Immunogenicity of biologic agents in rheumatology

Towards Personalized Medicine in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, incurable, multisystem, inflammatory disease characterized by synovitis and extra-articular features. Although several advanced therapies targeting inflammatory mechanisms underlying the disease are available, no advanced therapy is universally effective. Therefore, a ceiling of treatment response is currently accepted where no advanced therapy is superior to another. The current challenge for medical research is the discovery and integration of predictive markers of drug response that can be used to personalize medicine so that the patient is started on "the right drug at the right time". This review article summarizes our current understanding of predicting response to anti-rheumatic drugs in RA, obstacles impeding the development of personalized medicine approaches and future research priorities to overcome these barriers.

Safety of biologic agents for the management of rheumatic diseases during pregnancy

PURPOSE OF REVIEW

To discuss the current understanding regarding the use of biologic therapeutics in pregnancy.

RECENT FINDINGS

Our understanding of the mechanisms underlying the potential fetal and infant exposure to biologics as well as a growing body of empirical evidence from real world use of biologics in pregnancy have demonstrated that biologics are generally compatible preconception and during pregnancy. Long-term effects of exposure to biologic agents in utero are not known, but will be uncovered in time. Biosimilars, which are becoming more popular, may not always share the same safety profiles as their originators.

SUMMARY

Biologics have revolutionized the management of rheumatologic disease and ushered in a new era of clinical remission among patients. These agents, developed and introduced into clinical use at the beginning of the new millennium, are very potent, yet their efficacy in treating disease often in reproductive aged women, raises questions regarding their safety during pregnancy. These therapeutics can cause immunosuppression and can inhibit immunologic circuits that are not only involved in disease pathophysiology but hypothetically could impact the development of the fetal immune system. Reassuringly, biologics, typically antibodies or antibody-based proteins, are introduced to the fetus via the typical route of transplacental antibody transfer, and thus only begin to be transferred in appreciable amounts in the second trimester (after organogenesis). From theoretic and empirical standpoints, biologic use during pregnancy appears well tolerated for fetal development and to not substantially affect infant immune development.

A Phase I Clinical Study Comparing the Pharmacokinetics, Safety, and Immunogenicity of GB221 Injection and Trastuzumab (Herceptin®) in Healthy Chinese Adults

BACKGROUND AND OBJECTIVE

GB221 is a recombinant humanized anti-HER2 monoclonal antibody. The purpose of this study was to evaluate the pharmacokinetic, safety, and immunogenicity of GB221 in healthy Chinese adults in comparison to trastuzumab (Herceptin®).

METHODS

In this randomized, double-blind, parallel-group phase I clinical trial, 88 subjects were randomized 1:1 to receive a single intravenous infusion (90-100 min) of GB221 or trastuzumab (6 mg/kg). The primary pharmacokinetic parameters-maximum observed serum concentration (Cmax), area under the serum concentration-time curve from zero to the last quantifiable concentration at time t (AUC0-t), and area under the serum concentration-time curve from time zero to infinity (AUC0-∞)-of GB221 and trastuzumab were compared to establish whether the 90% confidence interval (CI) attained the 80-125% bioequivalence standard. Safety and immunogenicity were also evaluated.

RESULTS

The GB221 group (n = 43) and the trastuzumab group (n = 44) showed similar pharmacokinetic characteristics. The geometric mean ratios (90% CI) of Cmax, AUC0-t, and AUC0-∞ between the two groups were 107.53% (102.25-113.07%), 108.31% (103.57-113.26%), and 108.34% (103.57-113.33%), respectively. The incidence of treatment-emergent adverse events (TEAEs) was 83.7% (36/43) of the subjects in the GB221 group and 95.5% (42/44) of the subjects in the trastuzumab group. No subjects withdrew from the trial due to TEAEs, and there were no occurrences of serious adverse events. All subjects tested negative for antidrug antibodies (ADA).

CONCLUSION

GB221 demonstrated similar pharmacokinetics to trastuzumab and comparable safety and immunogenicity in healthy Chinese adults.

Clinical consequences of infliximab immunogenicity and the effect of proactive therapeutic drug monitoring: exploratory analyses of the randomised, controlled NOR-DRUM trials

BACKGROUND

Antidrug antibodies to TNF inhibitors might affect clinical outcomes. Proactive therapeutic drug monitoring allows for early detection of antidrug antibodies and might reduce negative clinical consequences. We aimed to explore how antidrug antibodies to the TNF inhibitor infliximab influence treatment outcomes, and to assess the effect of proactive therapeutic drug monitoring.

METHODS

This was a predefined exploratory analysis of data from the randomised, controlled NOR-DRUM trials. The trials were conducted in rheumatology, gastroenterology, and dermatology departments at 21 Norwegian hospitals. Adult patients (aged 18-75 years) with immune-mediated inflammatory diseases were randomly assigned to proactive therapeutic drug monitoring or standard infliximab dosing in the NOR-DRUM A trial (30-week follow-up) and the NOR-DRUM B trial (52-week follow-up). Antidrug antibodies were assessed with a drug-sensitive assay before each infusion. The outcomes of remission (at week 30), disease worsening (during 52 weeks), infusion reactions, and infliximab discontinuation were assessed according to the presence of antidrug antibodies and use of therapeutic drug monitoring.

FINDINGS

Between March 1, 2017, and Dec 12, 2019, 616 patients were included in the NOR-DRUM trials, of whom 615 had at least one serum infliximab and antidrug antibody assessment and were included in the present analyses. Mean age was 45 years (IQR 32-56), 305 (50%) patients were women, and 310 (50%) patients were men. Antidrug antibodies were detected in 147 (24%) patients. Remission at week 30 occurred in 25 (35%) of 72 patients with antidrug antibodies and 180 (54%) of 335 without antidrug antibodies (risk ratio 0·62 [95% CI 0·45-0·86]; p=0·0037). In patients with antidrug antibodies compared with patients without antidrug antibodies, higher rates were found for: disease worsening over 52 weeks (0·76 per person-year vs 0· 35 per person-year, hazard ratio [HR] 2·02 [95% CI 1·33-3·07]; p=0·0009), infusion reactions (0·16 per person-year vs 0·03 per person-year, HR 17·02 [6·98-41·47]; p<0·0001), and infliximab discontinuation (1·00 per person-year vs 0·20 per person-year, HR 6·64 [4·84-9·11]; p<0·0001). These associations were more pronounced in patients with high concentrations of antidrug antibodies than in those with low concentrations of antidrug antibodies. Independent of antibody status, therapeutic drug monitoring was associated with a lower risk of disease worsening (HR 0·41 [0·29-0·59]; p=0·0001) or an infusion reaction (HR 0·30 [0·12-0·73]; p=0·0076), and was associated with an increase in the rate of infliximab discontinuation (HR 1·37 [1·02-1·83]; p=0·037).

INTERPRETATION

In patients where antidrug antibodies were detected, remission was less likely to be reached and sustained, and infusion reaction or discontinuation of infliximab was more likely. Timely detection of antidrug antibodies by proactive therapeutic drug monitoring facilitated treatment decisions that reduced the negative consequences, both regarding infliximab effectiveness and safety. This highlights the role of proactive therapeutic drug monitoring in optimising infliximab therapy.

