Anti-infliximab antibody status and its relation to clinical response in psoriatic patients: A pilot study

Formation and clinical effects of anti-drug antibodies against biologics in psoriasis treatment: An analysis of current evidence

BACKGROUND

Formation of anti-drug antibodies (ADAs) against biologics is an important cause of psoriasis treatment failure.

OBJECTIVE

This study aimed to summarize the characteristics of ADAs formation under different biological therapies and the influence of ADAs on the clinical effects and safety of biologics in patients with psoriasis.

METHODS

PubMed, Embase, and Web of Science databases were searched from their inception to August 2022. Studies on biologics that assessed ADA levels in patients with psoriasis were included. The Cochrane risk-of-bias tool was used to assess the quality of randomized controlled trials (RCTs), the Newcastle-Ottawa Quality Assessment Scale (NOS) for case-control and cohort studies, and the Joanna Briggs Institute (JBI) critical appraisal checklist for single-arm studies. We calculated the pooled incidence with a random-effects model using R software. Subgroup analyses revealed that differences in patient characteristics, disease conditions, study design, and immunoassays may influence ADA generation and detection.

RESULTS

The analysis included 86 studies, with a total population of 42,280 individuals. The pooled ADA rates were 0.49%, 2.20%, 2.38%, 4.08%, 7.38%, 7.94%, 14.29%, 21.93%, 29.70%, 31.76%, and 39.58% for secukinumab, etanercept, brodalumab, ustekinumab, tildrakizumab, guselkumab, ixekizumab, risankizumab, infliximab, adalimumab, and bimekizumab, respectively. >70% (95% CI, 0.71-0.81) of ADAs against adalimumab were neutralizing antibodies, and over 70% of ADAs against secukinumab and brodalumab were transient. Concomitant methotrexate therapy with tumor necrosis factor-α (TNF-α) inhibitors decreased ADA levels. Lower infliximab doses and intermittent therapy with interleukin (IL)-23 p19 inhibitors increased ADA formation. Additionally, ADA formation under treatment using TNF-α inhibitors and IL-12/23 p40 inhibitors was associated with lower response rates or serum drug levels, but only high ADA titers reduced the clinical effects of IL-17 inhibitors. The occurrence of IL-23 p19 and TNF-α inhibitors has been linked to injection-site reactions.

CONCLUSIONS

Among the 11 biologics, secukinumab, etanercept, and brodalumab resulted in the lowest ADA formation rates. Immunogenicity contributes to lower biological efficacy and a higher likelihood of injection-site reactions. Low doses, intermittent treatment may increase ADA formation. An appropriate biologic should be selected based on the ADA formation rate and course of treatment.

Anti-drug antibodies of IL-17 inhibitors for psoriasis: a systematic review

Biologics may elicit the production of anti-drug antibodies (ADAs), the clinical significance of which is not fully understood. ADA development in psoriasis patients on IL-17 inhibitors was evaluated by incidence, impact on efficacy, and relationship with adverse events. We systematically searched PubMed, Cochrane, and Embase databases, identifying 456 references. 17 studies met inclusion criteria. ADA incidence was: 0% to 5.5% (secukinumab), 11% to 19.4% (ixekizumab), 0% to 3.3% (brodalumab), and 19% to 39% (bimekizumab). Neutralizing antibody incidence was: 0% to 1.5% (secukinumab), 0% to 3.5% (ixekizumab), and 0% (brodalumab). ADA presence alone with secukinumab, ixekizumab, and bimekizumab did not impact drug efficacy. Brodalumab was the only one of the IL-17 inhibitors, which showed a reduction in efficacy in ADA + patients. In one analysis, high ADA titers to ixekizumab were associated with diminished treatment response. ADAs to secukinumab and bimekizumab were not associated with adverse events. There were limited data on ADAs and safety with ixekizumab or brodalumab. Overall, when monitoring patients on secukinumab, ADAs, titers, and the presence of neutralizing antibodies were not prognostic of outcomes. However, monitoring for ADAs with brodalumab and measuring titers with ixekizumab may be of value clinically.

Impact of Pharmacokinetic and Pharmacodynamic Properties of Monoclonal Antibodies in the Management of Psoriasis

The treatment of psoriasis has been revolutionized by the emergence of biological therapies. Monoclonal antibodies (mAb) generally have complex pharmacokinetic (PK) properties with nonlinear distribution and elimination. In recent years, several population pharmacokinetic/pharmacodynamic (PK/PD) models capable of describing different types of mAb have been published. This study aims to summarize the findings of a literature search about population PK/PD modeling and therapeutic drug monitoring (TDM) of mAb in psoriasis. A total of 22 articles corresponding to population PK/PD models of tumor necrosis factor (TNF)-α inhibitors (adalimumab and golimumab), interleukin (IL)-23 inhibitors (guselkumab, tildrakizumab, and risankizumab), IL-23/IL-12 inhibitor (ustekinumab), and IL-17 inhibitors (secukinumab, ixekizumab, and brodalumab) were collected. A summary of the clinical trials conducted so far in psoriasis was included, together with the current structural population PK and PD models. The most significant and clinical covariates were body weight (BW) and the presence of immunogenicity on clearance (CL). The lack of consensus on PK/PD relationships has prevented establishing an adequate dosage and, therefore, accentuates the need for TDM in psoriasis.

