Low immunogenicity of tocilizumab in patients with rheumatoid arthritis

Chemical Synthesis of Interleukin-6 for Mirror-Image Screening

Interleukin-6 (IL-6), a multifunctional cytokine, is an attractive therapeutic target for immunological and inflammatory diseases. We investigated the chemical synthesis of IL-6 and its enantiomer (d-IL-6) using a sequential N-to-C native chemical ligation strategy from six peptide segments. Solubilizing Trt-K10 tags improved the intermediate solubility and served as protecting groups during the metal-free desulfurization to facilitate the synthesis of full-length IL-6 protein. Synthetic l-IL-6 and recombinant IL-6 exhibited nearly identical structural and binding properties. The symmetrical binding property of d-IL-6 was also demonstrated by functional analysis using IL-6-binding peptides. The resulting functional d-IL-6 was employed to screen a phage-displayed antibody fragment library, leading to the identification of several d-IL-6-binding single-domain antibodies. This work will contribute to the development of novel, potent IL-6 inhibitors without the adverse effects of undesired immune activation.

Mitigating target interference challenges in bridging immunogenicity assay to detect anti-tocilizumab antibodies

Aim: An assay to detect anti-tocilizumab antibodies in the presence of high levels of circulating target and drug is needed for immunogenicity assessment in comparative clinical studies.Methods: An assay was developed and validated using a combination of blocking agents and dilutions to overcome target interference challenges.Results: No false-positive signal was detected in serum samples spiked with 350-500 ng/ml of IL-6 receptor. As low as 50 ng/ml of positive control antibodies could be detected in the presence of either 500 ng/ml of IL-6 or 250 μg/ml of the drug product. Assay also demonstrated high sensitivity, selectivity and precision.Conclusion: A robust, easy to perform immunogenicity assay was developed and validated for detecting anti-tocilizumab antibodies.

Tocilizumab Dose Tapering Based on a Model-Based Algorithm is Feasible in Clinical Practice: A Short Communication

BACKGROUND

Tocilizumab in the treatment of rheumatoid arthritis (RA) is a potential candidate for concentration-guided tapering because the standard dose of tocilizumab results in a wide range of serum concentrations, usually above the presumed therapeutic window, and an exposure-response relationship has been described. However, no clinical trials have been published to date on this subject. Therefore, the objective of this study was to assess the feasibility of the tapering of intravenous (iv) tocilizumab with the use of a pharmacokinetic model-based algorithm in RA patients.

METHODS

A randomized controlled trial with a double-blind design and follow-up of 24 weeks was conducted. RA patients who received the standard of tocilizumab for at least the past 24 weeks, which is 8 mg/kg every 4 weeks, were included. Patients with a tocilizumab serum concentration above 5 mg/L at trough were randomized between concentration-guided dose tapering, referred to as therapeutic drug monitoring (TDM), or the standard 8 mg/kg dose. In the TDM group, the tocilizumab dose was tapered with a recently published model-based algorithm to achieve a target concentration of 4-6 mg/L after 20 weeks of dose tapering.

RESULTS

Twelve RA patients were included and 10 were randomized between the TDM and standard dose group. The study was feasible regarding the predefined feasibility criteria and patients had a positive attitude toward therapeutic drug monitoring. In the TDM group, the tocilizumab trough concentration within patients decreased on average by 24.5 ± 18.3 mg/L compared with a decrease of 2.8 ± 12 mg/L in the standard dose group. None of the patients in the TDM group reached the drug range of 4-6 mg/L. Instead, tocilizumab concentrations of 1.6 and 1.5 mg/L were found for the 2 patients who completed follow-up on the tapered dose. No differences in RA disease activity were observed between the 2 study groups.

CONCLUSIONS

This study was the first to show that it is feasible to apply a dose-reduction algorithm based on a pharmacokinetic model in clinical practice. However, the current algorithm needs to be optimized before it can be applied on a larger scale.

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.

Comparison of the efficacy and safety of a proposed biosimilar MSB11456 with tocilizumab reference product in subjects with moderate-to-severe rheumatoid arthritis: results of a randomised double-blind study

OBJECTIVE

To evaluate the efficacy, immunogenicity and safety of the proposed biosimilar MSB11456 versus European Union (EU)-approved tocilizumab reference product in patients with rheumatoid arthritis (RA) in a multicentre, randomised, double-blind, multinational, parallel-group study (NCT04512001).

METHODS

Adult patients with moderate-to-severe active RA and inadequate clinical response to ≥1 disease-modifying antirheumatic drug (synthetic or biologic) receiving methotrexate were randomised to receive 24 weekly subcutaneous 162 mg injections of either MSB11456 or EU-approved tocilizumab. Equivalence between treatments was considered if the 95% CI (European Medicines Agency)/90% CI (US Food and Drug Administration) for the difference in mean change from baseline to week 24 in Disease Activity Score-28 Joint Count with erythrocyte sedimentation rate (DAS28-ESR) between treatments was entirely within prespecified equivalence intervals (-0.6 to 0.6 and -0.6 to 0.5, respectively). At week 24, patients were rerandomised to continued treatment or MSB11456. Secondary efficacy endpoints to week 52, and safety and immunogenicity to week 55 were also evaluated.

RESULTS

At week 24, the least squares mean difference in the change from baseline in DAS28-ESR between treatments was 0.01 (95% CI -0.19 to 0.22) in the 604 randomised patients. Similarity between treatments was shown for all other efficacy, safety and immunogenicity endpoints, including in patients who switched from EU-approved tocilizumab to MSB114466.

CONCLUSIONS

Therapeutic equivalence was demonstrated for efficacy endpoints, and safety and immunogenicity analyses support the similarity of the two treatments. The results of this study strengthen the evidence that the proposed biosimilar MSB11456 and EU-approved tocilizumab exert similar clinical effects.

Immunogenicity of Cemiplimab: Low Incidence of Antidrug Antibodies and Cut-Point Suitability Across Tumor Types

The immunogenicity of cemiplimab, a fully human immunoglobulin G4 monoclonal antibody directed against programmed cell death 1, was assessed in patients across multiple tumor types. The development of antidrug antibodies (ADAs) against cemiplimab was monitored using a validated bridging immunoassay. To identify ADA-positive samples in the assay, statistically determined cut points were established by analyzing baseline clinical study samples from a mixed population of different tumor types, and this validation cut point was used to assess immunogenicity in all subsequent studies. Regulatory guidance requires that ADA assay cut points be verified for appropriateness in different patient populations. Thus, for the cemiplimab ADA assay, we evaluated whether each new oncology population was comparable with the validation population used to set the cut point. Assay responses from 2393 individual serum samples from 8 different tumor types were compared with the validation population, using established statistical methods for cut-point determination and comparison, with no significant differences observed. Across tumor types, the immunogenicity of cemiplimab was low, with an overall treatment-emergent ADA incidence rate of 1.9% and 2.5% at intravenous dose regimens of 3 mg/kg every 2 weeks and 350 mg every 3 weeks, respectively. Moreover, no neutralizing antibodies to cemiplimab were detected in patients with ADA-positive samples, and there was no observed impact of cemiplimab ADAs on pharmacokinetics. Study-specific cut points may be required in some diseases, such as immune and inflammatory diseases; however, based on this analysis, in-study cut points are not required for each new oncology disease indication for cemiplimab.

Comparing tocilizumab biosimilar BAT1806/BIIB800 with reference tocilizumab in patients with moderate-to-severe rheumatoid arthritis with an inadequate response to methotrexate: a phase 3, randomised, multicentre, double-blind, active-controlled clinical trial

BACKGROUND

Biosimilars provide an opportunity to address unmet medical need by expanding access to biological treatments. This study aimed to show equivalent efficacy, and comparable safety, immunogenicity, and pharmacokinetic profiles of a proposed tocilizumab biosimilar BAT1806/BIIB800, to reference tocilizumab, in participants with rheumatoid arthritis with an inadequate response to methotrexate.

