Adalimumab has been approved for treating juvenile idiopathic arthritis (JIA). This study aimed to develop a physiologically-based pharmacokinetic (PBPK) model for adalimumab in JIA patients to optimize personalized treatment.

A comprehensive literature search identified 13 clinical studies as the dataset for constructing and validating a PBPK model of adalimumab. Initially, a PBPK model for adalimumab in adults was constructed using PK-Sim and Mobi software. Subsequently, virtual pediatric populations were created by incorporating age-dependent parameters from the PK-Sim database, extending the model to JIA patients. Finally, based on the developed PBPK model for adalimumab in JIA patients, dosing regimens were evaluated for different age groups.

This study successfully developed and validated a PBPK model for adalimumab in both adult and pediatric populations. The model for adults accurately predicted 92.90% of the concentrations within 0.5-2 times the observed values, while the pediatric model predicted 90.62% of the concentrations within 0.5-2-fold range. For pediatric patients with JIA, age- and weight-based dosing is recommended to achieve trough concentrations comparable to those in adults.

A PBPK model for adalimumab in pediatric patients with JIA was developed, providing a basis for personalized dosing regimens in this population.

Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here, we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across three donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.

CT-P13, a biosimilar of infliximab, is widely used for treating ankylosing spondylitis (AS). However, the formation of anti-drug antibodies (ADAs) can reduce its efficacy. This study aimed to identify risk factors associated with high ADA levels in AS patients treated with CT-P13.

A prospective observational study enrolled patients with intravenous CT-P13. Clinical data and disease activity was assessed at baseline, 24 weeks, and 54 weeks after CT-P13 treatment. Blood concentrations of CT-P13 and ADAs were measured at 24 and 54 weeks, and their correlation was investigated. Patients were grouped by ADA levels at 54 weeks. Univariable and multivariable logistic regression identified factors associated with high ADA concentrations.

A total of 34 patients was enrolled. Significant decreases in Bath Ankylosing Spondylitis Disease Activity Index and Bath Ankylosing Spondylitis Functional Index scores were observed relative to baseline after 24 weeks of CT-P13 therapy. Serum concentrations of CT-P13 and ADA levels increased following treatment. The median serum CT-P13 concentration was 17.6 [12.8, 22.7] µg/mL at 24 weeks and 23.5 [11.7, 34.2] µg/mL at 54 weeks. ADA levels were 6.7 [6.5, 9.1] AU/mL at 24 weeks and 11.4 [9.0, 28.4] AU/mL at 54 weeks. The serum concentrations of CT-P13 and ADA exhibited a negative correlation. In multivariable analysis, current smoking was associated with high ADA production at 54 weeks.

Smoking is identified as a significant risk factor for elevated ADAs in AS patients treated with CT-P13. The findings underscore the importance of smoking-cessation strategies in the management of AS patients.

Production of antibodies against protein-based therapeutics (e.g., monoclonal antibodies (mAbs)) by a recipient's immune system can vary from benign symptoms to chronic neutralization of the compound, and in rare cases, a lethal cytokine storm. One critical factor that can induce or contribute to an anti-drug antibody (ADA) response is believed to be the presence of aggregated proteins in protein-based therapeutics. There is a high level of variability in the aggregation of different proteins, which adds to the complexity in understanding the immune response to these drugs. Furthermore, the level of glycosylation of proteins, which increases drug stability, functionality, and serum half-life, is highly variable and may influence their immunogenicity. Considering the abundance of literature on the effect of aggregation and glycosylation on the immunogenicity of protein-based therapeutics, this review aims to summarize the current knowledge and clarify the immunogenic effects of different protein-based therapeutics such as mAbs. This review focuses on the properties of aggregated proteins and elucidates their relationship with immunogenicity. The contribution of different immune cell subsets and the mechanisms in aggregation-induced immunogenicity are also reviewed. Finally, the potential effects of each glycan, such as sialic acid, mannose, and fucose, on protein-based therapeutics' immunogenicity and stability is discussed.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that predominantly affects the sacroiliac joints and spine. Tumor necrosis factor (TNF) and interleukin (IL)-17A are key cytokines in disease pathogenesis and are established axSpA treatment targets. Recently, axSpA treatment options have been complemented by Janus kinase inhibitors (JAKi), which inhibit various cytokines without directly impacting TNF or IL-17 signaling. The effect of JAKi on axSpA remains under investigation: besides a JAK2-mediated (and potentially tyrosine kinase 2 [TYK2]-mediated) effect on the IL-23/IL-17 axis, emerging evidence suggests γδ T cells, type 3 innate lymphoid cells, and mucosa-associated invariant T cells, which are dependent on IL-7 and/or IL-15 and thus on JAK1, are strongly inhibited by JAKi used to treat axSpA. This review summarizes potential effects of JAKi on axSpA and shows evidence from pre-clinical/clinical studies. Greater understanding of the mechanisms of action of available treatments may improve knowledge of axSpA and pave the road for future therapies.

Cardiac sarcoidosis (CS) remains the second leading cause of death in patients with sarcoidosis, primarily because of its association with heart failure and arrhythmias. While corticosteroids are first-line therapy, their long-term use in CS is associated with serious adverse events, necessitating alternative immunosuppressive therapies, such as tumor necrosis factor inhibitors. Although infliximab is the most studied tumor necrosis factor inhibitor for refractory CS, adalimumab has emerged as a potential alternative. To that end, we reviewed the literature on adalimumab treatment in CS, identifying 12 publications published between January 2000 and September 2024 encompassing 240 patients, of whom 100 (42%) received adalimumab and were followed for at least 6 months. Most patients demonstrated stable or improved left ventricular ejection fraction, even those with initially low left ventricular ejection fraction and reduced cardiac 18F-fluorodeoxyglucose uptake on positron emission tomography-computed tomography. Adalimumab was generally well-tolerated with few reported infections or adverse events. However, these findings are limited by significant heterogeneity in study design, variability in patient populations, and a lack of standardized outcome measures, which restrict their generalizability. While adalimumab shows promise as a therapeutic option for refractory CS, robust, multicenter, randomized controlled trials are needed to validate these findings and define adalimumab's role in clinical practice.

