Anti-tumor Necrosis Factor-alpha Exposure Impacts Vedolizumab Mucosal Healing Rates in Pediatric Inflammatory Bowel Disease

Adenosine-generating CD39+ plasmablasts predispose to successful infliximab therapy in pediatric IBD

B cells display several immunoregulatory mechanisms including the production of interleukin-10. Ectonucleotidases like CD39 and CD73 influence immune homeostasis by metabolizing eATP and generating immunosuppressive adenosine. The major objective was to examine the expression of those immunoregulatory molecules on B-cell subsets, and, more specifically, to determine their association with an infliximab (IFX) treatment in a pediatric inflammatory bowel disease (IBD) cohort. 42 IBD patients were assessed for IFX response after 12 mo of therapy and compared against 14 healthy controls (HC). Although IL10-producing plasmablasts were decreased in IFX nonresponders (NRS), we detected an up-regulation of CD39 on plasmablasts and increased fractions of CD39/CD73-co-expressing naïve and memory B cells in responding patients (RS). In addition, B cells of responders proved to have superior ATP degradation capacities and adenosine production before therapy initiation compared with NRS and HC. Moreover, IFX nonresponders had a marked deficiency of α4β7hi plasmablasts, whereas both cohorts had fewer CCR9-expressing plasmablasts. Consequently, CD39+ plasmablasts were decreased in biopsies of inflamed mucosal tissues, especially in IFX nonresponders. Our results highlight the regulatory potential of CD39/CD73-expressing B cells in pediatric IBD and suggest CD39+ plasmablasts as a potential determinant of a successful immunosuppressive therapy with IFX.

Biologics in the management of pediatric inflammatory bowel disease: When and what to choose

Pediatric inflammatory bowel disease (PIBD) is a chronic inflammatory disorder of the gastrointestinal tract, with rising global incidence and prevalence. Over the past two decades, biologics have added to the therapeutic armamentarium and revolutionized the approach to treatment of inflammatory bowel disease. The available biologics include monoclonal antibodies which target inflammatory cytokines (anti-tumor necrosis factor alpha, anti-interleukin 12/23) or recruitment of leucocytes to the gastrointestinal tract (anti-alpha4beta7 integrin) and small molecules (Janus kinase inhibitors, sphingosine 1-phosphate-inhibitors) which modify the proinflammatory signaling. Considering their potential disease-modifying ability, recent pediatric guidelines from the West have advocated upfront use of biologics in appropriate clinical scenarios as a top-down approach rather than the conventional step-up approach. Although real-world studies are available regarding the clinical efficacy of biologics in PIBD, there is paucity of long-term outcome and safety data in children. Also, little information is available about the best approach in the newly industrialized - developing countries where PIBD is rising but at the same time, infections are prevalent and resources are limited. In this review, we summarize the efficacy and safety profile of biologics and small molecule drugs and discuss the challenges in the management of PIBD, especially in the developing world, and future directions.

Maintenance treatment with vedolizumab in paediatric inflammatory bowel disease (VEDOKIDS): 54-week outcomes of a multicentre, prospective, cohort study

BACKGROUND

Infliximab and adalimumab are the only biologics thus far approved for paediatric patients with inflammatory bowel disease (IBD), so other biologics, such as vedolizumab, are prescribed off-label. Despite its frequent use, prospective data for vedolizumab treatment in children are available only for short-term induction outcomes. We aimed to evaluate the long-term efficacy and safety of maintenance therapy with vedolizumab in paediatric patients with IBD.

METHODS

In this multicentre, prospective, cohort study (VEDOKIDS), children younger than 18 years with Crohn's disease, ulcerative colitis, or IBD unclassified (analysed with the ulcerative colitis group) who had initiated intravenous vedolizumab were enrolled from 17 centres in six countries (Israel, the USA, Italy, Ireland, Denmark, and Slovenia). Patients initiating vedolizumab to prevent postoperative recurrence were excluded. Vedolizumab dose or schedule were not standardised, and concomitant treatment with any other medication was permitted. Patients were prospectively followed up for 54 weeks, with repeated biosampling. The primary outcome was complete remission at week 54, defined as clinical remission (weighted Paediatric Crohn's Disease Activity Index [wPCDAI] of <12·5 points in Crohn's disease and Paediatric Ulcerative Colitis Activity Index [PUCAI] of <10 in ulcerative colitis) without the need for surgery, exclusive enteral nutrition for children with Crohn's disease, or steroids (steroid-free and exclusive enteral nutrition-free clinical remission) plus CRP concentration lower than 1·5 times the upper limit of normal (ULN) of 0·5 mg/dL. In cases of missing data on CRP, ESR was used instead (concentrations <1·5 times the ULN, which was 25 mm/h). Data were analysed by intention to treat. This study is registered with ClinicalTrials.gov, NCT02862132.

