Anti-Drug Antibody Formation Against Biologic Agents in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Mogroside V reduced the excessive endoplasmic reticulum stress and mitigated the Ulcerative colitis induced by dextran sulfate sodium in mice

Ulcerative colitis (UC) is an idiopathic, chronic inflammatory condition of the colon, characterized by repeated attacks, a lack of effective treatment options, and significant physical and mental health complications for patients. The endoplasmic reticulum (ER) is a vital intracellular organelle in maintaining cellular homeostasis. Endoplasmic reticulum stress (ERS) is induced when the body is exposed to adverse external stimuli. Numerous studies have shown that ERS-induced apoptosis plays a vital role in the pathogenesis of UC. Mogroside V (MV), an active ingredient of Monk fruit, has demonstrated excellent anti-inflammatory and antioxidant effects. In this study, we investigated the therapeutic effects of MV on dextran sulfate sodium (DSS)-induced UC and its potential mechanisms based on ERS. The results showed that MV exerted a protective effect against DSS-induced UC in mice as reflected by reduced DAI scores, increased colon length, reduced histological scores of the colon, and levels of pro-inflammatory cytokines, as well as decreased intestinal permeability. In addition, the expression of ERS pathway including BIP, PERK, eIF2α, ATF4, CHOP, as well as the apoptosis-related protein including Caspase-12, Bcl-2 and Bax, was found to be elevated in UC. However, MV treatment significantly inhibited the UC and reversed the expression of inflammation signaling pathway including ERS and ERS-induced apoptosis. Additionally, the addition of tunicamycin (Tm), an ERS activator, significantly weakened the therapeutic effect of MV on UC in mice. These findings suggest that MV may be a therapeutic agent for the treatment of DSS-induced UC by inhibiting the activation of the ERS-apoptosis pathway, and may provide a novel avenue for the treatment of UC.

Risk factors for development of anti-adalimumab antibodies in non-infectious uveitis

Purpose

To evaluate risk factors associated with development of anti-adalimumab antibodies (AAA) in patients with non-infectious uveitis treated with adalimumab.

Methods

A retrospective, cross-sectional, case-control study was done evaluating patients with non-infectious uveitis treated with adalimumab for at least 12 months and have undergone testing for AAA levels. Demographics, clinical characteristics, grading of ocular inflammation, and previous and concomitant immunomodulatory therapy were assessed. Univariate and multivariate analysis were done to estimate odds ratio (OR) with 95% confidence intervals for the various risk factors.

Results

A total of 31 patients were included in the analysis, in which 12 patients who tested positive (Group 1) were matched with 19 patients who tested negative for AAA (Group 2). The groups differed significantly in terms of sex (female) (91.7% vs 52.6%, p = 0.046), presence of systemic disease (91.7% vs 42.1%, p = 0.008), and presence of anterior chamber inflammation at baseline (100% vs 63.2%, p = 0.026). A history of interruption in anti-TNF therapy prior to starting or restarting adalimumab was found to have an increased odds for development of AAA (OR 16.89 [2.92, 107.11], p = 0.008), as well as flare-ups (reactivation of disease) during adalimumab therapy (OR 6.77 [1.80, 61.80], p = 0.027). Weekly dosing of adalimumab was shown to decrease odds of AAA development (OR 0.34 [0.02, 0.70], p = 0.040), while concomitant anti-metabolite therapy was not shown to be a statistically significant protective factor (OR 2.22 [0.50, 9.96], p = 0.148).

Conclusions

History of interruption in anti-TNF therapy and flare during adalimumab were associated with development of AAA, while weekly dosing of adalimumab was protective against AAA. Identification of those with higher risk of developing AAA may guide in clinical decision making to optimize management for these patients.

Therapeutic drug monitoring in inflammatory bowel diseases. Position statement of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis

The treatment of inflammatory bowel disease has undergone a significant transformation following the introduction of biologic drugs. Thanks to these drugs, treatment goals have evolved from clinical response and remission to more ambitious objectives, such as endoscopic or radiologic remission. However, even though biologics are highly effective, a significant percentage of patients will not achieve an initial response or may lose it over time. We know that there is a direct relationship between the trough concentrations of the biologic and its therapeutic efficacy, with more demanding therapeutic goals requiring higher drug levels, and inadequate exposure being common. Therapeutic drug monitoring of biologic medications, along with pharmacokinetic models, provides us with the possibility of offering a personalized approach to treatment for patients with IBD. Over the past few years, relevant information has accumulated regarding its utility during or after induction, as well as in the maintenance of biologic treatment, in reactive or proactive strategies, and prior to withdrawal or treatment de-escalation. The aim of this document is to establish recommendations regarding the utility of therapeutic drug monitoring of biologics in patients with inflammatory bowel disease, in different clinical practice scenarios, and to identify areas where its utility is evident, promising, or controversial.