Therapeutic drug monitoring (TDM) in inflammatory rheumatic diseases (RMDs) is gaining interest. However, there are unresolved questions about the best practices for implementing TDM effectively in clinical settings.

The primary objective of this study was to evaluate whether early TDM of adalimumab predicts drug survival at 52 weeks in patients with RMDs. The secondary objective was to identify factors associated with pharmacokinetic failure and treatment discontinuation.

A retrospective cohort study included patients aged ≥ 18 years with RMDs who initiated adalimumab therapy. Early TDM was performed within the first 26 weeks, and adalimumab trough levels (ATL) and anti-drug antibodies were measured. Drug survival was assessed at 52 weeks and defined as the time from adalimumab initiation to discontinuation for any reason. Multivariate analyses were conducted to identify factors influencing outcomes.

The study included 194 patients, of whom 56.7% exhibited ATL below the therapeutic range during the first 26 weeks. In the multivariate analysis, subtherapeutic concentrations were significantly associated with higher weight (OR = 1.02; p = 0.040) and ankylosing spondylitis diagnosis (OR = 3.68; p < 0.001). At 52 weeks, 43.8% of patients had discontinued adalimumab. Low ATL (< 1 µg/mL) was strongly associated with treatment discontinuation (OR = 7.31; p < 0.001), while concomitant methotrexate reduced this risk (OR = 0.46; p = 0.026).

Early TDM of adalimumab predicts drug persistence and underscores its clinical relevance as a proactive tool to guide personalized treatment and reduce the risk of treatment failure. These findings highlight the importance of incorporating TDM into routine practice to optimize therapeutic outcomes. Key Points • Early TDM of adalimumab in rheumatic diseases shows that low drug exposure predicts reduced drug survival at 52 weeks. • Approximately half of the patients exhibit low adalimumab exposure with the standard dose (40 mg every other week). • Body weight and methotrexate use significantly impact adalimumab levels. • Immunogenicity, found in 14.4% of patients with low ADL levels, underscores the need for early ADA detection to prevent non-response and discontinuation.

Immunogenicity of biologic agents for inflammatory bowel disease (IBD) is a critical issue, especially for tumor necrosis factor (TNF) inhibitors, where anti-drug antibodies (ADAs) significantly impact drug clearance, efficacy, and safety. Studies have demonstrated that non-TNF biologics tend to have lower susceptibility to immunogenicity, potentially offering advantages, especially in long-term management. Understanding these differences is important for optimizing IBD treatment outcomes.

This review examines immunogenicity associated with different classes and individual biologic agents used in IBD; including TNF inhibitors and biologics targeting integrins and interleukins. We discuss key factors influencing ADAs formation, including drug structure, route of administration, and patient-specific factors. The literature reviewed includes recent clinical studies and long-term trials focusing on strategies to reduce immunogenicity such as therapeutic drug monitoring (TDM) and advanced combination.

While newer biologics demonstrate lower immunogenicity compared to anti-TNF agents, challenges remain in management to overcome existing ADAs responses while advances in genetic profiling, point-of-care TDM, and combination therapies offer promising pathways to reduce immunogenicity and enhance treatment durability. Continued research and innovation in biologic delivery methods, such as oral and subcutaneous formulations, will be critical in the next decade to further mitigate immunogenic risks and improve patient outcomes.

Behçet's disease is an autoinflammatory disorder characterized by relapsing and remitting vasculitis that can manifest in various forms, including gastrointestinal Behçet's disease (GIBD). Its complications (e.g., intestinal perforation) are among the primary causes of morbidity and mortality. GIBD pathogenesis involves the enhanced production of certain cytokines, e.g., tumor necrosis factor α and interleukin-6 (IL-6), which could serve as a target for potential therapies. This review provides an overview of GIBD, including the diagnosis and immunopathogenesis as it is currently understood, and evaluates the emerging role of the inhibition of IL-6 (classic and trans-signaling) as an alternative treatment option for patients with GIBD. Given the current paucity of data, we reflected on the potential of IL-6 inhibitors such as tocilizumab and olamkicept based on immunopathogenic considerations and available clinical data in patients with inflammatory bowel disease (IBD), in whom clinical response or remission was induced. The selective inhibition of IL-6 trans-signaling may bring new impetus to the development of this drug class, particularly regarding safety. Still, the benefits of IL-6 inhibitors for patients with GIBD need to be evaluated in appropriate proof-of-concept studies. The clinical outcomes of IL-6 inhibitors in IBD are promising and may suggest their potential relevance in GIBD.

Rheumatoid arthritis (RA) is an immune-mediated disease characterized by polyarthritis that affects the small joints of the bilateral upper and lower extremities. RA shares several common clinical symptoms with Sjögren's syndrome (SS), another rheumatic disease caused by the lymphocytic infiltration of exocrine glands, with dry eye and dry mouth being the two most common symptoms. Anti-Ro/SS-A antibodies, a diagnostic biomarker of SS, are positive in patients with RA at a certain rate. The coexistence of SS and/or positivity for anti-Ro/SS-A antibodies in patients with RA influences disease activity and the effectiveness of several classes of disease-modifying antirheumatic drugs (DMARDs). Furthermore, RA, SS, and certain DMARDs, including methotrexate, are associated with the onset of lymphoproliferative disorders (LPD). In contrast, several biological DMARDs, such as tocilizumab and rituximab, are plausible options without the risk of LPD relapse. Considering the results of the studies introduced in this article, RA with SS and/or positivity for anti-Ro/SS-A antibodies could be considered a phenotype different from isolated RA from the perspective of refractoriness to DMARD therapy and LPD risk. Hence, rheumatologists should observe caution when choosing DMARDs. Further studies are needed to establish the appropriate treatment for patients with RA, SS, and/or the presence of anti-Ro/SS-A antibodies.