FINDINGS

Between May 19, 2016, and April 1, 2022, we enrolled 142 patients. Five children who had received only one or two infusions of their three-infusion induction before switching drugs due to COVID-19 pandemic-related reasons were excluded, leaving 137 children (64 [47%] with Crohn's disease, 64 [47%] with ulcerative colitis, and nine [7%] with IBD unclassified; 63 [46%] male and 74 [54%] female; age range of 0·7-17·6 years) in the intention-to-treat population. The median wPCDAI score in children with Crohn's disease decreased from 35 (IQR 18 to 49) at baseline to 13 (0 to 25; median of differences -14 [95% CI -33 to 0]) at week 54, and the median PUCAI score in children with ulcerative colitis decreased from 25 (IQR 15 to 50) at baseline to 5 (0 to 25) at week 54 (median of difference -10 [-30 to 0]). Improvements in disease activity were significant by week 6, with no further significant changes between visits. At week 54, 16 (25%) of 64 children with Crohn's disease and 34 (47%) of 73 with ulcerative colitis or IBD unclassified were in complete remission. 38 vedolizumab-related adverse events were recorded in 29 (21%) of 137 children, the most common being headache (n=7), myalgia (n=4), and fever (n=4), and none were serious.

INTERPRETATION

Vedolizumab maintenance seems safe and efficacious in children, with a higher efficacy in those with ulcerative colitis than in those with Crohn's disease.

FUNDING

The European Crohn's and Colitis Organisation, the European Society for Paediatric Gastroenterology Hepatology and Nutrition, and Takeda.

[Position paper of the Society for Paediatric Gastroenterology and Nutrition (GPGE) on the off-label use of biologics and signal inhibitors in children and adolescents with IBD that have already been approved for adults]

Therapy for children and adolescents with chronic inflammatory bowel disease (IBD) is basically no different from that for adult patients. However, of the steadily increasing number of biologics and signalling inhibitors for adults, only two TNFα antibodies are currently approved in Germany for the treatment of IBD from the age of 6. This means that a large proportion of the drugs authorised for adults with IBD are not available for children and adolescents with moderate to severe disease. The small number of approved drugs also makes it difficult to achieve the prognostically important goal of achieving a sustained remission of IBD soon after diagnosis, which is characterised by the patient being free of symptoms and also the objectifiable goal of mucosa healing. This position paper is intended to present the current study situation on the drug treatment of children and adolescents with IBD outside the age limit and to serve as a basis for information and decision-making for the Medical Service in the assessment of individual case applications as well as for the treating physicians, the cost bearers, health policy and social court decision-makers.

Efficacy of vedolizumab and ustekinumab in pediatric-onset inflammatory bowel disease: A real-world multicenter study

OBJECTIVES

Vedolizumab and ustekinumab are effective in inducing and maintaining corticosteroid-free clinical remission (CFR) in adult patients with inflammatory bowel disease (IBD). This study describes the efficacy and safety of vedolizumab and ustekinumab in pediatric IBD.

METHODS

All patients ≤18 years of age with Crohn's disease (CD) or ulcerative colitis (UC) treated with vedolizumab or ustekinumab in three centers in Northern France were followed retrospectively. The primary outcome was CFR at Week 14 (W14).

RESULTS

Twenty-five patients (9 CD, 16 UC) and 33 patients (28 CD, 5 UC) were started on vedolizumab and ustekinumab respectively between 2016 and 2021. All were previously treated with antitumor necrosis factor (TNF). The median time from diagnosis to treatment initiation was 21.0 (12.0-44.0) and 42.0 (22.0-73.5) months for vedolizumab and ustekinumab, respectively. Among vedolizumab-treated patients, 36% were in CFR at W14, including 22% in CD and 44% in UC. At W52, 56% were in CFR, including 33% in CD and 69% in UC. Among ustekinumab-treated patients, 49% were in CFR at W14, including 54% in CD and 20% in UC. At W52, 55% were in CFR, including 57% in CD and 40% in UC. There was a significant increase in median growth velocity between W0 and W52 of +2 SD in vedolizumab-treated patients (p = 0.0002). Four adverse events were reported during vedolizumab treatment, none for ustekinumab-treated patients.

