Perianal fistulising Crohn's disease: utilising the TOpClass classification in clinical practice to provide targeted individualised care.

BACKGROUND AND AIMS: Perianal fistulation is a challenging phenotype of Crohn's disease with significant impact on quality of life. Historically, fistulae have been classified anatomically in relation to the sphincter complex, and management guidelines have been generalised, with lack of attention to the clinical heterogenicity seen. The recent 'TOpClass classification system' for perianal fistulising Crohn's disease (PFCD) addresses this issue, and classifies patients into defined groups, which provide a focus for fistula management that aligns with disease characteristics and patient goals. In this article, we discuss the clinical applicability of the TOpClass model and provide direction on its use in clinical practice. METHODS: An international group of perianal clinicians participated in an expert consensus to define how the TOpClass system can be incorporated into real-life practice. This included gastroenterologists, IBD surgeons, and radiologists specialised in PFCD. The process was informed by the multi-disciplinary team management of eight high-volume fistula centres in North America, Europe, and Australia. RESULTS: The process produced position statements to accompany the classification system and guide PFCD management. The statements range from the management of patients with quiescent perianal disease to those with severe PFCD requiring diverting-ostomy and/or proctectomy. The optimisation of medical therapies, as well as the use of surgery, in fistula closure and symptom management is explored across each classification group. CONCLUSION: This article provides an overview of the system's use in clinical practice. It aims to enable clinicians to have a pragmatic and patient-goal centred approach to medical and surgical management options for individual patients with PFCD.

Long-term safety and efficacy of filgotinib for the treatment of moderately to severely active ulcerative colitis: Interim analysis from up to 4 years of follow-up in the SELECTION open-label long-term extension study.

BACKGROUND: Filgotinib, an oral, once-daily, Janus kinase 1 preferential inhibitor, is an approved treatment for moderately to severely active ulcerative colitis. AIMS: The aim of this study is to assess the safety and efficacy of continued filgotinib therapy over ~4 years in the long-term extension of the phase 2b/3 SELECTION trial (SELECTIONLTE; NCT02914535). METHODS: In this interim analysis of SELECTIONLTE, SELECTION completers (week 10 responders to filgotinib who completed the maintenance study) continued their assigned treatment (double-blind filgotinib 200 mg [FIL200] or filgotinib 100 mg) and SELECTION week 10 non-responders received open-label FIL200. We assessed safety by adverse events (AEs), and efficacy by partial Mayo Clinic Score (pMCS), inflammatory biomarkers and health-related quality of life (HRQoL). We compared safety and efficacy between achievers and non-achievers of a multi-component endpoint, comprehensive disease control (CDC), comprising symptomatic, endoscopic, inflammatory biomarker and HRQoL improvements. RESULTS: Data for completers (n = 250) and non-responders (n = 372) were reported for ≤202 weeks. AE occurrences were low and consistent with previous analyses. The as-observed proportion of FIL200-treated patients in pMCS, biomarker and HRQoL remission during SELECTIONLTE remained high among completers (week 144: 80.0%, 86.4% and 86.0%, respectively) and increased among non-responders (week 192: 62.1%, 76.7% and 59.3%, respectively). Significantly higher proportions of CDC achievers at SELECTION week 58 achieved pMCS, IBDQ and corticosteroid-free pMCS remission than non-achievers, up to LTE week 96. CONCLUSIONS: Filgotinib induced and maintained symptomatic remission and improved HRQoL over 4 years. Safety results showed a proven long-term benefit-risk profile. FIL200-treated CDC achievers had better long-term outcomes than non-achievers.

The Impact of PAD4-dependent Neutrophil Extracellular Trap Formation on the Early Development of Intestinal Fibrosis in Crohn's Disease.