METHODS

This phase 3, multicentre, randomised, double-blind, active-controlled, equivalence study comprised a 24-week initial treatment period (results reported here) and a 24-week secondary treatment period. Participants were recruited at 54 centres across five countries (China, Ukraine, Poland, Georgia, and Bulgaria). Patients with active rheumatoid arthritis with an inadequate response to methotrexate were randomly assigned (1:1:2) to receive reference tocilizumab up to week 48, or reference tocilizumab up to week 24 followed by BAT1806/BIIB800 up to week 48 (the two reference tocilizumab groups were analysed as a single group in this analysis), or BAT1806/BIIB800 up to week 48 (the BAT1806/BIIB800 group), administered by intravenous infusion once every 4 weeks at a starting dose of 8 mg/kg. The primary endpoint was the proportion of participants who had a 20% improvement in American College of Rheumatology criteria (ACR20) at week 12 (for the European Medicines Agency [EMA]) or week 24 (for the US Food and Drug Administration [FDA] and China National Medical Products Administration [NMPA]) using prespecified equivalence margins (95% CI -14·5 to +14·5 [EMA], 90% CI -12·0 to +15·0 [FDA], and 95% CI -13·6 to +13·6 [NMPA]). The International Council for Harmonisation E9(R1) estimand framework, with strategies for addressing intercurrent events, was implemented for the efficacy evaluations with expected differences as per the predefined equivalence margins. This trial is registered at ClinicalTrials.gov (NCT03830203) and EudraCT (2018-002202-31), and is closed to new participants.

FINDINGS

Between Dec 19, 2018, and Jan 5, 2021, we randomly assigned 621 participants: 309 to the reference tocilizumab group and 312 to the BAT1806/BIIB800 group. The mean age was 50·5 years (SD 12·0), 534 (86%) were women, 87 (14%) were men, and 368 (59%) were White. For the primary estimands, estimated ACR20 response rates were 64·8% in the reference tocilizumab group and 69·0% in the BAT1806/BIIB800 group (treatment difference 4·1% [95% CI -3·6 to 11·9]) at week 12, and 67·9% in the reference tocilizumab group and 69·9% in the BAT1806/BIIB800 group (treatment difference 1·9% [90% CI -4·0 to 7·9; 95% CI -5·2 to 9·1]) at week 24. All confidence intervals were contained within the predefined equivalence margins. Comparable pharmacokinetic and immunogenicity profiles were observed for the reference tocilizumab and BAT1806/BIIB800 groups. Adverse events were reported by 201 (65%) participants in the reference tocilizumab group and 206 (66%) in the BAT1806/BIIB800 group; 196 (63%) participants in the reference tocilizumab group and 201 (64%) participants in the BAT1806/BIIB800 group reported a treatment-emergent adverse event. Five participants had a fatal event (reference tocilizumab n=1; BAT1806/BIIB800 n=4).

INTERPRETATION

BAT1806/BIIB800 showed equivalent efficacy, and comparable safety, immunogenicity, and pharmacokinetic profiles as reference tocilizumab.

FUNDING

Bio-Thera Solutions and Biogen.

A mechanistic marker-based screening tool to predict clinical immunogenicity of biologics

BACKGROUND

The efficacy and safety of therapeutic proteins are undermined by immunogenicity driven by anti-drug antibodies. Immunogenicity risk assessment is critically necessary during drug development, but current methods lack predictive power and mechanistic insight into antigen uptake and processing leading to immune response. A key mechanistic step in T-cell-dependent immune responses is the migration of mature dendritic cells to T-cell areas of lymphoid compartments, and this phenomenon is most pronounced in the immune response toward subcutaneously delivered proteins.

METHODS

The migratory potential of monocyte-derived dendritic cells is proposed to be a mechanistic marker for immunogenicity screening. Following exposure to therapeutic protein in vitro, dendritic cells are analyzed for changes in activation markers (CD40 and IL-12) in combination with levels of the chemokine receptor CXCR4 to represent migratory potential. Then a transwell assay captures the intensity of dendritic cell migration in the presence of a gradient of therapeutic protein and chemokine ligands.

RESULTS

Here, we show that an increased ability of the therapeutic protein to induce dendritic cell migration along a gradient of chemokine CCL21 and CXCL12 predicts higher immunogenic potential. Expression of the chemokine receptor CXCR4 on human monocyte-derived dendritic cells, in combination with activation markers CD40 and IL-12, strongly correlates with clinical anti-drug antibody incidence.

CONCLUSIONS

Mechanistic understanding of processes driving immunogenicity led to the development of a predictive tool for immunogenicity risk assessment of therapeutic proteins. These predictive markers could be adapted for immunogenicity screening of other biological modalities.

Real-world Comparative Effectiveness of Methotrexate-based Combinations for Rheumatoid Arthritis: A Retrospective Cohort Study

PURPOSE

Guidelines recommend using disease-modifying antirheumatic drugs (DMARDs) in combination with methotrexate (MTX) for patients with rheumatoid arthritis (RA) after monotherapy. Little is known about the real-world comparative effectiveness of these MTX-DMARD combinations. This study compared the effectiveness of various MTX-based DMARD combinations for patients with RA initiating MTX-DMARD combination therapy using administrative claims database.

METHODS

This retrospective cohort study included adults (aged ≥18 years) with RA who initiated MTX combination treatment with conventional synthetic DMARDs (csDMARDs), tumor necrosis factor inhibitor (TNFi) biologic DMARDs (bDMARDs), non-TNFi bDMARDs, or targeted synthetic DMARDs (tsDMARDs) between July 1, 2012, and December 31, 2013 (index date), from the MarketScan Commercial Claims Data. Patients had continuous enrollment from the 6 months of preindex period until the 12 months of postindex period. The MTX-based DMARD combination therapy cohort was defined as ≥1 MTX prescription in the first 30 days from the index date and ≥14 days overlapping use of the prescription fills of the MTX and the index DMARD. Effectiveness was measured by using the claims algorithm (dosing, switching, addition, oral glucocorticoid use, or multiple glucocorticoid injection). Propensity score analysis with the inverse probability of treatment weighting (PS-IPTW), estimated by using the generalized boosted machine learning method, was used to balance the distribution of baseline variables between the combination groups. Multivariable logistic regression using PS-IPTW was conducted to compare the effectiveness of the combination groups. Sensitivity analysis evaluated the modified effectiveness algorithms or the time to the first treatment failure.

FINDINGS

A total of 3174 adult patients with RA starting an MTX-DMARD combination therapy were identified (mean [SD] age, 50 [9] years), including 1568 (49%) initiating a csDMARD + MTX, 1343 (42%) initiating TNFi + MTX, and 240 (8%) initiating non-TNFi bDMARD + MTX, and 23 (1%) initiating tsDMARD + MTX. Owing to the small sample, the tsDMARD combination group was not included in the comparative analysis. Algorithm-based therapy effectiveness was found in 9.95% of the csDMARD + MTX, 20.48% of the TNFi + MTX, and 20.83% of the non-TNFi + MTX groups. PS-IPTW showed that the csDMARD combination is less effective (adjusted odds ratio, 0.422; 95% CI, 0.341-0.524) than the TNFi combination; however, the non-TNFi biologic combination had similar effectiveness (aOR, 1.063; 95% CI, 0.680-1.662) compared to the TNFi combination. Sensitivity analyses confirmed the main results.

IMPLICATIONS

Among RA patients initiating MTX-DMARD combinations, both non-TNFi biologics and TNFi-based combinations with MTX were equally effective, but csDMARD + MTX was less effective than the TNFi plus MTX.

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.

Methylene blue reduces the serum levels of interleukin-6 and inhibits STAT3 activation in the brain and the skin of lipopolysaccharide-administered mice

It is valuable to search for novel and economical agents for inhibiting STAT3 activation and blocking increases in IL-6 levels, due to the important roles of STAT3 and IL-6 in inflammation. Since Methylene Blue (MB) has shown therapeutical potential for multiple diseases, it has become increasingly important to investigate the mechanisms underlying the effects of MB on inflammation. Using a mouse model of lipopolysaccharide (LPS)-induced inflammation, we investigated the mechanisms underlying the effects of MB on inflammation, obtaining the following findings: First, MB administration attenuated the LPS-induced increases in the serum levels of IL-6; second, MB administration attenuated LPS-induced STAT3 activation of the brain; and third, MB administration attenuated LPS-induced STAT3 activation of the skin. Collectively, our study has suggested that MB administration can decrease the levels of IL-6 and STAT3 activation - two important factors in inflammation. Since MB is a clinically used and relatively economical drug, our findings have suggested therapeutic potential of MB for multiple inflammation-associated diseases due to its effects on STAT3 activation and IL-6 levels.

