support the clinical usefulness of a monitoring of ADAb or ETN concentrations for the management of this group of JIA patients if they fail to achieve clinical inactive disease.

Antibody-mediated delivery of VEGF-C potently reduces chronic skin inflammation.

VEGF-C is an important mediator of lymphangiogenesis and has been shown to alleviate chronic inflammation in a variety of disease models. In this study, we investigated whether targeted delivery of VEGF-C to sites of inflammation and site-specific activation of lymphatic vessels would represent a clinically feasible strategy for treating chronic skin inflammation. To this end, we generated a fusion protein consisting of human VEGF-C fused to the F8 antibody (F8-VEGF-C), which is specific for the alternatively spliced, angiogenesis-marking extradomain A (EDA) of fibronectin. In two mouse models of psoriasis-like skin inflammation, mediated by transgenic VEGF-A overexpression or repeated application of imiquimod, intravenous treatment with F8-VEGF-C but not with untargeted VEGF-C significantly reduced ear skin edema and was as effective as the clinically used TNF-α receptor-Fc fusion protein (TNFR-Fc). Treatment with F8-VEGF-C led to a marked expansion of lymphatic vessels in the inflamed skin and significantly improved lymphatic drainage function. At the same time, treatment with F8-VEGF-C significantly reduced leukocyte numbers, including CD4+ and γδ T cells. In sum, our results reveal that targeted delivery of VEGF-C and site-specific induction of lymphatic vessels represent a potentially new and promising approach for the treatment of chronic inflammatory diseases.

Self-Adjusting Cytokine Neutralizer Cells as a Closed-Loop Delivery System of Anti-Inflammatory Biologicals.

The cytokines tumor necrosis factor α (TNFα) and interleukin 1 ß (IL-1ß) are both strong NF-κB activators and some of the first cytokines to be released in an inflammatory process. TNFα and IL-1ß are present in many autoimmune diseases, such as rheumatoid arthritis (RA). TNFα and IL-1ß-blocking therapies are quite successful and established in the treatment of RA, but may also be promising in other diseases. For the treatment of recurring autoimmune diseases, strong controlled sensor-effector cells inhibiting TNFα or IL-1ß appear highly predestined. Such cells detect a disease biomarker and autonomously react with the dose-dependent production of therapeutic proteins. Hence, we aim to harness and assemble the interactions of TNFα, IL-1ß, and NF-κB, which are an ideal match for synthetic biology-based circuits to rewire the transmission to approved TNFα- or IL-1ß-blocking biologicals. Considering the high impact of environmental influences on the dynamics of cell-based systems, we established closed-loop controllable cytokine neutralizer cells, monitoring cytokine levels and autonomously delivering powerful biologicals. This real-time processing system may provide dose-dependent drug delivery, which may be tailored for prospective cell and gene therapies against RA, and may offer a more personalized medicine than calculated drug dosing based on body weight.

[Development and Optimization of Therapeutic Analogues of Anti-TNFα Antibody Infliximab].

Previously, we have reported the crystal structures of Fab fragment of Infliximab in complex with TNFα. The structurally identified epitope on TNFα revealed the mechanism of TNFα inhibition by partially overlapping with the TNFα-receptor interface and the possibility to optimize the binding affinity. In this study, we launched a screen of a phage display library to isolate novel anti-TNFα antibodies based on the infliximab epitope. To develop novel anti-TNFα antibodies, structural analysis, the phage display antibody isolation, step by step antibody optimization, CDR residues random mutagenesis, and binding affinity characterization were performed. One of the novel antibodies generated on the backbone of infliximab, Inf3D6, has the superior binding affinity to TNFα, thus, demonstrating the potential for structure guided optimization for improvement of existing antibody-based therapeutics.

An explorative study on deep profiling of peripheral leukocytes to identify predictors for responsiveness to anti-tumour necrosis factor alpha therapies in ankylosing spondylitis: natural killer cells in focus.

