Body Mass Index Does Not Impact Clinical Efficacy of Ustekinumab in Crohn's Disease: A Post Hoc Analysis of the IM-UNITI Trial

Recommendations on the management of severe obesity in patients with inflammatory bowel disease of the Spanish Group on Crohn's Disease and Ulcerative Colitis (GETECCU), Spanish Society of Obesity (SEEDO), Spanish Association of Surgery (AEC) and Spanish Society of Digestive Endoscopy (SEED)

Obesity is a multifactorial, chronic, progressive and recurrent disease considered a public health issue worldwide and an important determinant of disability and death. In Spain, its current prevalence in the adult population is about 24% and an estimated prevalence in 2035 of 37%. Obesity increases the probability of several diseases linked to higher mortality such as diabetes, cardiovascular disease, hyperlipidemia, arterial hypertension, non-alcoholic fatty liver disease, several types of cancer, or obstructive sleep apnea. On the other hand, although the incidence of inflammatory bowel disease (IBD) is stabilizing in Western countries, its prevalence already exceeds 0.3%. Paralleling to general population, the current prevalence of obesity in adult patients with IBD is estimated at 15-40%. Obesity in patients with IBD could entail, in addition to its already known impact on disability and mortality, a worse evolution of the IBD itself and a worse response to treatments. The aim of this document, performed in collaboration by four scientific societies involved in the clinical care of severe obesity and IBD, is to establish clear and concise recommendations on the therapeutic possibilities of severe or typeIII obesity in patients with IBD. The document establishes general recommendations on dietary, pharmacological, endoscopic, and surgical treatment of severe obesity in patients with IBD, as well as pre- and post-treatment evaluation.

Impact of Obesity and Metabolic Syndrome on IBD Outcomes

PURPOSE OF REVIEW

The recent surge in inflammatory bowel disease (IBD) cases has paralleled a significant rise in obesity and metabolic comorbidities rates. In this article, we explore the potential influence of obesity and associated metabolic comorbidities on disease progression, complications, treatment response, surgical outcomes, health economics, and the potential impact of obesity treatment on the course of IBD.

FINDINGS

Contrary to visceral adiposity, obesity does not consistently result in an increased risk of IBD-related complications. Patients with IBD have a higher risk of acute arterial events, likely linked to systemic inflammation. Substantial evidence suggests that obesity has a negative impact on the response to IBD treatment, with this effect being most thoroughly studied in biologics and immunomodulators. The rates of overall complications and post-operative infections are higher in patients who are obese. There are limited but promising data regarding the impact of weight loss techniques, including exercise, medications, and bariatric interventions, on the outcomes in IBD. Both obesity and diabetes have adverse effects on the overall quality of life and place an increased financial burden on the IBD population. A growing body of evidence indicates a connection between obesity and associated metabolic comorbidities and negative outcomes in IBD, yet further efforts are required to fully understand this relationship.

A High Visceral-to-Skeletal Muscle Area Ratio on Cross-Sectional Imaging Is Associated With Failure of Standard Ustekinumab Doses: A Multicenter Study

INTRODUCTION

Anti-interleukin 12/23 agents have shown greater durability in response compared with anti-tumor necrosis factor α agents. Data on the association between body composition (BC) or body mass index (BMI) and ustekinumab's therapeutic response is limited. We aimed to evaluate the impact of BC on time to failing standard doses of ustekinumab in patients with Crohn's disease (CD).

METHOD

Patients with CD aged 16 years and older from 2 tertiary centers were studied retrospectively. Included patients had abdominal imaging within 6 months of ustekinumab induction and were followed until April 30, 2022. An experienced abdominal radiologist blinded to the clinical information measured the area of visceral fat area and skeletal muscle area at the mid L3 vertebral level, with values corrected for height 2 to derive respective indices (visceral fat index [VFI], skeletal muscle index [SMI]) and the VFI:SMI ratio.