Systematic Review and Recommendations to Combine Newer Therapies With Conventional Therapy in Psoriatic Disease

Background: Psoriasis continues to have unmet needs in its management despite introduction of newer molecules. Monotherapy with these newer agents may not achieve therapeutic goals in all cases, hence necessitating their combinations with other molecules. Improved understanding of newer as well as conventional treatment modalities and experiences in their combinations hence necessitates therapeutic guidelines for their use in psoriasis. Objective: To review the combinations of treatments reported in literature and recommendations for their use based on best current evidence in literature. Methods: A literature review of MEDLINE database for studies evaluating combinations of newer therapies with conventional therapies in psoriasis was done. Newer therapies were identified as biologic disease modifying anti rheumatic drugs and other molecules such as apremilast while conventional therapies included methotrexate, cyclosporine, or retinoids, phototherapy and others. The therapeutic guidelines are proposed with the aim to provide evidenced based approach to combine newer and conventional agents in day-to-day psoriasis management. Findings: Combination of acitretin and narrow band ultraviolet B (NB-UVB)/Psoralen with ultraviolet A (PUVA) achieves faster clearance and allows reduction of dose of the latter. A variable outcome is reported of methotrexate with TNF-α inhibitors vs. TNF-α inhibitors alone, although addition of methotrexate appears to reduce immunogenicity of TNF-α inhibitors thereby preventing formation of anti-drug antibodies especially in case of infliximab. While combination of acitretin and PUVA is beneficial, combining TNF-α inhibitors and phototherapy too produces better and faster results but long term risks of Non Melanoma Skin Cancers (NMSCs) may preclude their use together. Combination of cyclosporine and phototherapy is not recommended due to greater chances of NMSCs. Adding phototherapy to Fumaric Acid Esters (FAEs) improves efficacy. Apremilast can be safely combined with available biologic agents in patients with plaque psoriasis or psoriatic arthritis not responding adequately to biologics alone. Hydroxyurea and acitretin may be used together increasing their efficacy and reducing doses of both and hence their adverse effects. Conclusion: Selected clinical scenarios shall benefit from combinations therapies, improving efficacy of both conventional and newer agents and at the same time helping reduce toxicity of higher dosages when used individually.

Immunogenicity of Infliximab Among Patients With Behçet Syndrome: A Controlled Study

Background

Immunogenicity of tumor necrosis factor alpha inhibitors (TNFis) has been recognized as an important problem that may cause loss of efficacy and adverse events such as infusion reactions. TNFis are being increasingly used among patients with Behçet syndrome (BS) and scarce data exist on this topic.

Objective

We aimed to investigate the prevalence of anti-infliximab (IFX) antibodies in patients with Behçet syndrome together with suitable controls.

Methods

We collected serum samples from 66 consecutive Behçet syndrome patients (51 M, 15 F, mean age 37 ± 9 years) who were treated with IFX. Additionally, similarly treated 27 rheumatoid arthritis, 53 ankylosing spondylitis, 25 Crohn's disease patients, and 31 healthy subjects were included as controls. Samples were collected just before an infusion, stored at -80°C until analysis, and serum IFX trough levels and anti-IFX antibodies were measured by ELISA. We used a cut-off value of 1 μg/ml for serum IFX trough level, extrapolating from rheumatoid arthritis studies.

Results

Anti-IFX antibodies were detected in four (6%) Behçet syndrome, five (18.5%) rheumatoid arthritis, three (12%) Crohn's disease, and one (2%) ankylosing spondylitis patient. The median serum IFX trough level was significantly lower in patients with anti-IFX antibodies compared to those without antibodies [2.32 (IQR: 0.6-3.6) vs. 3.35 (IQR: 1.63-5.6); p = 0.019]. The serum IFX trough level was lower than the cut-off value in 6/13 (46%) patients with anti-IFX antibodies and in 25/158 (16%) patients without anti-IFX antibodies (p = 0.015). Among the four Behçet syndrome patients with anti-IFX antibodies, two experienced relapses and two had infusion reactions.

Conclusions

Immunogenicity does not seem to be a frequent problem in Behçet syndrome patients treated with IFX, but may be associated with relapses and infusion reactions, when present.

Systemic treatment of psoriasis: from methotrexate to biologics

Psoriasis is one of the most frequent chronic inflammatory skin diseases and it has been of interest to many scientists for ages. The review presents data on all systemic treatment options, that are to date officially registered in Russian Federation for moderate-to-severe psoriasis. Aspects of the mechanism of action, efficacy and tolerability of both basic drugs (methotrexate, cyclosporine, acitretin) and biologics (infliximab, adalimumab, etanercept, certolizumab pegol, ustekinumab, guselkumab, secukinumab, ixekizumab, netakimab) and small molecules (tofacitinib, apremilast) are considered in detail. Special emphasis is placed on the important nuances of biological therapy: immunogenicity, drugs' survival and switch due to lack of efficacy. Invention of biologics signified a new era of moderate-to-severe psoriasis treatment. It became possible to achieve complete clinical remission more safely, which significantly improved the quality of life of patients. However, due to the unknown etiology of psoriasis, there is still no universal remedy that would allow to cure every patient, this fact makes scientists from all over the world keep conducting numerous clinical trials to find even more effective and safe therapeutic options.

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 (T_H cell assay) using flow cytometry analysis that can detect a slight increase in proliferating T_H 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 T_H 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.

Antidrug antibody formation during tumor necrosis factor α inhibitor treatment of severe psoriatic patients in the real-life practice

Introduction

Antidrug antibody (ADA) production may be the reason behind secondary inefficacy of anti-TNF-α therapy in psoriasis.

Aim

To investigate the production of ADA, serum tumor necrosis factor α (TNF-α) and drug levels as predictors of clinical response in real-life circumstances.

Material and methods

Serum drug concentrations (TNFi), the presence of ADAs and serum TNF-α levels were measured in 158 patients by the ELISA method. Clinical response was evaluated by calculating PASI. Their correlation has been statistically analysed.