BACKGROUND AND AIMS: During early phases of inflammation, activated neutrophils extrude neutrophil extracellular traps (NETs) in a PAD4-dependent manner, aggravating tissue injury and remodelling. In this study, we investigated the potential pro-fibrotic properties and signalling of NETs in Crohn's disease (CD). METHODS: NETs and activated fibroblasts were labelled on resected ileum from CD patients by multiplex immunofluorescence staining. NETs-treated human primary intestinal fibroblasts were analysed by bulk RNA-sequencing to uncover cell signalling pathways, and by high-throughput imaging to assess collagen production and migratory activity. Consequentially, TLR2/NF-kB pathway was evaluated by transfection of CCD-18Co fibroblasts with NF-kB-luciferase reporter plasmid, incorporating C29 to block TLR2 signalling. A chronic DSS mouse model was used to define the specific role of PAD4 deletion in neutrophils (MRP8-Cre, Pad4fl/fl). RESULTS: Immunofluorescence showed spatial co-localisation of NETs and activated fibroblasts in ileal ulcerations of CD patients. Transcriptomic analysis revealed upregulation of pro-fibrotic genes and activation of TLR-signalling pathways in NETs-treated fibroblasts. NETs treatment induced fibroblast proliferation, diminished migratory capability, and increased collagen release. Transfection experiments indicated a substantial increase in NF-kB expression with NETs, whereas C29 led to decreased expression and release of collagen. In line, a significantly reduction in collagen content was observed in the colon of MRP8-Cre, Pad4fl/fl mice subjected to chronic DSS colitis. CONCLUSIONS: NETs potentially serve as an initial stimulus for pathological activation of fibroblasts within the intestine via the TLR2/NF-kB pathway. Given their early involvement in inflammation, inhibition of PAD4 might offer a strategy to modulate both inflammation and fibrogenesis in CD.

Benefit-Risk Trade-offs and Patient Preferences for Therapy Selection in Ulcerative Colitis: a Multicountry Preference Study.

BACKGROUND: To help navigate the complex treatment landscape of ulcerative colitis (UC), we quantified the benefit-risk trade-offs that patients were willing to make when choosing treatment. METHODS: Patients completed an online discrete choice experiment. Eligible patients had a UC diagnosis for ≥6 months, were aged ≥18 years, and resided in France, Germany, Italy, Spain, or the UK. Patients chose between 2 hypothetical treatments set up to ensure trade-offs were made. Clinical trial data, literature review, and patient interviews identified treatment attributes. Relative attribute importance (RAI) scores and maximum acceptable risks were generated. A patient-centric benefit-risk assessment of 200 mg of filgotinib was conducted as an example to show how measured trade-offs can be used. RESULTS: Overall, 631 patients participated; patients had a mean age of 42.2 years and were predominantly male (75.3%). Achieving and maintaining clinical remission was the most important factor for patients (RAI 32.4%); to achieve this, patients were willing to accept slightly higher risks of blood clots, serious infections, and malignancies compared with lower risk treatment profiles. Patients also valued the convenience of oral treatments, avoiding steroids, and the ability to attend school/work. The patient-centric benefit-risk assessment suggested patients are significantly more likely to prefer Janus kinase 1 preferential inhibitor filgotinib over placebo. CONCLUSIONS: Achieving clinical remission was the highest treatment priority for patients. To attain this, patients were willing to accept some slightly higher risk treatment profiles. Patient choices in the benefit-risk assessment suggested patients were significantly more likely to prefer filgotinib over placebo.

Patients were willing to accept slightly higher risk treatment profiles over lower risk treatment profiles for an increased chance of achieving and maintaining remission. A patient-centric benefit-risk assessment suggested 200 mg of filgotinib had an acceptable benefit-risk profile.

Eosinophil Depletion as a Potential Therapeutic Strategy in Acute and Chronic Intestinal Inflammation Based on a Dextran Sulfate Sodium Colitis Model.

BACKGROUND: A role for eosinophils in intestinal inflammation and fibrosis in the context of inflammatory bowel disease has been suggested, yet the precise nature, whether causal or secondary remains debated. Hence, it remains unclear whether targeting eosinophils should be further explored as a treatment option in inflammatory bowel disease. METHODS: Acute and chronic dextran sulfate sodium colitis was induced in wild-type C57BL/6 mice. Eosinophils were depleted by anti-CCR3 injections before colitis induction in a chronic model and after colitis onset in an acute model in order to investigate the impact of eosinophil depletion on pre-existing colitis. Inflammation was assessed using the disease activity index, macroscopic damage, and histological disease activity score. In the chronic model, fibrosis was assessed by examining colon weight/length ratio, collagen deposition through Martius Scarlet Blue staining, hydroxyproline assay, and COL1A1 expression. Protein and gene expression were assessed using the Meso Scale Discovery platform and real-time quantitative polymerase chain reaction. RESULTS: In the acute and chronic colitis model, eosinophil depletion resulted in reduced disease activity and faster recovery, as observed via the total area under the curve of the disease activity index (P = .004 and P = .02, respectively), macroscopic damage score (P = .009 and P = .08, respectively), and histological disease activity score (P = .09 and P = .002, respectively). In the acute model, the accelerated recovery was accompanied by an increase in interleukin (IL)-10 (P = .03) and a decrease in IL-4 (P = .03) and IL-6 (P = .009). Colon weight/length ratio and collagen deposition were not affected by eosinophil depletion. CONCLUSIONS: Eosinophil depletion prevents and decreases intestinal inflammation in a preclinical dextran sulfate sodium model without affecting fibrosis. These results pave the way for exploring eosinophil depletion as a novel treatment modality in addressing intestinal inflammation.