RESULTS

Ninety-nine patients met inclusion criteria. The mean age at ustekinumab induction was 46.6 (±1.6) years. The median BMI (interquartile range) was 26.5 (22.6-30.8). Twenty-four patients (24.2%) did not respond or lost response to standard doses of ustekinumab over the follow-up duration. A younger age (hazard ratio 0.96, 95% confidence interval 0.94-0.99, P = 0.01) and a VFI:SMI ratio >1.6 (hazard ratio 4.65, 95% confidence interval 1.73-12.45, P = 0.002) were both associated with a shorter time to failing ustekinumab at standard doses on multivariate analysis. BMI, notably, had no association with the primary outcome.

DISCUSSION

A high VFI:SMI ratio is associated with an increased risk of failing standard doses of ustekinumab. BC measurements derived from cross-sectional imaging at the start of ustekinumab therapy is a useful indicator for therapeutic durability.

Obesity and novel management of inflammatory bowel disease

Obesity is prevalent within the inflammatory bowel disease (IBD) population, particularly in newly developed countries. Several epidemiological studies have suggested that 15%-40% of IBD patients are obese, and there is a potential role of obesity in the pathogenesis of IBD. The dysfunction of mesenteric fat worsens the inflammatory course of Crohn’s disease and may induce formation of strictures or fistulas. Furthermore, obesity may affect the disease course or treatment response of IBD. Given the increasing data supporting the pathophysiologic and epidemiologic relationship between obesity and IBD, obesity control is being suggested as a novel management for IBD. Therefore, this review aimed to describe the influence of obesity on the outcomes of IBD treatment and to present the current status of pharmacologic or surgical anti-obesity treatments in IBD patients.

Real-world effectiveness and safety of ustekinumab induction therapy for Korean patients with Crohn's disease: a KASID prospective multicenter study

BACKGROUND/AIMS

We investigated the real-world effectiveness and safety of ustekinumab (UST) as induction treatment for Koreans with Crohn's disease (CD).

METHODS

CD patients who started UST were prospectively enrolled from 4 hospitals in Korea. All enrolled patients received intravenous UST infusion at week 0 and subcutaneous UST injection at week 8. Clinical outcomes were assessed using Crohn's Disease Activity Index (CDAI) scores at weeks 8 and 20 among patients with active disease (CDAI ≥150) at baseline. Clinical remission was defined as a CDAI <150, and clinical response was defined as a reduction in CDAI ≥70 points from baseline. Safety and factors associated with clinical remission at week 20 were also analyzed.

RESULTS

Sixty-five patients were enrolled between January 2019 and December 2020. Among 49 patients with active disease at baseline (CDAI ≥150), clinical remission and clinical response at week 8 were achieved in 26 (53.1%) and 30 (61.2%) patients, respectively. At week 20, 27 (55.1%) and 35 (71.4%) patients achieved clinical remission and clinical response, respectively. Twenty-seven patients (41.5%) experienced adverse events, with serious adverse events in 3 patients (4.6%). One patient (1.5%) stopped UST therapy due to poor response. Underweight (body mass index <18.5 kg/m2) (odds ratio [OR], 0.085; 95% confidence interval [CI], 0.014-0.498; P=0.006) and elevated C-reactive protein at baseline (OR, 0.133; 95% CI, 0.022-0.823; P=0.030) were inversely associated with clinical remission at week 20.

CONCLUSIONS

UST was effective and well-tolerated as induction therapy for Korean patients with CD.

Effect of Obesity on Risk of Hospitalization, Surgery, and Serious Infection in Biologic-Treated Patients With Inflammatory Bowel Diseases: A CA-IBD Cohort Study

INTRODUCTION

Obesity is variably associated with treatment response in biologic-treated patients with inflammatory bowel diseases (IBD). We evaluated the association between obesity and risk of hospitalization, surgery, or serious infections in patients with IBD in new users of biologic agents in a large, multicenter, electronic health record (EHR)-based cohort (CA-IBD).

METHODS

We created an EHR-based cohort of adult patients with IBD who were new users of biologic agents (tumor necrosis factor [TNF-α] antagonists, ustekinumab, and vedolizumab) between January 1, 2010, and June 30, 2017, from 5 health systems in California. Patients were classified as those with normal body mass index (BMI), overweight, or obese based on the World Health Organization classification. We compared the risk of all-cause hospitalization, IBD-related surgery, or serious infections among patients with obesity vs those overweight vs those with normal BMI, using Cox proportional hazard analyses, adjusting for baseline demographic, disease, and treatment characteristics.

