P4363 - A Retrospective Analysis of the Impact of Body Mass Index on Treatment FaiLure of UsTekinumab Within an Inflammatory Bowel Disease Population (BELT-IBD)

Chukwunonso Ezeani, MBBS¹, Jamie Mooney, RN¹, Prabhu Ramalingam, MD¹, Mounika Lakhmalla, MD¹, Ifeanyichukwu Onor, PharmD², Hartmann Brunt, MD¹, Casey Chapman, MD^1
1Baton Rouge General Medical Center, Baton Rouge, LA; ²Louisiana State University School of Medicine, New Orleans, LA

Introduction: Environmental factors including obesity play significant role in Inflammatory Bowel Disease (IBD). Obese patients have been thought to have increased volume of distribution as well as increased medication clearance leading to lower drug trough concentrations and potential suboptimal clinical outcomes. In addition, induction dose of some IBD medications including Ustekinumab (UST) is based on BMI but there is limited real world data on clinical outcomes. We aim to determine the relationship between BMI and UST drug failure.

Methods: We identified all adult patients with IBD who received UST in our Crohn’s and Colitis clinic and grouped them based on BMI into underweight (< 18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese ( >30 kg/m2) groups. Patients with no endoscopic and pathologic diagnosis of IBD, received UST for less than 16 weeks, and age less than 18 years were excluded. The primary outcome was the effect of BMI on treatment failure, a composite of primary and secondary non-reponse. Secondary outcomes were effect of BMI on 1. primary non-response defined as lack of response to Ustekinumab requiring change of therapy up to week 16 and 2. secondary non-response, defined worsening clinical, biochemical, or endoscopic features requiring discontinuation of UST beyond 16 weeks of therapy. Patients who discontinued UST due to development of antibodies or inability to achieve adequate therapeutic levels were not regarded as secondary failure as these more correctly represent immunologic and pharmacokinetic failures respectively. Outcomes were compared using chi-square. Alpha significance level of 5% was adopted.

Results: A total of 151 patients were included in the study, 58.3% were females and mean age was 44.4 years. There was no statistically significant difference in treatment failure based on BMI (p=0.326). Similarly, there was no difference in primary non-response (p=0.881) and secondary non-response (p=0.211) among the four groups stratified by BMI status (figure 1)

Discussion: Treatment failure as well as primary and secondary nonresponse rates in Crohn’s disease and ulcerative colitis patients on UST are similar irrespective of BMI status. Further studies evaluating the effect on reinduction status, UST drug levels, as well as corticosteroid and immunomodulator use during treatment is warranted.


Disclosures:


Chukwunonso Ezeani, MBBS¹, Jamie Mooney, RN¹, Prabhu Ramalingam, MD¹, Mounika Lakhmalla, MD¹, Ifeanyichukwu Onor, PharmD², Hartmann Brunt, MD¹, Casey Chapman, MD¹. P4363 - A Retrospective Analysis of the Impact of Body Mass Index on Treatment FaiLure of UsTekinumab Within an Inflammatory Bowel Disease Population (BELT-IBD), ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.