This study investigated the effect of eosinophil depletion on intestinal inflammation and fibrosis in a dextran sulfate sodium colitis model. Our findings suggest a proinflammatory role for eosinophils and therefore warrant further investigation into eosinophil targeting as a treatment option for inflammatory bowel disease patients.

Intercellular interaction between FAP+ fibroblasts and CD150+ inflammatory monocytes mediates fibrostenosis in Crohn's disease.

Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibrostenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate the mechanisms underlying fibrostenosis in CD, we analyzed the transcriptome of cells isolated from the transmural ileum of patients with CD, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from patients without CD. Our computational analysis revealed that profibrotic signals from a subset of monocyte-derived cells expressing CD150 induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. The transcription factor TWIST1 was identified as a key modulator of fibroblast activation and extracellular matrix (ECM) deposition. Genetic and pharmacological inhibition of TWIST1 prevents fibroblast activation, reducing ECM production and collagen deposition. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibrostenosis in CD.

Re-evaluating Methods for Assessing Differences in Response in Ileal vs. Colonic Crohn's Disease: A Post-hoc Analysis of the FITZROY Trial.

BACKGROUND AND AIMS: The ileum is the most commonly affected segment of the gastrointestinal tract in Crohn's disease (CD). We aimed to determine whether disease location affects response to filgotinib, a Janus kinase (JAK) inhibitor, in patients with moderate-to-severely active Crohn's disease (CD) and applying appropriate methods to account for differences in measuring disease activity in the ileum compared to the colon. METHODS: This post-hoc analysis of data from the FITZROY phase 2 trial (NCT02048618) compared changes in the Crohn's Disease Activity Index (CDAI) and Simple Endoscopic Score for Crohn's Disease (SES-CD) amongst patients with ileal-dominant and isolated colonic CD treated with 10 weeks of filgotinib 200 mg daily or placebo. A mixed effects model for repeated measures was used to test whether ileal disease responded differently than colonic disease, by evaluating for effect modification using the interaction term of treatment assignment-by-disease location. RESULTS: Numerically greater proportions of patients with isolated colonic disease compared to ileal-dominant CD achieved clinical remission (CDAI <150, 75.9% vs. 41.6%) and endoscopic response (SES-CD reduction by 50%, 52.5% vs. 15.5%) at Week 10. However, after adjusting for baseline disease activity by disease location and within-patient clustering effects, there was no significant difference in treatment response by disease location (mean difference in ΔCDAI between ileal-dominant vs. isolated colonic disease +9.24 [95% CI: -87.19, +105.67], p=0.85; mean difference in ΔSES-CD -1.93 [95% CI: -7.03, +3.44], p=0.48). CONCLUSIONS: Filgotinib demonstrated similar efficacy in ileal-dominant and isolated colonic CD when controlling for baseline disease activity and clustering effects.

Impact of Prior Biologic or Janus Kinase Inhibitor Therapy on Efficacy and Safety of Etrasimod in the ELEVATE UC 52 and ELEVATE UC 12 Trials.