RESULTS

Of 3,038 biologic-treated patients with IBD (69% with Crohn's disease and 76% on TNF-α antagonists), 28.2% (n = 858) were overweight, and 13.7% (n = 416) were obese. On a follow-up after biologic initiation, obesity was not associated with an increased risk of hospitalization (adjusted hazard ratio [aHR] vs normal BMI, 0.90; [95% confidence interval, 0.72-1.13]); IBD-related surgery (aHR, 0.62 [0.31-1.22]); or serious infection (aHR, 1.11 [0.73-1.71]). Similar results were observed on stratified analysis by disease phenotype (Crohn's disease vs ulcerative colitis) and index biologic therapy (TNF-α antagonists vs non-TNF-α antagonists).

DISCUSSION

In a multicenter, EHR-based cohort of biologic-treated patients with IBD, obesity was not associated with hospitalization, surgery, or serious infections. Further studies examining the effect of visceral obesity on patient-reported and endoscopic outcomes are needed.

Comparison of Ustekinumab Trough Concentrations Measured by 2 ELISA Kits and Evaluation of Clinical Response in Crohn's Disease

BACKGROUND

Ustekinumab is a recently introduced biological agent for the treatment of Crohn's disease. The clinical use of the trough concentration of ustekinumab is not as standardized as that of infliximab. The authors aimed to introduce a measurement method and the results of trough concentrations of ustekinumab in clinical applications.

METHODS

Thirty-two blood samples from 10 young adult patients diagnosed with Crohn's disease were analyzed. During the maintenance treatment, injection intervals were shortened from 12 weeks to 8 weeks in 4 patients who exhibited a loss of response. Ustekinumab trough concentrations were measured using 2 commercial ELISA kits, kit A and kit B.

RESULTS

The median trough concentrations measured with kits A and B were 0.26 and 0.38 mcg/mL, respectively. In the case of kit A, low trough concentrations were undetected on many occasions and measured as zero, whereas kit B displayed their relative values even at low concentrations. Poor clinical parameters, elevated erythrocyte sedimentation rate, C-reactive protein, and calprotectin levels were significantly correlated with lower trough concentrations ( P < 0.05). The area under the receiver operating characteristics curve of kit B (0.921) was greater than that of kit A (0.744). The optimal cutoff values for prediction clinical responses were 0.17 and 0.41 mcg/mL for kit A and kit B, respectively.

CONCLUSIONS

The trough concentration of ustekinumab measured by the 2 ELISA kits correlated with laboratory results that indicated the activity of Crohn's disease. Furthermore, kit B detected even minute changes in trough concentrations.

Visceral Adipose Tissue Volumetrics Inform Odds of Treatment Response and Risk of Subsequent Surgery in IBD Patients Starting Antitumor Necrosis Factor Therapy

BACKGROUND

Data describing the effect of obesity on antitumor necrosis factor (anti-TNF) treatment response are inconsistent. Visceral adipose tissue (VAT) is a superior marker of adiposity to body mass index. However, its effect on treatment response is unclear. We aimed to evaluate the effect of VAT on anti-TNF treatment response.

METHODS

Inflammatory bowel disease (IBD) patients starting anti-TNF agents between January 1, 2009, and July 31, 2019, were included. 3-dimensional measurements of VAT volume and visceral fat index (visceral:subcutaneous adipose tissue ratio; VFI) were obtained from computed tomography (CT) scans. Subjects were categorized by predefined volume cutoffs (<1500cm3, 1500-2999cm3, ≥3000cm3) and VFI (<0.33, 0.33-0.66, ≥0.67). Primary outcomes included a composite treatment response end point at 6 and 12 months. Secondary outcomes were surgery at 6 and 12 months. Multivariable logistic regression was used to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

The final cohort included 176 patients. No significant differences in treatment response at 6 months was observed. At 12 months, compared with volume <1500cm3, patients with volume 1500-2999cm3 had higher odds of response (aOR, 3.52; 95% CI, 1.16-10.71; P = .023), whereas volume ≥3000cm3 did not. Compared with VFI<0.33, VFI ≥0.67 had higher odds of surgery at 6 (aOR, 48.22; 95% CI, 4.73-491.57; P = .023) and 12 months (aOR, 20.94; 95% CI, 3.14-139.67; P = .004). Post hoc analysis suggested VAT may affect drug pharmacokinetics.