To investigate the appearance of anti-drug antibodies (ADA) against infliximab (IFX) determined by drug-sensitive and drug-tolerant assays and their relationship with drug levels and drug survival.

This longitudinal observational study included 45 patients with RA and 61 with SpA. Serum samples were obtained at weeks 2, 6, 12, 24 and 52. Serum IFX levels were measured by a capture ELISA and ADA by an in-house drug-sensitive two-site (bridging) ELISA (bELISA) and a commercially available drug-tolerant ELISA (IDK, Immundiagnostik, Germany).

ADA were detected earlier by IDK than by bELISA. Once ADA appeared, positivity persisted throughout the study period. Patients who were bELISA ADA+ had higher IDK ADA levels (than bELISA ADA- patients). Circulating IFX levels were detected in all patients except those found to be bELISA ADA+. Serum IFX levels were lower in IDK ADA+ than in IDK ADA- patients. Most patients (64%) discontinued due to inefficacy. The early onset of immunogenicity was related to IFX survival. In both RA and SpA, the median survival (years) was shorter in patients with earlier development of ADA (IDK+ before or at week 24) than those who became IDK+ later (after week 24) or never developed ADA.

A drug-tolerant assay detects ADA during IFX therapy earlier and more frequently than a drug-sensitive assay. The onset of immunogenicity detected by drug-tolerant assays is related to the subsequent detection of ADA by drug-sensitive assays and drug survival.

The introduction of tumor necrosis factor inhibitors has led to a paradigm shift in the management of inflammatory bowel disease (IBD). The subsequent introduction of both anti-integrins and cytokine blockers has since expanded the biologic armamentarium. However, immunogenicity, defined as the production of anti-drug antibodies (ADAs) to the prescribed biopharmaceutical, means a significant fraction of patients exposed to biologic agents will experience a secondary loss of response to one or more of the drugs. In clinical settings, immunogenicity may be caused by several factors, both patient related (e.g., underlying chronic disease, systemic immune burden, including previous biologic therapy failure, and [epi]genetic background) and treatment related (e.g., dose and administration regimens, drug physical structure, photostability, temperature, and agitation). Here, we outline these elements in detail to enhance biopharmaceutical delivery and therapy for patients with IBD. Moreover, concurrent immunomodulator medication may reduce the risks of ADA generation, especially when using the chimeric drug infliximab. Summarizing the latest developments and knowledge in the field, this review aims to provide strategies to prevent ADA production and information on managing non-responsiveness or loss of response to biologics. Better understanding of the molecular mechanisms underlying the formation of ADAs and the critical factors influencing the immunogenicity of biopharmaceuticals may lead to improved health outcomes in the IBD community that may benefit both the individual patient and society through lower healthcare expenses.

Crohn's disease (CD) involves immune system interactions with intestinal tissue, driven by pro-inflammatory cytokines like Tumor Necrosis Factor (TNF-α). Adalimumab, targeting TNF-α, regulates associated inflammatory responses. Despite being humanized, it may induce immunogenic processes, affecting treatment effectiveness. Thus, monitoring serum adalimumab and anti-drug antibody (ADA) levels can optimize therapy. Understanding genetic factors influencing adalimumab response can enhance personalized treatment and improve patient quality of life. We aimed to quantify adalimumab serum levels, assess test interchangeability, detect ADA, examine immune complex formation, and investigate genetic phenotypes related to immunogenicity in CD patients. Seventy CD patients in the maintenance phase with adalimumab were classified into active (CDA) and remission (CDR) groups. Adalimumab concentration was determined via enzyme-linked immunosorbent assay (ELISA-Promonitor) and lateral flow assay (Quantum Blue), with assay interchangeability assessed statistically. ADA and immune complex formation were quantified using ELISA assays. DNA was genotyped for the genes ATG16L1, CD96, and CD155. No significant differences in adalimumab serum concentrations were observed between groups, regardless of the assay. However, a statistical difference between the tests indicated measurement disparity (P = 0.003), with moderate agreement (Lin's correlation of 0.247). ADA was detected in 4 of 27 of the patients with infratherapeutic levels, 3 in the CDA group and 1 in the CDR group. Analysis of immune complexes revealed significantly higher concentrations in the CDA group (P = 0.0125). The genotypic evaluation revealed significant associations for the CD96 CC (wild-type) genotype with higher CRP levels, colonic involvement, and infratherapeutic levels of adalimumab. ATG16L1 CC genotype was associated with higher CDEIS and fecal calprotectin values, while the variant (TT) genotype had lower platelet counts. The effectiveness of treatment with adalimumab was not directly related to higher medication levels in this cohort. The disparity between tests indicates the need to use only one test in patient follow-up to ensure accuracy in therapeutic monitoring. Genotypic differences highlight the correlation between the wild genotype for CD96 and ATG16L1 with unfavorable laboratory and endoscopic response to adalimumab. Finally, the more significant levels of immune complexes in the CDA group indicate an association with a worse response to adalimumab.

Ulcerative colitis (UC) is an idiopathic, chronic, relapsing inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract. The pathophysiology of UC is complicated and involves several factors including immune, genetic, and environmental factors. Recently, a huge amount of research has concentrated on the role of interleukins including interleukin-6 (IL-6) in its pathophysiology. Thus, this study aims to examine the colo-protective and immunomodulatory effect of Tocilizumab (TCZ) in an experimental model of dextran sulfate sodium (DSS) induced UC. In the current study, we analyzed the inflammatory, immunomodulatory, apoptotic, autophagy, and endoplasmic reticulum (ER) stress markers and other clinical features including stool consistency, rectal bleeding, and edema markers in rats. Our results showed that induction of colitis caused bloody diarrhea and increased IL-6 levels. Treatment with TCZ significantly ameliorated DSS-induced injury via decreasing inflammatory markers of colon injury (IL-6), signal transducer and activator of transcription-3 (STAT-3), and C-reactive protein (CRP). Furthermore, TCZ attenuated the apoptotic marker (caspase-3), and down-regulated endoplasmic reticulum stress sensor proteins (inositol- requiring transmembrane kinase endonuclease-1 (IRE-1) and activated transcription factor-6 (ATF-6)) and autophagy proteins (autophagy-related 16-like protein 1 (ATG16L1) and nucleotide-binding oligomerization domain-containing protein-2 (NOD2)), as compared to DSS group. Altogether, the current data suggest TCZ to be a promising protective therapy against UC.