BACKGROUND AND AIMS: Etrasimod is an oral, once daily, selective sphingosine 1-phosphate [S1P]1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis [UC]. This subgroup analysis evaluated the efficacy and safety of etrasimod 2 mg once daily vs placebo by prior biologic/Janus kinase inhibitor [bio/JAKi] exposure in ELEVATE UC 52 and ELEVATE UC 12. METHODS: Pre-defined efficacy endpoints were assessed at Weeks 12 and 52 in ELEVATE UC 52 and Week 12 in ELEVATE UC 12 in bio/JAKi-naïve and -experienced patients, and at Week 12 [pooled] based on prior advanced therapy exposure mechanism. RESULTS: In the ELEVATE UC 52 and ELEVATE UC 12 analysis populations, 80/274 [29.2%] and 74/222 [33.3%] patients receiving etrasimod and 42/135 [31.1%] and 38/112 [33.9%] patients receiving placebo, respectively, were bio/JAKi-experienced. In both bio/JAKi-naïve and -experienced patients, a significantly greater proportion receiving etrasimod vs placebo achieved clinical remission (p<0.05) in ELEVATE UC 52 at Weeks 12 [naïve: 30.9% vs 9.7%; experienced: 17.5% vs 2.4%] and 52 [naïve: 36.6% vs 7.5%; experienced: 21.3% vs 4.8%]; in ELEVATE UC 12, this was observed only for bio/JAKi-naïve patients [naïve: 27.7% vs 16.2%, p=0.033; experienced: 18.9% vs 13.2%, p=0.349]. Similar patterns were observed for most efficacy endpoints. Among patients with prior anti-integrin exposure [N=90], a significantly greater proportion achieved clinical response [54.1% vs 27.6%, p=0.030], but not clinical remission [9.8% vs 3.4%, p=0.248], with etrasimod vs placebo. CONCLUSIONS: Bio/JAKi-naïve and -experienced patients had clinically meaningful induction and maintenance treatment benefits with etrasimod vs placebo.

Recommendations for Broadening Eligibility Criteria in Inflammatory Bowel Disease Clinical Trials.

BACKGROUND: Clinical trial recruitment for patients with inflammatory bowel disease (IBD) has become more challenging over time. We aimed to develop recommendations for broadening IBD clinical trial eligibility to improve the inclusion of a more representative patient population in a more efficient timeline. METHODS: We applied the RAND/UCLA Appropriateness Method focused on broadening IBD clinical trial eligibility. A literature review was performed for 7 domains, each representing a different area related to trial recruitment. Based on these domains, 32 statements were developed. A questionnaire was sent to IBD specialists to anonymously vote on each statement with regards to its appropriateness and feasibility. After the first round of voting, participants met for a moderated discussion to review all statements. At the end of the discussion a second round of anonymous voting led to the final recommendations. RESULTS: The final round of voting resulted in 26 statements. All were rated as feasible and 25 of 26 rated as appropriate. Recommendations generally are to be more inclusive of complicated disease phenotypes, more liberal around safety criteria, to recognize the importance of non-invasive imaging and biomarkers, to minimize the washout period and to not enforce a minimum or maximum number of prior medications, to allow a recently recorded colonoscopy to count as a baseline study, and to be less restrictive of age. CONCLUSION: Recommendations to broaden clinical trial eligibility were found to be both appropriate and feasible with a high degree of agreement amongst an international group of IBD specialists.

Fibrostricturing Crohn's Disease Is Marked by an Increase in Active Eosinophils in the Deeper Layers.

INTRODUCTION: Approximately 50% of patients with Crohn's disease (CD) develop intestinal strictures necessitating surgery. The immune cell distribution in these strictures remains uncharacterized. We aimed to identify the immune cells in intestinal strictures of patients with CD. METHODS: During ileocolonic resections, transmural sections of terminal ileum were sampled from 25 patients with CD and 10 non-inflammatory bowel disease controls. Macroscopically unaffected, fibrostenotic, and inflamed ileum was collected and analyzed for immune cell distribution (flow cytometry) and protein expression. Collagen deposition was assessed through a Masson Trichrome staining. Eosinophil and fibroblast colocalization was assessed through immunohistochemistry. RESULTS: The Masson Trichrome staining confirmed augmented collagen deposition in both the fibrotic and the inflamed regions, though with a significant increased collagen deposition in the fibrotic compared with inflamed tissue. Distinct Th1, Th2, regulatory T cells, dendritic cells, and monocytes were identified in fibrotic and inflamed CD ileum compared with unaffected ileum of patients with CD as non-inflammatory bowel disease controls. Only minor differences were observed between fibrotic and inflamed tissue, with more active eosinophils in fibrotic deeper layers and increased eosinophil cationic protein expression in inflamed deeper layers. Last, no differences in eosinophil and fibroblast colocalization were observed between the different regions. DISCUSSION: This study characterized immune cell distribution and protein expression in fibrotic and inflamed ileal tissue of patients with CD. Immunologic, proteomic, and histological data suggest inflammation and fibrosis are intertwined, with a large overlap between both tissue types. However strikingly, we did identify an increased presence of active eosinophils only in the fibrotic deeper layers, suggesting their potential role in fibrosis development.

Forecasted infliximab concentrations during induction predict time to remission and sustained disease control of inflammatory bowel disease.