Results

In adalimumab and infliximab treated patients, ADA formation was observed in 18.4% and 33%, respectively, and the serum TNFi concentration was significantly higher in the ADA negative groups. In contrast there was no ADA formation detected among etanercept treated patients. The serum TNFi concentration was significantly lower among non-responders (n = 33). The serum TNF-α level was also measured and the correlation with the concentration of the serum TNFi level was analysed. Having evaluated the results of all patients together, the serum TNFi and TNF-α concentrations showed a significant negative correlation. However, when groups were analysed separately, in case of adalimumab, a significant negative correlation was detected between serum TNFi and TNF-α concentrations. With respect to infliximab, there was no significant correlation, and an inverse correlation was found in the etanercept group. The TNF-α levels and ADA positivity were significantly higher in non-responders.

Conclusions

This study revealed the major role of ADAs against TNFi in case of secondary inefficacy in real-life circumstances. ADA levels show a stronger correlation with PASI failure than serum TNFi or TNF-α levels.

Association between infliximab concentrations and clinical response in psoriasis: a prospective cohort study

BACKGROUND

Infliximab (IFX) trough concentrations (C_min) have been linked to treatment efficacy in psoriatic patients. Inter-individual IFX C_min variability and factors influencing IFX pharmacokinetics could explain differences in treatment response.

OBJECTIVE

To evaluate the association between IFX C_min and clinical outcomes in psoriatic patients.

METHODS

Prospective study of 33 patients with moderate to severe psoriasis receiving IFX at Bellvitge University Hospital, between October 2013 and November 2016. IFX C_min and antibodies toward infliximab (ATI) were measured.

RESULTS

We collected 155 IFX C_min and ATI values (mean age, 46 (14) years; 11 (33.3%) women). Mean IFX C_min was 2.5 (2.4) mg/L and ATIs were detected in six patients, resulting in undetectable IFX C_min. IFX C_min was significantly associated with ATI and body mass index (BMI) (β -2.51, 95% CI -3.56 to -1.4 and β -0.05, 95% CI -0.09 to -0.01). PASI score and PASI 90/100 response were significantly associated with IFX C_min (IRR 0.80, 95% CI 0.70 to 0.92; OR 1.79, 95% CI 1.18 to 2.71 and OR 1.79, 95% CI 1.14 to 2.81).

CONCLUSION

IFX C_min significantly influences PASI 90/100 response rates. IFX C_min wa significantly associated with ATI and BMI. The observed inter-individual variability in IFX C_min supports the need for IFX drug monitoring.

Clinical response correlates with 4-week postinjection ustekinumab concentrations in patients with moderate-to-severe psoriasis

Background

Cost‐effective use of biologicals is important. As drug concentrations have been linked to clinical outcomes, monitoring drug concentrations is a valuable tool to guide clinical decision‐making. A concentration–response relationship for ustekinumab at trough is uncertain owing to the contradictory results reported.

Objectives

To investigate the relationship between 4‐week postinjection ustekinumab concentrations and clinical response in patients with psoriasis.

Methods

Forty‐nine patients with moderate‐to‐severe psoriasis treated with 45 mg or 90 mg ustekinumab every 12 weeks for ≥ 16 weeks were included. Ustekinumab serum concentrations and anti‐ustekinumab antibodies were measured at week 4 after injection and disease severity was assessed by Psoriasis Area and Severity Index (PASI).

Results

At week 4 after injection, a significantly negative correlation was observed between ustekinumab concentrations and absolute PASI score up to 5·9 μg mL⁻¹ (ρ = –0·357, P = 0·032). Ustekinumab concentrations were higher in optimal responders (PASI ≤ 2) than in suboptimal responders (PASI > 2) (4·0 vs 2·8 μg mL⁻¹, P = 0·036). The ustekinumab concentration threshold associated with optimal response was determined to be 3·6 μg mL⁻¹ (area under the curve 0·71, sensitivity 86%, specificity 63%). Only one patient (2%) had anti‐ustekinumab antibodies. Psoriatic arthritis was identified as an independent predictor of higher PASI scores and higher ustekinumab concentrations (P = 0·003 and P = 0·048, respectively).

Conclusions

A concentration–response relationship at week 4 after injection was observed for patients with psoriasis treated with ustekinumab. Monitoring 4‐week postinjection ustekinumab concentrations could timely identify underexposed patients who might benefit from treatment optimization.

What's already known about this topic?

Monitoring drug concentrations is a valuable tool that can guide clinical decision‐making when drug concentrations are linked to clinical outcomes.

The presence of a concentration–response relationship for ustekinumab at trough is still debated owing to the contradictory results reported.

What does this study add?

A concentration–response relationship at week 4 after injection for ustekinumab‐treated patients with psoriasis was demonstrated.

Monitoring 4‐week postinjection ustekinumab concentrations could timely identify underexposed patients who might benefit from treatment optimization.

Based on the findings of this study, a treatment algorithm for patients with a suboptimal response is proposed.

Linked Comment: https://doi.org/10.1111/bjd.18709.

https://doi.org/10.1111/bjd.18709 available online

Infliximab and biosimilar infliximab in psoriasis: efficacy, loss of efficacy, and adverse events

Psoriasis is a chronic immune-mediated skin disease affecting multiple systems, and tumor necrosis factor-α (TNF-α) plays a significant role in the initiation and progression of the disease process. Psoriasis has a high prevalence rate in the Western world, especially in the USA and Australia; in China, although the prevalence rate is much lower, there is still a large number of patients suffering from psoriasis and its comorbidities. As TNF-α is thought to be crucial in the pathogenesis of psoriasis, specific therapy blocking TNF-α may be beneficial in the treatment of this disease. Infliximab, a murine-human monoclonal antibody, is highly efficacious in the treatment of moderate-to-severe psoriasis, with better skin clearance and faster onset of action than topical medications such as methotrexate, narrow-band ultraviolet B, and calcipotriol. Lack of adherence to infliximab therapy is mainly due to loss of response (LOR) over time and adverse events, particularly because infusion reactions are usually encountered. Anti-infliximab antibody is thought to be responsible for the LOR and infusion reactions. However, the mechanism underlying the formation of anti-infliximab antibody and its side effects remains unclear. Further studies identifying patients at risk for LOR will probably help clinicians to select the right patients for anti-TNF-α therapy and to increase the durability of the treatment. This review discusses the efficacy of infliximab as demonstrated by various clinical trials, LOR to infliximab, combatting LOR, as well as the adverse events usually faced during the use of infliximab therapy and the infliximab biosimilar Remsima^®. We hope that we can discover a better way to use infliximab in the therapy of psoriasis from the current research data.