FUNDING

Inter-regional KLINBEFORSK grants and South-Eastern Norway Regional Health Authority grants.

New, Old, and Shared Antibody Specificities in Autoimmune Diseases

Autoantibodies represent a primary characteristic of many systemic autoimmune diseases [...].

Influence of sex on the persistence of different classes of targeted therapies for psoriatic arthritis: a cohort study of 14 778 patients from the French health insurance database (SNDS)

BACKGROUND

Sex differences in phenotype presentation, disease trajectory and treatment response in psoriatic arthritis (PsA) have been reported. Nevertheless, whether classes of targeted therapies differentially affect men and women with PsA remains unclear.

OBJECTIVES

To assess the effect of sex on the long-term persistence of each class of targeted therapies in PsA.

METHODS

This nationwide cohort study involved the administrative healthcare database of the French health insurance scheme linked to the hospital discharge database. We included all adults with PsA who were new users of targeted therapies (not in the year before the index date) during 2015-2021 and studied all treatment lines during the study period. Persistence was defined as the time from treatment initiation to discontinuation and was estimated by the Kaplan-Meier method. Comparison of persistence by sex involved multivariate frailty models with conventional synthetic disease-modifying antirheumatic drugs and prednisone as time-dependant variables.

RESULTS

We included 14 778 patients with PsA who were new users of targeted therapies: 8475 (57%) women (mean age 50±13 years; 15 831 lines), 6303 (43%) men (mean age 51±13 years; 10 488 lines). Overall, 1-year persistence was 52% for women and 62% for men and at 3 years it was 27% and 39%, respectively. After adjustments, persistence was lower for women than men for inhibitors of tumour necrosis factor (TNFi) (adjusted HR (HRa) 1.4, 99% CI 1.3 to 1.5) and interleukin 17 inhibitor (IL17i) (HRa 1.2, 99% CI 1.1 to 1.3) but not IL12/23i (HRa 1.1, 99% CI 0.9 to 1.3), IL23i (HRa 1.1, 99% CI 0.7 to 1.5) or Janus kinase inhibitor (JAKi) (HRa 1.2, 99% CI 0.9 to 1.6).

CONCLUSION

The treatment persistence was lower for women than men for TNFi and IL17i but not for IL12/23i, IL23i or JAKi.

The role of antidrug antibodies in ustekinumab therapy and the impact of methotrexate

OBJECTIVE

We investigated the impact of concomitant MTX on ustekinumab (UST) levels and antidrug antibody (ADA) formation in PsA and evaluated consequences in pharmacodynamics and pharmacokinetics.

METHODS

We conducted a post-hoc analysis on 112 PsA serum samples of subjects treated with open-label UST and either concomitant MTX (UST/MTX, n = 58) or placebo (UST/pbo, n = 54) obtained in a randomized (1:1), double-blind, multicentre trial. A validated antibody-binding-based multitiered testing was used to detect ADA and ADA with neutralizing capacity (nADA). The impact of MTX on UST immunogenicity was analysed by comparison of UST/pbo with UST/MTX cohorts at different time points. Patient- and disease-related predispositions for ADA formation were investigated with multiple linear regression analysis. Immunogenicity impact on pharmacokinetics, safety and efficacy was determined by cohort comparison between patients with and without ADA formation.

RESULTS

Over 52 weeks, 11 UST/pbo- and 19 UST/MTX-treated patients developed ADA (P > 0.05). In the UST/pbo cohort, the visit-dependent UST levels were in the range of 0.047 (0.05) -0.110 (0.07) µg/ml overall, and 0.037 (0.04)-0.091 (0.08) µg/ml in ADA-confirmed subjects. In UST/MTX-treated patients, the UST levels exhibited an intervisit variation in the range of 0.0502 (0.04)-0.106 (0.07) µg/ml overall and 0.029 (0.03)-0.097 (0.07) µg/ml in ADA positive subjects (P > 0.05). At week 52, ADA-confirmed patients did not differ significantly (P > 0.05) in safety or clinical outcomes from ADA-negative patients.

CONCLUSION

Concomitant MTX had no significant impact on UST immunogenicity. Furthermore, ADA formation was not associated with impairments in UST safety, efficacy or trough levels.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03148860.

Diligent Design Enables Antibody-ASO Conjugates with Optimal Pharmacokinetic Properties

Antisense-oligonucleotides (ASOs) are a promising drug modality for the treatment of neurological disorders, but the currently established route of administration via intrathecal delivery is a major limitation to its broader clinical application. An attractive alternative is the conjugation of the ASO to an antibody that facilitates access to the central nervous system (CNS) after peripheral application and target engagement at the blood-brain barrier, followed by transcytosis. Here, we show that the diligent conjugate design of Brainshuttle-ASO conjugates is the key to generating promising delivery vehicles and thereby establishing design principles to create optimized molecules with drug-like properties. An innovative site-specific transglutaminase-based conjugation technology was chosen and optimized in a stepwise process to identify the best-suited conjugation site, tags, reaction conditions, and linker design. The overall conjugation performance was found to be specifically governed by the choice of buffer conditions and the structure of the linker. The combination of the peptide tags YRYRQ and RYESK was chosen, showing high conjugation fidelity. Elaborate conjugate analysis revealed that one leading differentiating factor was hydrophobicity. The increase of hydrophobicity by the ASO payload could be mitigated by the appropriate choice of conjugation site and the heavy chain position 297 proved to be the most optimal. Evaluating the properties of the linker suggested a short bicyclo[6.1.0]nonyne (BCN) unit as best suited with regards to conjugation performance and potency. Promising in vitro activity and in vivo pharmacokinetic behavior of optimized Brainshuttle-ASO conjugates, based on a microtubule-associated protein tau (MAPT) targeting oligonucleotide, suggest that such designs have the potential to serve as a blueprint for peripherally delivered ASO-based drugs for the CNS in the future.

Identification of Covariates Modulating B-Cell Repopulation Kinetics in Subjects Receiving Rituximab Treatment

OBJECTIVE

B-cell depletion using the anti-CD20 monoclonal antibody rituximab is a cornerstone in the therapeutic concept of multiple autoimmune diseases. B-cell depletion is associated with a higher risk for severe infections, and the time span of B-cell repopulation differs greatly between individuals. Data on factors influencing B-cell repopulation kinetics are limited. This study aims to identify patient-specific and therapy-associated covariates that modulate B-cell repopulation.

METHODS

This single-center retrospective observational study presents data of 839 subjects receiving 2,017 courses of rituximab for autoimmune diseases. Assessed covariates are patient-specific factors (sex, age, kidney function, and underlying disease) and co-immunosuppression with common agents (azathioprine, cyclosporine A, cyclophosphamide, hydroxychloroquine, methotrexate, mycophenolate mofetil, tacrolimus, and corticosteroids). The primary end point is the time to B-cell repopulation (≥5/μl). The secondary end point is the time to B-cell reconstitution (≥50/μl). Multivariate time-to-event analysis and logistic regression models were applied to estimate the influence of covariates.