BACKGROUND: Infliximab (IFX) exposure is established as a predictive factor of pharmacokinetic (PK) origin in inflammatory bowel disease (IBD), and expert consensus is to achieve adequate exposure during induction to achieve and sustain remission. METHODS: We retrospectively evaluated the performance of a Bayesian PK tool in IBD patients starting IFX. Trough IFX serum levels collected immediately before the third (at week 6) and fourth (at week 14) infusions were evaluated from 307 IBD patients (median age=17 years, 50 % females, 83 % with Crohn's disease). Forecasted IFX concentration at the fourth infusion were estimated using serum IFX, antibodies to IFX, albumin and weight determined immediately before the third infusion using population PK calculator with Bayesian prior. The outcome variable was a clinical & biochemical remission status achieved (CRP levels below 3 mg/L in presence of clinical remission). Statistics consisted of Kaplan Meier analysis with calculation of Hazard ratio (HR), and logistic regression. RESULTS: IFX concentration above 15 µg/mL immediately before the third infusion associated with shorter time to clinical & biochemical remission than concentration below 15 µg/mL without reaching significance (163±14 days vs 200±16 days, respectively; p=0.052). However, using PK parameters at the third infusion, forecasted IFX concentrations above 10 µg/mL immediately before the fourth infusion were significantly associated with a higher rate (HR=1.6 95 %CI: 1.1 to 2.1 p<0.01) and shorter time to remission (148±18 days vs 200±13 days p<0.01). In the presence of IFX concentration above 15 µg/mL at the third infusion, there was a significant 2.5-fold higher likelihood of sustained clinical & biochemical remission status during maintenance as compared to IFX concentrations below 15 µg/mL (p<0.01). Forecasted IFX level above 10 µg/mL at fourth infusion associated with significantly 3.9-fold higher likelihood of clinical & biochemical remission as compared to forecasted IFX concentrations below 10 µg/mL (p<0.01). CONCLUSIONS: These data further support that optimized IFX concentrations during induction are associated with enhanced disease control in IBD.

Efficacy and Safety of Ustekinumab for Chronic Pouchitis: A Prospective Open-label Multicenter Study.

BACKGROUND & AIMS: Seventeen percent of patients with ulcerative colitis that undergo proctocolectomy with pouch surgery will develop chronic pouchitis. We evaluated the efficacy of ustekinumab for these patients. METHODS: We performed a prospective study of patients with chronic pouchitis receiving ustekinumab intravenously at baseline (∼6 mg/kg) and 90 mg ustekinumab subcutaneously every 8 weeks thereafter. The Modified Pouchitis Disease Activity Index (mPDAI) was assessed at baseline and weeks 16 and 48. The primary endpoint was the proportion of patients achieving steroid-free remission (mPDAI <5 and reduction by ≥2 points) at week 16. Secondary endpoints included the proportion of patients achieving remission at week 48, the proportion of patients achieving response (reduction of mPDAI by ≥2 points) at weeks 16 and 48, and change in mPDAI. RESULTS: We enrolled 22 patients (59% male; median age, 42.2 years). Remission was achieved in 27.3% at week 16 and 36.4% at week 48. Response was achieved in 54.5% both at weeks 16 and 48. The median mPDAI decreased from 8 (interquartile range [IQR], 7-10) to 7 (IQR, 4-9) at week 16 (P = .007) and 4 (IQR, 1.75-7.25) at week 48 (P < .001). The clinical mPDAI subscore decreased from 3.5 (IQR, 2-4) to 2 (IQR, 1-3) at week 16 (P = .009) and 1 (IQR, 0-2.25) at week 48 (P = .001). The endoscopic mPDAI subscore decreased from 5.5 (IQR, 4-6) to 4 (IQR, 3-6) at week 16 (P = .032) and 3 (IQR, 1.75-4.25) at week 48 (P = .001). CONCLUSION: Ustekinumab was efficacious in one-half of the patients suffering from chronic pouchitis. Ustekinumab should therefore be positioned in the treatment algorithm of chronic pouchitis. (ClinicalTrials.gov Number NCT04089345).

Rigorous Donor Selection for Fecal Microbiota Transplantation in Active Ulcerative Colitis: Key Lessons From a Randomized Controlled Trial Halted for Futility.