Antibiotics influence the risk of anti-drug antibody formation during anti-TNF therapy in Chinese inflammatory bowel disease patients

Aims: The formation of anti-drug antibodies (ADAs) during anti-tumor necrosis factor (anti-TNF) therapy is reported to lead to reducing serum drug levels, which may bring about a loss of response to treatment. Previous research has suggested an association between specific antibiotic classes and ADA formation during anti-TNF therapy. However, there are few studies specifically examining this association in Chinese inflammatory bowel disease (IBD) patients. Therefore, our study aimed to evaluate the possible effect of antibiotic use on ADA formation to anti-TNF therapy in Chinese patients with IBD. Methods: A total of 166 patients with IBD, including 149 with Crohn's disease (CD) and 17 with ulcerative colitis (UC), were included in this retrospective analysis. These patients were initially treated with anti-TNF therapy (infliximab or adalimumab) after January 2018 and reviewed with available ADA levels before October 2023. After univariable analysis of all the variables, a multivariate Cox proportional hazards model was used to assess the association between antibiotic use and ADA development. Results: Among 166 IBD patients treated with infliximab (108/166, 65.1%) or adalimumab (58/166, 34.9%), 31 patients (18.7%) were measured as positive ADA levels. Cox proportional hazard model demonstrated an increased risk of ADA formation in IBD patients who used β-lactam-β-lactamase inhibitor combinations (BL-BLIs) (HR = 5.143, 95%CI 1.136-23.270, p = 0.033), or nitroimidazoles (HR = 4.635, 95%CI 1.641-13.089, p = 0.004) during 12 months before the ADA test. On the contrary, a reduced risk was noted in patients treated with fluoroquinolones (HR = 0.258, 95% CI 0.072-0.924, p = 0.037). Moreover, the median serum infliximab or adalimumab concentration in patients with positive ADA levels was significantly lower than that in patients with negative ADA levels (infliximab: 0.30 vs. 1.85 μg/mL, p < 0.0001; adalimumab: 0.45 vs. 7.55 μg/mL, p = 0.0121). Conclusion: ADA development is associated with various antibiotic classes. BL-BLIs and nitroimidazoles might increase the risk of ADA formation during anti-TNF therapy in Chinese IBD patients, while the treatment with fluoroquinolones could probably reduce such risk. There were certain limitations in the retrospective analysis of the study, therefore, the results are just for reference, and other studies are needed to further confirm our findings.

Upadacitinib for the treatment of moderate-to-severe Crohn's disease

Despite an increasing number of therapies for Crohn's disease (CD), half of patients do not respond to initial treatment or lose response over time, highlighting the need for novel therapies. Inhibition of Janus kinases (JAKs) has emerged as an important therapeutic target for CD. Upadacitinib is an orally administered selective JAK1 inhibitor, which is effective for the induction and maintenance of remission in moderately-to-severely active CD, including in patients with prior failure of biological therapy. Nonselective JAK inhibition has been associated with thromboembolic disease, cardiovascular events and malignancy in patients older than 50 years with rheumatoid arthritis and pre-existing cardiovascular risk factors, which should be considered upon prescription. Upadacitinib is the first and currently only oral advanced therapy for CD.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

The first case report of de novo Crohn's disease after heart transplantation successfully treated with ustekinumab

Inflammatory bowel disease (IBD) is a complex chronic inflammatory intestinal disease. The development of de novo IBD after solid organ transplantation with immunosuppressive agents has been rarely reported. We present the case of a 65-year-old man with repeated colitis after heart transplantation (HTx) who was diagnosed with Crohn's disease (CD). The patient underwent HTx due to non-ischemic dilated cardiomyopathy. Six months after HTx, he developed serious diarrhea and a transient fever, which persisted for about 6 months. Valganciclovir or any antibiotic agents were not effective for his symptoms and longitudinal ulcers in colonoscopy aggravated during the course, so that we made a diagnosis of CD. We started 5-aminosalicylic acid and found improvement in his symptoms and colonoscopic findings. However, 7 months after improvement, CD worsened. We started ustekinumab by which his condition successfully went into remission again. While oral immunosuppressive drugs are thought to suppress autoimmune diseases in general, IBD should be included in the differential diagnoses for recurring enterocolitis after HTx. Poorly controlled CD can lead to serious and potentially fatal complications, but in this case, ustekinumab has been used safely and effectively for the treatment of CD.

Learning objective

Colitis is a common complication after heart transplantation (HTx). Although cytomegalovirus colitis or posttransplant lymphoproliferative disorder are observed commonly, de novo inflammatory bowel disease (IBD) should be considered when serious refractory colitis occurs. Not only 5-aminosalicylic acid but also ustekinumab, which is a monoclonal antibody to the p40 subunit of interleukin (IL)-12 and IL-23, may be a safe and effective treatment for de novo IBD after HTx.