RESULTS

Age over 60 years (hazard ratio [HR] 0.71 for repopulation, P = 0.008), impaired kidney function (HR 0.72, P = 0.001), antineutrophil cytoplasmic antibody-associated vasculitis (HR 0.61, P < 0.001), solid organ transplantation (HR 0.4, P < 0.001), and co-immunosuppression with corticosteroids (HR 0.64, P < 0.001) or azathioprine (HR 0.49, P < 0.001) were associated with impaired B-cell repopulation and reconstitution. Effects of corticosteroids (P = 0.043) and azathioprine (P = 0.025) were dose dependent.

CONCLUSION

Prolonged rituximab dosing intervals may be effective to achieve B-cell depletion and reduce risk of infection in advanced age or patients with impaired kidney function. Co-medication with corticosteroids or azathioprine prolongs B-cell recovery, which may increase therapeutic effects but also the rate of adverse events.

Ocrelizumab and ofatumumab, but not rituximab, trigger complement induction in vitro

The clinical and adverse effects of the therapeutic monoclonal antibodies (mAb) ocrelizumab, ofatumumab and rituximab in multiple sclerosis (MS) are presently subject to extensive study. While the two former are approved for MS, the older and less costly rituximab is used off label, and adverse effect profiles are important in their evaluation. The three mAbs all induce B cell depletion, with complement-dependent cytotoxicity (CDC) as one of several mechanisms of action. Complement activation is also postulated to underlie adverse reactions related to infusion/injection. Such administration-related reactions are associated with all three mAbs, but comparisons have so far been indirect, resting on incidence reports from separate clinical trials. The objective of this study was to perform head-to-head comparison of complement activation by ofatumumab, ocrelizumab and rituximab. In vitro experiments were performed in whole blood from healthy donors. The complement-activating potential of the three mAbs was analyzed after 30 min of exposure to 0.3 mg/mL or 0.9 mg/mL of each drug, and compared with those of the well-known TNF inhibitory mAbs adalimumab and infliximab, the latter with recognized potential for infusion reactions. Ofatumumab, ocrelizumab, and infliximab, but not rituximab and adalimumab, triggered statistically significant complement activation measured as increased levels of terminal C5b-9 complement complex (TCC), a sensitive marker of such activation. While results demand careful interpretation, they provide an indication of distinct complement-inducing potential among anti-CD20 mAbs currently used to treat MS.

Efficacy of Combined Initial Treatment of Methotrexate with Infliximab in Pediatric Crohn's Disease: A Pilot Study

BACKGROUND

The combination of antitumor necrosis factor-alpha (TNF-α) agents with immunomodulators (IMMs) is a common treatment for pediatric Crohn's disease (CD). Although methotrexate (MTX) can be a first-line medication as an IMM, most clinicians in real-life practice, especially in South Korea, are more familiar with thiopurines. This study aimed to compare the efficacy and immunogenicity of MTX and azathioprine (AZA) as concurrent therapies for pediatric CD.

METHODS

In this pilot study, 29 newly diagnosed pediatric patients with moderate-to-severe CD were randomized to receive either MTX (n = 15) (15 mg/body surface area (BSA) per week) or oral AZA (n = 14) (0.5 mg/kg per day) in combination with Infliximab (IFX). The primary outcomes were the proportion of patients in endoscopic, biochemical, and transmural remission after 14 and 54 weeks of IFX therapy. The trough levels (TLs) of IFX and anti-drug antibody (ADA) levels were also compared.

RESULTS

Among the 29 patients, there were no significant differences in the biochemical (p = 1.0 at week 14, p = 0.45 at week 54), endoscopic (p = 0.968 at week 14, p = 0.05 at week 54), or transmural (p = 0.103 at week 54) remission rates between the two medications during the concurrent therapy. Additionally, the trends in the IFX trough and ADA levels over time during the treatments were similar for both medications, with no significant differences (p = 0.686, p = 0.389, respectively).

CONCLUSION

The MTX showed comparable efficacy to the AZA in pediatric CD patients with moderate-to-severe disease. This effectively maintained adequate IFX levels and reduced ADA production. Therefore, although additional large-scale clinical trials are needed, this study demonstrated that either MTX or AZA can be selected as IMMs in the concurrent treatment of pediatric CD, depending on individual medical institutions' circumstances.

Inappropriate treatment response to DMARDs: A pathway to difficult-to-treat rheumatoid arthritis

In recent years, difficult-to-treat rheumatoid arthritis (D2T RA) has attracted significant attention from rheumatologists due to its poor treatment response and the persistent symptoms or signs experienced by patients. The therapeutic demands of patients with D2T RA are not properly met due to unclear pathogenic causes and a lack of high-quality data for current treatment options, creating considerable management difficulties with this patient population. This review describes the clinical challenges associated with disease-modifying antirheumatic drugs (DMARDs) and explores contributing factors associated with inappropriate response to DMARDs that may lead to D2T RA and related immunological dysregulation. It is now understood that D2T RA is a highly heterogeneous pathological status that involves multiple factors. These factors include but are not limited to genetics, environment, immunogenicity, comorbidities, adverse drug reactions, inappropriate drug application, poor adherence, and socioeconomic status. Besides, these factors may manifest in the selection and utilization of specific DMARDs, either individually or in combination, thereby contributing to inadequate treatment response. Finding these variables may offer hints for enhancing DMARD therapy plans and bettering the condition of D2T RA patients.

Biosimilars in the treatment of rheumatoid arthritis: a pharmacokinetic overview

INTRODUCTION

As of May 2023, 19 and 18 biosimilars have been approved for the treatment of rheumatoid arthritis (RA) by the European Medicines Agency (EMA) and United States Food and Drug Administration (US FDA) respectively.

AREA COVERED

Pharmacokinetic results of phase 1 studies of approved biosimilars were reviewed by systematic literature search. The impact of immunogenicity on the pharmacokinetic data and clinical response was assessed, and the potential benefit of monitoring serum concentrations of biologic drugs is discussed. The advantage of subcutaneous CT-P13 (an infliximab biosimilar) in clinical practice is reviewed.

EXPERT OPINION

Biosimilars are approved based on the totality of evidence including comparable physiochemical properties, PK / PD profiles, and clinical efficacy and safety to the originator. To utilize biosimilars more effectively, physicians should be aware of the utility of combination DMARD therapy to reduce immunogenicity and maintain efficacy and PK profile. PK monitoring, however, is not currently recommended in clinical practice. CT-P13 subcutaneous (SC) is the first SC infliximab used for treatment of RA patients. Based on data from clinical studies and the real world, SC-infliximab is an attractive therapeutic option compared to IV formulations of infliximab based on its efficacy, pharmacokinetics, patient-reported outcomes, and safety profile.

Tailored therapeutic decision of rheumatoid arthritis using proteomic strategies: how to start and when to stop?