BACKGROUND & AIMS: Rigorous donor preselection on microbiota level, strict anaerobic processing, and repeated fecal microbiota transplantation (FMT) administration were hypothesized to improve FMT induction of remission in ulcerative colitis (UC). METHODS: The RESTORE-UC trial was a multi-centric, double-blind, sham-controlled, randomized trial. Patients with moderate to severe UC (defined by total Mayo 4-10) were randomly allocated to receive 4 anaerobic-prepared allogenic or autologous donor FMTs. Allogenic donor material was selected after a rigorous screening based on microbial cell count, enterotype, and the abundance of specific genera. The primary endpoint was steroid-free clinical remission (total Mayo ≤2, no sub-score >1) at week 8. A pre-planned futility analysis was performed after 66% (n = 72) of intended inclusions (n = 108). Quantitative microbiome profiling (n = 44) was performed at weeks 0 and 8. RESULTS: In total, 72 patients were included, of which 66 received at least 1 FMT (allogenic FMT, n = 30 and autologous FMT, n = 36). At week 8, respectively, 3 and 5 patients reached the primary endpoint of steroid-free clinical remission (P = .72), indicating no treatment difference of at least 5% in favor of allogenic FMT. Hence, the study was stopped due to futility. Microbiome analysis showed numerically more enterotype transitions upon allogenic FMT compared with autologous FMT, and more transitions were observed when patients were treated with a different enterotype than their own at baseline (P = .01). Primary response was associated with lower total Mayo scores, lower bacterial cell counts, and higher Bacteroides 2 prevalence at baseline. CONCLUSION: The RESTORE-UC trial did not meet its primary endpoint of increased steroid-free clinical remission at week 8. Further research should additionally consider patient selection, sterilized sham-control, increased frequency, density, and viability of FMT prior to administration. CLINICALTRIALS: gov, Number: NCT03110289.

Enhancing probiotic impact: engineering Saccharomyces boulardii for optimal acetic acid production and gastric passage tolerance.

Saccharomyces boulardii has been a subject of growing interest due to its potential as a probiotic microorganism with applications in gastrointestinal health, but the molecular cause for its probiotic potency has remained elusive. The recent discovery that S. boulardii contains unique mutations causing high acetic acid accumulation and inhibition of bacterial growth provides a possible clue. The natural S. boulardii isolates Sb.P and Sb.A are homozygous for the recessive mutation whi2S270* and accumulate unusually high amounts of acetic acid, which strongly inhibit bacterial growth. However, the homozygous whi2S270* mutation also leads to acetic acid sensitivity and acid sensitivity in general. In the present study, we have constructed a new S. boulardii strain, derived from the widely therapeutically used CMCN I-745 strain (isolated from the pharmaceutical product Enterol), producing even higher levels of acetic acid while keeping the same tolerance toward low pH as the parent Enterol (ENT) strain. This newly engineered strain, named ENT3, has a homozygous deletion of ACH1 and strong overexpression of ALD4. It is also able to accumulate much higher acetic acid concentrations when growing on low glucose levels, in contrast to the ENT wild-type and Sb.P strains. Moreover, we show the antimicrobial capacity of ENT3 against gut pathogens in vitro and observed that higher acetic acid production might correlate with better persistence in the gut in healthy mice. These findings underscore the possible role of the unique acetic acid production and its potential for improvement of the probiotic action of S. boulardii.IMPORTANCESuperior variants of the probiotic yeast Saccharomyces boulardii produce high levels of acetic acid, which inhibit the growth of bacterial pathogens. However, these strains also show increased acid sensitivity, which can compromise the viability of the cells during their passage through the stomach. In this work, we have developed by genetic engineering a variant of Saccharomyces boulardii that produces even higher levels of acetic acid and does not show enhanced acid sensitivity. We also show that the S. boulardii yeasts with higher acetic acid production persist longer in the gut, in agreement with a previous work indicating competition between probiotic yeast and bacteria for residence in the gut.

Analysis of tofacitinib safety in ulcerative colitis from the completed global clinical developmental program up to 9.2 years of drug exposure.