BACKGROUND: Therapeutic targeting of tumour necrosis factor (TNF)-α is highly effective in ankylosing spondylitis (AS) patients. However, since one-third of anti-TNF-treated AS patients do not show an adequate clinical response there is an urgent need for new biomarkers that would aid clinicians in their decision-making to select appropriate therapeutic options. Thus, the aim of this explorative study was to identify cell-based biomarkers in peripheral blood that could be used for a pre-treatment stratification of AS patients. METHODS: A high-dimensional, multi-parametric flow cytometric approach was applied to identify baseline predictors in 31 AS patients before treatment with the TNF blockers adalimumab (TNF-neutralisation) and etanercept (soluble TNF receptor). RESULTS: As the major result, the frequencies of natural killer (NK) cells, and in particular CD8-positive (CD8+) NK cell subsets, were most predictive for therapeutic outcome in AS patients. While an inverse correlation between classical CD56+/CD16+ NK cells and reduction of disease activity was observed, the CD8+ NK cell subset behaved in the opposite direction. At baseline, responders showed significantly increased frequencies of CD8+ NK cells compared with non-responders. CONCLUSIONS: This is the first study demonstrating that the composition of the NK cell compartment has predictive power for prediction of therapeutic outcome for anti-TNF-α blockers, and we identified CD8+ NK cells as a potential new player in the TNF-α-driven chronic inflammatory immune response of AS.

Depression induced by chronic stress leads to penile cavernosal dysfunction: protective effect of anti-TNF-α treatment.

Psychological stress may lead to erectile dysfunction (ED), and inflammation has been evaluated as a major contributing factor. The goal of this study was to investigate the effects of etanercept (ETN), an anti-tumor necrosis factor α (TNF-α) protein, on cavernosal function in the unpredictable chronic mild stress (UCMS) rat model of depression. Animals were divided into 4 groups: animals not exposed to UCMS, animals not exposed to UCMS and treated with ETN, animals exposed to UCMS, and animals treated with ETN while exposed to UCMS. UCMS significantly impaired the neurogenic and endothelium-dependent relaxation responses; reduced cavernosal endothelial nitric oxide (NO) synthase (eNOS) and neuronal NO synthase (nNOS) expressions; decreased testosterone levels; enhanced systemic levels of corticosterone, TNF-α, interleukin 1ß (IL-1ß), interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule 1 (ICAM-1); and also increased cavernosal levels of TNF-α, IL-1ß, and IL-6 in rats. ETN administration restored NO-mediated neurogenic and endothelium-dependent relaxation responses of the corpus cavernosum, increased cavernosal eNOS and nNOS expressions, enhanced testosterone levels, and decreased corticosterone levels in UCMS-exposed rats. Also, systemic inflammatory markers and cavernosal proinflammatory cytokine levels were reduced by ETN. Our results demonstrate the role of TNF-α-mediated inflammation in the development of depression and ED in rats exposed to chronic stress.

GP2015 as a promising therapy for rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis is a common inflammatory joint disease with a myriad of systemic manifestations. Over the last 20 years its treatment has been revolutionised by the introduction of a number of different biologic drugs, including the TNF-receptor Fc fusion protein, Etanercept. However, these drugs are expensive and their widespread use puts a financial burden on healthcare systems. As many biologic treatments begin to come off patent new 'biosimilar' versions are being developed which can lead to significant cost savings. GP2015 (Erelzi®) is the second biosimilar version of Etanercept which is licensed for the treatment of rheumatoid arthritis. Areas covered: We discuss the Chemistry, pharmacokinetics and pharmacodynamics of GP2015 in relation to reference Etanercept. Preclinical trials have shown pharmacokinetic equivalence between GP2015 and the reference drug. The recently completed Phase III, randomised, double blind EQUIRA study has shown equivalent efficacy and safety between GP2015 and Etanercept in patients with rheumatoid arthritis. Expert opinion: GP2015 has shown equivalent efficacy and safety to reference Etanercept. With a growing number of biosimilar medications becoming available and another biosimilar Etanercept already being widely prescribed it is likely to be the cost of the drug that will determine if it is used widely.

Drug immunogenicity in patients with inflammatory arthritis and secondary failure to tumour necrosis factor inhibitor therapies: the REASON study.