Secondary failure of TNF-α inhibitors in clinical practice

Tumor necrosis factor alpha (TNF-α) is a leading inflammatory cytokine that plays a pivotal role in the pathogenesis of psoriasis. In case of a severe course of psoriasis and moderate-to-severe disease in which traditional systemic treatments are ineffective or contraindicated, TNF-α inhibitors (iTNF-α) are used. This class of drugs includes monoclonal antibodies and a fusion protein (etanercept) and can induce a humoral or cell-mediated immune response, leading to formation of anti-drug antibodies (ADAs). The immunogenicity may affect iTNF-α drug pharmacokinetics, which would lead to hampering the clinical response (secondary drug failure), so a need to increase the drug dose arises. Antibodies against monoclonal antibodies (adalimumab, infliximab) have been associated with diminished clinical response, while against etanercept are non-neutralizing and appear to have no significant effect on clinical response and treatment safety. Switching of biologic agents may be one strategy in ADA-associated secondary failure of iTNF-α. However researches are needed to identify risk factors for ADA development and investigate management strategies for optimized treatment response. The authors reviewed the literature on the effectiveness of iTNF-α and pointed out the prevention of secondary failure in clinical practice.

Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Current Practice of Therapeutic Drug Monitoring of Biopharmaceuticals in Psoriasis Patients

The high prevalence of psoriasis and the high spending on pharmaceuticals motivate a more evidence-based and cost-effective usage of biopharmaceuticals. A growing body of evidence exists that the implementation of therapeutic drug monitoring for biopharmaceuticals in psoriasis patients optimizes patient management and clinical outcome and enhances their efficacy. Therefore, the aim of this review was to give an overview of the literature on therapeutic drug monitoring of biopharmaceuticals in the treatment of psoriasis and to provide the useful information to dermatologists to improve health care in psoriasis patients.

The impact of immunogenicity of TNFα inhibitors in autoimmune inflammatory disease. A systematic review and meta-analysis

BACKGROUND

Monoclonal antibodies drugs directed against TNFα, TNFα inhibitors, are immunogenic, and consequent anti-drug antibodies (ADA) formation may decrease the functional drug concentration, resulting in a loss of response. We evaluated the impact of ADA on TNFα therapeutic response.

METHODS

We considered studies enrolling adult patients affected by autoimmune inflammatory disease in therapy with TNFα inhibitors. We collected data about study and population characteristics, treatment dosage, determination of ADA and adverse events (AE). We combined data in meta-analysis, calculating risk ratios (RR) for each study. p-Values<0.05 were considered as statistically significant. Methodological quality was evaluated. Analyses were performed with the STATA 11 and RevMan 5.3 softwares.

RESULTS

We included 34 studies enrolling 4273 patients. Of these, 794 (18.6%) developed ADA. Our analysis showed a significant reduction of response (RR 0.43, 95%CI 0.3-0.63) in patients with ADA respect to patients without, especially in patients treated with Infliximab (RR 0.37) or Adalimumab (RR 0.40). Furthermore, the administration of TNFα inhibitors produced a reaction at the infusion site in 17%, infection in 30% and serious AE in 5% of patients.

CONCLUSION

Detectable ADA significantly reduced TNFα inhibitors response. Drug administration can also cause injection site reaction and infections. Early detection of serum ADA levels may improve patients' management. Currently, there are many indications about the use of immunogenicity tests to guide the therapy, but information regarding how to implement it in clinical practice is needed.

Mucosal Healing in Paediatric Patients with Moderate-to-Severe Luminal Crohn's Disease Under Combined Immunosuppression: Escalation versus Early Treatment

BACKGROUND AND AIMS

We aimed to compare the efficacy of combined immunosuppression in terms of mucosal healing in paediatric patients with moderate-to-severe luminal Crohn's disease receiving infliximab according to either an 'escalated combined immunosuppression' or an 'early combined immunosuppression' strategy.

METHODS

In this prospective observational study, the efficacy of combined immunosuppression was evaluated in terms of mucosal healing at weeks 14 and 54 from baseline infliximab infusion. Comparison was performed between the escalated combined immunosuppression group [group A] and the early combined immunosuppression group [group B]. Factors associated with mucosal healing at weeks 14 and 54 from baseline infliximab infusion were also investigated.

RESULTS

Seventy-six patients initiated infliximab with concomitant azathioprine [group A = 28; group B = 48]. Comparison of baseline characteristics revealed a significantly longer duration from initial diagnosis to infliximab infusion in group A [median 8.1 vs. 0.7 months; p < 0.001]. Mucosal healing was achieved in 32% of patients in group A and 51% in group B at week 14 [p = 0.121], and in 42% in group A and 74% in group B at week 54 [p = 0.007]. Group B was also positively associated with mucosal healing at week 54 on multivariate logistic regression [odds ratio = 6.216, 95% confidence interval = 1.782-21.686, p = 0.004].

CONCLUSIONS

Mucosal healing during combined immunosuppression is more effectively achieved by treatment with an early combined immunosuppression strategy without corticosteroid induction administered within 1 month rather than escalating to receive combination therapy later during the course. The therapeutic window of opportunity in early Crohn's disease may be shorter than generally thought, especially in children.