CONCLUSIONS

We found VAT volume is associated with anti-TNF treatment response in a nondose dependent manner, and VFI may inform risk of surgery after anti-TNF initiation. If confirmed by prospective studies, VAT volumetrics are potentially useful biomarkers to inform IBD treatment decisions.

Impact of Obesity on Response to Biologic Therapies in Patients with Inflammatory Bowel Diseases

Approximately 20-40% of patients with inflammatory bowel disease (IBD) are obese. Obesity is associated with inferior outcomes in patients with IBD, with lower rates of achieving remission, poor quality of life, and higher burden of unplanned healthcare utilization. Multiple cohort studies in patients with immune-mediated inflammatory diseases, including IBD, treated with biologic agents like tumor necrosis factor-α antagonists have suggested that obesity is associated with inferior response to biologic therapy. This may be related to the negative impact of obesity on the pharmacokinetics of biologic agents. Pharmacokinetic studies of multiple biologic agents have demonstrated that high body weight is associated with more rapid clearance and a higher volume of distribution of biologic agents, which leads to low trough concentrations. Randomized trials in patients with psoriasis and psoriatic arthritis treated with biologic agents suggest that diet- or lifestyle-induced weight loss is associated with improved response to therapy. This provides an opportunity to explore intentional weight loss as adjunctive therapy in obese patients with IBD. However, diet and lifestyle interventions for weight loss are hard to implement in patients with IBD; hence, long-term therapy with weight-loss agents (such as with phentermine-topiramate, naltrexone-bupropion) is attractive as adjunctive therapy in obese patients with IBD.

Population pharmacokinetics of subcutaneous infliximab CT-P13 in Crohn's disease and ulcerative colitis

BACKGROUND

Infliximab is a chimeric monoclonal antibody against tumour necrosis factor-alpha for the treatment of Crohn's disease (CD) and ulcerative colitis (UC). Recently, a subcutaneous formulation of CT-P13, an infliximab biosimilar, was approved for clinical use.

AIMS

To characterise CT-P13 pharmacokinetics (PK) and its clinically relevant determinants after subcutaneous administration through population PK modelling.

METHODS

Data from a two-part Phase I study with intravenous (5 mg/kg) and variable maintenance subcutaneous dosing of CT-P13 with frequent PK sampling in patients with CD or UC were used. Population PK analysis was conducted by non-linear mixed effects modelling. Covariates affecting PK parameters were chosen based on their clinical relevance (effect size of ≥20%) using a full fixed-effect modelling approach.

RESULTS

CT-P13 PK was described by a two-compartment model with linear elimination. The half-life in a typical 70 kg patient with serum albumin of 44 g/L was 10.8 days. The typical value for clearance was 0.355 L/d, absorption constant 0.273/d, bioavailability 79.1%, central volume of distribution 3.10 L and peripheral volume of distribution 1.93 L. Clinically relevant covariates affecting clearance were body weight (+43.2% from 70 to 120 kg), the presence of anti-drug antibodies (+39%) and serum albumin concentration (+30.1% from 44 to 32 g/L). Simulated drug exposure was comparable between routes of administration for patients weighing 50 or 70 kg, but lower with subcutaneous dosing in patients weighing 120 kg.

CONCLUSIONS

This first population PK model for subcutaneous CT-P13 supports fixed subcutaneous maintenance dosing, although heavy patients had lower cumulative drug exposure.