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.

Pharmacokinetics of a proposed tocilizumab biosimilar (MSB11456) versus US-licensed tocilizumab: results of a randomized, double-blind, single-intravenous dose study in healthy adults

BACKGROUND

Tocilizumab, a recombinant monoclonal immunoglobulin G, targets the interleukin-6 receptor. MSB11456 is a proposed tocilizumab biosimilar.

OBJECTIVES

To assess pharmacokinetic equivalence of intravenous MSB11456 to US-licensed tocilizumab.

RESEARCH DESIGN AND METHODS

In this double-blind, parallel-group, single-dose study, 128 healthy adults were randomized to a single one-hour 8 mg/kg IV infusion of either MSB11456 or US-licensed tocilizumab. Blood samples were collected pre-dose and at regular intervals up to day 48 post-dose. The primary endpoint pharmacokinetic parameter was analyzed using analysis of variance (ANOVA) model on the natural logarithm of the endpoint (AUC_0-last), with treatment as a fixed effect. Immunogenicity and safety data were summarized descriptively.

RESULTS

Subjects received either MSB11456 (N = 62) or US-licensed tocilizumab (N = 66). Pharmacokinetic bioequivalence, defined as 90% confidence intervals for the geometric least squares mean ratio entirely contained within the 80.00% to 125.00% equivalence limits, was demonstrated between MSB11456 and US-licensed tocilizumab for the primary and secondary pharmacokinetic endpoints. Anti-drug antibody responses, frequency of neutralizing antibodies against tocilizumab, and safety profiles showed no notable between-treatment differences. Safety was comparable between treatments.

CONCLUSIONS

Pharmacokinetic similarity of MSB11456 and US-licensed tocilizumab was demonstrated, with comparable immunogenicity and safety profiles, supporting MSB11455 as a biosimilar to US-licensed tocilizumab. The trial is registered at EudraCT, number 2019-003484-22.

Evaluation of Early Tocilizumab Effect on Multiorgan Dysfunction in Critically Ill Patients With COVID-19: A Propensity Score-Matched Study

Background: Tocilizumab (TCZ) has been proposed as potential rescue therapy for severe COVID-19. No previous study has primarily assessed the role of TCZ in preventing severe COVID-19-related multiorgan dysfunction. Hence, this multicenter cohort study aimed to evaluate the effectiveness of TCZ early use versus standard of care in preventing severe COVID-19-related multiorgan dysfunction in COVID-19 critically ill patients during intensive care unit (ICU) stay. Methods: A multicenter, retrospective cohort study includes critically ill adult patients with COVID-19 admitted to the ICUs. Patients were categorized into two groups, the treatment group includes patients who received early TCZ therapy within 24 hours of ICU admission and the control group includes patients who received standard of care. The primary outcome was the multiorgan dysfunction on day three of the ICU admission. The secondary outcomes were 30-day, and in-hospital mortality, ventilator-free days, hospital length of stay (LOS), ICU LOS, and ICU-related complications. Results: After propensity score matching, 300 patients were included in the analysis based on predefined criteria with a ratio of 1:2. Patients who received TCZ had lower multiorgan dysfunction score on day three of ICU admission compared to the control group (beta coefficient: -0.13, 95% CI: -0.26, -0.01, P-value = 0.04). Moreover, respiratory failure requiring MV was statistically significantly lower in patients who received early TCZ compared to the control group (OR 0.52; 95% CI 0.31, 0.91, P-value = 0.02). The 30-day and in-hospital mortality were significantly lower in patients who received TCZ than those who did not (HR 0.56; 95% CI 0.37, 0.85, P-value = 0 .006 and HR 0.54; 95% CI 0.36, 0.82, P-value = 0.003, respectively). Conclusion: In addition to the mortality benefits associated with early TCZ use within 24 hours of ICU admission, the use of TCZ was associated with a significantly lower multiorgan dysfunction score on day three of ICU admission in critically ill patients with COVID-19.

The prospects of interleukin-6 inhibition in rheumatoid arthritis: Olokizumab (novel monoclonal antibodies to IL-6)

Rheumatoid arthritis (RA) is a chronic immune-mediated rheumatic diseases (IMRDs) manifested with progressive destruction of joints, systemic inflammation of visceral organs and a wide range of co-morbidities associated with chronic inflammation. Among the cytokines involved in the pathogenesis of RA and certain other IMRDs, the role of interleukin (IL) 6 is of special interest. The introduction of mAbs tocilizumab (TCZ) and later sarilumab (SAR), both blocking the receptor of this cytokine, into clinical practice was an important achievement in the treatment of IIRDs at the beginning of the 21st century. As a novel approach in the treatment of RA, the humanized mAb against IL-6 olokizumab (OKZ) is in development by the Russian company R-PHARM under the license agreement with UCB Pharma. The review examines new data on efficacy and safety of OKZ in RA and the prospects of its use in rheumatology

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.

Consensus statement on blocking interleukin-6 receptor and interleukin-6 in inflammatory conditions: an update

BACKGROUND

Targeting interleukin (IL)-6 has become a major therapeutic strategy in the treatment of immune-mediated inflammatory disease. Interference with the IL-6 pathway can be directed at the specific receptor using anti-IL-6Rα antibodies or by directly inhibiting the IL-6 cytokine. This paper is an update of a previous consensus document, based on most recent evidence and expert opinion, that aims to inform on the medical use of interfering with the IL-6 pathway.

METHODS

A systematic literature research was performed that focused on IL-6-pathway inhibitors in inflammatory diseases. Evidence was put in context by a large group of international experts and patients in a subsequent consensus process. All were involved in formulating the consensus statements, and in the preparation of this document.

RESULTS

The consensus process covered relevant aspects of dosing and populations for different indications of IL-6 pathway inhibitors that are approved across the world, including rheumatoid arthritis, polyarticular-course and systemic juvenile idiopathic arthritis, giant cell arteritis, Takayasu arteritis, adult-onset Still's disease, Castleman's disease, chimeric antigen receptor-T-cell-induced cytokine release syndrome, neuromyelitis optica spectrum disorder and severe COVID-19. Also addressed were other clinical aspects of the use of IL-6 pathway inhibitors, including pretreatment screening, safety, contraindications and monitoring.

CONCLUSIONS

The document provides a comprehensive consensus on the use of IL-6 inhibition to treat inflammatory disorders to inform healthcare professionals (including researchers), patients, administrators and payers.

Immunogenicity of Monoclonal Antibodies and the Potential Use of HLA Haplotypes to Predict Vulnerable Patients

The use of monoclonal antibodies (mAbs) in the clinic has successfully expanded to treatment of cancer, viral infections, inflammations, and other indications. However, some of the classes of mAbs that are used in the clinic show the formation of anti-drug antibodies (ADAs) leading to loss of efficacy. This review describes ADA formation for the various mAbs, and its clinical effect. Lastly, this review considers the use of HLA-haplotypes as biomarkers to predict vulnerability of patients sensitive to formation of ADAs.

Therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal disease: a systematic literature review informing EULAR points to consider

The objectives of this review were to collect and summarise evidence on therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases and to inform the EULAR Task Force for the formulation of evidence-based points to consider. A systematic literature review (SLR) was performed, covering technical aspects and (clinical) utility of TDM, to answer 13 research questions. MEDLINE, Embase and Cochrane were searched until July 2020. American College of Rheumatology and EULAR abstracts were also considered for inclusion. Data were extracted in evidence tables and risk of bias assessment was performed. For the search on technical aspects, 678 records were identified, of which 22 papers were selected. For the clinical utility search, 3846 records were identified, of which 108 papers were included. Patient-related factors associated with biopharmaceutical blood concentrations included body weight, methotrexate comedication and disease activity. The identification of a target range was hampered by study variability, mainly disease activity measures and study type. Evidence was inconsistent for multiple clinical situations in which TDM is currently applied. However, for some particular scenarios, including prediction of future treatment response, non-response to treatment, tapering and hypersensitivity reactions, robust evidence was found. There is currently no evidence for routine use of proactive TDM, in part because published cost-effectiveness analyses do not incorporate the current landscape of biopharmaceutical costs and usage. This SLR yields evidence in favour of TDM of biopharmaceuticals in some clinical scenarios, but evidence is insufficient to support implementation of routine use of TDM.