Immunogenicity is the propensity of a therapeutic protein to generate an immune response to itself. While reporting of antidrug antibodies (ADAs) is increasing, model-based analysis of such data is seldom performed. Model-based characterization of factors affecting the emergence and dissipation of ADAs may inform drug development and/or improve understanding in clinical practice. This analysis aimed to predict ADA dynamics, including the potential influence of individual covariates, following subcutaneous satralizumab administration. Satralizumab is a humanized IgG2 monoclonal recycling IL-6 receptor antagonist antibody approved for treating neuromyelitis optica spectrum disorder (NMOSD). Longitudinal pharmacokinetic (PK) and ADA data from 154 NMOSD patients in two pivotal Phase 3 studies (NCT02028884, NCT02073279) and PK data from one Phase 1 study (SA-001JP) in 72 healthy volunteers were available for this analysis. An existing population PK model was adapted to derive steady-state concentration without ADA for each patient. A mixed hidden Markov model (mHMM) was developed whereby three different states were identified: one absorbing Markov state for non-ADA developer, and two dynamic and inter-connected Markov states-transient ADA negative and positive. Satralizumab exposure and body mass index impacted transition probabilities and, therefore, the likelihood of developing ADAs. In conclusion, the mHMM model was able to describe the time course of ADA development and identify patterns of ADA development in NMOSD patients following treatment with satralizumab, which may allow for the formulation of strategies to reduce the emergence or limit the impact of ADA in the clinical setting.

The camelid single-domain antibody fragment, commonly referred to as a nanobody, achieves the targeting power of conventional monoclonal antibodies (mAbs) at only a fraction of their size. Isolated from camelid species (including llamas, alpacas, and camels), their small size at ∼15 kDa, low structural complexity, and high stability compared with conventional antibodies have propelled nanobody technology into the limelight of biologic development. Nanobodies are proving themselves to be a potent complement to traditional mAb therapies, showing success in the treatment of, for example, autoimmune diseases and cancer, and more recently as therapeutic options to treat infectious diseases caused by rapidly evolving biological targets such as the SARS-CoV-2 virus. This review highlights the benefits of applying a proteomic approach to identify diverse nanobody sequences against a single antigen. This proteomic approach coupled with conventional yeast/phage display methods enables the production of highly diverse repertoires of nanobodies able to bind the vast epitope landscape of an antigen, with epitope sampling surpassing that of mAbs. Additionally, we aim to highlight recent findings illuminating the structural attributes of nanobodies that make them particularly amenable to comprehensive antigen sampling and to synergistic activity-underscoring the powerful advantage of acquiring a large, diverse nanobody repertoire against a single antigen. Lastly, we highlight the efforts being made in the clinical development of nanobodies, which have great potential as powerful diagnostic reagents and treatment options, especially when targeting infectious disease agents.

The objectives of this study are to identify a therapeutic serum level for adalimumab associated with remission and low disease activity in patients with rheumatoid arthritis.

Associations between serum adalimumab trough levels and disease activity were examined using longitudinal data from a 48-week randomised phase III trial including patients with tumour necrosis factor inhibitor-naïve rheumatoid arthritis with active disease starting adalimumab treatment. Disease activity was classified according to 28-joint Disease Activity Score (DAS28)-erythrocyte sedimentation rate and C reactive protein (CRP) levels.

Adalimumab trough levels were recorded longitudinally for 336, 330 and 302 patients at weeks 12, 24 and 48, respectively. All patients received concomitant methotrexate. Median adalimumab trough levels were 6.4 mg/L (IQR 3.4-9.5) at week 12, 7.5 mg/L (IQR 3.5-10.9) at week 24 and 7.6 mg/L (IQR 3.6-12.0) at week 48. In serial serum samples from weeks 12, 24 and 48, trough levels ≥3.9 mg/L were associated with DAS28 remission (OR 3.88 (95% CI 1.80, 8.38), p<0.001) and lower CRP levels (p<0.001). Week 12 trough levels ≥3.5 mg/L were associated with DAS28 low disease activity at week 24 (OR 2.62 (1.50, 4.56), p<0.001) and remission at week 48 (OR 1.99 (1.02, 3.88), p=0.04), as well as lower CRP levels at both time points (p<0.001).

Adalimumab trough levels above 4.0 mg/L were associated with remission/low disease activity throughout the first year of adalimumab therapy and can be considered a lower target level for therapeutic drug monitoring of adalimumab therapy.

Development of anti-drug antibodies (ADAs) and neutralizing antibodies (NAbs) to monoclonal antibodies may adversely impact pharmacokinetics, efficacy, and/or safety.

To describe incidence, titer, and persistence of dupilumab ADAs and NAbs, and their effects on pharmacokinetics, efficacy, and safety in patients with atopic dermatitis (AD).

This analysis included seven phase 3 randomized, placebo-controlled (N=2,992) and two long-term open-label extension (N=2,287) trials of subcutaneous dupilumab in adults and pediatric patients with moderate-to-severe AD. ADA, NAb, and dupilumab concentration in serum were assessed using validated immunoassays. ADA impacts on efficacy (EASI) and safety were assessed.