CONCLUSIONS

Vedolizumab and ustekinumab appear to be effective in inducing and maintaining CFR in pediatric-onset IBD. Randomized controlled trials are needed to confirm these results.

Efficacy of Second-Line Biological Therapies in Moderate to Severe Ulcerative Colitis Patients with Prior Failure of Anti-Tumor Necrosis Factor Therapy: A Multi-Center Study

BACKGROUND

Few studies have compared the efficacy and safety of second-line biological therapies in ulcerative colitis (UC) patients with prior exposure to anti-tumor necrosis factor (TNF) therapy. We aim to compare the efficacy and safety between ustekinumab, vedolizumab, and tofacitinib, a current option as second-line biological therapy with different mechanisms in those patients.

METHODS

This retrospective multi-center study was conducted across five institutions from 2011 to 2022. We enrolled patients with moderate to severe UC who failed anti-TNF therapy and subsequently received ustekinumab, vedolizumab, or tofacitinib as second-line biological therapy. The outcomes were analyzed for clinical response/remission and endoscopic improvement/remission rates after induction therapy, drug persistency, and adverse events.

RESULTS

A total of 70 UC patients were included and grouped into ustekinumab (11 patients), vedolizumab (40 patients), and tofacitinib (19 patients) treatments. The clinical response/remission rates after induction therapy were similar between ustekinumab (90.9/81.8%), vedolizumab (92.5/65.0%), and tofacitinib (94.7/73.7%). There were no significant differences in the endoscopic improvement/remission rates between the three groups: 90.9/18.2% for ustekinumab, 72.5/12.5% for vedolizumab, and 84.2/26.3% for tofacitinib. Drug persistence was similar across the three agents (p = 0.130). Three patients of the tofacitinib group experienced adverse events (herpes zoster and hypertriglyceridemia).

CONCLUSIONS

Based on real-world data, second-line biological therapy with ustekinumab, vedolizumab, and tofacitinib showed comparable efficacy in patients with moderate to severe UC with prior exposure to anti-TNF therapy.

Medical management of pediatric inflammatory bowel disease

Management of inflammatory bowel disease, both Crohn's disease (CD) and ulcerative colitis (UC), has seen a seismic shift over the past decade. Over the past five years, there has been the introduction of many new therapies with differing mechanisms of action and a goal of achieving mucosal healing, as well as clinical and biochemical remission (1,2). In addition, management is aimed at restoring normal growth and normalizing quality of life. The ultimate goal is to individualize medical management and determine the right drug for the right patient by identifying which inflammatory pathway is predominant and avoiding unwarranted lack of efficacy or side effects through biomarkers and risk prognostication. Patient's age, location of disease, behavior (inflammatory vs. penetrating/structuring), severity and growth delay all play into deciding on the best treatment approach. Ultimately, early intervention is key in preventing complications. The therapeutic approaches to management can be broken down to nutritional therapy, biologic agents, immunomodulators (including corticosteroids), aminosalicylates and antibiotics. There are numerous other therapies, such as small molecule agents recently approved in adults, which are garnering a great deal of interest.