Objectives: The aims were to evaluate the prevalence of anti-drug antibodies (ADA) in patients with RA or SpA experiencing secondary failure to anti-TNF therapy and to correlate ADA presence with anti-TNF concentration and clinical response. Methods: This was a cross-sectional, observational study of patients with active RA or SpA experiencing secondary failure to etanercept (ETN), infliximab (INF) or adalimumab (ADL). Concomitant non-biologic DMARDs were permitted. Serum anti-TNF and ADA levels were measured with two-site ELISA. Results: Among 570 evaluable patients, those with RA (n = 276) were mostly female (80 vs 39%), older (56 vs 48 years), received concomitant DMARDs (83 vs 47%) and had maintained good clinical disease control for longer (202 vs 170 weeks) compared with patients with SpA (n = 294). ADA were found in 114/570 (20.0%) patients; 51/188 (27.1%) against INF and 63/217 (29.0%) against ADL; none against ETN. Of these 114 patients, 92 (81%) had no detectable serum drug concentrations. Proportionately more patients with SpA (31.3%) had anti-INF antibodies than those with RA (21.1%; P = 0.014). A significantly lower proportion of patients receiving concomitant DMARDs (16.5%) developed ADA than those on monotherapy (26.4%; P < 0.05). Conclusion: In patients with RA or SpA and secondary failure, the development of ADA against ADL or INF, but not ETN, appears to be one of the main reasons for secondary treatment failure, but not the only one. Further investigations are needed to determine other causes of anti-TNF failure.

Incidence of Antidrug Antibodies in Rheumatoid Arthritis Patients From Argentina Treated With Adalimumab, Etanercept, or Infliximab in a Real-World Setting.

BACKGROUND: Biologic agents may induce immune responses that could impact drug action. OBJECTIVES: The aims of this study were to assess antidrug antibodies (ADAs) in patients with rheumatoid arthritis (RA) from Argentina treated with etanercept, adalimumab, or infliximab at a single visit and correlate it with efficacy outcomes. METHODS: In this subset analysis of a noninterventional, multinational, cross-sectional study (NCT01981473), adult patients with RA treated continuously for 6 to 24 months with etanercept, adalimumab, or infliximab were evaluated for ADAs and trough drug concentrations of 2 days or less prior to the next scheduled dose. Efficacy measurements included Disease Activity Score based on a 28-joint count-erythrocyte sedimentation rate, low disease activity, and Health Assessment Questionnaire-Disability Index. Targeted medical history of injection site/infusion reactions, serum sickness, and thromboembolic events were reported. RESULTS: Baseline demographics, disease characteristics, and duration of treatment of the 119 patients (etanercept: n = 54, adalimumab: n = 52, infliximab: n = 13) were similar across all groups. No etanercept-treated patient tested positive for ADAs compared with 19 (36.5%) of 52 patients and 4 (30.8%) of 13 patients treated with adalimumab and infliximab, respectively. In adalimumab- and infliximab-treated patients, ADA presence correlated negatively with trough drug levels. A greater proportion of ADA-negative patients achieved Health Assessment Questionnaire-Disability Index of 0.5 or less and had better composite efficacy measures compared with ADA-positive patients. The rate of targeted medical events reported was low. CONCLUSIONS: In this subset analysis, RA patients from Argentina treated with adalimumab or infliximab, but not etanercept, tested positive for ADAs. Antidrug antibody-negative patients showed a tendency toward better clinical outcomes compared with ADA-positive patients.

The prevalence and clinical effect of immunogenicity of TNF-α blockers in patients with axial spondyloarthritis.

OBJECTIVES: To evaluate the prevalence of immunogenicity of TNF-α blockers in axial spondyloarthritis (SpA) patients and to assess the effect of immunogenicity on drug levels and clinical response. METHPDS: Patients with axial SpA treated with either infliximab (INF), adalimumab (ADA) or etanercept (ETN) were recruited to our observational cross-sectional study. Demographic and clinical data were collected and disease activity scores were assessed. Drug trough levels and anti-drug antibodies were measured in serum samples and collected before the next administration. RESULTS: Thirty-nine patients with axial SpA with a mean age of 46.3±12.7 (10 women) were recruited to the study (14 receiving INF, 16 ADA and 9 ETN). Patients' mean therapy duration was 50.6 months (±46.4) and 6 (15%) of them were using MTX concomitantly with the TNF-α blockers. Anti-drug antibodies were found in 6 (15%) patients (4 with INF and 2 with ADA), all of which had undetectable drug level. No anti-drug antibodies were detected in patients treated with ETN. Immunogenicity was associated with higher BASDAI (Bath Ankylosing Spondylitis Disease Index), ASDAS-CRP (Ankylosing Spondylitis Disease Activity Score) and ASDAS-ESR. CONCLUSIONS: Axial SpA patients failure to respond to TNF-α blockers may be at least partially related to immunogenicity. Measurement of anti-drug antibodies and drug levels in these patients may assist in determining further treatment strategies.