Treatment-emergent ADAs were observed in up to 8.6% (aged ≥18 years), 16.0% (12-17 years), 5.3% (6-11 years), and 2.0% (6 months to 5 years) dupilumab-treated patients. Among dupilumab-treated patients, ≤3.7% had persistent responses, <1% had high titers (≥10,000), and ≤5.1% were NAb-positive. NAbs were more common in patients with moderate- and high-titer ADA responses. High-titer ADAs, while infrequent, were the variable most associated with lower dupilumab concentrations in serum and loss of efficacy, independent of NAb status. Efficacy was generally similar in ADA-positive and -negative patients. For most patients with high- or moderate-titer ADAs, titers decreased and efficacy improved over time with continued dupilumab treatment. ADA-positive and -negative patients had similar incidences of treatment-emergent and serious treatment-emergent adverse events. One patient with high-titer ADAs developed serum sickness.

In patients with AD, ADAs and NAbs had minimal impact on dupilumab concentration, efficacy, and safety, except for high-titer ADAs in a small number of patients.

ClinicalTrials.gov, identifiers (NCT02277743, NCT02277769, NCT02260986, NCT02395133, NCT01949311, NCT03054428, NCT03345914, NCT02612454, and NCT03346434).

Pseudomonas aeruginosa (PA) is an opportunistic, frequently multidrug-resistant pathogen that can cause severe infections in hospitalized patients. Antibodies against the PA virulence factor, PcrV, protect from death and disease in a variety of animal models. However, clinical trials of PcrV-binding antibody-based products have thus far failed to demonstrate benefit. Prior candidates were derivations of antibodies identified using protein-immunized animal systems and required extensive engineering to optimize binding and/or reduce immunogenicity. Of note, PA infections are common in people with cystic fibrosis (pwCF), who are generally believed to mount normal adaptive immune responses. Here we utilized a tetramer reagent to detect and isolate PcrV-specific B cells in pwCF and, via single-cell sorting and paired-chain sequencing, identified the B cell receptor (BCR) variable region sequences that confer PcrV-specificity. We derived multiple high affinity anti-PcrV monoclonal antibodies (mAbs) from PcrV-specific B cells across 3 donors, including mAbs that exhibit potent anti-PA activity in a murine pneumonia model. This robust strategy for mAb discovery expands what is known about PA-specific B cells in pwCF and yields novel mAbs with potential for future clinical use.

To evaluate tumour necrosis factor inhibitor (TNFi) drug-levels and presence of anti-drug antibodies (ADAb) in patients with inflammatory arthritis who taper TNFi compared to TNFi continuation. Patients with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis on stable TNFi dose and in low disease activity ≥ 12 months were randomised (2:1) to disease activity-guided tapering or control. Blood samples at baseline, 12- and 18-months were evaluated for TNFi drug-levels and ADAb. In total, 129 patients were randomised to tapering (n = 88) or control (n = 41). Between baseline and month 18, a significant shift in TNFi drug-levels were observed in the tapering group resulting in fewer patients with high drug-levels (change: - 14% [95% CI - 27 to - 1%]) and more with low drug-levels (change: 18% [95% CI 5-31%]). Disease activity was equivalent between groups at 18 months, mean difference: RA - 0.06 (95% CI - 0.44 to 0.33), PsA 0.03 (95% CI - 0.36 to 0.42), and axSpA 0.16 (- 0.17 to 0.49), equivalence margins ± 0.5 disease activity points. ADAb were detected in eight patients, all from the tapering group. TNFi drug-level category or ADAb were not predictive for achieving successful tapering at 18 months. TNFi drug-levels decreased during tapering which indicate adherence to the tapering algorithm. Despite the difference in TNFi drug-levels at 18 months, disease activity remained equivalent, and only few tapering patients had detectable ADAb. These data do not support using TNFi drug-level and/or ADAb to guide the tapering decision but future research with larger trials is needed.Trial registration: EudraCT: 2017-001970-41, December 21, 2017.

The therapeutic arsenal for psoriatic arthritis (PsA) is gradually being expanded, but the use of these targeted treatments must be optimal. Our objective was to guide the choice of targeted therapy to use as first-line treatment in a patient with PsA in whom methotrexate (MTX) has failed.

We searched for literature data in PubMed with the appropriate keywords for the six points of our argument: (1) the tolerance of MTX; (2) the efficacy of targeted therapies combined with MTX vs monotherapy; (3) immunogenicity of anti-tumor necrosis alpha (TNFα) monoclonal antibodies (mAbs); (4) immunogenicity of anti-interleukin (IL)-17, anti-IL-12/23, and anti-IL-23 mAbs; (5) the therapeutic maintenance of anti-TNFα mAbs when combined or not with MTX; (6) the therapeutic maintenance of anti-IL-17 vs anti-TNFα mAbs as first-line targeted therapy.

The proposed rational strategy is as follows: in case of initiation of an anti-TNFα agent, maintaining treatment with MTX seems preferable, even in the absence of evidence of the superior efficacy of the combination, to avoid immunization and reduced therapeutic maintenance; in case of initiation of anti-IL-17, anti-IL-12/23, anti-IL-23 agents, or Janus kinase (JAK) inhibitors, again in the absence of evidence of the superior efficacy of the combination, discontinuing MTX therapy may be possible, at least in two steps, after verifying the efficacy of the targeted therapy initiated on the joints and skin.

We have data from the literature to guide the choice of targeted therapy to use as first-line treatment in a patient with PsA in whom MTX has failed.

Psoriasis is a chronic, immune-mediated, inflammatory skin disease, associated with multiple comorbidities and psychological and psychiatric disorders. The quality of life of patients with this disease is severely compromised, especially in moderate-to-severe plaque psoriasis. Secukinumab, a fully humanized monoclonal antibody, was the first anti-interleukin (IL)-17 biologic approved for treating psoriasis. Secukinumab demonstrated long-lasting efficacy and a good safety profile in individuals with plaque psoriasis, and it is associated with an improvement in health-related quality of life. While there is evidence that early treatment with systemic therapy can affect disease progression and improve long-term outcomes in other autoimmune diseases, evidence is limited in psoriasis, especially in real-world settings. This review provides an overview of studies describing the effectiveness of secukinumab in the treatment of psoriasis summarizing the literature and focusing on real-world evidence and early intervention.