The Impact of Immunogenicity on the Pharmacokinetics, Efficacy, and Safety of Sotatercept in a Phase III Study of Pulmonary Arterial Hypertension

Sotatercept, a soluble fusion protein comprising the extracellular domain of activin receptor type IIA linked to the Fc portion of human IgG1, is a first-in-class activin signaling inhibitor under development for the treatment of pulmonary arterial hypertension (PAH). We evaluated antidrug antibody (ADA) development and determined the effects of immunogenicity on the pharmacokinetics (PKs), efficacy, and safety of sotatercept in STELLAR, a multicenter, double-blind phase III trial (NCT04576988) wherein participants with PAH were randomized 1:1 to receive sotatercept (starting dose 0.3; target dose 0.7 mg/kg) or placebo subcutaneously every 3 weeks in combination with background therapies for ≤ 72 weeks. ADA-positive (ADA-POS) participants were identified and characterized for neutralizing antibodies (NAbs). PKs, efficacy, and safety were evaluated by ADA and NAb status. Of 162 evaluable participants, 42 (25.9%) were ADA-POS through week 24, of whom 11 (6.8%) were also NAb-POS. Median onset of ADAs was 3.29 weeks (interquartile range (IQR): 3.14-6.14), and median duration was 6 weeks (IQR: 3.14-17.86). No clinically meaningful differences were found across subgroups that were ADA-NEG, ADA-POS/NAb-NEG, and ADA-POS/NAb-POS, in terms of PKs (sotatercept trough concentration over time, mean postdose trough concentration at the end of treatment, and clearance), efficacy (changes from baseline in 6-minute walk distance, pulmonary vascular resistance, and N-terminal pro-B-type natriuretic peptide levels), and safety (incidence of hypersensitivity, anaphylactic reactions, and administration site reactions). We conclude that ADA incidence from sotatercept treatment was 25.9% and did not meaningfully affect the PKs, efficacy, or safety of sotatercept in participants with PAH.

Immunogenicity and Loss of Effectiveness of Biologic Therapy for Inflammatory Bowel Disease Patients Due to Anti-Drug Antibody Development

Many patients with inflammatory bowel disease (IBD) experience a loss of effectiveness to biologic therapy (i.e., anti-TNF therapy, etc.). Therefore, in addition to the adverse effects of the treatment, these patients also face failure to achieve and maintain remission. Immunogenicity, the process of production of antibodies to biological agents, is fundamental to the evolution of loss of response to treatment in IBD patients. The presence of these antibodies in patients is linked to decreased serum drug levels and inhibited biological activity. However, immunogenicity rates exhibit significant variability across inflammatory disease states, immunoassay formats, and time periods. In this review, we aimed to elucidate the immunogenicity and immune mechanisms of antibody formation to biologics, the loss of therapy response, clinical results of biological treatment for IBD from systematic reviews and meta-analyses, as well as to summarize the most recent strategies for overcoming immunogenicity and approaches for managing treatment failure in IBD.

Therapeutic drug monitoring of vedolizumab therapy in inflammatory bowel disease

BACKGROUND

Therapeutic drug monitoring is effective for optimizing anti-tumor necrosis factor therapies in inflammatory bowel disease, but for vedolizumab, a gut-selective leucocyte migration inhibitor, data are scarce.

METHODS

Observational cohort study including 116 bio-experienced inflammatory bowel disease patients treated with vedolizumab for active luminal disease. Biobanked trough blood samples (n = 676) covering 96% of patients were analyzed using a drug-binding immunofluorometric assay. Steroid-free treatment outcomes were classified by clinical disease activity indices and objective findings, primarily endoscopy.

RESULTS

Patients with clinical remission to vedolizumab induction therapy (37%) had significantly higher trough levels than those without at weeks 6 (mean 34.1 vs 28.0 μg/mL, P = 0.03) and 10 (34.8 vs 27.5 μg/mL, P = 0.01). Optimal thresholds for discrimination were 32.4 μg/mL (AUCROC 0.66, P = 0.04) and 23.5 (AUCROC 0.67, P = 0.01), respectively. This positive association persisted during maintenance phase with 11.9 μg/mL (AUCROC 0.69, P < 0.01) associated with clinical remission (37%) and 15.3 (AUCROC 0.74, P < 0.001) for objective remission (46%). Stratification by temporal evolution of treatment effects revealed higher induction and maintenance vedolizumab levels in persistent and slow responders as compared to secondary or persistent failures. Pharmacokinetics was influenced by rare formation of anti-vedolizumab antibodies (2%), and to a lesser extent gender and albumin during induction, but not disease severity, concomitant steroids, or thiopurine metabolites. Switching to subcutaneous administrations resulted in 2.3-fold increase in steady-state trough levels.

CONCLUSION

Our study supports maintaining adequate drug exposure being essential for sustained positive outcomes of vedolizumab and emphasizes individualized, therapeutic drug monitoring-based treatment regimens. Controlled trials and pharmacokinetic modeling are, however, needed.

Anti-drug antibodies against anti-TNF in patients with inflammatory bowel disease: an evaluation of possible strategies

OBJECTIVE

Immunogenicity against anti-TNF antibodies usually leads to loss of response. We aimed to evaluate the efficacy of clinical strategies to improve clinical remission and pharmacokinetics upon detection of anti-drug antibodies (ADA).

METHODS

Inflammatory bowel disease (IBD) patients with ADA against infliximab or adalimumab were identified through a single centre database search covering 2004-2022. Criteria for successful intervention upon ADA detection (baseline) were clinical remission after 1 year without further change in strategy.