Pharmacokinetics, Immunogenicity, and Efficacy of Etanercept in Pediatric Patients With Moderate to Severe Plaque Psoriasis.

Etanercept has been recently approved in the United States for the treatment of moderate to severe plaque psoriasis in patients aged 4-17 years. The objective of this study was to characterize etanercept pharmacokinetics, immunogenicity, and efficacy in pediatric patients. Data from a phase 3 study and open-label extension study were analyzed. Etanercept serum concentrations in pediatric patients receiving etanercept 0.8 mg/kg (maximum, 50 mg) weekly were compared with adult psoriasis patients and pediatric patients with juvenile idiopathic arthritis (JIA) who received etanercept 0.4 mg/kg twice weekly. The developments of antietanercept antibodies and efficacy based on the Psoriasis Area and Severity Index were evaluated. Steady-state trough etanercept concentrations were similar across visits from weeks 12-48, between patients aged 4-11 and 12-17 years, between pediatric and adult psoriasis patients, and between pediatric patients with psoriasis or JIA. Etanercept serum concentrations and safety profiles were similar in patients with (15.9%) and without antietanercept antibodies. Dosing used in the study provided similar exposures and efficacy across ranges of weight and body mass index. Pharmacokinetic, immunogenicity, and efficacy data support 0.8 mg/kg (maximum, 50 mg) weekly dosing of etanercept in patients aged 4-17 years.

Subcutaneous Injectable Drugs Hypersensitivity and Desensitization: Insulin and Monoclonal Antibodies.

Injectable drugs, including monoclonal antibodies, are becoming crucial components in the management of chronic diseases. The most common side effects are local reactions at the site of administration. With the increased and prolonged use of these medications, we are seeing increased reports of hypersensitivity reactions. The aim of this article is to discuss the signs and symptoms of these reactions as well as management, which may involve desensitization for 3 commonly encountered injectable drugs: tumor necrosis factor-α inhibitors (etanercept and adalimumab), insulin, and omalizumab.

Quartz crystal microbalance as an assay to detect anti-drug antibodies for the immunogenicity assessment of therapeutic biologics.

Because of their biological origins, therapeutic biologics can trigger an unwanted deleterious immune response with some patients. The immunogenicity of therapeutic biologics can affect drug efficacy and patient safety by the production of circulating anti-drug antibodies (ADA). In this study, quartz crystal microbalance (QCM) was developed as an assay to detect ADA. Etanercept (Enbrel®) was covalently grafted to dextran-modified QCM surfaces. Rabbits were immunized with etanercept to generate ADA. Results showed the QCM assay could detect purified ADA from rabbits at concentrations as low as 50 ng/mL, within the sensitivity range of ELISA. The QCM assay could also assess the ADA isotype. It was shown that the ADA were composed of the IgG isotype, but not IgM, as expected. Furthermore, it was shown that QCM surfaces that had been used to detect ADA could be regenerated in glycine-HCl solution and reused. The QCM assay was also demonstrated to detect ADA in crude serum samples. Serum was collected from the rabbits and analyzed before and after etanercept immunization. ADA were clearly detected in serum from rabbits after immunization, but not in serum before immunization. Serum from patients administered with etanercept for rheumatoid arthritis (RA) treatment was also analyzed and compared to serum from healthy donors. Sera from 10 RA patients were analyzed. Results showed one of the RA patient serum samples may have ADA present. In conclusion, QCM appears to be a viable assay to detect ADA for the immunogenicity assessment of therapeutic biologics.

GP2015: An Etanercept Biosimilar.

GP2015 is the second biosimilar of the reference p75 TNF receptor-Fc fusion protein etanercept. It is approved for use in all indications for which reference etanercept is approved, including rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, non-radiographic axial spondyloarthritis, plaque psoriasis and paediatric plaque psoriasis. GP2015 has similar physiochemical and pharmacodynamic properties to those of reference etanercept, and the pharmacokinetic biosimilarity of the agents has been shown in healthy volunteers. GP2015 demonstrated clinical efficacy equivalent to that of reference etanercept in patients with moderate-to-severe plaque psoriasis; the tolerability, safety and immunogenicity profiles of the two agents were also generally similar. Switching between GP2015 and reference etanercept had no impact on clinical efficacy, tolerability or immunogenicity. The role of reference etanercept in the management of inflammatory autoimmune conditions is well established and GP2015 provides an effective biosimilar alternative for patients requiring etanercept therapy.