The EXXELERATE study revealed poorer clinical outcomes in patients treated with adalimumab (ADL) and baseline rheumatoid factor (RF) above 203 IU/mL. However, responses were similar in patients treated with certolizumab pegol (CZP) regardless of RF levels.

This study investigated the impact of RF levels >203 IU/mL on TNF inhibitors (TNFi) serum levels and the association with secondary nonresponse in RA patients treated with TNFi.

We performed an observational ambispective study with RA patients treated with infliximab (IFX), ADL, or CZP. Patients were stratified according to baseline RF levels: ≤ or >203 IU/mL. After 6 months, serum drug levels and antidrug antibodies were measured, and reasons for discontinuation were collected.

We included 170 RA patients: 90 (53%) received IFX, 48 (28%) ADL, and 32 (19%) CZP. While CZP serum levels did not differ between RF groups at 6 months (p = 0.6), RF levels >203 IU/mL were linked to lower serum drug levels in patients treated with IFX (p = 0.09) or ADL (p = 0.02). Secondary nonresponse was 3.6 times higher in patients with high versus low RF levels in patients under IFX or ADL. However, the reasons for withdrawal were not affected by RF levels in patients treated with CZP.

Baseline RF above 203 IU/mL is associated with lower serum drug levels and an increased risk of discontinuation due to secondary nonresponse in patients treated with IFX or ADL. In contrast, drug levels and clinical outcomes are not significantly impacted by baseline RF levels in patients under CZP.

The aim of this study was to compare the short- and long-term retention rates of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) in Korean patients with seropositive rheumatoid arthritis.

This study was conducted with 1,538 treatment courses of 1,063 patients, including adalimumab (n = 332), etanercept (n = 369), infliximab (n = 146), abatacept (n = 152), tocilizumab (n = 299), tofacitinib (n = 136), and baricitinib (n = 104), in patients with seropositive rheumatoid arthritis who started b/tsDMARD treatment between 2008 and 2020 at Seoul St. Mary's Hospital. Discontinuation 1 and 3 years after the first prescription of each drug was investigated. Kaplan- Meier estimates of time to discontinuation were calculated to compare the difference in drug retention rate for each drug. Patient-level predictors of drug discontinuation were evaluated using a Cox proportional hazards model.

The overall 1-year drug retention rate was from 60.1% for adalimumab to 90.0% for tofacitinib in the b/tsDMARD-naïve group, and from 55.2% for infliximab to 84.8% for tofacitinib in the b/tsDMARD-experienced group. The 3-year drug retention rate was from 36.9% for infliximab to 86.5% for tofacitinib in the b/tsDMARD-naïve group, and from 31.0% for infliximab to 65.4% for tocilizumab in the b/tsDMARD-experienced group. Drug discontinuation appeared to be affected by specific types of b/tsDMARDs.

Tocilizumab and tofacitinib are less commonly discontinued compared to tumor necrosis factor-α inhibitors at 1 and 3 years. Specifically, tofacitinib in the b/tsDMARD-naïve group and tocilizumab in the b/tsDMARD-experienced group showed the highest 3-year retention rates.

To investigate the factors associated with cause-specific discontinuation of long-term anti-tumor necrosis factor (TNF) agent use in patients with ankylosing spondylitis (AS).

AS patients who initiated first-line anti-TNF treatment between 2004 and 2018 and continued treatment for at least two years were enrolled in the study. Enrolled patients were observed until the last visit, discontinuation of treatment, or September 2022. Reasons for discontinuation of the first-line anti-TNF agent were categorized into the following: (1) clinical remission, (2) loss of efficacy, (3) adverse events, and (4) other reasons including loss to follow-up, cost, or reimbursement issues. A cumulative incidence function curve was used to visualize the cumulative failure rates over time for each specific reason. Univariable and multivariable cause-specific hazard models were utilized to identify factors associated with cause-specific discontinuation of the first-line anti-TNF agent.

A total of 429 AS patients was included in the study, with 121 treated with adalimumab (ADA), 176 with etanercept (ETN), 89 with infliximab (INF), and 43 with golimumab (GLM). The median overall survival on the first-line anti-TNF agent was 10.6 (7.9-14.5) years. Among the patients, 103 (24.0%) discontinued treatment, with 36 (34.9%) due to inefficacy, 31 (30.1%) due to clinical remission, 15 (14.6%) due to adverse events, and 21 (20.4%) due to other reasons. Patients treated with ETN had a lower risk of discontinuation due to clinical remission compared to those receiving ADA (hazard ratio [HR] 0.45 [0.21-0.99], P = 0.048). Higher baseline Bath Ankylosing Spondylitis Disease Activity Index (BASDAI; HR 1.31 [1.04-1.65], P = 0.023) and INF use were linked to a higher risk of treatment discontinuation for inefficacy compared to ADA use (HR 4.53 [1.45-14.16], P = 0.009). Older age was related to an increased risk of discontinuation due to infection-related adverse events (HR 1.07 [1.02-1.12], P = 0.005), and current smoking was a risk factor for discontinuation due to other reasons (HR 6.22 [1.82-21.28], P = 0.004).

AS patients on their first anti-TNF treatment for at least two years demonstrated a favorable long-term treatment retention rate, with a 24.0% discontinuation rate over a 10.6-year overall survival period. The predictors for discontinuation varied by causes, underscoring the complexity of treatment response and the importance of personalized approaches to treatment management.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic inflammatory disease of the gastrointestinal tract. The introduction of biologics, particularly anti-interleukin (IL) agents, has revolutionized IBD treatment. This review summarizes the role of ILs in IBD pathophysiology and describes the efficacy and positioning of anti-IL therapies. We discuss the functions of key ILs in IBD and their potential as therapeutic targets. The review then discusses anti-IL therapies, focusing primarily on ustekinumab (anti-IL-12/23), risankizumab (anti-IL-23), and mirikizumab (anti-IL-23). Clinical trial data demonstrate their efficacy in inducing and maintaining remission in Crohn's disease and ulcerative colitis. The safety profiles of these agents are generally favorable. However, long-term safety data for newer agents are still limited. The review also briefly discusses emerging therapies such as guselkumab and brazikumab. Network meta-analyses suggest that anti-IL therapies perform well compared to other biological agents. These agents may be considered first- or second-line therapies for many patients, especially those with comorbidities or safety concerns. Anti-IL therapies represent a significant advancement in IBD treatment, offering effective and relatively safe options for patients with moderate to severe disease.