RESULTS

Two-hundred-and-fifty-five IBD patients (206 Crohn's disease) were identified. At baseline, median ADA level was 77 AU/ml; 50.2% of patients were in clinical remission. Implemented strategies were: (1) 81/255 (32%) conservative management, (2) 102/255 (40%) anti-TNF optimisation, (3) 72/255 (28%) switch within or out of class. Switching was the most successful strategy for clinical remission (from 19% at baseline to 69% at 1 year, p < 0.001). Patients that continued the same dose anti-TNF or discontinued biological therapy were often in clinical remission, but deteriorated significantly (-22.7%, p = 0.004). Anti-TNF dose intensification with immunomodulator optimisation was the fastest (median 3.0 months, p = 0.009) and most effective (65% ADA suppression, p < 0.001) strategy to suppress ADA compared to solely anti-TNF or immunomodulator optimisation.

CONCLUSIONS

Switching therapy, within or out of class, is the most successful strategy to regain and maintain clinical remission upon immunogenicity. When switching to another anti-TNF, concomitant immunomodulatory therapy should be started or continued to prevent repeated immunogenic loss of response. Anti-TNF dose escalation with concomitant immunomodulator optimisation is the fastest and most effective strategy to suppress ADA.

Cardiovascular Risk Factors and the Risk of Discontinuation of Advanced Therapies Due to Treatment Failure in Rheumatoid Arthritis: Results From the Ontario Best Practices Research Initiative

OBJECTIVES

Our goal was to investigate whether cardiovascular disease (CVD) risk factors are associated with the retention of biologic disease-modifying antirheumatic drugs (bDMARDs) or targeted-synthetic DMARDs (tsDMARDs) in patients with rheumatoid arthritis (RA).

METHODS

We included participants in the Ontario Best Practices Initiative RA registry who initiated their first bDMARD or tsDMARD. Participants were grouped by the number of baseline CVD risk factors (0, 1, or ≥2). The primary outcome was time-to-discontinuation of therapy for any reason. Secondary outcomes included discontinuation for primary failure, secondary failure, or due to adverse events. Competing risks hazards model, adjusted for clinically important confounders, estimated the association between CVD risk factors and treatment retention.

RESULTS

The sample included 872 patients, of which 58% (n = 508) discontinued their b/tsDMARD after a median of 13 months from the time of initiation. The most common causes for treatment discontinuation were primary failure (n = 72), secondary failure (n = 126), or adverse events (n = 133). Patients with no CVD risk factors experienced significantly longer treatment survival compared to patients with 1 or ≥2 CVD risk factors. In multivariable-adjusted analysis, there was no association between all-cause discontinuation and CVD risk factors. However, there was a significant association between the presence of >1 CVD risk factor and treatment discontinuation, notably due to secondary treatment failure, but not due to adverse events.

CONCLUSION

Multiple CVD risk factors increase the risk of treatment failure in RA, particularly for secondary treatment failure. To improve patient outcomes, future research should focus on developing strategies to identify early treatment nonresponse and investigate the potential modifiability of this association.

The HLA-DQA1*05 genotype does not influence the clinical response to ustekinumab and vedolizumab

BACKGROUND

the success of strategies with earlier anti-TNF drugs for the treatment of inflammatory bowel disease (IBD) have been shadowed by the development of anti-drug antibodies that reduce their effectiveness. The HLA-DQA1*05 allele has been shown to increase the risk of immunogenicity to anti-TNF drugs by approximately two-fold. The negative impact of this allele has not been fully investigated for newer biotherapies.

OBJECTIVE

whether the presence of the HLA-DQA1*05 allele is associated with a reduction of response to ustekinumab and vedolizumab was investigated.

MATERIAL AND METHODS

the impact of HLA-DQA1*05 on disease activity in 93 patients with IBD, treated with ustekinumab (n = 39) or vedolizumab (n = 54) was investigated in a retrospective cohort study. Treatment response and remission was assessed at 6 and 12 months for ustekinumab, and up to 18 and 24 months for vedolizumab, using Harvey-Bradshaw index (Crohn's disease) and Mayo score (ulcerative colitis).

RESULTS

the HLA-DQA1*05 allele was found in 35.9 % and 38.9 % of patients treated with ustekinumab and vedolizumab, respectively. Clinical response was not affected by the presence of the HLA-DQA1*05 allele for both treatment groups.

CONCLUSIONS

in contrast to anti-TNF drugs, HLA-DQA1*05 presence does not correlate with the decreased response to ustekinumab or vedolizumab.

HLA-DQA1∗05 Genotype and Immunogenicity to Tumor Necrosis Factor-α Antagonists: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Identifying patients at high risk of immunogenicity is important when selecting tumor necrosis factor (TNF)-α antagonists in patients with immune-mediated inflammatory diseases (IMIDs). We evaluated the association HLA-DQA1∗05 genotype and risk of immunogenicity with TNF-α antagonists.

METHODS

Through a systematic review through July 14, 2022, we identified studies in patients with IMIDs treated with TNF-α antagonists, which reported the risk of immunogenicity and/or secondary loss of response in patients with HLA-DQA1∗05 variants. Primary outcome was risk of immunogenicity. We performed random effects meta-analysis and used GRADE to appraise certainty of evidence.