A dermatologist guide to immunogenicity

Dermatologists should be aware that autoantibody formation may occur after the initiation of biologic therapy. This phenomenon has been referred to as immunogenicity and biologic fatigue. Because of this, patients may experience loss of clinical efficacy to a particular drug. To combat this phenomenon, low-dose immunomodulators may be used in hopes of preventing autoantibodies. We review the current literature and provide a basic treatment algorithm for patients with moderate to severe psoriasis.

Presence of antidrug antibodies correlates inversely with the plasma tumor necrosis factor (TNF)-α level and the efficacy of TNF-inhibitor therapy in psoriasis

Antidrug antibodies have been shown to be associated with a loss of response during biologic therapy. Despite the potential association, there has been no report on the simultaneous monitoring of the following parameters in psoriasis: presence of neutralizing antibodies, plasma tumor necrosis factor (TNF)-α concentration, TNFi concentration and disease activity. Plasma concentrations of adalimumab, infliximab, etanercept and their respective antidrug antibodies, as well as plasma concentrations of TNF-α were measured in 77 psoriasis patients receiving biologic therapy, and the values were correlated with the clinical activity of the skin disease. Antidrug antibodies were identified in the plasma of 25% of infliximab-treated patients and 29.6% of adalimumab-treated patients, but not in the etanercept group. Clinical severity scores were significantly higher in the antibody-positive patients. In patients receiving infliximab or adalimumab therapy, the presence of antidrug antibodies was directly associated with reduced plasma TNF-inhibitor concentration and elevated plasma TNF-α level.

Recommendations for managing a suboptimal response to biologics for moderate-to-severe psoriasis: A Belgian perspective

Over the past decade, biologics have become the gold standard in the treatment of moderate-to-severe psoriasis for patients who have failed or who have contraindications to traditional systemic treatments. However, although practical recommendations on how to treat a suboptimal response to biologics exist in other chronic inflammatory diseases, they are only just beginning to emerge for psoriasis. This article aims to formulate recommendations in the case of a suboptimal response of psoriasis to biologics in the Belgian setting. A Belgian taskforce of psoriasis experts was convened to review the results of a literature search and formulate recommendations based on the available evidence and provide expert opinion to address gaps in the evidence. The taskforce has proposed a treatment algorithm for patients with a primary non-response or a secondary loss of response to help address an unmet need. Expert recommendations have been developed to address treatment strategies in case of a primary or secondary suboptimal response to biologics in the treatment of moderate-to-severe psoriasis in Belgium.

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.

Immunogenicity of biologic treatments for psoriasis: therapeutic consequences and the potential value of concomitant methotrexate

The five biologic agents approved for the treatment of psoriasis-etanercept, infliximab, adalimumab, ustekinumab, and secukinumab-have been transformative in the clinical management of severe forms of the disease. However, a significant number of patients fail to respond to these agents or experience a loss of efficacy over time, which may be attributable to the development of antidrug antibodies (ADAs). Increasing evidence, primarily in the context of rheumatoid arthritis or other chronic inflammatory diseases, suggests that concomitant administration of methotrexate may prevent or diminish the development of ADAs, thereby improving response rates. However, methotrexate is infrequently coadministered with biologic agents in patients with psoriasis, and the potential benefits of this strategy in the context of psoriasis are largely unexplored. In this review, we discuss clinical studies regarding the development and consequences of antibodies targeting biologic agents used in the treatment of psoriasis and present key findings describing the potential role of methotrexate as an inhibitor of immunogenicity. We also discuss clinical considerations pertaining to the use of methotrexate as a tool to reduce immunogenicity, and encourage further investigation into potential techniques to optimize this treatment approach in patients with psoriasis.

Infliximab "Top-Down" Strategy is Superior to "Step-Up" in Maintaining Long-Term Remission in the Treatment of Pediatric Crohn Disease

OBJECTIVES

We aimed to compare the efficacy of remission maintenance between infliximab "top-down" and "step-up" strategies in moderate to severe pediatric Crohn disease during 3 years. We also aimed to determine prognostic factors that may influence the relapse-free rate in these patients.

METHODS

The present study was a retrospective review of a prospective cohort, based on an infliximab treatment protocol for pediatric Crohn disease used at Samsung Medical Center. A total of 31 patients (group A) were treated with early infliximab induction ("top-down" strategy) and 20 patients (group B) refractory to conventional therapy underwent infliximab treatment ("step-up" strategy). The efficacy of infliximab treatment was assessed by relapse-free rate and remission period rate for 3 years. A total of 11 prognostic factors that may influence the relapse-free rate were further analyzed.

RESULTS

The relapse-free rates at 3 years were 35.5% (95% confidence interval [CI] 0.194-0.519) in group A and 15.0% (95% CI 0.037-0.335) in group B (P = 0.0094). Overall remission period rate for 3 years also showed a significant difference between the 2 groups (92.1%  ± 7.2% vs 78.3%  ± 16.6%; P = 0.005). Multivariable analysis revealed that the duration from the initial diagnosis to infliximab infusion was the only factor associated with relapse-free remission for 3 years (hazard ratio = 1.077; 95% CI 1.025-1.131).

CONCLUSIONS

"Top-down" strategy had a longer remission period compared with the "step-up" strategy in pediatric Crohn disease during a study period of 3 years, based on relapse-free rate and remission period rate. Earlier introduction of infliximab is recommended in pediatric patients with moderate to severe Crohn disease.

Prevalence of TNF-α Blocker Immunogenicity in Psoriatic Arthritis

Objective.