Consenso colombiano de la enfermedad inflamatoria intestinal pediátrica

Introducción: la colitis ulcerativa pediátrica (CUP), la enfermedad de Crohn pediátrica (ECP) y la enfermedad inflamatoria intestinal pediátrica no clasificable (EIIPNC) tienen particularidades clínicas y psicosociales que las diferencian de las del adulto y pueden condicionar enfoques terapéuticos distintos por las posibles repercusiones nutricionales, crecimiento y desarrollo, lo que representa un desafío para el pediatra y el gastroenterólogo. Objetivo: desarrollar recomendaciones basadas en la evidencia por consenso de expertos para el diagnóstico y el tratamiento oportunos y seguros de la enfermedad inflamatoria intestinal pediátrica (EIIP) en menores de 18 años, para los profesionales que atienden estos pacientes y los pagadores en salud. Metodología: a través de un panel de expertos del Colegio Colombiano de Gastroenterología, Hepatología y Nutrición Pediátrica (COLGAHNP) y un grupo multidisciplinario se formularon 35 preguntas en relación con el cuadro clínico, el diagnóstico y el tratamiento de la EIIP. A través de una revisión y un análisis crítico de la literatura, con especial énfasis en las principales guías de práctica clínica (GPC), estudios clínicos aleatorizados (ECA) y metaanálisis de los últimos 10 años, los expertos plantearon 77 recomendaciones que respondían a cada una de las preguntas de investigación con sus respectivos puntos prácticos. Posteriormente, cada una de las afirmaciones se sometieron a votación dentro del grupo desarrollador, incluyendo las afirmaciones que alcanzaron > 80 %. Resultados: todas las afirmaciones alcanzaron una votación > 80 %. La EIIP tiene mayor extensión, severidad y evolución hacia la estenosis, enfermedad perianal, manifestaciones extraintestinales y retraso en el crecimiento en comparación con los pacientes adultos, por lo que su manejo debe ser realizado por grupos multidisciplinarios liderados por gastroenterólogos pediatras y prepararlos para una transición a la edad adulta. Los criterios de Porto permiten una clasificación práctica de la EIIP. En la ECP, debemos usar la clasificación de París y debemos realizar ileocolonoscopia y esofagogastroduodenoscopia, ya que el 50 % tienen un compromiso superior, usando el SES-CD (UCEIS/Mayo en CUP) y tomando múltiples biopsias. Los laboratorios iniciales deben incluir marcadores de inflamación, calprotectina fecal y descartar infecciones intestinales. El tratamiento, la inducción y el mantenimiento de la EIIP deben ser individualizados y decididos según la estratificación de riesgo. En el seguimiento se debe usar el Pediatric Crohn Disease Activity Index (PCDAI) y Pediatric Ulcerative Colitis Activity Index (PUCAI) de las últimas 48 horas. Los pacientes con EIIP temprana e infantil, deben ser valorados por inmunólogos y genetistas. Conclusión: se proporciona una guía de consenso con recomendaciones basadas en la evidencia sobre el diagnóstico y los tratamientos oportunos y seguros en los pacientes con EIIP.

Real world population pharmacokinetic study in children and young adults with inflammatory bowel disease discovers novel blood and stool microbial predictors of vedolizumab clearance

BACKGROUND

Vedolizumab for inflammatory bowel disease (IBD) is often intensified based on distinct pharmacokinetics in children. Prior adult-specific population pharmacokinetic models have identified limited covariates of drug clearance.

AIMS

To establish a population pharmacokinetic model for children and young adults to identify novel covariates of drug clearance to better account for paediatric-specific inter-patient variability in vedolizumab pharmacokinetics; a key secondary exploratory aim was to identify microbial signatures of pharmacokinetic outcomes in a subset of patients.

METHODS

The study included data from 463 observed vedolizumab concentrations (59 peaks and 404 troughs) from 74 patients with IBD (52 with Crohn's disease and 22 with ulcerative colitis or unclassified IBD, median age 16 years). Pharmacokinetic analysis was conducted with non-linear mixed effects modelling. For the evaluation of the exposure-response relationship, clinical outcomes were evaluated by trough levels, clearance and vedolizumab exposure. Whole-genome metagenomic sequencing was conducted at baseline and week 2.

RESULTS

A two-compartment population pharmacokinetic model was identified with a clear correlation between CL and weight, erythrocyte sedimentation rate, and hypoalbuminemia. Trough concentrations before infusion 3 (37 μg/ml) and before infusion 4 (20 μg/ml) best predicted steroid-free clinical remission at infusion 4. Using faecal metagenomics, we identified an early (baseline and week 2) abundance of butyrate-producing species and pathways that were associated with an infusion 4 trough concentration >20 μg/ml.

CONCLUSIONS

This novel paediatric vedolizumab pharmacokinetic model could inform precision dosing. While additional studies are needed, an abundance of faecal butyrate producers is associated with early response to vedolizumab, suggesting that microbial analysis may be beneficial to biological selection.

Outcomes, dosing, and predictors of vedolizumab treatment in children with inflammatory bowel disease (VEDOKIDS): a prospective, multicentre cohort study

BACKGROUND

Scarce data are available on the use of vedolizumab in children with inflammatory bowel disease (IBD). We aimed to evaluate the safety, effectiveness, and dosing of vedolizumab to induce remission of IBD.