Unpredictable treatment responses have been an obstacle for the successful management of rheumatoid arthritis. Although numerous serum proteins have been proposed, there is a lack of integrative survey to compare their relevance in predicting treatment outcomes in rheumatoid arthritis. Also, little is known about their applications in various treatment stages, such as dose modification, drug switching or withdrawal. Here we present an in-depth exploration of the potential usefulness of serum proteins in clinical decision-making and unveil the spectrum of immunopathology underlying responders to different drugs. Patients with robust autoimmunity and inflammation are more responsive to biological treatments and prone to relapse during treatment de-escalation. Moreover, the concentration changes of serum proteins at the beginning of the treatments possibly assist early recognition of treatment responders. With a better understanding of the relationship between the serum proteome and treatment responses, personalized medicine in rheumatoid arthritis will be more achievable in the near future.

Anti-Drug Antibodies in the Biological Therapy of Autoimmune Rheumatic Diseases

Autoimmune rheumatic diseases are a cluster of heterogeneous disorders that share some clinical symptoms such as pain, tissue damage, immune deregulation, and the presence of inflammatory mediators. Biologic disease-modifying antirheumatic drugs are some of the most effective treatments for rheumatic diseases. However, their molecular and pharmacological complexity makes them potentially immunogenic and capable of inducing the development of anti-drug antibodies. TNF inhibitors appear to be the main contributors to immunogenicity because they are widely used, especially in rheumatoid arthritis. Immunogenicity response on these treatments is crucial since the appearance of ADAs has consequences in terms of safety and efficacy. Therefore, this review proposes an overview of the immunogenicity of biological agents used in autoimmune rheumatic diseases highlighting the prevalence of anti-drug antibodies.

The abscopal effect: Implications for drug discovery in autoimmunity

The emergence of novel targeted therapies and the tools that increase the stability and delivery of drugs have greatly improved treatment outcomes in autoimmune diseases (ADs). Recently-developed strategies deplete specific deleterious T- and B-cell subsets, interrupt receptor-ligand interactions, and/or inhibit the secretion or activity of inflammatory mediators linked to tissue damage. Although generally efficient, these lines of intervention have limitations, with documented cases of drug-resistance and undesired side effects. They are also difficult to apply to non-organ-specific ADs, where the trigger and effector antigens are unknown and in which autoimmune activity is widely spread throughout the body. The potential of cellular modulators that act at a distance from the affected site, by abscopal effect, as described in the case of cancer radio- and immuno-therapy might be especially efficient in the context of ADs. Future research to discover small molecule- and peptide-based treatments will need to explore potential drugs with abscopal effects that could elicit potent immune tolerance and clinical quiescence to restore quality of life of affected patients.

The establishment of B cell-deficient Igh-J KO mouse model by gene editing and efficacy evaluation

Over the last few years, immunotherapy has made significant progress in treating various cancers with therapeutic antibodies. However, therapeutic antibodies have been validated for inducing an unintended immune response in human and animal models, which leads to the emergence of anti-drug antibodies (ADAs) and affects their effectiveness and safety. In preclinical research, ADAs production by B cells may accelerate antibody metabolism and result in missing potential candidate molecules. Thus, it is urgent to develop preclinical models that remove only B cells without affecting the function of T and NK cells. Rearrangement of immunoglobulin heavy chain J gene fragment (Igh-J) is the first link in B cell development, and immunotherapies are currently leaning toward combination treatments with PD-1/PD-L1 antibodies, here we created humanized PD-1, PD-L1 and Igh-J knockout (hPD-1/hPD-L1, Igh-J KO) mice and validated by using the reported high immunogenicity drug M7824 (a protein designed to simultaneously block PD-L1 and TGF-β pathways, poorly anti-tumor efficacy in immunocompetent mice). Phenotypic analysis revealed that human PD-1 and PD-L1 were detectable in hPD-1/hPD-L1, Igh-J KO mice, but not mouse IgM and IgD. Igh-J KO depleted B cells while increased the percentage of other immune cell types. Meanwhile, the humanization of PD-1/PD-L1 and Igh-J KO had neither effect on the overall development, differentiation, or distribution of T cell subtypes, nor on the activation of NK and T cells, indicating that mice can be used for T and NK-related immunotherapies. Furthermore, M7824 treatment of these B cell-deficient mice inhibited tumor growth significantly, with higher M7824 analog concentrations and lower ADA-positive rates. These findings demonstrate that Igh-J KO mice are an effective and stable preclinical model for testing drugs based on T and NK cells with high immunogenicity in vivo.

Alternative Biologic Therapy in Children Failing Conventional TNFα Inhibitors for Refractory, Noninfectious, Chronic Anterior Uveitis

PURPOSE

A significant number of children with noninfectious, chronic anterior uveitis (CAU) fail to respond to conventional therapy; however, successful alternative biologic treatments (ABT) have not been well described. This study aims to review the clinical and treatment characteristics of children with CAU who require ABT.

DESIGN

Retrospective, nonrandomized clinical study.

METHODS

Setting: Tertiary center.

STUDY POPULATION

Children with noninfectious CAU.

OBSERVATION PROCEDURES

Clinical characteristics, uveitis course, complications, and treatment were compared among patients treated with methotrexate (MTX) monotherapy, conventional TNFα inhibitors (cTNFi), and ABT for >3 months.

MAIN OUTCOME MEASURE

Success of ABT (abatacept, tocilizumab, and/or golimumab) in children failing conventional treatment.

RESULTS

Of the 52 children with CAU, 75% had juvenile idiopathic arthritis. CAU was controlled in 15 children receiving MTX monotherapy, 28 receiving cTNFi, and 9 receiving ABT (n = 1, abatacept; n = 3, tocilizumab; n = 5, golimumab). Patients in the ABT group had a greater number of total ocular complications per person before ABT than those in the control groups (3.4 vs 0.7 [MTX], P < .001, and 1.5 [cTNFi], P < .001, respectively). In all 9 children on ABT, treatment led to control of CAU and topical glucocorticoids tapered to ≤2 drops/d with no new ocular complications.

CONCLUSIONS

In this study, alternative biologics (abatacept, golimumab, and tocilizumab) were useful for treating CAU in children who fail MTX and cTNFi therapy. Patients who were controlled on ABT had more disease activity, ocular complications, and anti-cTNFi neutralizing antibodies (before ABT) than those managed with conventional therapy. Larger studies are required to confirm these findings.

An orally available small molecule that targets soluble TNF to deliver anti-TNF biologic-like efficacy in rheumatoid arthritis

Tumor necrosis factor (TNF) is a pleiotropic cytokine belonging to a family of trimeric proteins with both proinflammatory and immunoregulatory functions. TNF is a key mediator in autoimmune diseases and during the last couple of decades several biologic drugs have delivered new therapeutic options for patients suffering from chronic autoimmune diseases such as rheumatoid arthritis and chronic inflammatory bowel disease. Attempts to design small molecule therapies directed to this cytokine have not led to approved products yet. Here we report the discovery and development of a potent small molecule inhibitor of TNF that was recently moved into phase 1 clinical trials. The molecule, SAR441566, stabilizes an asymmetrical form of the soluble TNF trimer, compromises downstream signaling and inhibits the functions of TNF in vitro and in vivo. With SAR441566 being studied in healthy volunteers we hope to deliver a more convenient orally bioavailable and effective treatment option for patients suffering with chronic autoimmune diseases compared to established biologic drugs targeting TNF.