Ustekinumab Dosing Individualization in Crohn's Disease Guided by a Population Pharmacokinetic-Pharmacodynamic Model

Ustekinumab is a monoclonal antibody used in Crohn’s disease (CD). Dose optimization in case of non-response and the role of pharmacokinetic–pharmacodynamic (PK-PD) monitoring remain unresolved dilemmas in clinical practice. We aimed to develop a population PK-PD model for ustekinumab in CD and simulate efficacy of alternative dosing regimens. We included 57 patients and recorded their characteristics during 32 weeks after starting with ustekinumab therapy. Serum ustekinumab concentration was prospectively measured and fecal calprotectin (FC) concentration was used to monitor the disease activity. Ustekinumab PK-PD was described by a two-compartment target-mediated drug disposition model linked to an indirect response model. Lower fat-free mass, higher serum albumin, previous non-exposure to biologics, FCGR3A-158 V/V variant and lower C-reactive protein were associated with higher ustekinumab exposure. Model-based simulation suggested that 41.9% of patients receiving standard dosing achieve biochemical remission at week 32. In patients not achieving remission with standard dosing at week 16, transition to 4-weekly subcutaneous maintenance dosing with or without intravenous reinduction resulted in comparably higher remission rates at week 32 (51.1% vs. 49.2%, respectively). Our findings could be used to guide stratified ustekinumab treatment in CD, particularly in patients with unfavorable characteristics, who might benefit from early transition to 4-weekly maintenance dosing.

The impact of body mass index on efficacy and safety in the tofacitinib OCTAVE ulcerative colitis clinical programme

BACKGROUND

Obesity may affect efficacy and safety of biologic treatments for ulcerative colitis (UC). Tofacitinib is an oral, small molecule Janus kinase inhibitor for the treatment of UC.

AIMS

To assess efficacy and safety of tofacitinib in patients with UC, by baseline body mass index (BMI).

METHODS

This post hoc analysis evaluated patients with UC receiving placebo or tofacitinib from the 8-week OCTAVE Induction 1 and 2 (NCT01465763, NCT01458951) and 52-week OCTAVE Sustain (NCT01458574) studies. Patients were stratified by BMI at OCTAVE Induction 1 and 2 baseline (<25, 25 to <30 and ≥30 kg/m² ). Outcomes included remission, endoscopic improvement, clinical response, sustained steroid-free remission, Inflammatory Bowel Disease Questionnaire total score and Short Form-36 Health Survey scores. Adverse events were evaluated.

RESULTS

At Week 8 of OCTAVE Induction 1 and 2, and Week 52 of OCTAVE Sustain, higher proportions of patients receiving tofacitinib 5 or 10 mg twice daily (b.d.) achieved clinical response vs placebo, regardless of baseline BMI subgroup (all P < 0.05). Proportions of patients achieving efficacy endpoints were generally similar across BMI subgroups; in univariate and multivariate regression analyses, BMI was not a significant predictor (all P ≥ 0.05; univariate BMI [continuous] odds ratio for remission: 0.98 [95% confidence interval 0.95, 1.02]). There was no consistent trend between BMI and adverse events. Among patients receiving tofacitinib 10 mg b.d. in OCTAVE Induction 1 and 2, serious infections were numerically greater in the BMI ≥30 subgroup (3.2%) vs other subgroups (0.4%). Limitations included small patient numbers in the BMI ≥30 subgroup.

CONCLUSIONS

Efficacy and safety of tofacitinib were similar in patients with UC regardless of baseline BMI.

Obesity in inflammatory bowel disease: A review of its role in the pathogenesis, natural history, and treatment of IBD

In contrast to previous perceptions that inflammatory bowel disease (IBD) patients are generally malnourished and underweight, there is mounting evidence to suggest that rates of obesity in IBD now mirror that of the general population. IBD is an immune-mediated condition that appears to develop in individuals who have not only a genetic predisposition to immune dysregulation but also likely exposure to various environmental factors which further potentiate this risk. With the surge in obesity alongside the rising incidence of IBD, particularly in developing nations, the role that obesity may play, not only in the pathogenesis but also in the natural history of disease has become a topic of growing interest. Currently available data exploring obesity's impact on the natural history of IBD are largely conflicting, potentially limited by the use of body mass index as a surrogate measure of obesity at varying time points throughout the disease course. While there are pharmacokinetic data to suggest possible detrimental effects that obesity may have on the response to medical therapy, results in this realm are also inconsistent. Moreover, not only is it unclear whether weight loss improves IBD outcomes, little is known about the safety and efficacy of available weight-loss strategies in this population. For these reasons, it becomes increasingly important to further understand the nature of any interaction between obesity and IBD.