RESULTS

On meta-analysis of 13 studies (3756 patients; median follow-up, 12 months; 41% with variants), HLA-DQA1∗05 variants were associated with 75% higher risk of immunogenicity compared with non-carriers (relative risk, 1.75; 95% confidence interval, 1.37-2.25) with considerable heterogeneity (I2 = 62%) (low certainty evidence). Positive and negative predictive values of HLA-DQA1∗05 variants for predicting immunogenicity were 30% and 80%, respectively. Proactive therapeutic drug monitoring, but not concomitant use of IMMs, IMIDs, and TNF-α antagonist-type, modified this association. Patients with HLA-DQA1∗05 variants experienced 2.2-fold higher risk of secondary loss of response (6 cohorts; relative risk, 2.24; 95% confidence interval, 1.67-3.00; I2 = 0%) (moderate certainty evidence).

CONCLUSION

Variants in HLA-DQA1∗05 are associated with an increased risk in immunogenicity and secondary loss of response in patients with IMIDs treated with TNF-α antagonists. However, the positive and negative predictive value is moderate, and decisions on concomitant use of IMMs to prevent immunogenicity should be individualized based on all factors that influence drug clearance.

Four-year review of New Zealand laboratory infliximab and adalimumab concentration results indicating potential for improved dosing

A review of laboratory results across New Zealand for therapeutic drug monitoring (TDM) of infliximab and adalimumab concentrations and antidrug antibodies (ADAs) over 4 years was completed. Of 6591 results, the median serum concentration for infliximab was 5.7 mg/L and for adalimumab was 5.5 mg/L. Subtherapeutic drug concentrations (<7 mg/L) were measured in 54% of samples. Drug concentrations <2 mg/L were measured in 23% of samples, with ADAs detected in 51% of these. The high number of samples with subtherapeutic drug concentrations and common ADA detection is consistent with failing therapy but could also suggest that standard dosing is frequently too low for patients. These results reinforce the value of antitumour necrosis factor drug TDM in making decisions to adjust dosing or switch agents in patients taking infliximab and adalimumab.

Mirikizumab for the treatment of moderate to severe ulcerative colitis

Despite a growing number of available therapeutic options for ulcerative colitis (UC), up to 50% of patients do not respond to initial treatment or lose response over time, highlighting the need for novel therapies. The IL-23 pathway has emerged as an important therapeutic target for UC. Mirikizumab is a humanized IgG4 monoclonal antibody against the p19 subunit of IL-23, dosed intravenously during induction and subcutaneously during maintenance. It is effective for the induction and maintenance of remission in moderately to severely active UC, including patients with prior failure of biological or tofacitinib therapy. Like other IL-23 antagonists, mirikizumab has a favorable safety profile. It is the first agent of its class to receive regulatory approval for moderately to severely active UC in Europe.

Ustekinumab trough levels in children with Crohn's disease refractory to anti-tumor necrosis factor agents: a prospective case series of off-label use

Background: Ustekinumab is used off-label in pediatric Crohn's disease refractory to anti-tumor necrosis factor. Data on optimal dosing, target trough levels, and potential benefit of therapeutic drug monitoring in children treated with ustekinumab are limited. Materials and Methods: We describe a series of six adolescents who consented to be treated with ustekinumab. We measured their trough levels, C-reactive protein, and fecal calprotectin before every administration. Results: Standard adult dosing was effective to achieve biochemical remission (fecal calprotectin < 250 mg/kg) in one patient and clinical remission (resolution of symptoms) in another. The other four patients failed to respond on standard dosing and underwent intravenous re-induction and interval shortening to increase ustekinumab trough levels. This resulted in biochemical remission in one patient and clinical remission in another, suggesting an exposure-response relationship. The remaining two patients had no therapeutic benefit, and ustekinumab was discontinued. Conclusion: In this report, we show that ustekinumab can induce remission in pediatric patients with anti-tumor necrosis factor refractory Crohn's disease. It is worth escalating the dose before abandoning the drug as ineffective. Prospective studies in children are needed to determine long-term efficacy of ustekinumab, usefulness of therapeutic drug monitoring strategies, and, if applicable, optimal target trough levels.

Polymorphisms indicating risk of inflammatory bowel disease or antigenicity to anti-TNF drugs as biomarkers of response in children

Few genetic polymorphisms predict early response to anti-TNF drugs in inflammatory bowel disease (IBD), and even fewer have been identified in the pediatric population. However, it would be of considerable clinical interest to identify and validate genetic biomarkers of long-term response. Therefore, the aim of the study was to analyze the usefulness of biomarkers of response to anti-TNFs in pediatric IBD (pIBD) as long-term biomarkers and to find differences by type of IBD and type of anti-TNF drug. The study population comprised 340 children diagnosed with IBD who were treated with infliximab or adalimumab. Genotyping of 9 selected SNPs for their association with early response and/or immunogenicity to anti-TNFs was performed using real-time PCR. Variants C rs10508884 (CXCL12), A rs2241880 (ATG16L1), and T rs6100556 (PHACTR3) (p value 0.049; p value 0.03; p value 0.031) were associated with worse long-term response to anti-TNFs in pIBD. DNA variants specific to disease type and anti-TNF type were identified in the pediatric population. Genotyping of these genetic variants before initiation of anti-TNFs would enable, if validated in a prospective cohort, the identification of pediatric patients who are long-term responders to this therapy.