Assessing Immunogenicity of Biologic Drugs in Inflammatory Joint Diseases: Progress Towards Personalized Medicine

Biologic drugs have greatly improved treatment outcomes of inflammatory joint diseases, but a substantial proportion of patients either do not respond to treatment or lose response over time. Drug immunogenicity, manifested as the formation of anti-drug antibodies (ADAb), constitute a significant clinical problem. Anti-drug antibodies influence the pharmacokinetics of the drug, are associated with reduced clinical efficacy, and an increased risk of adverse events such as infusion reactions. The prevalence of ADAb differs among drugs and diseases, and the detection of ADAb also depends on the assay format. Most data exist for the tumor necrosis factor-alpha inhibitors infliximab and adalimumab, with a frequency of ADAb that ranges from 10 to 60% across studies. Measurement of ADAb and serum drug concentrations, therapeutic drug monitoring, has been suggested as a strategy to optimize therapy with biologic drugs. Although the recent randomized clinical Norwegian Drug Monitoring (NOR-DRUM) trials show promise towards a personalized medicine prescribing approach by therapeutic drug monitoring, several challenges remain. A plethora of assay formats, with widely differing properties, is currently used for measuring ADAb. Comparing results between different assays and laboratories is difficult, which complicates the development of cut-offs necessary for guidelines and the implementation of ADAb measurements in clinical practice. With the possible exception of infliximab, limited data on clinical relevance and cost effectiveness exist to support therapeutic drug monitoring as a routine clinical strategy to monitor biologic drugs in inflammatory joint diseases. The aim of this review is to provide an overview of the characteristics and prevalence of ADAb, predisposing factors to ADAb formation, commonly used assessment methods, clinical consequences of ADAb, and the potential implications of ADAb assessments for everyday treatment of inflammatory joint diseases.

Non-Trough adalimumab and certolizumab drug levels associated with a therapeutic EULAR response in adherent patients with rheumatoid arthritis

OBJECTIVES

Interventions aimed at increasing tumour-necrosis factor-alpha inhibitor serum drug levels (SDLs) may improve treatment response; however, previous studies suggesting SDL cut-offs have not accounted for treatment adherence. The aim of this study was to establish the relationship between Adalimumab/Certolizumab SDLs and EULAR good vs non/moderate response, and to define SDL cut-offs associated with good response in fully adherent patients.

METHODS

In a prospective observational study, 475 patients with RA were treated with Certolizumab (n = 192) or Adalimumab (n = 283). At baseline, 3/6/12-months patients had DAS28, self-reported treatment adherence, and SDLs measured. Fully adherent patients were analysed as a subgroup. Follow-up data at 3/6/12-months was analysed separately. Median SDLs were compared in good vs non/moderate response, and receiver-operator characteristics curves (ROC) were used to establish cut-off SDLs.

RESULTS

Fully adherent good responders had significantly higher median Adalimumab/Certolizumab SDLs compared with non/moderate responders (p= 0·04 and p= 0·0005, respectively). ROC analysis reported 3-month non-trough Adalimumab SDLs discriminated good vs non/moderate response with an AUC of 0·63 (95% CI 0·52-0·75), with a cut-off of 7·5mg/l being 39·1% specific, and 80·9% sensitive. Similarly, 3-month non-trough Certolizumab SDLs discriminated good vs non/moderate response with an AUC of 0·65 (95% CI 0·51-0·78), with a cut-off of 26·0mg/l being 43·9% specific, and 77·8% sensitive.

CONCLUSION

In fully adherent patients, higher SDLs are detected in good responders suggesting that interventions to improve SDLs such as encouraging adherence could improve treatment response. 3-month non-trough SDL cut-offs of 7·5mg/l for Adalimumab and 26·0mg/l for Certolizumab may be useful in clinical practice.

Under the Umbrella of Clinical Pharmacology: Inflammatory Bowel Disease, Infliximab and Adalimumab, and a Bridge to an Era of Biosimilars

Monoclonal antibodies (MAbs) have revolutionized the treatment of many chronic inflammatory diseases, including inflammatory bowel disease (IBD). IBD is a term that comprises two quite similar, yet distinctive, disorders—Crohn’s disease (CD) and ulcerative colitis (UC). Two blockbuster MAbs, infliximab (IFX) and adalimumab (ADL), transformed the pharmacological approach of treating CD and UC. However, due to the complex interplay of pharmacology and immunology, MAbs face challenges related to their immunogenicity, effectiveness, and safety. To ease the burden of IBD and other severe diseases, biosimilars have emerged as a cost-effective alternative to an originator product. According to the current knowledge, biosimilars of IFX and ADL in IBD patients are shown to be as safe and effective as their originators. The future of biosimilars, in general, is promising due to the potential of making the health care system more sustainable. However, their use is accompanied by misconceptions regarding their effectiveness and safety, as well as by controversy regarding their interchangeability. Hence, until a scientific consensus is achieved, scientific data on the long-term effectiveness and safety of biosimilars are needed.

Switching Between Adalimumab Reference Product and BI 695501 in Patients with Chronic Plaque Psoriasis (VOLTAIRE-X): A Randomized Controlled Trial

Background

BI 695501 is an FDA-approved biosimilar to adalimumab reference product (RP). VOLTAIRE-X was a randomized clinical trial to assess outcomes with a biosimilar monoclonal antibody in line with the FDA requirements for designation as an ‘interchangeable’ biosimilar.

Objective

The aim of this study was to assess whether multiple switches between adalimumab RP and BI 695501 lead to equivalent pharmacokinetics and a similar safety and immunogenicity profile compared with continuous adalimumab RP.

Methods

We conducted a phase III, double-blind, randomized controlled trial between July 19, 2017, and April 16, 2019. There were 49 investigational sites across Europe and North America. Of 323 screened patients with moderate-to-severe chronic plaque psoriasis, 259 were treated with adalimumab RP during the run-in period. Of these, 118 and 120 were randomized to the continuous or switching arms, respectively. Interventions consisted of a run-in period with adalimumab RP 80 mg subcutaneously (SC) on Day 1, then 40 mg SC every other week (EOW) Weeks 2–12. Patients were then randomized to receive adalimumab RP 40 mg EOW Weeks 14–48 (continuous arm) or BI 695501 40 mg Weeks 14 and 16, adalimumab RP 40 mg Weeks 18 and 20, and BI 695501 40 mg EOW Weeks 22 to 48 (switching arm); all interventions were given SC. Primary endpoints were pharmacokinetics parameters, area under the plasma concentration–time curve (AUC_τ,30–32) and maximum observed drug plasma concentration (C_max,30–32), measured after the third switch during the Week 30–32 dosing interval.