Pharmacokinetics and pharmacodynamics of a proposed tocilizumab biosimilar MSB11456 versus both the US-licensed and EU-approved products: a randomized, double-blind trial

BACKGROUND

Tocilizumab is a recombinant humanized monoclonal immunoglobulin G1 antibody against the interleukin-6 receptor (IL-6R). MSB11456 is a proposed tocilizumab biosimilar.

OBJECTIVES

To assess the pharmacokinetic and pharmacodynamic similarity of MSB11456 to both US-licensed and EU-approved tocilizumab.

METHODS

Healthy adult volunteers (N=685) received a single 162 mg subcutaneous injection of MSB11456, US-licensed tocilizumab, or EU-approved tocilizumab in this randomized, double-blind, parallel-group study. Blood samples were taken predose and for up to 48 days postdose. Primary endpoint pharmacokinetic parameters were analyzed using analysis of covariance. Secondary pharmacodynamic measures included serum-soluble IL-6R and serum C-reactive protein. Safety data were analyzed descriptively.

RESULTS

Pharmacokinetic equivalence (with all corresponding 90% confidence intervals for the geometric least squares mean ratios within the predefined 80.00% to 125.00% equivalence margin) was demonstrated between MSB11456 and both US-licensed and EU-approved tocilizumab, as well as between the reference products. Pharmacodynamic analyses demonstrated similarity of MSB11456 and both US-licensed and EU-approved tocilizumab, as well as between the reference products. Safety, tolerability and immunogenicity were comparable between treatments.

CONCLUSION

: Pharmacokinetic and pharmacodynamic similarity of MSB11456, US-licensed tocilizumab, and EU-approved tocilizumab were demonstrated, and the three products had comparable immunogenicity and safety, supporting MSB11456 as a biosimilar to tocilizumab.

Mechanisms underlying DMARD inefficacy in difficult-to-treat rheumatoid arthritis: a narrative review with systematic literature search

Management of RA patients has significantly improved over the past decades. However, a substantial proportion of patients is difficult-to-treat (D2T), remaining symptomatic after failing biological and/or targeted synthetic DMARDs. Multiple factors can contribute to D2T RA, including treatment non-adherence, comorbidities and co-existing mimicking diseases (e.g. fibromyalgia). Additionally, currently available biological and/or targeted synthetic DMARDs may be truly ineffective (‘true’ refractory RA) and/or lead to unacceptable side effects. In this narrative review based on a systematic literature search, an overview of underlying (immune) mechanisms is presented. Potential scenarios are discussed including the influence of different levels of gene expression and clinical characteristics. Although the exact underlying mechanisms remain largely unknown, the heterogeneity between individual patients supports the assumption that D2T RA is a syndrome involving different pathogenic mechanisms.

Pegylation Reduces the Uptake of Certolizumab Pegol by Dendritic Cells and Epitope Presentation to T-Cells

Pegylation of biopharmaceuticals is the most common strategy to increase their half-life in the blood and is associated with a reduced immunogenicity. As antigen presentation is a primary event in the activation of CD4 T-cells and initiation of Anti-Drug Antibody (ADA) response, we investigated the role of the PEG molecule on the T-cell reactivity of certolizumab pegol (CZP), a pegylated anti-TNFα Fab. We generated T-cell lines raised against CZP and its non-pegylated form (CZNP) and demonstrated CZP primed few T-cells in comparison to CZNP. CZP-primed lines from 3 donors responded to a total of 5 epitopes, while CZNP-primed lines from 3 donors responded to a total of 7 epitopes, 4 epitopes were recognized by both CZP- and CZNP-primed lines. In line with this difference of T-cell reactivity, CZP is less internalized by the dendritic cells than CZNP. In vitro digestion assay of CZP by Cathepsin B showed a rapid removal of the PEG moiety, suggesting a limited influence of PEG on CZP proteolysis. We therefore demonstrate that pegylation diminishes antigen capture by dendritic cells, peptide presentation to T-cells and T-cell priming. This mechanism might reduce immunogenicity and contribute to the long half-life of CZP and possibly of other pegylated molecules.

A Novel Humanized Anti-Interleukin-6 Antibody HZ0408b With Anti-Rheumatoid Arthritis Therapeutic Potential

Interleukin-6 (IL-6), a pleiotropic cytokine that regulates immune responses and inflammatory reactions, plays a pivotal role in the development of rheumatoid arthritis (RA). Blockade of IL-6 signaling with the monoclonal antibody (mAb) represents an important advancement in RA treatment. Although two IL-6 receptor antibodies are already available in the clinic, there is no mAb specifically targeting the human IL-6 to block IL-6 signaling for RA treatment. In this study, we have developed a novel humanized anti-IL-6 mAb HZ-0408b with potent binding and neutralizing activity to human IL-6. We demonstrated that HZ-0408b has a high species specificity and low cross-reactivity. Moreover, HZ-0408b showed a more potent inhibitory effect on IL-6 signaling than Siltuximab, an FDA-approved anti-IL-6 chimeric mAb. HZ-0408b is comparable to Olokizumab, a humanized mAb against IL-6 that is already in phase III studies. We observed that HZ-0408b is well tolerated at doses that can achieve therapeutic serum levels in cynomolgus monkey. Most importantly, we proved that HZ-0408b treatment significantly ameliorated joint swelling after the onset of arthritis and dramatically reduced plasma C-reactive protein (CRP) levels in a monkey collagen-induced arthritis (CIA) model. Collectively, our findings using non-human primates indicate that humanized anti-IL-6 mAb HZ-0408b has excellent safety and efficacy profiles for RA therapy.

Experts document on methotrexate use in combined therapy with biological or targeted synthetic disease modifying drugs in patients with rheumatoid arthritis

OBJECTIVE

We aimed to develop recommendations for the management of methotrexate (MTX) when considering the combination with biological (b) or targeted synthetic (ts) disease modifying drugs (DMARDs) in rheumatoid arthritis (RA).

METHODS

Eleven experts on RA were selected. Two coordinators formulated 13 questions about the combination therapy of MTX with bDMARDs or tsDMARDs. A systematic review was conducted to answer the questions. Inclusion and exclusion criteria were established as well as the search strategies (Medline, Embase and the Cochrane Library were searched up to January 2019). Two reviewers selected the articles and collected data. Simultaneously, EULAR and ACR meeting abstracts were evaluated. Based on this evidence, the coordinators proposed preliminary recommendations that the experts discussed and voted in a nominal group meeting. The level of evidence and grade of recommendation was established using the Oxford Center for Evidence Based Medicine and the level of agreement with a Delphi. Agreement was established if at least 80% of the experts voted 'yes' (yes/no).

RESULTS

The systematic review retrieved 513 citations of which 61 were finally included. A total of 10 recommendations were generated, voted and accepted. The level of agreement was very high in all of them and it was achieved in the first Delphi round. Final recommendations cover aspects such as the optimal MTX dosage, tapering strategy or patients' risk management.

CONCLUSIONS

This document is intended to help clinicians solve usual clinical questions and facilitate decision making when treating RA patients with MTX in combination with bDMARDs or tsDMARDs.

Toward Overcoming Treatment Failure in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by inflammation and bone erosion. The exact mechanism of RA is still unknown, but various immune cytokines, signaling pathways and effector cells are involved. Disease-modifying antirheumatic drugs (DMARDs) are commonly used in RA treatment and classified into different categories. Nevertheless, RA treatment is based on a "trial-and-error" approach, and a substantial proportion of patients show failed therapy for each DMARD. Over the past decades, great efforts have been made to overcome treatment failure, including identification of biomarkers, exploration of the reasons for loss of efficacy, development of sequential or combinational DMARDs strategies and approval of new DMARDs. Here, we summarize these efforts, which would provide valuable insights for accurate RA clinical medication. While gratifying, researchers realize that these efforts are still far from enough to recommend specific DMARDs for individual patients. Precision medicine is an emerging medical model that proposes a highly individualized and tailored approach for disease management. In this review, we also discuss the potential of precision medicine for overcoming RA treatment failure, with the introduction of various cutting-edge technologies and big data.