IL-12 and IL-23 pathway inhibition in inflammatory bowel disease

Interleukin-12 (IL-12) and interleukin-23 (IL-23), which belong to the IL-12 family of cytokines, have a key role in intestinal homeostasis and inflammation and are implicated in the pathogenesis of inflammatory bowel disease. Upon their secretion by antigen-presenting cells, they exert both pro-inflammatory and anti-inflammatory receptor-mediated effects. An increased understanding of these biological effects, particularly the pro-inflammatory effects mediated by IL-12 and IL-23, has led to the development of monoclonal antibodies that target a subunit common to IL-12 and IL-23 (p40; targeted by ustekinumab and briakinumab), or the IL-23-specific subunit (p19; targeted by risankizumab, guselkumab, brazikumab and mirikizumab). This Review provides a summary of the biology of the IL-12 family cytokines IL-12 and IL-23, discusses the role of these cytokines in intestinal homeostasis and inflammation, and highlights IL-12- and IL-23-directed drug development for the treatment of Crohn's disease and ulcerative colitis.

Recurring Fatigue After Biologic Administration: Patient-Reported Data from the Dutch Biologic Monitor

BACKGROUND

Fatigue is a common problem in immune-mediated inflammatory disease (IMID) patients, significantly impacting their quality of life.

OBJECTIVES

In this study, we describe the pattern and characteristics of fatigue as a patient-reported adverse drug reaction (ADR) of biologics, and compared patient and treatment characteristics with patients reporting other ADRs or no ADRs.

METHODS

In this cohort event monitoring study, the description and characteristics of fatigue reported as a possible ADR in the Dutch Biologic Monitor were assessed and analysed for commonly recurring themes or patterns. Baseline and treatment characteristics of patients with fatigue and patients reporting other ADRs or no ADRs were compared.

RESULTS

Of 1382 participating patients, 108 patients (8%) reported fatigue as an ADR of a biologic. Almost half of these patients (50 patients, 46%) described episodes of fatigue during or shortly after biologic injection, which often recurred following subsequent injections. Patients with fatigue were significantly younger than patients with other ADRs or patients without ADRs (median age for patients with fatigue, 52 years; median age for patients with other ADRs, 56 years; and median age for patients without ADRs, 58 years); significantly more often smoked (25% vs. 16% and 15%); used infliximab (22% vs. 9% and 13%), rituximab (9% vs. 3% and 1%) or vedolizumab (6% vs. 2% and 1%); and significantly more often had Crohn's disease (28% vs. 13% and 13%) and other comorbidities (31% vs. 20% and 15%). Patients with fatigue significantly less frequently used etanercept (12% vs. 29% and 34%) or had rheumatoid arthritis (30% vs. 45% and 43%).

CONCLUSIONS

IMID patients may experience fatigue as a postdosing effect of biologics.

Physicochemical characterization and functionality comparison of Humira®(adalimumab), Remicade®(infliximab) and Simponi Aria®(golimumab)

FDA-approved anti-TNFα biopharmaceuticals are successful in treating a range of autoimmune diseases. However, not all anti-TNFα products are identical in their patient outcomes, suggesting that there may be product-specific differences stemming from protein structural differences, doses and routes of administration. In this work, we focus only on structural and functional differences across three full-length anti-TNFα mAbs (Humira®, Remicade®, and Simponi Aria®) to better understand the implications of such differences on the products' efficacy. For structural characterization, we quantified N-glycans using mass spectrometry and fluorescence labeling. From these studies, we observed that Remicade® had the highest percent of afucosylated glycans (15.5 ± 1.3 %) and the largest number of unique glycans, 28. While Humira® had the fewest unique glycans, 15, and 11.4 ± 0.8 % of afucosylated, high-mannose glycans. For the functional studies we tested TNFα binding via ELISA, FcγRIIIa binding via AlphaLISA and effector function using an ADCC bioreporter assay. Humira® had a significantly lower EC50 (1.9 ± 0.1 pM) for ELISA and IC50 (10.5 ± 1.1 nM) for AlphaLISA, suggesting that Humira® has higher TNFα and FcγRIIIa binding affinity than Remicade® and Simponi Aria®. Humira® was also the most potent in the bioreporter assay with an EC50 value of 0.55 ± 0.03 nM compared to Remicade® (0.64 ± 0.04 nM) and Simponi Aria® (0.67 ± 0.03 nM). This comparison is significant as it highlights functional differences between mAbs with shared mechanisms of action when examined in a single laboratory and under one set of conditions.

HLA-DQ2 is associated with anti-drug antibody formation to infliximab in patients with immune-mediated inflammatory diseases

BACKGROUND

Immunogenicity to tumour necrosis factor inhibitors is a significant clinical problem leading to treatment failure and adverse events. The study aimed to assess human leukocyte antigen (HLA) associations with anti-drug antibody (ADAb) formation to infliximab.

METHODS

Immune-mediated inflammatory disease patients on infliximab therapy (n = 612) were included. Neutralising ADAb were assessed with a drug-sensitive assay. Next generation sequencing-based HLA typing was performed.

RESULTS

Overall, 147 (24%) patients developed ADAb. Conditional analyses indicated HLA-DQB1 (p = 1.4 × 10^-6 ) as a primary risk locus. Highest risk of ADAb was seen when carrying at least one of the HLA-DQ2 haplotypes; DQB1*02:01-DQA1*05:01 or DQB1*02:02-DQA1*02:01 (OR 3.18, 95% CI 2.15-4.69 and p = 5.9 × 10^-9 ). Results were consistent across diseases and when adjusting for concomitant immunomodulator. Computational predictions indicated that these HLA-DQ2 haplotypes bind to peptide motifs from infliximab light chain.