The longterm use of tumor necrosis factor (TNF)-α blockers is limited by the formation of neutralizing antibodies. To the best of our knowledge, immunogenicity in psoriatic arthritis (PsA) has not been investigated in depth. Our objective was to evaluate the prevalence and significance of TNF-α blocker immunogenicity in PsA.

Methods.

Consecutive patients with PsA treated with either infliximab (IFX), adalimumab (ADA), or etanercept (ETN) > 3 months participated in our cross-sectional study. Their demographic and clinical characteristics, skin and joint disease activity, and records of use of methotrexate (MTX) and other medications were collected. Drug levels (ELISA) and antidrug antibodies (ADAb; Bridging ELISA) were evaluated before the next injection or infusion.

Results.

A total of 93 patients with PsA were recruited (48 receiving ADA, 24 IFX, and 21 ETN), with a mean age of 53 years (range 21–83 yrs), composed of 53% women. One-fourth of the patients were concomitantly treated with MTX. Altogether, 77% of the patients demonstrated therapeutic drug levels. High levels of ADAb were found in 29% of patients taking ADA, 21% taking IFX, and 0% taking ETN. ADAb significantly correlated with lower drug levels, higher 28-joint Disease Activity Scores, and higher global assessments. MTX use correlated significantly with a lower prevalence of ADAb.

Conclusion.

Significant levels of ADAb were present in up to 29% of patients with PsA treated with ADA or IFX. ADAb clearly correlated with low therapeutic drug levels and higher disease activity variables. The use of MTX significantly decreased ADAb prevalence, and its use should be strongly considered in combination with TNF-α blocker antibodies in patients with PsA.

Tumour necrosis factor inhibitor monotherapy vs combination with MTX in the treatment of PsA: a systematic review of the literature

OBJECTIVES

The aim of this study was to review the available evidence on TNF inhibitor monotherapy vs combination therapy with MTX in PsA.

METHODS

A literature search was conducted up to and including October 2013 for randomized controlled trials (RCTs) and observational studies comparing TNF inhibitor monotherapy vs combination therapy with MTX in patients with PsA. Key information was extracted from the abstracts and/or full text of the articles retrieved.

RESULTS

Eleven published articles and three conference abstracts were retrieved, reporting on six RCTs of four TNF inhibitors. Most RCTs found no differences in efficacy for peripheral arthritis between patients treated with or without MTX. However, the studies were not powered to answer this question. Some data suggest that concomitant MTX may reduce the progression of structural damage. No significant differences in other outcomes have been reported. Data on TNF inhibitor monotherapy vs MTX combination therapy were reported from six registries. Three registries reported that the use of concomitant MTX did not affect the efficacy of TNF inhibitor therapy. Data from three European Union registries suggest that TNF inhibitor (especially mAbs) drug survival is superior in patients taking concomitant MTX, while one Canadian registry reported no difference.

CONCLUSION

Available evidence on the efficacy and safety of TNF inhibitor monotherapy vs add-on MTX therapy shows little or no improvement with combination therapy, although the use of concomitant MTX appears to prolong TNF inhibitor drug survival of mAb TNF inhibitors. Registries and observational studies have the potential to fill some of the knowledge gaps in this area.

Infliximab in psoriasis and psoriatic arthritis

Psoriasis is a chronic inflammatory disorder of the skin and joints. Although rarely life threatening, psoriasis can significantly impair quality of life (QOL) and cause considerable physical and psychological distress. Between 6 and 42% of patients with psoriasis develop psoriatic arthritis, which is characterized by stiffness, pain, swelling and tenderness of the joints. Nail psoriasis is highly prevalent in both plaque-type psoriasis and psoriatic arthritis and is found in approximately 50% of patients with psoriasis and in 80% of patients with psoriatic arthritis. Infliximab, a chimeric human-murine monoclonal antibody directed against tumour necrosis factor α, is approved in the USA and EU for the treatment of plaque psoriasis and psoriatic arthritis at a recommended dosage of 5 mg/kg administered by intravenous infusion at 0,2 and 6 weeks, then every 8 weeks thereafter. The EXPRESS and EXPRESS II trials demonstrated that infliximab is efficacious as induction and maintenance therapy in the treatment of moderate to severe plaque psoriasis and also improved health-related QOL. Infliximab is also efficacious in the treatment of psoriatic arthritis, as shown in the IMPACT and IMPACT II studies. Infliximab is generally well tolerated, with a similar adverse event profile in both psoriasis and psoriatic arthritis. The use of infliximab in three case reports is presented. The patients are similar to those normally seen by clinicians, and include a male patient with plaque psoriasis and a history of severe psoriatic arthritis who was corticosteroid dependent and in whom other systemic treatments were not effective or were not able to be used. This patient showed a rapid response to infliximab with no skin lesions or arthritis after 7 weeks' treatment. Infliximab was also safe and effective in the treatment of a female patient with plaque and nail psoriasis and a history of psoriatic arthritis. Importantly, this case report supports the efficacy of infliximab in psoriatic nail disease in the context of severe skin and joint involvement. Case 3 describes a young male patient with moderate plaque-type psoriasis associated with severe nail involvement and early signs of psoriatic arthritis. Treatment with infliximab improved nail psoriasis and appears to be an effective biological treatment for nail psoriasis. Importantly, ultrasound was able to diagnose joint involvement, as seen from the proliferative synovitis in the distal interphalangeal joint and mild enthesitis, despite there being no clinical evidence of psoriatic arthritis. This case report highlights the importance of early screening. If such abnormalities are detected early on in the course of psoriasis, clinicians may be able to predict which patients are more likely to develop psoriatic arthritis, and therefore offer effective and long-term treatment that may reduce the disability and impairment of daily activities that can be associated with psoriatic arthritis.