Management of Rheumatoid Arthritis: An Overview

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease of unknown etiology, primarily affecting the joints, then extra-articular manifestations can occur. Due to its complexity, which is based on an incompletely elucidated pathophysiological mechanism, good RA management requires a multidisciplinary approach. The clinical status of RA patients has improved in recent years due to medical advances in diagnosis and treatment, that have made it possible to reduce disease activity and prevent systemic complications. The most promising results were obtained by developing disease-modifying anti-rheumatic drugs (DMARDs), the class to which conventional synthetic, biologic, and targeted synthetic drugs belong. Furthermore, ongoing drug development has led to obtaining molecules with improved efficacy and safety profiles, but further research is needed until RA turns into a curable pathology. In the present work, we offer a comprehensive perspective on the management of RA, by centralizing the existing data provided by significant literature, emphasizing the importance of an early and accurate diagnosis associated with optimal personalized treatment in order to achieve better outcomes for RA patients. In addition, this study suggests future research perspectives in the treatment of RA that could lead to higher efficacy and safety profiles and lower financial costs.

Drug efficacy and safety of biologics and Janus kinase inhibitors in elderly patients with rheumatoid arthritis

Elderly patients with rheumatoid arthritis (RA) are frequently associated with higher disease activity and impaired physical function, although they show intolerance for conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), such as methotrexate, because of their comorbidities. However, the present treatment recommendation based on randomized controlled trials is not distinguished by age or comorbidities. Therefore, this review aimed to investigate the efficacy and safety of biological DMARDs (bDMARDs) and Janus kinase inhibitors (JAKi) in elderly patients. Present bDMARDs, including tumor necrosis factor inhibitors (TNFi), cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (abatacept), interleukin (IL)-6 receptor antibody (tocilizumab and salirumab), and anti-CD20 antibody (rituximab), may be similarly or slightly less effective or safe in elderly patients compared with younger patients. Oral glucocorticoid use, prolonged disease duration, and very old patients appear to be associated with an increased risk of adverse events, such as serious infection. Some recent cohort studies demonstrated that non-TNFi showed better retention than TNFi in elderly patients. Both TNFi and non-TNFi agents may not strongly influence the risk of adverse events such as cardiovascular events and malignancy in elderly patients. Regarding JAKi, the efficacy appears to be similar, although the safety (particularly for serious infections, including herpes zoster) may be attenuated by aging.

Tocilizumab and Systemic Corticosteroids in the Management of Patients with COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND

To date, there is no effective treatment for the new coronavirus disease (COVID-19). We aimed to systematically review the literature on the association between the combination of tocilizumab (TCZ) and systemic corticosteroid therapy (SCT) on outcomes of COVID-19 patients.

METHODS

We searched MEDLINE, Cochrane Central, and preprints, for studies in which health outcomes were compared between adults with severe COVID-19 who received TCZ and SCT and those who received standard of care without TCZ. Record screening, data extraction, and risk of bias assessment were performed in duplicate. Random effect models were used when pooling crude numbers and adjusted effect estimates of study outcomes.

RESULTS

Our search identified seventeen studies. The pooled crude mortality rate was lower in the combination arm (relative risk, RR=0.62, 95% confidence interval [CI]=0.42 - 0.91; I²=60%). The adjusted mortality rates were also lower in the combination arm (RR=0.58, 95% CI=0.42 - 0.81; I²=71%). The rate of superinfections did not differ between the two interventions.

CONCLUSIONS

The findings of this study show that combination of TCZ and SCT compared to SOC has lower mortality rates. There is an urgent need for well-designed randomized trials to assess the safety and efficacy of this combination in subjects with severe COVID-19.

Impact of immunogenicity on clinical efficacy and toxicity profile of biologic agents used for treatment of inflammatory arthritis in children compared to adults

The treatment of inflammatory arthritis has been revolutionised by the introduction of biologic treatments. Many biologic agents are currently licensed for use in both paediatric and adult patients with inflammatory arthritis and contribute to improved disease outcomes compared with the pre-biologic era. However, immunogenicity to biologic agents, characterised by an immune reaction leading to the production of anti-drug antibodies (ADAs), can negatively impact the therapeutic efficacy of biologic drugs and induce side effects to treatment. This review explores for the first time the impact of immunogenicity against all licensed biologic treatments currently used in inflammatory arthritis across age, and will examine any significant differences between ADA prevalence, titres and timing of development, as well as ADA impact on therapeutic drug levels, clinical efficacy and side effects between paediatric and adult patients. In addition, we will investigate factors associated with differences in immunogenicity across biologic agents used in inflammatory arthritis, and their potential therapeutic implications.

Old and New Challenges in Uveitis Associated with Behçet's Disease

Behçet’s disease (BD) is a systemic vasculitis disease of unknown origin occurring in young people, which can be venous, arterial or both, classically occlusive. Ocular involvement is particularly frequent and severe; vascular occlusion secondary to retinal vasculitis may lead to rapid and severe loss of vision. Biologics have transformed the management of intraocular inflammation. However, the diagnosis of BD is still a major challenge. In the absence of a reliable biological marker, diagnosis is based on clinical diagnostic criteria and may be delayed after the appearance of the onset sign. However, therapeutic management of BD needs to be introduced early in order to control inflammation, to preserve visual function and to limit irreversible structural damage. The aim of this review is to provide current data on how innovations in clinical evaluation, investigations and treatments were able to improve the prognosis of uveitis associated with BD.

Efficacy and Safety of Tocilizumab for Polyarticular-Course Juvenile Idiopathic Arthritis in the Open-Label Two-Year Extension of a Phase III Trial

Objective

To report the 2‐year efficacy and safety of tocilizumab (TCZ) in patients with polyarticular‐course juvenile idiopathic arthritis (JIA).

Methods

Patients ages 2–17 years with active polyarticular‐course JIA, in whom treatment with methotrexate was unsuccessful, received 16 weeks of open‐label intravenous TCZ in part 1 (once every 4 weeks: 8 mg/kg or 10 mg/kg for body weight [BW] <30 kg; 8 mg/kg for BW ≥30 kg). Assessments were based on the JIA–American College of Rheumatology (ACR) response (defined as percentage of improvement in ≥3 of the 6 JIA core response variables [CRVs]). Patients with at least a JIA‐ACR30 response (defined as ≥30% improvement in ≥3 of the 6 JIA CRVs without worsening in >1 of the remaining JIA CRVs by >30%) at week 16 were randomly assigned (1:1) to receive TCZ or placebo in part 2. Patients remained in part 2 until either week 40 or the occurrence of JIA flare. Upon starting part 3, all patients received open‐label TCZ. At week 104 of the study, efficacy was assessed using JIA‐ACR50/70/90 response rates (defined as 50%, 70%, or 90% improvement, respectively), achievement of inactive disease, and the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS‐71). Safety was assessed in the all‐exposure population per 100 patient‐years of exposure.

Results

Overall, 188 patients entered part 1, 166 patients entered part 2, and 160 patients entered part 3. By week 104, among the 188 patients in the modified intent‐to‐treat group who received TCZ, JIA‐ACR50/70/90 response rates were 80.3%/77.1%/59.6%, respectively, the median JADAS‐71 score decreased from 3.6 at week 40 to 0.7 at week 104, 51.1% of patients had achieved inactive disease, and 31 of 66 patients who had been receiving glucocorticoids discontinued them. Adverse event (AE) and serious AE rates were 406.5 per 100 patient‐years and 11.1 per 100 patient‐years, respectively. The infection rate was 151.4 per 100 patient‐years, and the serious infection rate was 5.2 per 100 patient‐years.

Conclusion

Patients treated with TCZ for polyarticular‐course JIA showed high‐level disease control for up to 2 years. The TCZ safety profile was consistent with that previously reported.