CONCLUSION

A genome-wide significant association between two HLA-DQ2 haplotypes and the risk of ADAb formation to infliximab was identified, suggesting that HLA-DQ2 testing may facilitate personalised treatment decisions.

Treatment persistence of ustekinumab and vedolizumab in IBD patients is independent of prior immunogenicity to anti-TNFs: a retrospective study

BACKGROUND AND AIMS

Immunological treatment failure of anti-TNF therapy negatively influences treatment persistence of a second anti-TNF in IBD patients. So far it is unknown if this effect is also observed for other monoclonal antibodies. We assessed the influence of immunogenicity to anti-TNFs on treatment persistence of subsequent ustekinumab and vedolizumab therapy.

METHODS

IBD patients with and without immunogenicity to anti-TNFs (undetectable trough levels and antibody titers ≥20 ng/mL) and subsequent ustekinumab (UST) and/or vedolizumab (VDZ) therapy were included in this retrospective, single-center study. The Kaplan-Meier method with the log-rank test and Cox proportional hazards were used as statistical methods.

RESULTS

One hundred patients (Crohn's disease: 62, Ulcerative colitis: 31, IBD unclassified: 7) with 127 treatment lines (62 with UST, 65 with VDZ) were included in the analysis. Immunogenicity to previous anti-TNFs did not influence treatment persistence of subsequent ustekinumab and vedolizumab therapy (UST: Log rank: p = .95, Immunogenicity: HR for treatment discontinuation: 0.97 [95% CI 0.31-3.04]; VDZ: p = .65, HR: 0.85 [0.41-1.75]; total cohort [UST and VDZ]: p = .62, HR: 0.86 [0.47-1.57]). Azathioprine co-treatment did not lengthen treatment persistence (UST: Log rank: p = .77, azathioprine: HR: 1.20 [0.34-4.27]; VDZ: p = .92, HR: 0.58 [0.17-1.99]; total cohort: p = .79, HR: 1.10 [0.55-2.20]). In this anti-TNF experienced cohort, patients with ustekinumab remained longer on treatment than patients receiving vedolizumab (Log rank: p = .005, UST: HR: 0.43 [0.23-0.79]).

CONCLUSIONS

Immunogenicity to anti-TNFs does not influence treatment persistence of subsequent ustekinumab and vedolizumab therapy.

A Systematic Review on the interest of Drug Tolerant assay in the monitoring of Inflammatory Bowel Disease

Many patients with inflammatory bowel disease (IBD) are treated with anti-tumor necrosis factor (TNF) therapies, of which infliximab (IFX) is most commonly used. Loss of response (LOR) to anti-TNF therapy due to immunogenic failure accounts for 20% of subsequent medical intervention and is defined, using a drug sensitive assay, as low or undetectable concentration of drug with high titers of anti-drug antibodies (ADAb). We performed a systematic review to investigate the use of a drug tolerant assay during both induction and maintenance to monitor patients treated with anti-TNFs. After the search on PubMed, 90 publications were reviewed. Most ADAb detection methods are drug sensitive, cannot detect ADAb in the presence of drug, and therefore cannot be used close to drug administration, when the drug concentration is too high. To overcome this major limitation, several drug-tolerant techniques have been developed and will be discussed in this review. Using drug-tolerant assays ADAb against infliximab (IFX) or adalimumab (ADM) can be detected during induction and predict primary non-response or LOR. Drug sensitive assays do not allow detection of ADAb during the induction phase as IFX or ADM concentration is typically high.

Risk factors for anti-drug antibody formation to infliximab: Secondary analyses of a randomised controlled trial

BACKGROUND

Anti-drug antibodies (ADAb) frequently form early in the treatment course of infliximab and other tumour necrosis factor (TNF) inhibitors, leading to treatment failure and adverse events.

OBJECTIVE

To identify risk factors for ADAb in the early phase of infliximab treatment.

METHODS

Patients (n = 410) with immune-mediated inflammatory diseases who initiated infliximab treatment were included in the 38-week Norwegian Drug Monitoring Trial (NOR-DRUM) A and randomised 1:1 to therapeutic drug monitoring (TDM) or standard therapy. Serum levels of infliximab and ADAb were measured at each infusion. Possible risk factors for ADAb formation were assessed using logistic regression, adjusting for potential confounders.

RESULTS

ADAb were detected in 78 (19%) patients. A diagnosis of rheumatoid arthritis (RA) (odds ratio [OR], 1.9 [95% confidence interval [CI] 1.0-3.6]) and lifetime smoking (OR, 2.0 [CI 1.1-3.6]) were baseline risk factors, while baseline use of concomitant immunosuppressors (OR, 0.4 [CI 0.2-0.8]) and a diagnosis of spondyloarthritis (SpA) (OR, 0.4 [CI 0.2-0.8]) reduced the risk of ADAb. Higher disease activity during follow-up (OR, 1.1 [CI 1.0-1.1]) and "drug holidays" of more than 11 weeks (OR, 4.1 [CI 1.2-13.8]) increased the risk of ADAb, whereas higher infliximab doses (OR, 0.1 [CI 0.0-0.3) and higher serum infliximab concentrations (OR, 0.7 [CI 0.6-0.8]) reduced the risk of immunogenicity.