Results

238 patients (mean [standard deviation] age 44.9 [13.8]; 66.0% male) were treated in the switching (n = 118) or continuous arms (n = 120). Adjusted mean C_max,30–32 was 7.08 and 7.00 μg/mL in the switching and continuous treatment arms, respectively; adjusted mean AUC_τ,30–32 was 2025.8 and 1925.9 μg h/mL. Point estimate for mean ratio for AUC_τ,30–32 was 105.2% (90.2% confidence interval [CI] 96.6–114.6), and 101.1% (90.2% CI 93.3–109.7) for C_max,30–32. Both CIs were within a predefined bioequivalence range of 80.0–125.0%. Treatment-emergent adverse events led to discontinuation in 0.8% and 1.7% of patients in the switching and continuous treatment arms, and Psoriasis Area and Severity Index (PASI) scores were highly similar in the two arms across the entire trial period.

Conclusions

Pharmacokinetic equivalence was demonstrated, with highly similar efficacy and immunogenicity, and comparable safety observed in patients with chronic plaque psoriasis who received either adalimumab RP continuously or who switched between adalimumab RP and BI 695501.

Trial Registration

ClinicalTrials.gov: NCT03210259 (registered July 2017); Eudract.ema.europa.eu: 2016-002254-20.

Video abstract

Sex- and gender-related differences in psoriatic arthritis

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease with a chronic, progressive course. Various aspects of PsA, including its clinical features, disease course and response to treatment, are influenced by sociodemographic characteristics of the patient. This includes patient sex, the biological attributes associated with being male or female, and gender, a sociocultural construct that comprises attitudes, traits and behaviours associated with being a man or a woman. An understanding of sex- and gender-related differences in PsA, as well as their underlying mechanisms, is therefore important for individualized care. In this narrative review, the influence of sex and gender on PsA manifestation and course, patient function and quality of life, and their association with comorbidities are described. Sex- and gender-related disparities in response to advanced therapies and their potential underlying mechanisms are delineated. Differences in pathophysiological mechanisms between male and female patients including genetics, immune and hormonal mechanisms are discussed. Finally, fertility and pregnancy outcomes in PsA are outlined. By adopting sex and gender lenses, this review is aimed at highlighting key differences between male and female patients with PsA and uncovering mechanisms underlying these differences, ultimately promoting individualized care of men and women with PsA and informing future research in this area.

Prevalence and characterization of treatment-refractory psoriasis and super-responders to biologic treatment: a nationwide study

INTRODUCTION

Treatment with biologics often leads to clearance of psoriasis. However, some patients do repeatedly fail to respond and/or lose an achieved response (treatment refractory) to the biologic, whereas other patients achieve excellent response to one biologic and remain clear of psoriasis for several years (super-responders).

OBJECTIVE

To identify and characterize patients with treatment refractory psoriasis and patients who are super-responders to biologic treatment.

MATERIAL AND METHODS

Patients registered in DERMBIO between January 2007 and November 2019 were included. Patients were categorized as being treatment refractory if they had had treatment failure to ≥3 biologics targeting ≥2 different pathways. Super-responders were patients treated with their first biologic for minimum 5 years without an absolute psoriasis area and severity index (PASI) > 3 between 6 months and 5 years of treatment. All remaining patients from DERMBIO served as comparators.

RESULTS

In total, 3280 patients were included with a mean age of 45.0 years. 1221 (37%) of the patients were females. Of the included patients, 214 (6.5%) were categorized as treatment refractory and 207 (6.3%) were categorized as super-responders. Treatment refractory patients had higher mean body weight (100.6 kg vs. 90.6 kg, P < 0.0001) and higher mean BMI (32.2 vs. 29.4, P < 0.0001) compared with the rest of patients in DERMBIO. Super-responders had higher socioeconomic status and fewer comorbidities compared with the comparator group (P < 0.0001).

CONCLUSION

A small proportion of patients with psoriasis treated with biologics are either super-responders or treatment refractory. Treatment refractory patients have higher body weight, whereas super-responders have fewer comorbidities and higher socioeconomic status.

Multidrug Resistance of Cancer Cells and the Vital Role of P-Glycoprotein

P-glycoprotein (P-gp) is a major factor in the multidrug resistance phenotype in cancer cells. P-gp is a protein that regulates the ATP-dependent efflux of a wide range of anticancer medicines and confers resistance. Due to its wide specificity, several attempts have been made to block the action of P-gp to restore the efficacy of anticancer drugs. The major goal has been to create molecules that either compete with anticancer medicines for transport or function as a direct P-gp inhibitor. Despite significant in vitro success, there are presently no drugs available in the clinic that can "block" P-gp-mediated resistance. Toxicity, unfavourable pharmacological interactions, and a variety of pharmacokinetic difficulties might all be the reason for the failure. On the other hand, P-gp has a significant effect in the body. It protects the vital organs from the entry of foreign bodies and other toxic chemicals. Hence, the inhibitors of P-gp should not hinder its action in the normal cells. To develop an effective inhibitor of P-gp, thorough background knowledge is needed in this field. The main aim of this review article was to set forth the merits and demerits of the action of P-gp on cancer cells as well as on normal cells. The influence of P-gp on cancer drug delivery and the contribution of P-gp to activating drug resistance were also mentioned.

Embracing Change: An International Survey Study on the Beliefs and Attitudes of Pediatric Rheumatologists Towards Biosimilars

BACKGROUND

Biosimilars have been adopted by clinicians more slowly than anticipated in the post-marketing phase.

OBJECTIVES

We aimed to reveal the perceptions and attitudes of pediatric rheumatologists towards biosimilars and the obstacles to biosimilar therapy.

METHODS

A web-based survey designed to determine the knowledge, experience, and perceptions of pediatric rheumatologists about biosimilars was electronically mailed to the participants between April and August 2021. Responses were collected anonymously and subsequently analyzed.

RESULTS

A total of 114 pediatric rheumatologists including fellows (32.4%), specialists (29.8%), and seniors (37.7%) responded to the questionnaire. According to the data, 75 (65.8%) physicians had already prescribed at least one biosimilar. The vast majority of participants were aware of the potential cost savings of biosimilars (84, 73.3%). Participants who felt insufficiently informed were 41.8%, 67.6%, and 83.7% among seniors, specialists, and fellows, respectively. In pediatric rheumatology, the scarcity of clinical trials and real-life data (64%) and inadequate information about tolerance to the biosimilars and related side effects in children (49.1%) were the most common barriers expressed by prescribers. Nearly half (45%) of the pediatric rheumatologists preferred to prescribe biosimilars in the treatment of biologic-naive cases. However, most (93%) were reluctant to switch a reference molecule to a biosimilar while the patient was doing well under the originator medicine.

CONCLUSIONS

This survey provided insights into the concerns about prescribing biosimilars among pediatric rheumatologists. In the field of pediatric rheumatology, further education about biosimilars and real-life experiences is required to better inform about treatment options in children.