Predicting treatment response in psoriasis using serum levels of adalimumab and etanercept: a single-centre, cohort study

BACKGROUND

A substantial proportion of patients with psoriasis do not respond, or lose initial response to tumour necrosis factor-α antagonists. One possible mechanism relates to subtherapeutic drug levels due to an immunogenic antibody response.

OBJECTIVES

To investigate the association between serum adalimumab and etanercept levels, antidrug antibody levels and clinical response in a cohort of patients with psoriasis using a commercially available enzyme-linked immunoassay.

METHODS

In a single-centre cohort of 56 adults with chronic plaque psoriasis initiated on adalimumab or etanercept monotherapy between 2009 and 2011, drug and antidrug antibody levels were measured at the patients' routine clinic reviews (4, 12 and 24 weeks of treatment and the last available observation). Patients' responses at 6 months were stratified into responders [75% reduction in Psoriasis Area and Severity Index from baseline (PASI 75) or Physician's Global Assessment score of 'clear' or 'nearly clear'] and nonresponders (failure to achieve PASI 50).

RESULTS

After 4 weeks, adalimumab levels were significantly higher in responders compared with nonresponders (P = 0·003) and these higher levels were sustained at 12 and 24 weeks. Anti adalimumab antibodies were detected in 25% of nonresponders (two of eight patients, average 22·5 weeks' follow-up) and none of the responders (n = 23, average 26·1 weeks' follow-up). There was no significant association between etanercept levels and clinical response at 4 weeks (P = 0·317) and no antietanercept antibodies were detected. Lack of serum trough levels may have resulted in underestimation of the prevalence of antidrug antibodies.

CONCLUSIONS

Early adalimumab drug level monitoring at 4 weeks may be useful in predicting treatment response and potentially reduce drug exposure (and associated cost) with earlier review of treatment in those with low levels. No conclusions about the value of etanercept drug monitoring can be made due to the paucity of data. Larger studies are now required to assess the clinical utility and cost-effectiveness of these assays in personalizing therapy in psoriasis.

The immunogenicity of anti-TNF therapy in immune-mediated inflammatory diseases: a systematic review of the literature with a meta-analysis

BACKGROUND

Immunogenicity of aTNFs is one of the mechanisms behind treatment failure.

OBJECTIVE

To assess the effect of anti-drug antibodies (ADA) on drug response to infliximab, adalimumab and etanercept, and the effect of immunosuppression on ADA detection, in patients with Rheumatoid Arthritis, Spondyloarthritis, Psoriasis and Inflammatory Bowel Diseases.

DATA SOURCES

PubMed, EMBASE, Cochrane databases, article reference lists (through August 19 2012).

STUDY SELECTION

Out of 2082 studies, 17 were used in the meta-analysis (1RCT; 16 observational studies).

DATA EXTRACTION

Two reviewers extracted data. Risk ratios (RR), 95% CI, using random-effect models, sensitivity analysis, meta-regressions and Egger's test were calculated.

DATA SYNTHESIS

Of 865 patients, ADA against infliximab or adalimumab reduced drug response rate by 68% (RR=0.68, 95% CI=0.12 to 0.36), an effect attenuated by concomitant methotrexate (MTX): <74% MTX+: RR=0.23, 95% CI=0.15 to 0.36; ≥74% MTX+: RR=0.32, 95% CI=0.22 to 0.48. Anti-etanercept antibodies were not detected. Of 936 patients, concomitant MTX or azathioprine/mercaptopurine reduced ADA frequency by 47% (RR=0.53, 95% CI=0.42 to 0.67), particularly when ADA were assessed by RIA (RR=0.36, 95% CI=0.23 to 0.55) compared with ELISA (RR=0.63, 95% CI=0.53 to 0.74).

CONCLUSIONS

ADA reduces drug response, an effect that can be attenuated by concomitant immunosuppression, which reduces ADA frequency. Drug immunogenicity should be considered for the management of patients receiving biological therapies.

Infliximab trough levels may predict sustained response to infliximab in patients with Crohn's disease

BACKGROUND AND AIMS

Over 10% of Crohn's disease (CD) patients annually lose response to infliximab. Infliximab trough levels (TL), concomitant immunosuppressants and endoscopic healing were proposed as predictors of favourable infliximab outcome. We assessed infliximab TL measured after induction therapy as predictors of sustained clinical response. Furthermore, we tried to identify other predictors of long-term benefit of infliximab therapy.

METHODS

We included CD patients treated with infliximab between October 2007 and March 2010 who responded to 3-dose induction followed by maintenance therapy and in whom blood samples taken at treatment week 14 or 22 were available in blood bank. Sustained response to infliximab was defined as absence of treatment failure due to loss of response or drug intolerance.

RESULTS

Eighty four patients were included. Sustained response to infliximab was observed in 47 (56%) patients during a median follow-up of 25 months (14-37). Infliximab TL>3μg/ml were associated with a decreased risk of treatment failure (HR 0.34; 95% CI: 0.16-0.75), whereas the presence of antibodies against infliximab and need for corticosteroids increased this risk (HR 4.34; 95% CI: 1.51-12.5 and HR 2.49, 95% CI: 1.08-5.73, respectively). No impact of concomitant thiopurines was observed, although patients receiving thiopurines had higher infliximab TL than those without immunomodulators (5.51 vs. 0.71μg/ml; p=0.01).

CONCLUSION

During a median follow up of 2 years sustained response to infliximab was observed in slightly more than half of CD patients. Infliximab TL>3μg/ml at the start of maintenance regime were predicative of sustained response to infliximab.