Innovative approaches to biologic development on the trail of CT-P13: biosimilars, value-added medicines, and biobetters

The biosimilar concept is now well established. Clinical data accumulated pre- and post-approval have supported biosimilar uptake, in turn stimulating competition in the biologics market and increasing patient access to biologics. Following technological advances, other innovative biologics, such as “biobetters” or “value-added medicines,” are now reaching the market. These innovative biologics differ from the reference product by offering additional clinical or non-clinical benefits. We discuss these innovative biologics with reference to CT-P13, initially available as an intravenous (IV) biosimilar of reference infliximab. A subcutaneous (SC) formulation, CT-P13 SC, has now been developed. Relative to CT-P13 IV, CT-P13 SC offers clinical benefits in terms of pharmacokinetics, with comparable efficacy, safety, and immunogenicity, as well as increased convenience for patients and reduced demands on healthcare system resources. As was once the case for biosimilars, nomenclature and regulatory pathways for innovative biologics require clarification to support their uptake and ultimately benefit patients.

Biologic Drugs for Rheumatoid Arthritis in the Context of Biosimilars, Genetics, Epigenetics and COVID-19 Treatment

Rheumatoid arthritis (RA) affects around 1.2% of the adult population. RA is one of the main reasons for work disability and premature retirement, thus substantially increasing social and economic burden. Biological disease-modifying antirheumatic drugs (bDMARDs) were shown to be an effective therapy especially in those rheumatoid arthritis (RA) patients, who did not adequately respond to conventional synthetic DMARD therapy. However, despite the proven efficacy, the high cost of the therapy resulted in limitation of the widespread use and unequal access to the care. The introduction of biosimilars, which are much cheaper relative to original drugs, may facilitate the achievement of the therapy by a much broader spectrum of patients. In this review we present the properties of original biologic agents based on cytokine-targeted (blockers of TNF, IL-6, IL-1, GM-CSF) and cell-targeted therapies (aimed to inhibit T cells and B cells properties) as well as biosimilars used in rheumatology. We also analyze the latest update of bDMARDs' possible influence on DNA methylation, miRNA expression and histone modification in RA patients, what might be the important factors toward precise and personalized RA treatment. In addition, during the COVID-19 outbreak, we discuss the usage of biologicals in context of effective and safe COVID-19 treatment. Therefore, early diagnosing along with therapeutic intervention based on personalized drugs targeting disease-specific genes is still needed to relieve symptoms and to improve the quality of life of RA patients.

Peripheral ulcerative keratitis in rheumatoid arthritis patients taking tocilizumab: paradoxical manifestation or insufficient efficacy?

Objectives

Peripheral ulcerative keratitis (PUK) is a severe corneal condition associated with uncontrolled RA. Tocilizumab (TCZ) is used to control RA, however, episodes of paradoxical ocular inflammation have been reported in TCZ-treated patients. We report a case series of PUK in TCZ-treated RA patients with ophthalmological and systemic findings and discuss the potential underlying mechanisms.

Methods

Four patients (six eyes), 47–62 years of age, were included. At the onset of PUK, the median duration of RA was 13 years [interquartile range (IQR) 3–13] and the median treatment with TCZ was 9 months (IQR 3–14). Two patients had active disease [28-joint DAS (DAS28) &gt;3.2] and the disease was controlled in two patients (DAS28 ≤3.2).

Results

TCZ was initially replaced by another immunomodulatory treatment in all patients and later reintroduced in two patients without PUK recurrence. Corneal inflammation was controlled in all cases with local and systemic treatments, with severe visual loss in one eye.

Conclusion

PUK may occur in patients with long-standing RA after a switch to TCZ and can be interpreted, depending on the context, as insufficient efficacy or a paradoxical manifestation. These cases highlight the urgent need for reliable biomarkers of the efficacy and paradoxical reactions of biologics.

Immunogenicity Challenges Associated with Subcutaneous Delivery of Therapeutic Proteins

The subcutaneous route of administration has provided convenient and non-inferior delivery of therapeutic proteins compared to intravenous infusion, but there is potential for enhanced immunogenicity toward subcutaneously administered proteins in a subset of patients. Unwanted anti-drug antibody response toward proteins or monoclonal antibodies upon repeated administration is shown to impact the pharmacokinetics and efficacy of multiple biologics. Unique immunogenicity challenges of the subcutaneous route have been realized through various preclinical and clinical examples, although subcutaneous delivery has often demonstrated comparable immunogenicity to intravenous administration. Beyond route of administration as a treatment-related factor of immunogenicity, certain product-related risk factors are particularly relevant to subcutaneously administered proteins. This review attempts to provide an overview of the mechanism of immune response toward proteins administered subcutaneously (subcutaneous proteins) and comments on product-related risk factors related to protein structure and stability, dosage form, and aggregation. A two-wave mechanism of antigen presentation in the immune response toward subcutaneous proteins is described, and interaction with dynamic antigen-presenting cells possessing high antigen processing efficiency and migratory activity may drive immunogenicity. Mitigation strategies for immunogenicity are discussed, including those in general use clinically and those currently in development. Mechanistic insights along with consideration of risk factors involved inspire theoretical strategies to provide antigen-specific, long-lasting effects for maintaining the safety and efficacy of therapeutic proteins.

Drug retention of sarilumab, baricitinib, and tofacitinib in patients with rheumatoid arthritis: the ANSWER cohort study

OBJECTIVES

The aim of this multicenter, retrospective study was to clarify the retention rates of sarilumab (SAR), baricitinib (BAR), and tofacitinib (TOF) in patients with rheumatoid arthritis (RA).

METHODS

Patients treated with either SAR (n = 62), BAR (n = 166), or TOF (n = 185) (females, 80.9%; age, 61.0 years; disease duration, 11.1 years; rheumatoid factor positivity, 84.4%; Disease Activity Score in 28 joints using erythrocyte sedimentation rate, 4.3; concomitant prednisolone dose, 5.3 mg/day [47.0%] and methotrexate dose, 8.8 mg/week [58.4%]; biologics- or Janus kinase inhibitors-switched cases 78.4%) were included. The reasons for drug discontinuation were classified into 4 major categories (lack of effectiveness, toxic adverse events, non-toxic reasons, and remission) by each attending physician. The drug retention rate was estimated at 18 months using the Kaplan-Meier method and adjusted for potential confounders by Cox proportional hazards modeling.

RESULTS

The discontinuation rates of SAR, BAR, and TOF for the corresponding reasons were as follows, respectively: lack of effectiveness (15.7%, 15.6%, and 21.5%; P = 0.84), toxic adverse events (15.8%, 12.1%, and 12.3%; P = 0.35), non-toxic reasons (10.9%, 7.7%, and 6.8%; P = 0.35), and remission (0.0%, 2.8%, and 0.0%; P = 1.0). The overall retention rates excluding non-toxic reasons and remission were as follows: 68.8% for SAR, 72.5% for BAR, and 66.7% for TOF (P = 0.54).

CONCLUSIONS

After adjustment by potent confounders, SAR, BAR, and TOF showed similar discontinuation rates due to lack of effectiveness and toxic adverse events. Key Points • This is the first retrospective multicenter study that aimed to clarify the retention rates and reasons for discontinuation of SAR, BAR, and TOF in patients with RA.

Immunogenicity of biologic agents in rheumatology

Biologic agents have become a core component of therapeutic strategies for many inflammatory rheumatic diseases. However, perhaps reflecting the specificity and generally high affinity of biologic agents, these therapeutics have been used by rheumatologists with less consideration of their pharmacokinetics than that of conventional synthetic DMARDs. Immunogenicity was recognized as a potential limitation to the use of biologic agents at an early stage in their development, although regulatory guidance was relatively limited and assays to measure immunogenicity were less sophisticated than today. The advent of biosimilars has sparked a renewed interest in immunogenicity that has resulted in the development of increasingly sensitive assays, an enhanced appreciation of the pharmacokinetic consequences of immunogenicity and the development of comprehensive and specific guidance from regulatory authorities. As a result, rheumatologists have a greatly improved understanding of the field in general, including the factors responsible for immunogenicity, its potential clinical consequences and the implications for everyday treatment. In some specialties, immunogenicity testing is becoming a part of routine clinical management, but definitive evidence of its cost-effectiveness in rheumatology is awaited.

Experts document on methotrexate use in combined therapy with biological or targeted synthetic disease modifying drugs in patients with rheumatoid arthritis

OBJECTIVE

We aimed to develop recommendations for the management of methotrexate (MTX) when considering the combination with biological (b) or targeted synthetic (ts) disease modifying drugs (DMARDs) in rheumatoid arthritis (RA).