METHODS

VEDOKIDS was a paediatric, multicentre, prospective cohort study done in 17 centres in six countries. We report the 14-week outcomes as the first analyses of the planned 3-year follow-up of the VEDOKIDS cohort. Children (aged 0-18 years) with IBD who had commenced vedolizumab were followed up at baseline and at 2, 6, and 14 weeks. Children were managed according to local prescribing practices without standardisation of dosing or criteria for escalation, but the study protocol suggested dosing of 177 mg/m² body surface area (up to 300 mg maximum). The primary outcome was steroid-free and exclusive enteral nutrition-free remission at 14 weeks, analysed according to the intention-to-treat principle. Serum samples were taken for analysis of drug concentration and faecal calprotectin at baseline, and at 2, 6, and 14 weeks. Adverse events were recorded in real time and classified as severe or non-severe and related or unrelated to vedolizumab. This study is registered with ClinicalTrials.gov, NCT02862132.

FINDINGS

Between May 19, 2016, and April 1, 2022, 142 children (76 [54%] girls and 66 [46%] boys; mean age 13·6 years [SD 3·6]) were enrolled. 65 (46%) children had Crohn's disease, 68 (48%) had ulcerative colitis, and nine (6%) had unclassified IBD (those with unclassified IBD were analysed with the ulcerative colitis group). 32 (42% [95% CI 30-54]) of 77 children with ulcerative colitis and 21 (32% [23-45]) of 65 children with Crohn's disease were in steroid-free and exclusive enteral nutrition-free remission at 14 weeks. Median drug concentrations at week 14 were higher in children with ulcerative colitis than in those with Crohn's disease (11·5 μg/mL [IQR 5·5-18·1] vs 5·9 μg/mL [3·0-12·7]; p=0·006). In children who weighed less than 30 kg, the optimal drug concentration associated with steroid-free and exclusive enteral nutrition-free clinical remission was 7 μg/mL at week 14 (area under the curve 0·69 [95% CI 0·41-0·98]), corresponding to a dose of 200 mg/m² body surface area or 10 mg/kg. 32 (23%) of 142 children reported at least one adverse event, the most common were headache (five [4%]), myalgia (four [3%]), and fever (three [2%]). None of the adverse events were classified as severe, and only two (1%) patients discontinued treatment due to adverse events.

INTERPRETATION

Vedolizumab showed good safety and effectiveness at inducing remission in children with IBD at 14 weeks, especially those with ulcerative colitis. Vedolizumab should be considered in children when other approved drug interventions for IBD are unsuccessful. In children who weigh less than 30 kg, vedolizumab should be dosed by the child's body surface area (200 mg/m²) or weight (10 mg/kg).

FUNDING

The European Crohn's and Colitis Organization, the European Society for Paediatric Gastroenterology Hepatology and Nutrition, and Takeda.

Vedolizumab as the first line of biologic therapy for ulcerative colitis and Crohn's disease - a systematic review with meta-analysis

BACKGROUND

The efficacy and safety of vedolizumab in bio-naïve patients with ulcerative colitis (UC) and Crohn's disease (CD) remain unknown.

AIMS

To perform a meta-analysis regarding vedolizumab as first line of biological therapy for UC or CD.

METHODS

A systematic review of Medline, EMBASE, and Cochrane databases per December 2020 was undertaken. Meta-analysis was conducted using random-effects models.

RESULTS

This systematic review identified 79 eligible studies with 4,520 and 3,494 bio-naïve patients with UC and CD, respectively, and 8,105 and 11,140 bio-exposed patients. Among bio-naïve patients with UC, a total of 40.0% (95%CI 27.0-54.0, I²=86%) and 63.9% (95%CI 47.0-79.2, I²=36%) achieved clinical remission at weeks 14 and 52, respectively. The corresponding rates in CD were 54.0% (95%CI 42.0-66.0, I²=23%), and 61.7% (95%CI 55.2-68.1, I²=0%). Bio-naïvety was associated with a higher probability of clinical remission at week 52 in UC (relative risk (RR)=1.32 (95%CI 1.14-1.53)), while this was only apparent until week 26 in CD (RR=1.60 (95%CI 1.30-1.95)). Finally, bio-naïve UC patients had a lower risk of serious adverse events (RR=0.29 (95%CI 0.09-0.95)).

CONCLUSION

Vedolizumab was found to have a favorable efficacy and safety profile in bio-naïve patients with UC and CD. The findings have implications in the management of IBD.

