Prior exposure to advanced therapy and timing of discontinuation and risk of serious infections in patients with inflammatory bowel disease initiating a new advanced therapy
Abstract Introduction Despite regulatory mandates for advanced therapy (AT) washout periods of up to 5 drug half-lives before enrolling patients in inflammatory bowel disease (IBD) trials, the evidence base for these requirements is largely empirical, and whether shorter intervals independently increase the risk of serious infections in real-world practice remains unknown. Methods Using the OptumLabs Data Warehouse, we identified adult patients with IBD who initiated a new AT (tumor necrosis factor antagonists, vedolizumab, interleukin (IL)-12/23 or IL-23 antagonists, or Janus kinase inhibitors) between 2018 and 2023 using a class-specific new-user design. We examined whether exposure to AT within the preceding 12 months (vs no exposure to AT within that window) and timing of discontinuation (≤1 month, 1-<3 months, or 3-12 months) were associated with risk of serious infections using multivariable Cox proportional hazards regression. Results Among 21 564 AT initiators (47 ± 18 years; 52% female; 57% Crohn’s disease), 7490 (34.7%) had AT exposure within the preceding 12 months. Over a mean follow-up of 1.6 ± 0.9 y, 1955 (9.1%) experienced a serious infection. Prior AT exposure was associated with higher infection risk (hazard ratio [HR]: 1.19, 95% confidence interval [CI]: 1.07-1.33), consistent in inverse probability of treatment-weighted analyses (HR, 1.20 [1.06-1.37]). Among patients with prior exposure, timing of discontinuation was not associated with infection risk (HR, 1.17 [0.95-1.43] for ≤1 month vs 3-12 months; HR, 1.01 [0.83-1.22] for 1-<3 months), with no dose–response relationship on continuous modeling. Discussion AT exposure within the preceding 12 months is associated with modestly higher risk of serious infection after initiating a new AT in IBD, but timing of discontinuation does not independently influence this risk.
The impact of global recruitment and country income on placebo rates in inflammatory bowel disease clinical trials
Abstract Introduction Despite progress in understanding placebo effects in clinical trials of inflammatory bowel disease (IBD), there is a limited understanding of how socioeconomic factors of recruiting countries impact placebo rates. We investigated the association of socioeconomic factors across recruitment sites on placebo rates in IBD randomized controlled trials. Methods We examined the association of clinical and endoscopic remission and response to the weighted Gross National Index (GNI) per capita, Human Development Index (HDI), and out-of-pocket health expenditures as a percentage of current health expenditures (OOP_CHE) of identified trials using mixed effects linear regression. Results Across 76 trials (Crohn’s disease [CD]: n = 32; ulcerative colitis [UC]: n = 44), placebo response rates over time were largely stable, with a small increase across time in clinical remission for CD trials (β = 0.4% per increase in study year, 95% CI: 0.3%-0.84%, P = .04) and a small decrease across time in endoscopic response for UC trials (β = −1.39% per increase in study year, 95% CI: −1.79, −0.99, P < .001). Clinical response was most susceptible to changes in socioeconomic factors in IBD trials (β = −2.96% per 10 000 USD increase in study GNI, 95% CI: −4.98, −0.95%, P = .004; P < .05 for HDI and OOP_CHE). Across both conditions, decreases in clinical response were associated with increases in HDI and OOP_CHE (CD HDI: β = −1.15% per 0.01 increase in study HDI, 95% CI: −2.24, −0.06%, P = .04; UC HDI: β = −0.66% per 0.01 increase in study HDI, 95% CI: −1.19, −0.12%, P = .02). Discussion We found that placebo clinical response was most susceptible to influences of site-level socioeconomic wellbeing. These findings highlight that estimation of placebo rates in trial planning should account for geographic location of recruiting sites.
