Serum Adalimumab Levels After Induction Are Associated With Long-Term Remission in Children With Inflammatory Bowel Disease

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.

Therapeutic drug monitoring of immunotherapies with novel Affimer-NanoBiT sensor construct

Concentration-therapeutic efficacy relationships have been observed for several therapeutic monoclonal antibodies (TmAb), where low circulating levels can result in ineffective treatment and high concentrations can cause adverse reactions. Rapid therapeutic drug monitoring (TDM) of TmAb drugs would provide the opportunity to adjust an individual patient's dosing regimen to improve treatment results. However, TDM for immunotherapies is currently limited to centralised testing methods with long sample-collection to result timeframes. Here, we show four point-of-care (PoC) TmAb biosensors by combining anti-idiotypic Affimer proteins and NanoBiT split luciferase technology at a molecular level to provide a platform for rapid quantification (<10 minutes) for four clinically relevant TmAb (rituximab, adalimumab, ipilimumab and trastuzumab). The rituximab sensor performed best with 4 pM limit of detection (LoD) and a quantifiable range between 8 pM-2 nM with neglectable matrix effects in serum up to 1%. After dilution of serum samples, the resulting quantifiable range for all four sensors falls within the clinically relevant range and compares favourably with the sensitivity and/or time-to-result of current ELISA standards. Further development of these sensors into a PoC test may improve treatment outcome and quality of life for patients receiving immunotherapy.

Precision Dosing of Anti-TNF Therapy in Pediatric Inflammatory Bowel Disease

PURPOSE OF THE REVIEW

This review focuses on recent advancements in anti-TNF therapeutic drug monitoring (TDM), pharmacogenetics and personalized drug selection for children with inflammatory bowel disease (IBD).

RECENT FINDINGS

Several real-world studies and one clinical trial in children have demonstrated that proactive TDM, targeting higher exposure concentrations (> 5 µg/mL), can improve disease remission rates and enhance durability of the anti-TNF biologics. Recent data from both adult and pediatric IBD patients have revealed an association between a genetic polymorphism (HLA-DQA1*05) and the development of auto-drug antibodies. The impact of this association on clinical outcomes, considering more routine use proactive TDM and dose optimization in children, is still under investigation. Additionally, recent studies have identified potential inflammatory signatures and biomarkers that may serve as companion diagnostics for anti-TNF biologics. The effective management of anti-TNF therapies in children with IBD requires evidence-based precision dosing strategies, including routine TDM and proactive pharmacodynamic assessments.

Managing pediatric Crohn's disease: recent insights

INTRODUCTION

Children and adolescents with Crohn's disease present unique challenges due to extensive disease at diagnosis and the effect of bowel inflammation on growth. Historical approaches with corticosteroids and immunomodulators are far less effective than early treatment with anti-TNF biologics.

AREAS COVERED

This review covers recent literature delineating the crucial role of early anti-TNF therapy in the treatment of moderate- to- severe Crohn's disease in children and adolescents. The potential risks and benefits of concomitant immunomodulators are discussed, along with therapeutic anti-TNF drug monitoring, and reassessment by endoscopy and cross-sectional imaging to evaluate success beyond symptom control.

EXPERT OPINION

Standard of care therapy for moderate-to-severe pediatric Crohn's disease now entails precision dosing of anti-TNF therapy with periodic reassessment of bowel inflammation. The role of dietary modification continues to evolve. Current and future efforts need to be directed to elucidating ways to predict response to anti-TNF therapy and quickly changing to agents with other mechanisms of action when needed. Inordinate regulatory delays in approval of new therapies approved for adults continue to handicap pediatric clinicians and frequently limits their treatment choices, or forces them to give medications "off label." Only a concerted effort by clinicians, pharma, and regulators will improve this situation.

Proactive monitoring of anti-TNF agents improves follow-up of paediatric patients with Crohn disease

INTRODUCTION AND AIMS

The incidence of paediatric inflammatory bowel disease has increased in recent decades. The aim of the present study was to evaluate the role of proactive and serial monitoring of tumour necrosis factor (TNF) inhibitor levels to maintain clinical remission and mucosal healing in the follow-up of paediatric patients with Crohn disease (CD).