Pediatric Management of Crohn's Disease

Pediatric Crohn's disease is often more severe, requires higher levels of immunosuppression, and is associated with greater morbidity compared with adult Crohn's disease. Unique considerations in pediatric Crohn's disease include growth impairment, pubertal delay, bone disease, longevity of disease burden, and psychosocial impact. Treatment options are limited, requiring off-label use of therapy in this challenging patient population. Understanding the medications available, the existing evidence supporting their use, and side effects is important. There is tremendous potential for growth and improvement in this field and it is essential that all gastroenterologists have an understanding of this complex and unique patient population.

Efficacy and safety of vedolizumab for pediatrics with inflammatory bowel disease: a systematic review

BACKGROUND

Vedolizumab use in pediatrics is still off-label and the data are limited. We conducted a systematic review evaluating the efficacy and safety of vedolizumab in children and adolescents with inflammatory bowel disease (IBD).

METHODS

PubMed, EMBASE and Cochrane databases were systematically searched for studies of vedolizumab in children and adolescents with IBD reporting clinical remission, response, corticosteroid-free (CS-free) remission, mucosal healing, or safety up to December 3rd 2021.

RESULTS

Ten studies, comprising 455 patients were included. For CD, the pooled clinical remission rates were 25% (19/75) at 6 weeks, 28% (25/85) at 14 weeks, 32% (17/53) at 22 weeks, and 46% (43/92) at 1 year. For UC/IBD-U, the pooled clinical remission rates were 36% (25/70) at 6 weeks, 48% (52/101) at 14 weeks, 53% (24/45) at 22 weeks, and 45% (50/112) at 1 year. Mucosal healing was found in 17%-39% of CD and 15%-34% of UC/IBD-U respectively. Six percent of patients reported serious adverse events.

CONCLUSIONS

According to low-quality evidence based on case series, approximately one-third and one-half of patients for CD and UC/IBD-U respectively achieved remission within 22 weeks, and about half of patients achieved remission at 1 year with reasonable safety profile. Long-term benefit profile data and high quality evidence are still needed.

Vedolizumab-associated pulmonary manifestations in children with ulcerative colitis

WHAT IS KNOWN AND OBJECTIVE

The off-label use of vedolizumab (VDZ) for inflammatory bowel disease in children is increasing. We report on possibly the first case of VDZ-associated pulmonary manifestations in paediatrics.

CASE SUMMARY

This report details the case of a 13-year-old child with ulcerative colitis who was initiated on VDZ due to persistent active disease. After the first three doses, he developed a persistent and productive cough. Microbiological work-up was normal. VDZ discontinuation led to the resolution of symptoms.

WHAT IS NEW AND CONCLUSION

To our knowledge, this is the first case report of VDZ-associated pulmonary manifestations in paediatrics. A direct, pro-inflammatory effect of VDZ has been hypothesized, but further studies are warranted.

Precision Medicine in Pediatric Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) describes a heterogenous group of diseases characterized by chronic inflammation of the intestinal tract. The IBD subtypes, Crohn's disease, ulcerative colitis, and IBD-Unspecified, each have characteristic features, but heterogeneity remains even among the subtypes. There has been an explosion of new knowledge on the possible pathogenesis of IBD over the last 2 decades mirroring innovation and refinement in technology, particularly the generation of large scale - "-omic" data. This knowledge has fostered a veritable renaissance of novel diagnostics, prognostics, and therapeutics, with patients with IBD seeing hope bloom in the increasingly large armamentarium of IBD therapies. However, while there are increased numbers of therapies and more pathways being targeted, the number of medications for IBD is still finite and the efficacy has reached a plateau. Precision medicine (PM) is much needed to rationally select and optimize IBD therapies in the new reality of wider but still limited choice with a concurrent, increasingly fine resolution on the significance and utility of clinical, genetic, microbial, and proteomic characteristics that define individual patients. PM is a rapidly changing art, but this review will strive to detail the current state and future directions of PM in pediatric IBD.

Vedolizumab: An Emerging Treatment Option for Pediatric Inflammatory Bowel Disease

Vedolizumab is a humanized α4β7-integrin antagonist that is currently FDA-approved for adult inflammatory bowel disease. Limited evidence is available to guide use in pediatric patients, though off-label use is described in the form of retrospective reviews and case series. Collectively these publications begin to establish safety and efficacy data in pediatric patients < 18 years of age. Additionally, dosing regimens described in the literature serve to guide weight-based dosing, which is not established at this time. This narrative review aims to summarize the available literature and provide recommendations for vedolizumab use in the pediatric population. A literature search was performed in PubMed (January 2014-December 2020) using the keyword vedolizumab. Based on the available evidence, vedolizumab appears to be a safe and moderately effective agent for treatment of refractory pediatric inflammatory bowel disease. Prospective, randomized trials are warranted to optimize dosing regimens and to establish long-term safety.