BACKGROUND AND AIMS: Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We report an integrated summary of tofacitinib safety from the completed global UC clinical program (9.2 years maximum tofacitinib exposure). METHODS: This analysis included patients receiving tofacitinib 5 or 10 mg twice daily (b.i.d.) from completed phase 2/3 placebo-controlled studies, an open-label, long-term extension study and a randomized phase 3b/4 study. Proportions and incidence rates (IRs; unique patients with events/100 patient-years [PY] of exposure) were evaluated for deaths and adverse events (AEs) of special interest (AESI). RESULTS: Overall, 1157 patients received ≥1 dose of tofacitinib 5 or 10 mg b.i.d.; 938 (81.1%) were in the predominant dose tofacitinib 10 mg b.i.d. group; 552 (47.7%) received tofacitinib for ≥2 years; total exposure: 3202.0 PY; 994 (85.9%) experienced AEs; 254 (22.0%) experienced serious AEs. Median treatment duration: 1.7 (range 0.0-9.2) years. IRs (95% CI) for combined tofacitinib doses: deaths 0.24 (0.10-0.48); serious infections (SIs) 1.80 (1.37-2.32); herpes zoster (HZ; non-serious and serious) 3.24 (2.63-3.94); serious HZ 0.24 (0.10-0.48); opportunistic infections 0.96 (0.65-1.36); malignancies (excluding non-melanoma skin cancer [NMSC]) 0.88 (0.59-1.26); NMSC 0.71 (0.45-1.07); major adverse cardiovascular events 0.27 (0.12-0.52); deep vein thrombosis 0.06 (0.01-0.22); pulmonary embolism 0.18 (0.07-0.40); and gastrointestinal perforations 0.09 (0.02-0.27). CONCLUSIONS: Except for HZ and SIs, IRs for AESI were <1 case/100 PY. Safety was consistent with previous analyses of shorter exposure and tofacitinib's known safety profile, including real-world data. CLINICALTRIALS: GOV: NCT00787202; NCT01465763; NCT01458951; NCT01458574; NCT01470612; NCT03281304.

Ozanimod Differentially Impacts Circulating Lymphocyte Subsets in Patients with Moderately to Severely Active Crohn's Disease.

BACKGROUND: Ozanimod showed efficacy and safety in the phase 2 STEPSTONE study conducted in patients with moderately to severely active Crohn's disease. AIMS: This analysis assessed the effects of ozanimod on circulating lymphocytes in Crohn's disease. METHODS: Patients received ozanimod 0.92 mg for 12 weeks. Lymphocyte subtypes were evaluated using multicolor flow analysis on blood samples collected before treatment and on Week 12. Absolute lymphocyte count changes were analyzed by Wilcoxon signed rank tests. Disease activity changes and efficacy outcomes were evaluated at Week 12, and associations with lymphocyte subtype levels were assessed using Spearman's correlation and logistic regression. RESULTS: Reductions in median total T, Th, and cytotoxic T cells occurred at Week 12 (45.4%-76.8%), with reductions in most subtypes of 47.5% to 91.3% (P < 0.001). CD8+ terminally differentiated effector memory cells were largely unaffected (median change, - 19%; P = 0.44). Reductions in median total B cells occurred at Week 12 (76.7%), with reductions in subtypes of 71.4% to 81.7% (P < 0.001). Natural killer and monocyte cell counts were unchanged. Greater baseline levels and changes in nonswitched memory B cells were significantly associated with clinical, endoscopic, and histologic efficacy (P < 0.05, all comparisons). CONCLUSIONS: Ozanimod reduced circulating levels of all B-cell and most T-cell subsets but not monocytes or natural killer cells. Key subsets relevant to immune surveillance were not reduced, supporting the low risk of infection and malignancy with ozanimod in chronic inflammatory diseases. Levels of nonswitched memory B cells were associated with efficacy, providing a potential marker for ozanimod response. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02531113, EudraCT: 2015-002025-19.

Efficacy and Safety of Etrasimod in Patients with Moderately to Severely Active Isolated Proctitis: Results From the Phase 3 ELEVATE UC Clinical Programme.

BACKGROUND AND AIMS: Pivotal trials in ulcerative colitis have historically excluded patients with isolated proctitis. Etrasimod is an oral, once-daily, selective sphingosine 1-phosphate1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis. This post hoc analysis assessed efficacy and safety of etrasimod 2 mg once daily in patients with isolated proctitis (centrally read) from the phase 3 ELEVATE UC 52 and ELEVATE UC 12 trials. METHODS: Patients, including those with isolated proctitis (<10 cm rectal involvement) who met all other inclusion criteria in ELEVATE UC 52 and ELEVATE UC 12, were randomised 2:1 to receive etrasimod or placebo. Primary, secondary and other identified efficacy endpoints and safety were assessed. RESULTS: We analysed data from 64 and 723 patients at Week 12 (both trials pooled), and 36 and 397 patients at Week 52 (ELEVATE UC 52 only) with isolated proctitis and more extensive colitis (≥10 cm rectal involvement), respectively. Patients with isolated proctitis receiving etrasimod demonstrated significant improvements versus placebo, including clinical remission rates at Weeks 12 (42.9% vs 13.6%) and 52 (44.4% vs 11.1%), endoscopic improvement (52.4% vs 22.7%) at Week 12 and bowel urgency numerical rating scale score at Week 12 (all p < 0.01). Generally similar trends were observed in patients with more extensive colitis. Safety was consistent across subgroups, with no new findings. CONCLUSIONS: Etrasimod demonstrated significant improvements versus placebo in patients with isolated proctitis, and those with more extensive disease, in most efficacy endpoints at Week 12 and 52. Clinicaltrials.gov: NCT03945188; NCT03996369.