METHODS

Eleven experts on RA were selected. Two coordinators formulated 13 questions about the combination therapy of MTX with bDMARDs or tsDMARDs. A systematic review was conducted to answer the questions. Inclusion and exclusion criteria were established as well as the search strategies (Medline, Embase and the Cochrane Library were searched up to January 2019). Two reviewers selected the articles and collected data. Simultaneously, EULAR and ACR meeting abstracts were evaluated. Based on this evidence, the coordinators proposed preliminary recommendations that the experts discussed and voted in a nominal group meeting. The level of evidence and grade of recommendation was established using the Oxford Center for Evidence Based Medicine and the level of agreement with a Delphi. Agreement was established if at least 80% of the experts voted 'yes' (yes/no).

RESULTS

The systematic review retrieved 513 citations of which 61 were finally included. A total of 10 recommendations were generated, voted and accepted. The level of agreement was very high in all of them and it was achieved in the first Delphi round. Final recommendations cover aspects such as the optimal MTX dosage, tapering strategy or patients' risk management.

CONCLUSIONS

This document is intended to help clinicians solve usual clinical questions and facilitate decision making when treating RA patients with MTX in combination with bDMARDs or tsDMARDs.

Recent progress in maintenance treatment of neuromyelitis optica spectrum disorder

Background

Treatment of neuromyelitis optica spectrum disorder (NMOSD) has so far been based on retrospective case series. The results of six randomized clinical trials including five different monoclonal antibodies targeting four molecules and three distinct pathophysiological pathways have recently been published.

Methods

Literature search on clinical trials and case studies in NMOSD up to July 10. 2020.

Results

We review mechanism of action, efficacy and side effects, and consequences for reproductive health from traditional immunosuppressants and monoclonal antibodies including rituximab, inebilizumab, eculizumab, tocilizumab and satralizumab.

Conclusion

In NMOSD patients with antibodies against aquaporin 4, monoclonal antibodies that deplete B cells (rituximab and inebilizumab) or interfere with interleukin 6 signaling (tocilizumab and satralizumab) or complement activation (eculizumab) have superior efficacy compared to placebo. Tocilizumab and rituximab were also superior to azathioprine in head-to-head studies. Rituximab, tocilizumab and to some extent eculizumab have well-known safety profiles for other inflammatory diseases, and rituximab and azathioprine may be safe during pregnancy.

Clinicogenomic factors of biotherapy immunogenicity in autoimmune disease: A prospective multicohort study of the ABIRISK consortium

BACKGROUND

Biopharmaceutical products (BPs) are widely used to treat autoimmune diseases, but immunogenicity limits their efficacy for an important proportion of patients. Our knowledge of patient-related factors influencing the occurrence of antidrug antibodies (ADAs) is still limited.

METHODS AND FINDINGS

The European consortium ABIRISK (Anti-Biopharmaceutical Immunization: prediction and analysis of clinical relevance to minimize the RISK) conducted a clinical and genomic multicohort prospective study of 560 patients with multiple sclerosis (MS, n = 147), rheumatoid arthritis (RA, n = 229), Crohn's disease (n = 148), or ulcerative colitis (n = 36) treated with 8 different biopharmaceuticals (etanercept, n = 84; infliximab, n = 101; adalimumab, n = 153; interferon [IFN]-beta-1a intramuscularly [IM], n = 38; IFN-beta-1a subcutaneously [SC], n = 68; IFN-beta-1b SC, n = 41; rituximab, n = 31; tocilizumab, n = 44) and followed during the first 12 months of therapy for time to ADA development. From the bioclinical data collected, we explored the relationships between patient-related factors and the occurrence of ADAs. Both baseline and time-dependent factors such as concomitant medications were analyzed using Cox proportional hazard regression models. Mean age and disease duration were 35.1 and 0.85 years, respectively, for MS; 54.2 and 3.17 years for RA; and 36.9 and 3.69 years for inflammatory bowel diseases (IBDs). In a multivariate Cox regression model including each of the clinical and genetic factors mentioned hereafter, among the clinical factors, immunosuppressants (adjusted hazard ratio [aHR] = 0.408 [95% confidence interval (CI) 0.253-0.657], p < 0.001) and antibiotics (aHR = 0.121 [0.0437-0.333], p < 0.0001) were independently negatively associated with time to ADA development, whereas infections during the study (aHR = 2.757 [1.616-4.704], p < 0.001) and tobacco smoking (aHR = 2.150 [1.319-3.503], p < 0.01) were positively associated. 351,824 Single-Nucleotide Polymorphisms (SNPs) and 38 imputed Human Leukocyte Antigen (HLA) alleles were analyzed through a genome-wide association study. We found that the HLA-DQA1*05 allele significantly increased the rate of immunogenicity (aHR = 3.9 [1.923-5.976], p < 0.0001 for the homozygotes). Among the 6 genetic variants selected at a 20% false discovery rate (FDR) threshold, the minor allele of rs10508884, which is situated in an intron of the CXCL12 gene, increased the rate of immunogenicity (aHR = 3.804 [2.139-6.764], p < 1 × 10-5 for patients homozygous for the minor allele) and was chosen for validation through a CXCL12 protein enzyme-linked immunosorbent assay (ELISA) on patient serum at baseline before therapy start. CXCL12 protein levels were higher for patients homozygous for the minor allele carrying higher ADA risk (mean: 2,693 pg/ml) than for the other genotypes (mean: 2,317 pg/ml; p = 0.014), and patients with CXCL12 levels above the median in serum were more prone to develop ADAs (aHR = 2.329 [1.106-4.90], p = 0.026). A limitation of the study is the lack of replication; therefore, other studies are required to confirm our findings.

CONCLUSION

In our study, we found that immunosuppressants and antibiotics were associated with decreased risk of ADA development, whereas tobacco smoking and infections during the study were associated with increased risk. We found that the HLA-DQA1*05 allele was associated with an increased rate of immunogenicity. Moreover, our results suggest a relationship between CXCL12 production and ADA development independent of the disease, which is consistent with its known function in affinity maturation of antibodies and plasma cell survival. Our findings may help physicians in the management of patients receiving biotherapies.

The Molecular Mechanisms That Underlie the Immune Biology of Anti-drug Antibody Formation Following Treatment With Monoclonal Antibodies

Monoclonal antibodies (mAbs) are a crucial asset for human health and modern medicine, however, the repeated administration of mAbs can be highly immunogenic. Drug immunogenicity manifests in the generation of anti-drug antibodies (ADAs), and some mAbs show immunogenicity in up to 70% of patients. ADAs can alter a drug's pharmacokinetic and pharmacodynamic properties, reducing drug efficacy. In more severe cases, ADAs can neutralize the drug's therapeutic effects or cause severe adverse events to the patient. While some contributing factors to ADA formation are known, the molecular mechanisms of how therapeutic mAbs elicit ADAs are not completely clear. Accurate ADA detection is necessary to provide clinicians with sufficient information for patient monitoring and clinical intervention. However, ADA assays present unique challenges because both the analyte and antigen are antibodies, so most assays are cumbersome, costly, time consuming, and lack standardization. This review will discuss aspects related to ADA formation following mAb drug administration. First, we will provide an overview of the prevalence of ADA formation and the available diagnostic tools for their detection. Next, we will review studies that support possible molecular mechanisms causing the formation of ADA. Finally, we will summarize recent approaches used to decrease the propensity of mAbs to induce ADAs.

Immunogenicity-unwanted immune responses to biological drugs - can we predict them?

INTRODUCTION

Biological agents (BAs) target molecules involved in disease mechanisms and have modified the natural history of several immune-mediated disorders. All BAs are immunogenic, resulting in the formation of antidrug antibodies (ADAs), which can neutralize drug activity leading to loss of response and potential relapse, or serious adverse events such as infusion hypersensitivity reactions. The production of ADAs is the result of a specific adaptive immune response in which T and B cells are involved.

AREAS COVERED

Factors conditioning the immunogenicity of BAs, including drug-, treatment- and patient-related factors are currently the subject of many studies. Among them, a lot of attention is dedicated to define the impact of BAs structure, the effect of targeting (soluble or membrane) molecules, the impact of interruption of therapy as well as the role of genetic (HLA and non-HLA) predisposing factors and disease activity.