Predicting Therapeutic Response in Pediatric Ulcerative Colitis-A Journey Towards Precision Medicine

Ulcerative colitis (UC) is a disabling disease, characterized by chronic inflammation of the colon, with a rising prevalence worldwide in the pediatric age group. Although UC presents in children with varying severity, disease extent, and comorbidities, initial treatment is essentially uniform, consisting of 5-aminosalicylate drugs with corticosteroid induction for those with moderately to severely active disease. With the advent of anti-tumor necrosis factor (TNF) biologic therapy and several new biologics and small-molecule drugs for UC, precision medicine approaches to treatment are needed to more rapidly achieve sustained remission, restore quality of life, normalize development, and limit exposure to toxic corticosteroids in children with UC. Here, we review available data on clinical, biochemical, histopathologic, and molecular predictors of treatment response in UC. We also address known predictors and special treatment considerations in specific relevant scenarios such as very-early-onset UC, acute severe UC, ileal pouch anal anastomosis, and UC with concomitant primary sclerosing cholangitis. The review concludes with a prediction of how machine learning will integrate multimodal patient data to bring precision medicine to the bedside of children with UC in the future.

Vedolizumab Trough Levels in Children With Anti-Tumor Necrosis Factor Refractory Inflammatory Bowel Disease

OBJECTIVES

Inflammatory bowel disease (IBD) can be successfully treated with vedolizumab. Studies in adult IBD patients have shown that differences in response to vedolizumab may be related to variability in vedolizumab trough levels, but in children with pediatric-onset IBD data regarding vedolizumab trough levels are not available. Thus far, the role of trough levels in pediatric-onset IBD treatment remains unclear. We aimed to investigate predictors of vedolizumab trough levels in pediatric-onset IBD patients.

METHODS

Data from anti-tumor necrosis factor refractory pediatric-onset IBD patients who received vedolizumab were collected retrospectively. Vedolizumab trough levels were measured in serum samples collected before each infusion. A linear mixed model was conducted to analyze factors that influence trough levels.

RESULTS

Twenty-six pediatric-onset IBD patients (14 ulcerative colitis [UC]), 9 Crohn Disease [CD], 3 IBD-unclassified [IBD-U]) received 258 vedolizumab infusions. Mean vedolizumab trough level at week 6 was 29.9 μg/mL (SD 17.8), and 11.5 μg/mL (SD 4.9) during maintenance therapy. CD patients had significantly lower trough levels than IBD-U patients (β 15.2; 95% confidence interval [CI] -1.1 to 29.2; P = 0.036). Higher fecal calprotectin (β -0.009; 95% CI -0.02 to -0.003; P = 0.007) and C-reactive protein levels (β -0.4; 95% CI -0.72 to -0.04; P = 0.027) were associated with lower trough levels, whereas shortening of time between infusions led to higher trough levels (β -0.77; 95% CI -0.9 to 0.64; P < 0.001).

CONCLUSIONS

In this group of pediatric-onset IBD patients, trough levels were significantly lower in CD patients compared with UC/IBD-U patients. Higher levels of inflammatory markers were associated with lower vedolizumab trough levels.

The Treatment of Pediatric Inflammatory Bowel Disease with Biologic Therapies

PURPOSE OF REVIEW

Biologics for the treatment of inflammatory bowel disease (IBD) have been transformative to the therapeutic goals in the pediatric population. We review the biologics used to treat IBD, highlighting the importance of patient selection, dosing considerations, and therapeutic drug monitoring in children.

RECENT FINDINGS

Infliximab is well-established as a safe and efficacious therapy for Crohn's disease and ulcerative colitis. Both dose escalation strategies and therapeutic drug monitoring increase the likelihood of response to anti-TNFα therapies. Early real-world experience of vedolizumab and ustekinumab in pediatric IBD shows promising results, including clinical response rates comparable to what is seen in adults, but there are limited data using them as first-line therapies. Biologic therapies have improved outcomes in pediatric IBD, including achieving mucosal healing as well as improved growth and pubertal development. Therapeutic drug monitoring improves likelihood of response to anti-TNFα therapies, but further studies for vedolizumab and ustekinumab are necessary.