Lipid metabolism in autoimmune rheumatic disease: implications for modern and conventional therapies

Suppressing inflammation has been the primary focus of therapies in autoimmune rheumatic diseases (AIRDs), including rheumatoid arthritis and systemic lupus erythematosus. However, conventional therapies with low target specificity can have effects on cell metabolism that are less predictable. A key example is lipid metabolism; current therapies can improve or exacerbate dyslipidemia. Many conventional drugs also require in vivo metabolism for their conversion into therapeutically beneficial products; however, drug metabolism often involves the additional formation of toxic by-products, and rates of drug metabolism can be heterogeneous between patients. New therapeutic technologies and research have highlighted alternative metabolic pathways that can be more specifically targeted to reduce inflammation but also to prevent undesirable off-target metabolic consequences of conventional antiinflammatory therapies. This Review highlights the role of lipid metabolism in inflammation and in the mechanisms of action of AIRD therapeutics. Opportunities for cotherapies targeting lipid metabolism that could reduce immunometabolic complications and potential increased cardiovascular disease risk in patients with AIRDs are discussed.

OUP accepted manuscript

Objective

To compare the outcome of various treatment de-escalation regimens in patients with RA who achieved sustained remission.

Methods

At period 1, 436 RA patients who were treated with MTX and bDMARDs and had maintained DAS28(ESR) at <2.6 were divided into five groups based on shared patient/physician decision-making; continuation, dose reduction and discontinuation of MTX or bDMARDs. At end of year 1, patients who achieved DAS28(ESR) <3.2 were allowed to enrol in period 2 for treatment using the de-escalation regimens for another year. The primary and secondary endpoints were the proportion of patients with DAS28(ESR) <2.6 at year 1 and 2, respectively.

Results

Based on shared decision-making, 81.4% elected de-escalation of treatment and 48.4% selected de-escalation of MTX. At end of period 1, similar proportions of patients maintained DAS28(ESR) <2.6 (continuation, 85.2%; MTX dose reduction, 79.0%; MTX-discontinuation, 80.0%; bDMARD dose reduction, 73.9%), although the rate was significantly different between the continuation and bDMARD-discontinuation. At end of period 2, similar proportions of patients of the MTX groups maintained DAS28(ESR) <2.6 (continuation or de-escalation), but the rates were significantly lower in the bDMARD-discontinuation group. However, half of the latter group satisfactorily discontinued bDMARDs. Adverse events were numerically lower in MTX and bDMARD-de-escalation groups during period 1 and 2, compared with the continuation group.

Conclusions

After achieving sustained remission by combination treatment of MTX/bDMARDs, disease control was achieved comparably by continuation, dose reduction or discontinuation of MTX and dose reduction of bDMARDs at end of year 1. Subsequent de-escalation of MTX had no impacts on disease control but decreased adverse events in year 2.

The efficacy of immunomodulators in the prevention and suppression of anti-drug antibodies to anti-tumor necrosis factor therapy in inflammatory bowel disease

The development of biological agents against tumor necrosis factor (TNF) has revolutionized the management of inflammatory bowel disease (IBD), frequently achieving induction and maintenance of remission in both ulcerative colitis and Crohn's disease. However, a loss of response due to the development of anti-drug antibodies (ADA) is seen annually in approximately 20% of IBD patients receiving anti-TNF therapy. Current evidence suggests that the use of immunomodulators (IMM), such as thiopurines (azathioprine and 6-mercaptopurine) or methotrexate, may prevent or suppress ADA formation. In this article, we present a comprehensive review of the available literature regarding the efficacy of IMM in the prevention and suppression of ADA development to anti-TNF therapy in patients with IBD.

Recent progress in treatments of rheumatoid arthritis: an overview of developments in biologics and small molecules, and remaining unmet needs

Through treatment with biological DMARDs (bDMARDs) or targeted synthetic (tsDMARDs) such as Janus kinase (JAK) inhibitors in addition to MTX, clinical remission has become a realistic therapeutic goal for the majority of patients with RA, and sustained remission facilitates prevention of joint damage and physical dysfunction. Long-term safety and sustained inhibition of structural changes and physical dysfunction by bDMARDs have been reported. The development of next-generation bDMARDs and expansion of their indications to various autoimmune diseases are expected. Five JAK inhibitors show comparable efficacy to bDMARDs, and the latest ones are effective for overcoming difficult-to-treat RA regardless of prior medications. Patients treated with JAK inhibitors should be adequately screened and monitored for infection, cardiovascular disorders, thrombosis, malignancies and so on. Advances in therapeutic strategies, including the differential use of therapeutic drugs and de-escalation of treatment after remission induction, are prioritized.

Treatment of Cardiovascular Disease in Rheumatoid Arthritis: A Complex Challenge with Increased Atherosclerotic Risk

Rheumatoid arthritis (RA) carries significant risk for atherosclerotic cardiovascular disease (ASCVD). Traditional ASCVD risk factors fail to account for this accelerated atherosclerosis. Shared inflammatory pathways are fundamental in the pathogenesis of both diseases. Considering the impact of RA in increasing cardiovascular morbidity and mortality, the characterization of therapies encompassing both RA and ASCVD management merit high priority. Despite little progress, several drugs discussed here promote remission and or lower rheumatoid disease activity while simultaneously conferring some level of atheroprotection. Methotrexate, a widely used disease-modifying drug used in RA, is associated with significant reduction in cardiovascular adverse events. MTX promotes cholesterol efflux from macrophages, upregulates free radical scavenging and improves endothelial function. Likewise, the sulfonamide drug sulfasalazine positively impacts the lipid profile by increasing HDL-C, and its use in RA has been correlated with reduced risk of myocardial infraction. In the biologic class, inhibitors of TNF-α and IL-6 contribute to improvements in endothelial function and promote anti-atherogenic properties of HDL-C, respectively. The immunosuppressant hydroxychloroquine positively affects insulin sensitization and the lipid profile. While no individual therapy has elicited optimal atheroprotection, further investigation of combination therapies are ongoing.

Risk of venous thromboembolism associated with Janus kinase inhibitors for rheumatoid arthritis: case presentation and literature review

Janus kinase (JAK) inhibitors have been developed as disease-modifying antirheumatic drugs. Despite the positive therapeutic impacts of JAK inhibitors, concerns have been raised regarding the risk of venous thromboembolism (VTE), such as deep vein thrombosis (DVT) and pulmonary embolism (PE). A recent post hoc safety analysis of placebo-controlled trials of JAK inhibitors in rheumatoid arthritis (RA) reported an imbalance in the incidence of VTE for a 4-mg daily dose of baricitinib versus placebo. In a recent postmarketing surveillance trial for RA, a significantly higher incidence of PE was reported in treatment with tofacitinib (10 mg twice daily) compared with tofacitinib 5 mg or tumor necrosis factor inhibitors. We also experienced a case of massive PE occurring 3 months after starting baricitinib (4 mg once daily) for multiple biologic-resistant RA. Nevertheless, the evidence to support the role of JAK inhibitors in VTE risk remains insufficient. There are a number of predisposing conditions and risk factors for VTE. In addition to the known risk factors that can provoke VTE, advanced age, obesity, diabetes mellitus, hypertension, hyperlipidemia, and smoking can also contribute to its development. Greater VTE risk is noted in patients with chronic inflammatory conditions, particularly RA patients with uncontrolled disease activity and any comorbidity. Prior to the initiation of JAK inhibitors, clinicians should consider both the number and strength of VTE risk factors for each patient. In addition, clinicians should advise patients to seek prompt medical help if they develop clinical signs and symptoms that suggest VTE/PE.