The role of DMARDs in reducing the immunogenicity of TNF inhibitors in chronic inflammatory diseases

The management of RA, SpA, psoriasis and inflammatory bowel disease has significantly improved over the last decade with the addition of tumour necrosis factor inhibitors (anti-TNFs) to the therapeutic armamentarium. Immunogenicity in response to monoclonal antibody therapies (anti-drug antibodies) may give rise to low serum drug levels, loss of therapeutic response, poor drug survival and/or adverse events such as infusion reactions. To combat these, the use of concomitant MTX may attenuate the frequency of anti-drug antibodies in RA, SpA and Crohn's disease. Although a similar effect to methotrexate has been observed with AZA usage in the management of Crohn's disease, there is insufficient evidence to suggest that other DMARDs impact immunogenicity. In this article we review the evidence to date on the effect of immunomodulatory therapy when co-administered with anti-TNFs. We also discuss whether such a strategy should be employed in SpA and psoriasis, and if optimization of the MTX dose could improve biologic drug survival and thereby benefit disease management.

Immunogenicity in biologic therapy: implications for dermatology

It is now known that all biologic drugs, even those that are fully human, are immunogenic, that is, they have the ability to induce an immune response in the treated patient. Since the presence of antidrug antibodies may influence the levels and function of the drug in the body, this immune response can alter the efficacy of the biologic treatment and even its safety profile, depending on the mechanism of action (neutralizing or nonneutralizing) and/or an accelerated clearance of the drug. Immunogenicity is a dynamic factor that should be taken into account when prescribing biologic therapy in psoriasis, especially in the case of long-term treatment and when assessing secondary loss of response. An understanding of the immunogenicity of biologic therapies and how this can be managed is useful not only for optimizing the treatment strategy used with each drug, but also for designing predictive models of response and even for tailoring therapy on a case-by-case basis.

Antidrug antibodies (ADAb) to tumour necrosis factor (TNF)-specific neutralising agents in chronic inflammatory diseases: a real issue, a clinical perspective

The introduction of biologics, especially tumour necrosis factor (TNF) inhibitors, has revolutionized the management of chronic inflammatory diseases. However, at least one third of patients with these diseases, receiving TNF inhibitors either do not respond to treatment, or lose initial responsiveness. For a significant proportion, improvement of clinical response is achieved after switching to another anti-TNF drug, suggesting a basis for failure unrelated to the therapeutic target itself. A likely explanation for this is immunogenicity, as all biologics are potentially immunogenic, and the resulting anti-drug antibodies (ADAb) can theoretically decrease the efficacy of biologics and/or induce adverse events. Indeed, in these chronic inflammatory diseases, many studies have now established correlations between ADAb formation, low serum drug levels, and the failure or loss of response to anti-TNF antibodies. This article will review key findings related to ADAb, and propose a model wherein monitoring of drug levels and ADAb may be a predictive tool leading to a better choice of biologics. Such an approach could improve chronic inflammatory disease management toward a personalized and more cost-effective approach.

Efficacy of Early Infliximab Treatment for Pediatric Crohn's Disease: A Three-year Follow-up

PURPOSE

To investigate the efficacy of early infliximab use and to follow the progress of pediatric cases of Crohn's disease for 3 years.

METHODS

We reviewed the medical records of 28 pediatric patients who had been treated with infliximab for Crohn's disease. Eighteen patients (the 'top-down' group) received infliximab and azathioprine for induction and maintenance therapy for the first year, and then were treated with azathioprine for 2 additional years. Ten patients who were refractory to conventional therapy were categorized in the 'step-up' group. All patients were followed for at least 36 months. Treatment efficacy was assessed by the relapse rate using the pediatric Crohn's disease activity index (PCDAI) score in each group at 12, 24, and 36 months. Blood samples were available from 10 patients, and were used to assess antibody to infliximab (ATI).

RESULTS

The relapse rate in 'top-down' group was lower than that in 'step-up' group at 1, 2, and 3 years. But, just the relapse rate at the 2 years was significantly different. At 3 years, the relapse rate according to different characteristic variables (sex, age at diagnosis, involvement, PCDAI at diagnosis) was not significantly different. Only one patient treated with infliximab had an adverse event, consisting of dyspnea and tachycardia. ATI was not detected in the blood samples from 10 patients.

CONCLUSION

Early induction with infliximab at diagnosis ('top-down' therapy) is effective for reducing the relapse rate compared to conventional therapies in pediatric Crohn's disease possibly for up to 3 years.

Correlation between elevation of serum antinuclear antibody titer and decreased therapeutic efficacy in the treatment of Behçet's disease with infliximab

BACKGROUND

Infliximab, an anti-TNF-α monoclonal antibody, administered to Behçet's disease (BD) patients in Japan with refractory intraocular inflammation, has shown excellent clinical results. However, some patients demonstrate a decreased response to infliximab during the course of the treatment. In the present study, we investigated the correlation between this reduced therapeutic effect and elevation of the serum antinuclear antibody (ANA) titers in patients with BD who were undergoing infliximab therapy.

METHODS

Seventeen patients (14 males and three females) with uveitis in BD who were undergoing treatment with infliximab for 2 years or longer were enrolled. Their blood test results and clinical histories were obtained from medical records.

RESULTS

One patient (5.9%) was ANA-positive prior to the initiation of infliximab, and 11 patients (64.7%) developed positive ANA during the therapy. The appearance of ANA was observed 6 months after the initiation of the infliximab therapy, and its titers gradually increased. None of the patients showed lupus symptoms. Five patients (29.4%) have suffered from ocular inflammatory attacks since the sixth month from the initiation of infliximab treatment and all of them were ANA-positive. In contrast, four patients (23.5%) who were ANA-negative experienced no ocular attacks during the follow-up period.

CONCLUSIONS

Here we report the positive conversion and subsequent elevation of serum ANA titers in some patients with BD after the initiation of infliximab therapy. Since all recurrences of uveitis were shown only in the ANA-positive patients, serum ANA titer may be a helpful biomarker for predicting the recurrence of ocular attacks in BD patients treated with anti-TNF-α antibody therapies.