METHODS

Prospective study that included all patients diagnosed with CD and treated with adalimumab or infliximab between May 2015 and November 2020 who underwent serial and proactive monitoring of TNF inhibitor levels.

RESULTS

The study included 30 patients, 21 male (70%). The mean age at diagnosis was 11.3 years (SD, 2.0), the mean age at initiation of TNF inhibitors was 12.6 years (SD, 1.9) with a mean duration of follow-up of 27.1 ± 9.1 months. Clinical remission was defined as a weighted Pediatric Crohn's Disease Activity Index (wPCDAI) of less than 12.5 and mucosal healing as a Mucosal Inflammation Non-invasive Index (MINI) of less than 8. During the follow-up, patients were in clinical remission in 87.1% of the visits, presented with mild disease in 11.4% and with moderate disease in 1.5%, and mucosal healing was assumed in 83% of the visits. The rates of clinical remission and mucosal healing at 1, 2, and 3 years of follow-up were 83.3%, 95.8%, 92.8%, and 86.7%, 87.5% and 85.7%, respectively.

CONCLUSIONS

Proactive and serial monitoring of serum TNF inhibitor levels may make it possible for patients to maintain clinical remission and mucosal healing in the maintenance phase, with individualised optimization of the required dosage and minimization of secondary loss of response.

A critical review of adalimumab for the treatment of moderate-to-severe active ulcerative colitis in children

INTRODUCTION

Anti-tumor necrosis factor (TNF) antibodies play a major role in treating inflammatory bowel disease (IBD), both in adult and pediatric patients. While there is a large number of studies on efficacy and safety of infliximab in treating children and adolescents with ulcerative colitis (UC), data on adalimumab (ADA) are scarce.

AREAS COVERED

Here, we review published case reports, cohort and real-time data, as well as the first randomized trial, ENVISION I, using ADA for treating pediatric UC. Available evidence confirms good efficacy in inducing and maintaining remission in children and adolescents with UC, with even higher response rates compared to adult UC. ENVISION I showed that in UC patients responding to ADA induction therapy, almost half of the patients remained in remission after 52 weeks of therapy on high-dosing ADA (weekly administration). As already well experienced with other biologics, dosing schemes are different between pediatric and adult patients, with children often requiring higher dosing.

EXPERT OPINION

Further data are required to better understand how to optimize ADA therapy. The present and still-growing evidence places subcutaneous (sc.) anti-TNF-medication as alternative first-line therapy also for pediatric UC. This is also reflected by the preference for sc. medication of adolescent patients allowing less frequent and autonomous drug administration.

Therapeutic Drug Monitoring of Biologics in Crohn's Disease

Reactive therapeutic drug monitoring (TDM) is considered the standard of care for optimizing biologics in inflammatory bowel disease (IBD) including Crohn's disease (CD). Preliminary data show that proactive TDM is associated with positive outcomes in IBD and can be also used to efficiently guide therapeutic decisions in specific clinical scenarios. Higher biological drug concentrations are associated with favorable therapeutic outcomes in specific IBD populations or phenotypes including pediatric CD, perianal fistulizing CD, small bowel CD, and following an ileocolonic resection for CD. Future perspectives of TDM include the use of rapid testing, pharmacogenomics, and pharmacokinetic dashboards toward individualized therapy.

Biomarkers for Optimization and Personalization of Anti-TNFs in Pediatric Inflammatory Bowel Disease

The use of biological drugs has improved outcomes in pediatric inflammatory bowel disease (IBD). Prediction of the response to biological drugs would be extremely useful in IBD, and even more so in children, who are still growing physically and psychologically. Specific clinical, biochemical, and genetic parameters are considered predictive of response to biological drugs, although few studies have been carried out in children with IBD. In this review, we present current evidence on biological treatments used in pediatric IBD and the available biomarkers of response. We examine demographics, clinical characteristics, biomarkers (genetic, genomic, and cellular), and microbiota.