Definitions, diagnosis, and management of postoperative recurrence in Crohn’s disease patients with permanent ileostomy—a systematic review and meta-analysis
Abstract Background and Aims Over 10% of patients with Crohn’s disease require permanent ileostomy. We aimed to summarize the existing data on diagnosis, definitions of recurrence, and management of Crohn’s disease patients with permanent ileostomy. Methods MEDLINE, Embase, and CENTRAL databases were searched from inception to February 6, 2024. Randomized controlled trials, cohort and cross-sectional studies, and case series of more than 5 patients reporting on postoperative recurrence or the need for surgery in patients with Crohn’s disease and permanent ileostomy were included. Search results were independently screened, and full text of all titles meeting eligibility criteria was obtained. Outcomes of interest included diagnostic techniques, recurrence definitions, and management approaches. We estimated pooled rates (with 95% confidence interval [CI]) of recurrence. Results Thirty cohort studies including 2055 Crohn’s patients with permanent ileostomy were included (53% female, median age at the time of ileostomy creation 32 years, the most common reason for ileostomy was refractory disease). The postoperative recurrence rate was 27% (95% CI, 21.3–33.3, 26 studies, 451/1805 patients). Modalities for diagnosis of Crohn’s disease recurrence were symptoms (15 studies), endoscopy (4 studies), histology from endoscopic biopsies (2 studies), imaging (5 studies), and surgery (22 studies). The reported definitions of recurrence for each modality were heterogeneous. Conclusions There is a lack of standardized monitoring tools and criteria for diagnosing recurrence in patients with Crohn’s disease and permanent ileostomy. The results of this systematic review will form the basis of a global expert recommendation exercise focused on developing management standards and trial endpoints for this condition.
P479 Reliability and responsiveness of histologic disease activity indices in Crohn’s Disease
Abstract Background The operating properties of histologic indices are poorly characterized in Crohn’s disease (CD) and no validated index exists. We assessed the reliability and responsiveness of histologic indices/items, developed an exploratory index, and compared different methods of scoring. Methods Using baseline and week 12 histologic image sets from the EXTEND placebo-controlled trial, blinded central readers scored 4 histologic indices (the Global Histologic Activity Score [GHAS], Geboes Score [GS], Robarts Histopathology Index [RHI], and Nancy Index [NHI]) and 3 additional novel items identified by an expert panel (mucin depletion, basal plasmacytosis, and pyloric gland metaplasia in the ileum). Reliability and responsiveness were evaluated for a global score (4 colonic segments + ileum), colonic score (4 colonic segments) and ileal score (ileum only) using the intraclass correlation coefficient (ICC) and area under the receiver operating curve (AUC), respectively. Change was defined using treatment assignment and improvement in histologic disease activity as measured on a 100-mm visual analogue scale (VAS) in responsiveness testing. Exploratory indices were developed using backward stepwise linear regression analysis. Candidate independent variables were items with an ICC ≥0.4 and AUC ≥0.56. The VAS served as the dependent variable. Results Paired histologic images were analysed from 55 subjects. Inter-rater reliability was substantial to almost perfect (ICC=0.73-0.85) and responsiveness was small to large (treatment assignment AUC=0.50-0.65; VAS AUC=0.71-0.94). The GHAS, GS, RHI, and NHI reached the minimum threshold for reliability (ICC ≥0.4) and responsiveness (AUC ≥0.56) regardless of whether the global and colonic scores were calculated using the worst affected segment, average of the included segments, or sum of the included segments (Table 1-3). Five items were tested as candidate predictors. Three exploratory indices were developed, each consisting of 3 items: a global index (neutrophils in the lamina propria, neutrophils in the epithelium, and erosion/ulceration), colonic index (chronic inflammatory infiltrate, neutrophils in the lamina propria, and erosion/ulceration) and ileal index (chronic inflammatory infiltrate, neutrophils in the epithelium, and erosion/ulceration). The novel indices highly correlated with the GHAS, GS, RHI, and NHI, with correlation coefficients ≥0.80 (Table 4). Conclusion The 4 existing indices were similarly reliable and responsive in measuring CD histologic activity, regardless of the method for calculating global and colonic scores and could be used in clinical trials. Attempts at novel index development did not offer benefit over current histologic indices.