Key Points • Patients with rheumatoid arthritis (RA) are at increased risk of venous thromboembolism (VTE), especially those with uncontrolled, high disease activity and those with comorbidities. • In addition to the well-known risk factors that provoke VTE events, advanced age and cardiovascular risk factors, such as obesity, diabetes mellitus, hypertension, hyperlipidemia, and smoking, should be considered risk factors for VTE. • Although a signal of VTE/pulmonary embolism (PE) risk with JAK inhibitors has been noted in RA patients who are already at high risk, the evidence is currently insufficient to support the increased risk of VTE during RA treatment with JAK inhibitors. • If there are no suitable alternatives, clinicians should prescribe JAK inhibitors with caution, considering both the strength of individual risk factors and the cumulative weight of all risk factors for each patient.

Immunogenicity of sarilumab and impact on safety and efficacy in Japanese patients with rheumatoid arthritis: analysis of two Phase 3 randomised clinical trials

OBJECTIVES

To describe the immunogenicity profile of sarilumab in Japanese patients with rheumatoid arthritis (RA).

METHODS

Patients enrolled in the KAKEHASI and HARUKA studies were included in our analysis. In these studies, patients received sarilumab 150 mg or 200 mg every 2 weeks for 52 or 28 weeks in combination with methotrexate (MTX) (KAKEHASI), or for 52 weeks as monotherapy or in combination with non-MTX conventional synthetic disease-modifying anti-rheumatic drugs (HARUKA). Anti-drug antibodies (ADAs) and neutralising antibodies (NAbs) were assessed in the pooled population.

RESULTS

Positive ADA assay responses occurred in 10/149 (7.1%) patients treated with sarilumab 150 mg and 13/185 (7.0%) patients treated with sarilumab 200 mg, with persistent responses in 2 (1.4%) and 4 (2.2%) patients, respectively. Peak ADA titre was 30. No patients treated with the 150 mg dose and one patient (0.5%) treated with the 200 mg dose exhibited NAbs. There was no evidence of an association between ADA formation and hypersensitivity reactions or reduced efficacy.

CONCLUSIONS

ADAs, which occurred at a low frequency and titre, did not affect the safety or efficacy of sarilumab 150 or 200 mg administered as monotherapy or combination therapy in Japanese patients with RA in the KAKEHASI or HARUKA studies.

First exposure to rituximab is associated to high rate of anti-drug antibodies in systemic lupus erythematosus but not in ANCA-associated vasculitis

Background

Anti-drug antibodies (ADAs) can impact on the efficacy and safety of biologicals, today used to treat several chronic inflammatory conditions. Specific patient groups may be more prone to develop ADAs. Rituximab is routinely used for ANCA-associated vasculitis (AAV) and as off-label therapy for systemic lupus erythematosus (SLE), but data on occurrence and predisposing factors to ADAs in these diseases is limited.

Objectives

To elucidate the rate of occurrence, and risk factors for ADAs against rituximab in SLE and AAV.

Methods

ADAs were detected using a bridging electrochemiluminescent (ECL) immunoassay in sera from rituximab-naïve (AAV; n = 41 and SLE; n = 62) and rituximab-treated (AAV; n = 22 and SLE; n = 66) patients. Clinical data was retrieved from medical records. Disease activity was estimated by the SLE Disease Activity Index-2000 (SLEDAI-2 K) and the Birmingham Vasculitis Activity Score (BVAS).

Results

After first rituximab cycle, no AAV patients were ADA-positive compared to 37.8% of the SLE patients. Samples were obtained at a median (IQR) time of 5.5 (3.7–7.0) months (AAV), and 6.0 (5.0–7.0) months (SLE). ADA-positive SLE individuals were younger (34.0 (25.9–40.8) vs 44.3 (32.7–56.3) years, p = 0.002) and with more active disease (SLEDAI-2 K 14.0 (10.0–18.5) vs. 8.0 (6.0–14), p = 0.0017) and shorter disease duration (4.14 (1.18–10.08) vs 9.19 (5.71–16.93), p = 0.0097) compared to ADA-negative SLE. ADAs primarily occurred in nephritis patients, were associated with anti-dsDNA positivity but were not influenced by concomitant use of corticosteroids, cyclophosphamide or previous treatments.

Despite overall reduction of SLEDAI-2 K (12.0 (7.0–16) to 4.0 (2.0–6.7), p < 0.0001), ADA-positive individuals still had higher SLEDAI-2 K (6.0 (4.0–9.0) vs 4.0 (2.0–6.0), p = 0.004) and their B cell count at 6 months follow-up was higher (CD19 + % 4.0 (0.5–10.0) vs 0.5 (0.4–1.0), p = 0.002). At retreatment, two ADA-positive SLE patients developed serum sickness (16.7%), and three had infusion reactions (25%) in contrast with one (5.2%) serum sickness in the ADA-negative group.

Conclusions

In contrast to AAV, ADAs were highly prevalent among rituximab-treated SLE patients already after the first course of treatment and were found to effect on both clinical and immunological responses. The high frequency in SLE may warrant implementations of ADA screening before retreatment and survey of immediate and late-onset infusion reactions.

Immunogenicity to biological drugs in psoriasis and psoriatic arthritis

Monoclonal antibodies or fusion proteins, defined as biological drugs, have modified the natural history of numerous immune-mediated disorders, allowing the development of therapies aimed at blocking the pathophysiological pathways of the disease, providing greater efficacy and safety than conventional treatment strategies. Virtually all therapeutic proteins elicit an immune response, producing anti-drug antibodies (ADAs) against hypervariable regions of immunoglobulins. Immunogenicity against biological drugs can alter their pharmacokinetic and pharmacodynamic properties, thereby reducing the efficacy of these drugs. In more severe cases, ADAs can neutralize the therapeutic effects of the drug or cause serious adverse effects, mainly hypersensitivity reactions. The prevalence of ADAs varies widely depending on the type of test used, occurrence of false-negative results, and non-specific binding to the drug, making it difficult to accurately assess their clinical impact. Concomitant use of immunosuppressors efficiently reduces the immunogenicity in a dose-dependent manner, either by decreasing the frequency of detectable ADAs or by delaying their appearance, thereby enhancing the effectiveness of biological therapies. Among the new therapeutic strategies for the management of psoriasis, biological agents have gained increasing importance in recent years as they interrupt key inflammation pathways involved in the physiopathology of the disease. Reports regarding ADA in new biologics are still scarce, but the most recent evidence tends to show little impact on the clinical response to the drug, even with prolonged treatment. It is therefore essential to standardize laboratory tests to determine the presence and titles of ADAs to establish their administration and management guidelines that allow the determination of the real clinical impact of these drugs.