The treatment options for inflammatory bowel disease (IBD) have grown over the last years. However, a significant fraction of patients either do not respond to their treatment or lose response over time.

Future treatment options could include antibodies that target the tumor necrosis factor-like ligand 1A (TL1A). TL1A is a key cytokine involved in the pathogenesis of a variety of autoimmune diseases including IBD. Studies have shown that IBD disease severity correlates well with serum levels of TL1A. Phase 2 data from two agents currently in clinical testing have been released. In line with requirements for modern therapeutics, companion diagnostic was part of these trials. This aims to identify those patients that are more likely to respond to the agents tested.

With regard to the available data the risk/benefit profile of TL1A inhibitors seems to be promising. This article gives a short update and overview, where we are at this point in time with antibodies targeting the TL1A protein in IBD.

Monitoring anti-drug antibodies (ADAs) to infliximab and adalimumab is critical to treatment management in various autoimmune disorders. The growing need for proactive therapeutic monitoring further requires the detection of ADAs in the presence of measurable concentrations of infliximab or adalimumab. To provide robust analytical assays for clinical application, we evaluated two automated immunoassays developed using ImmunoCAP™ technology and based on the bridging format to measure serum ADAs to infliximab and adalimumab respectively. Without an acid-dissociation step, these research prototype assays can detect a positive control monoclonal ADA towards infliximab and adalimumab, ranging from < 25 ng/ml to 10,000 ng/mL. Both assays exhibit imprecision less than 20% at different ADA titer levels and can distinguish ADAs towards different drug targets. In method comparison using authentic patient samples, the quantitative results of the ADA assays are not directly comparable to two existing clinical immunoassays for ADAs (correlation coefficient rs = 0.673 for infliximab ADAs; rs = 0.510 for adalimumab ADAs), presumably due to the lack of commutable ADA standards and the polyclonal nature of ADAs. Nevertheless, there is qualitative agreement between the methods when evaluating putative positive and negative patient samples (overall agreement 0.83 for infliximab ADAs; 0.76 for adalimumab ADAs). Biotin and high levels of rheumatoid factors may interfere with the performance of the automated assays due to competitive binding with the biotinylated drug and non-specific formation of bridging complexes. The two ImmunoCAP assays can provide new analytical methods for proactive therapeutic monitoring of adalimumab and infliximab.

Long-term data on ustekinumab in real-life Crohn's disease patients are still missing, though randomized controlled trials demonstrated it as a favorable therapeutic option. We aimed to evaluate ustekinumab's clinical efficacy, drug sustainability, and safety in a prospective, nationwide, multicenter Crohn's disease patient cohort with a three-year follow-up. Crohn's disease patients on ustekinumab treatment were consecutively enrolled from 9 Hungarian Inflammatory Bowel Disease centers between January 2019 and May 2020. Patient and disease characteristics, treatment history, clinical disease activity (Harvey Bradshaw Index (HBI)), biomarkers, and endoscopic activity (Simple Endoscopic Score for Crohn's Disease (SES-CD)) were collected for three-years' time. A total of 148 patients were included with an overall 48.9% of complex behavior of the Crohn's disease and 97.2% of previous anti-TNF exposure. The pre-induction remission rates were 12.2% (HBI), and 5.1% (SES-CD). Clinical remission rates (HBI) were 52.2%, 55.6%, and 50.9%, whereas criteria of an endoscopic remission were fulfilled in 14.3%, 27.5%, and 35.3% of the subjects at the end of the first, second, and third year, respectively. Dose intensification was high with 84.0% of the patients on an 8-weekly and 29.9% on a 4-weekly regimen at the end of year 3. Drug sustainability was 76.9% during the follow-up period with no serious adverse events observed. Ustekinumab in the long-term is an effective, sustainable, and safe therapeutic option for Crohn's disease patients with severe disease phenotype and high previous anti-TNF biological failure, requiring frequent dose intensifications.

Studies have investigated the efficacy and safety of switching to the biosimilar infliximab (CT-P13) in patients with inflammatory bowel disease (IBD). However, there is limited research directly comparing the effectiveness, drug survival, and pharmacokinetic profiles of the reference infliximab (IFX) and CT-P13 in real clinical settings.

To compare the effectiveness and drug survival of CPT-13 and reference IFX at weeks 26 and 52, and to determine the pharmacokinetic profiles and safety profile in real-world settings.

A retrospective observational cohort analysis was conducted at a single center. The study compared the proportion of patients achieving clinical remission and experiencing poor clinical outcomes at weeks 26 and 52. The drug survival rate of CT-P13 and reference infliximab was also assessed during the follow-up period.

A total of 153 patients were included in the study, 39.2% receiving CPT-13 and 60.8% reference IFX. At week 26, clinical remission rates were 66.7% (CPT-13: 74.4% vs. reference IFX: 62.3%, p=0.178), and at week 52, they were 64% (CPT-13: 85.4% vs. reference IFX: 63.0%, p=0.012). Subgroup analysis with therapeutic drug monitoring (TDM) found no significant differences at week 26 (CPT-13: 74.4% vs. reference IFX: 58.8%, p=0.235) or at week 52 (CPT-13: 85.4% vs. reference IFX: 68.8%, p=0.153).

Our study demonstrates comparable efficacy, drug survival, pharmacokinetic profiles, and incidence of immunogenicity between both drugs in a real clinical setting. Further studies with greater statistical power are needed to validate these findings.

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.