CONCLUSION

Several risk factors for ADAb formation during early-phase infliximab treatment were identified. This knowledge provides a basis for treatment strategies to mitigate the formation of ADAb and identify patients in whom these measures are of particular importance.

Alterations and Potential Applications of Gut Microbiota in Biological Therapy for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a chronic immune-mediated inflammatory disorder of the gastrointestinal tract that is closely associated with dysbiosis of the intestinal microbiota. Currently, biologic agents are the mainstream therapies for IBD. With the increasing incidence of IBD, limitations of biologic agents have gradually emerged during treatment. Recent studies have indicated that gut microbiota is highly correlated with the efficacy of biologic agents. This review focuses on alterations in both the components and metabolites of gut microbiota during biological therapy for IBD, systematically summarises the specific gut microbiota closely related to the clinical efficacy, and compares current predictive models for the efficacy of biologics, further highlighting the predictive value of intestinal microbiota. Based on the mechanistic analysis of faecal microbiota transplantation (FMT) and biologic agents, a new therapeutic strategy, comprising a combination of FMT and biologics, has been proposed as a promising treatment for IBD with improved efficacy.

Cost-Effectiveness of Therapeutic Drug Monitoring of Anti-TNF Therapy in Inflammatory Bowel Disease: A Systematic Review

Infliximab and adalimumab are monoclonal antibodies against tumor necrosis factor (anti-TNF) used to manage inflammatory bowel disease (IBD). Therapeutic Drug Monitoring (TDM) has been proven to prevent immunogenicity, to achieve better long-term clinical results and to save costs in IBD treatment. The aim of this study was to conduct a systematic review on cost-effectiveness analyses of studies that apply TDM of anti-TNF in IBD and to provide a critical analysis of the best scientific knowledge available in the literature. The quality of the included studies was assessed using Consolidated Health Economic Evaluation Reporting Standards (CHEERS). Cost-effectiveness of the TDM strategies was presented as total costs, cost savings, quality-adjusted life-years (QALY) and incremental cost-effectiveness ratio (ICER). Thirteen studies that examined the health economics of TDM of anti-TNF in IBD from 2013 to 2021 were included. Eight of them (61.5%) achieved a score between 17 and 23 on the CHEERS checklist. The comparison between the TDM strategy and an empirical strategy was cost saving. The ICER between reactive TDM and an empirical strategy was dominated (favorable) by reactive TDM, whereas the ICER value for proactive TDM compared to an empirical strategy ranged from EUR 56,845 to 3,901,554. This systematic review demonstrated that a TDM strategy is cost-effective or cost-saving in IBD.

Emerging therapies for ulcerative colitis

INTRODUCTION

Despite advances in the medical management of ulcerative colitis (UC), a subgroup of patients does not respond to currently available therapies. A number of novel drugs are in late stages of clinical development or have recently received regulatory approval for UC.

AREAS COVERED

This review focuses on three drug classes that have recently been approved or are awaiting approval for UC: antibodies against interleukin (IL)-23, sphingosine-1-phosphate receptor (S1PR) modulators, and selective inhibitors of Janus kinases (JAK). We provide an overview of their mechanism of action and summarize available evidence for their efficacy and safety. Finally, we discuss expected future challenges in UC management.

EXPERT OPINION

The evaluated drugs have demonstrated efficacy with an acceptable safety profile. IL-23 antagonists appear to be safest with very few (serious) adverse events, while the use of S1PR modulators or JAK inhibitors has been associated with infectious and cardiovascular/thromboembolic events, albeit in low numbers. Although advances in drug development are promising, there is an urgent need for (validated) biomarkers to guide rational treatment selection. The scarcity of head-to-head trials also complicates comparisons between available drugs. Breaking the therapeutic ceiling of efficacy in UC will require marked advances in management extending well beyond drug development.

Adverse Reactions to Biologic Medications Used in Allergy and Immunology Diseases

PURPOSE OF REVIEW

The use of biologic therapies has risen exponentially over recent years, allowing for unprecedented disease control within numerous areas of Allergy/Immunology. With this expanded use, awareness and understanding of adverse reactions to biologic agents have also increased.

RECENT FINDINGS

Multiple biologic adverse reaction phenotypes have been described, but significant overlap in clinical features across phenotypes exists. Given considerable phenotypic overlap, a targeted testing approach may not always be clear, and more recent classifications focus on management decision making using tools of diagnostic challenges and rapid drug desensitizations, guiding clinicians in developing a management plan when the exact underlying mechanism is not clearly known. With increased clinical experience with omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, tezepelumab, rituximab, and TNF-inhibitors, there is a growing appreciation to the spectrum and particularities of adverse reactions to these agents which are outlined in this review. Our understanding of the clinical presentation and management of adverse reactions to biologic medications encountered in Allergy/Immunology has grown. Opportunities remain to further define optimal diagnostic and management strategies for these reactions.