Best Practice for Therapeutic Drug Monitoring of Infliximab: Position Statement from the International Association of Therapeutic Drug Monitoring and Clinical Toxicology.

BACKGROUND: Infliximab, an anti-tumor necrosis factor monoclonal antibody, has revolutionized the pharmacological management of immune-mediated inflammatory diseases (IMIDs). This position statement critically reviews and examines existing data on therapeutic drug monitoring (TDM) of infliximab in patients with IMIDs. It provides a practical guide on implementing TDM in current clinical practices and outlines priority areas for future research. METHODS: The endorsing TDM of Biologics and Pharmacometrics Committees of the International Association of TDM and Clinical Toxicology collaborated to create this position statement. RESULTS: Accumulating data support the evidence for TDM of infliximab in the treatment of inflammatory bowel diseases, with limited investigation in other IMIDs. A universal approach to TDM may not fully realize the benefits of improving therapeutic outcomes. Patients at risk for increased infliximab clearance, particularly with a proactive strategy, stand to gain the most from TDM. Personalized exposure targets based on therapeutic goals, patient phenotype, and infliximab administration route are recommended. Rapid assays and home sampling strategies offer flexibility for point-of-care TDM. Ongoing studies on model-informed precision dosing in inflammatory bowel disease will help assess the additional value of precision dosing software tools. Patient education and empowerment, and electronic health record-integrated TDM solutions will facilitate routine TDM implementation. Although optimization of therapeutic effectiveness is a primary focus, the cost-reducing potential of TDM also merits consideration. CONCLUSIONS: Successful implementation of TDM for infliximab necessitates interdisciplinary collaboration among clinicians, hospital pharmacists, and (quantitative) clinical pharmacologists to ensure an efficient research trajectory.

Simulated cost-effectiveness of a novel precision-guided dosing strategy in adult patients with Crohn's disease initiating infliximab maintenance therapy.

BACKGROUND: Patients with Crohn's disease (CD) who lose response to biologics experience reduced quality of life (QoL) and costly hospitalizations. Precision-guided dosing (PGD) provides a comprehensive pharmacokinetic (PK) profile that allows for biologic dosing to be personalized. We analyzed the cost-effectiveness of infliximab (IFX) PGD relative to two other dose intensification strategies (DIS). METHODS: We developed a hybrid (Markov and decision tree) model of patients with CD who had a clinical response to IFX induction. The analysis had a US payer perspective, a base case time horizon of 5 years, and a 4-week cycle length. There were three IFX dosing comparators: PGD; dose intensification based on symptoms, inflammatory markers, and trough IFX concentration (DIS1); and dose intensification based on symptoms alone (DIS2). Patients that failed IFX initiated ustekinumab, followed by vedolizumab, and conventional therapy. Transition probabilities for IFX were estimated from real-world clinical PK data and interventional clinical trial patient-level data. All other transition probabilities were derived from published randomized clinical trials and cost-effectiveness analyses. Utility values were sourced from previous health technology assessments. Direct costs included biologic acquisition and infusion, surgeries and procedures, conventional therapy, and lab testing. The primary outcomes were incremental cost-effectiveness ratios (ICERs). The robustness of results was assessed via one-way sensitivity, scenario, and probabilistic sensitivity analyses (PSA). RESULTS: PGD was the cost-effective IFX dosing strategy with an ICER of 122,932 $ per quality-adjusted life year (QALY) relative to DIS1 and dominating DIS2. PGD had the lowest percentage (1.1%) of patients requiring a new biologic through 5 years (8.9% and 74.4% for DIS1 and DIS2, respectively). One-way sensitivity analysis demonstrated that the cost-effectiveness of PGD was most sensitive to the time between IFX doses. PSA demonstrated that joint parameter uncertainty had moderate impact on some results. CONCLUSIONS: PGD provides clinical and QoL benefits by maintaining remission and avoiding IFX failure; it is the most cost-effective under conservative assumptions.