While conventional in silico immunogenicity risk assessments focus on measuring immunogenicity based on the potential of therapeutic proteins to be processed and presented by a global population-wide set of human leukocyte antigen (HLA) alleles to T cells, future refinements might adjust for HLA allele frequencies in different geographic regions or populations, as well for as individuals in those populations. Adjustment by HLA allele distribution may reveal risk patterns that are specific to population groups or individuals, which current methods that rely on global-population HLA prevalence may obscure.

This analysis uses HLA frequency-weighted binding predictions to define immunogenicity risk for global and sub-global populations. A comparison of assessments tuned for North American/European versus Japanese/Asian populations suggests that the potential for anti-therapeutic responses (anti-therapeutic antibodies or ATA) for several commonly prescribed Rheumatoid Arthritis (RA) therapeutic biologics may differ, significantly, between the Caucasian and Japanese populations. This appears to align with reports of differing product-related immunogenicity that is observed in different populations.

Further definition of population-level (regional) and individual patient-specific immunogenic risk profiles may enable prescription of the RA therapeutic with the highest probability of success to each patient, depending on their population of origin and/or their individual HLA background. Furthermore, HLA-specific immunogenicity outcomes data are limited, thus there is a need to expand HLA-association studies that examine the relationship between HLA haplotype and ATA in the clinic.

To explore associations between serum adalimumab level, treatment response and drug survival in order to identify optimal drug levels for therapeutic drug monitoring of adalimumab. Also, to assess the occurrence and risk factors of anti-drug antibody (ADAb) formation.

Non-trough adalimumab and ADAb levels were measured by automated fluorescence assays in serum collected after 3 months of adalimumab treatment in patients with RA, PsA or axial SpA (axSpA) included in the observational NOR-DMARD study. Treatment response was evaluated after 3 months and drug survival was evaluated during long-term follow-up.

In 340 patients (97 RA, 69 PsA, 174 axSpA), the median adalimumab level was 7.3 mg/l (interquartile range 4.0-10.3). A total of 33 (10%) patients developed ADAbs. Findings were comparable across diagnoses. In RA and PsA, adalimumab levels ≥6.0 mg/l were associated with treatment response [odds ratio (OR) 2.2 (95% CI 1.0, 4.4)] and improved drug survival [hazard ratio 0.49 (95% CI 0.27, 0.80)]. In axSpA, a therapeutic level could not be identified, but higher adalimumab levels were associated with response. Factors associated with ADAb formation were previous bDMARD use, no methotrexate comedication and the use of adalimumab originator compared with GP2017.

Higher adalimumab levels were associated with a better response and improved drug survival for all diagnoses, with a suggested lower threshold of 6.0 mg/l for RA/PsA. This finding, the large variability in drug levels among patients receiving standard adalimumab dose and the high proportion of patients developing ADAbs encourages further investigations into the potential role of therapeutic drug monitoring of adalimumab.

There is concern that subvisible aggregates in biotherapeutic drug products pose a risk to patient safety. We investigated the threshold of biotherapeutic aggregates needed to induce immunogenic responses.

Highly aggregated samples were tested in cell-based assays and induced cellular responses in a manner that depended on the number of particles. The threshold of immune activation varied by disease state (cancer, rheumatoid arthritis, allergy), concomitant therapies, and particle number. Compared to healthy donors, disease state patients showed an equal or lower response at the late phase (7 days), suggesting they may not have a higher risk of responding to aggregates. Xeno-het mice were used to assess the threshold of immune activation in vivo. Although highly aggregated samples (~ 1,600,000 particles/mL) induced a weak and transient immunogenic response in mice, a 100-fold dilution of this sample (~ 16,000 particles/mL) did not induce immunogenicity. To confirm this result, subvisible particles (up to ~ 18,000 particles/mL, containing aggregates and silicone oil droplets) produced under representative administration practices (created upon infusion of a drug product through an IV catheter) did not induce a response in cell-based assays or appear to increase the rate of adverse events or immunogenicity during phase 3 clinical trials.

The ability of biotherapeutic aggregates to elicit an immune response in vitro, in vivo, and in the clinic depends on high numbers of particles. This suggests that there is a high threshold for aggregates to induce an immunogenic response which is well beyond that seen in standard biotherapeutic drug products.

Anti-C20 monoclonal antibodies (MAb), such as rituximab, are commonly used for the treatment of patients with severe or refractory systemic lupus erythematosus (SLE) but clinical outcomes are highly variable. We aimed to provide an update of a systematic review of predictive and prognostic factors of anti-CD20 MAb treatment in SLE.

A systematic literature search was undertaken to identify predictive and prognostic factors of clinical response following treatment with anti-CD20 therapies in SLE patients. Studies examining rituximab published prior to 2015 were excluded. Risk of bias was assessed for randomized controlled trials (RCTs) using the Cochrane Collaboration (RoB2) tool for RCTs and the Quality In Prognosis Studies Tool (QUIPS) for cohort studies. A narrative synthesis of the evidence was undertaken and quality of evidence (QoE) was assessed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

From 850 studies identified, 17 studies met the inclusion criteria. A further 8 studies were identified and included through search updates. There were two post-hoc analyses of RCTs of rituximab, one RCT of ocrelizumab and one of obinutuzumab; and 16 cohort studies examining rituximab treatment. The overall QoE was low or very low. There was wide heterogeneity in definitions of clinical disease activity and outcome measures, non-standardized laboratory cut-offs, failure to account for confounders and multiple subgroup analyses of differing outcomes. B cell depletion as well as novel biomarkers, such as S100 proteins, FCGR genotype, anti-vimentin and anti-drug antibodies showed some evidence of prognostic value but QoE was limited due to moderate to high risk of bias, early phase of investigation and imprecision of results.

There has been no validation of previously identified prognostic factors to guide outcome in anti-CD20 treated lupus patients. Hypothesis-driven studies of several novel markers however, demonstrate prognostic value and require replication and validation to support their use in routine clinical practice.

CRD42020220339.