EXPERT OPINION

Knowledge of factors capable of influencing the immunogenicity of BAs may help to understand, in a predictive manner and at the single patient level, the presence of risk factors influencing the production of ADAs and their impact on clinical outcomes.

Tocilizumab-induced immunocomplex glomerulonephritis: a report of two cases

We report here two cases of membranoproliferative glomerulonephritis that developed during treatment of rheumatoid arthritis with tocilizumab. In both cases, the initial findings were proteinuria and haematuria, followed by development of bilateral lower leg oedema. One of the patients was weakly positive for anti-nuclear antibody; both had hypocomplementaemia. The patients' renal impairment gradually resolved with discontinuation of tocilizumab followed by treatment with moderate doses of oral prednisolone. Pathological examination of renal biopsies resulted in diagnoses of immunocomplex glomerulonephritis and immunofluorescence staining revealed depositions of IgG, IgA, and IgM, accompanied by C3. Tocilizumab rarely induces autoimmune disorders; therefore, the underlying mechanism is unknown. One patient with immunocomplex glomerulonephritis that may have been associated with tocilizumab therapy for rheumatoid arthritis has been reported previously; that patient and our two are similar in their clinical courses and pathological findings. We conclude that such glomerulonephritis can occur during tocilizumab treatment, but this is rare. Clinicians should be aware of the possibility of paradoxical development of autoimmune diseases during tocilizumab therapy.

Translating IL-6 biology into effective treatments

In 1973, IL-6 was identified as a soluble factor that is secreted by T cells and is important for antibody production by B cells. Since its discovery more than 40 years ago, the IL-6 pathway has emerged as a pivotal pathway involved in immune regulation in health and dysregulation in many diseases. Targeting of the IL-6 pathway has led to innovative therapeutic approaches for various rheumatic diseases, such as rheumatoid arthritis, juvenile idiopathic arthritis, adult-onset Still’s disease, giant cell arteritis and Takayasu arteritis, as well as other conditions such as Castleman disease and cytokine release syndrome. Targeting this pathway has also identified avenues for potential expansion into several other indications, such as uveitis, neuromyelitis optica and, most recently, COVID-19 pneumonia. To mark the tenth anniversary of anti-IL-6 receptor therapy worldwide, we discuss the history of research into IL-6 biology and the development of therapies that target IL-6 signalling, including the successes and challenges and with an emphasis on rheumatic diseases.

In this Perspective article, the authors recount the earliest stages of translational research into IL-6 biology and the subsequent development of therapeutic IL-6 pathway inhibitors for the treatment of autoimmune rheumatic diseases and potentially numerous other indications.

Laboratory Monitoring of Biological Therapies in Rheumatology: The Role of Immunogenicity

Biological drugs, such as proteins and immunogens, are increasingly used to treat various diseases, including tumors and autoimmune diseases, and biological molecules have almost completely replaced synthetic drugs in rheumatology. Although biological treatments such as anti-tumor necrosis factor (TNF) drugs seem to be quite safe, they cause some undesirable effects, such as the onset of infections due to weakening of the immune system. Given the biological nature of these drugs, they might be recognized as extraneous; this would induce an immune reaction that neutralizes their effectiveness or lead to more serious consequences. Laboratories play a pivotal role in appropriate therapeutic management. The aim of this review was to underline the production of anti-drug antibodies during treatment with biological drugs and highlight the role of laboratories in ensuring appropriate use of these drugs.

Drug retention of secondary biologics or JAK inhibitors after tocilizumab or abatacept failure as first biologics in patients with rheumatoid arthritis -the ANSWER cohort study

OBJECTIVES

The aim of this multicenter, retrospective study was to clarify the retention of secondary biological disease-modifying antirheumatic drugs (bDMARDs) or Janus kinase inhibitors (JAKi) in patients with rheumatoid arthritis (RA) who were primarily treated by tocilizumab (TCZ) or abatacept (ABT) as first bDMARDs.

METHOD

Patients who were treated by either TCZ (n = 145) or ABT (n = 76) and then switched to either tumor necrosis factor inhibitors (TNFi), TCZ, ABT, or JAKi (including only cases switched from TCZ) from 2001 to 2019 (female 81.0%, age 59.5 years, disease duration 8.8 years; rheumatoid factor positivity 75.4%; Disease Activity Score in 28 joints using C-reactive protein 3.7; concomitant prednisolone (PSL) dose 6.0 mg/day (51.8%) and methotrexate (MTX) dose 8.0 mg/week (56.1%); 81.9% discontinued first bDMARDs due to lack of effectiveness) were included. Drug retention and discontinuation reasons were estimated at 24 months using the Kaplan-Meier method and adjusted for potential confounders by Cox proportional hazards modeling.

RESULTS

Drug retentions for each of the reasons for discontinuation were as follows: lack of effectiveness in TCZ-switched group (TNFi (59.5%), ABT (82.2%), and JAKi (84.3%); TNFi vs. ABT; P = 0.009) and ABT-switched group (TNFi (79.6%) and TCZ (92.6%); P = 0.053). Overall retention excluding non-toxic reasons and remission for discontinuation were TNFi (49.9%), ABT (72.7%), and JAKi (72.6%) (TNFi vs. ABT; P = 0.017) in the TCZ-switched group and TNFi (69.6%) and TCZ (72.4%) (P = 0.44) in the ABT-switched group.

CONCLUSIONS

Switching to ABT in TCZ-treated patients led to higher retention as compared with TNFi. Switching to TCZ in ABT-treated patients tended to lead to higher retention due to effectiveness, although total retention was similar as compared with TNFi. Key Point • This is the first retrospective, multi-center study aimed to clarify the retention rates of secondary bDMARDs or JAKi in patients with RA who were primarily being treated by TCZ or ABT as the first bDMARDs.

Retention of tocilizumab with and without methotrexate during maintenance therapy for rheumatoid arthritis: the ACTRA-RI cohort study

OBJECTIVES

To compare retention of tocilizumab (TCZ) as monotherapy vs combination therapy with MTX in RA patients achieving clinical improvements during the first year.

METHODS

We performed a multicentre cohort study using a real-life registry containing RA patients who had begun TCZ with or without MTX between April 2008 and November 2016. Among patients with ≥50% improvement of clinical disease activity index (CDAI) during the first year (CDAI50 responders), we evaluated whether MTX use may have affected TCZ discontinuation during the second and subsequent years (maintenance therapy).

RESULTS

Among 510 patients with high or moderate CDAI, 328 (64.3%) were CDAI50 responders. The rate of MTX use was 53.0% among responders and 54.4% among non-responders. During maintenance therapy (mean follow-up 30.7 months), 43.9% of CDAI50 responders discontinued TCZ. The most common cause was efficacy loss followed by adverse events. Kaplan-Meier estimates for TCZ retention were 48.3 months (95% CI 42.0, 54.5) for monotherapy and 50.0 months (95% CI 45.9, 54.0) for combination therapy. According to Gray's test, there was no significant impact of MTX use on cumulative incidence of efficacy loss or adverse events. In the Fine-Gray competing risk regression model, CDAI >10 at the start of maintenance therapy and age were predictive factors for TCZ discontinuation due to efficacy loss (hazard ratio 2.58, 95% CI 1.41, 4.72) and adverse events (hazard ratio 1.04, 95% CI 1.01, 1.08), respectively.

CONCLUSION

There was no significant difference in TCZ retention between monotherapy and combination therapy with MTX.

Salp15, a Multifunctional Protein From Tick Saliva With Potential Pharmaceutical Effects

Ixodes ticks are the main vectors for a number of zoonotic diseases, including Lyme disease. Ticks secrete saliva directly into a mammalian host while feeding on the host's blood. This action serves to modulate host immunity and coagulation, thus allowing ticks to attach and feed upon their host. One of the most extensively studied components of tick saliva is Salp15. Research has shown that this protein binds specifically to CD4 molecules on the surface of T lymphocytes, interferes with TCR-mediated signaling transduction, inhibits CD4+ T cell activation and proliferation, and impedes the secretion of interleukin 2 (IL-2). Salp15 also binds specifically to dendritic cell dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) to up-regulate the expression of CD73 in regulatory T cells. Collectively, these findings render this salivary protein a potential candidate for a range of therapeutic applications. Here, we discuss our current understanding of Salp15 and the mechanisms that might be used to treat disease.