Role of hyperbaric oxygen therapy in patients with inflammatory bowel disease.

PURPOSE OF REVIEW: Hypoxia is a known contributor to inflammation in inflammatory bowel diseases (IBD), and a growing interest has emerged in pharmacologically targeting hypoxia response pathways to treat IBD. The most basic form of treatment for hypoxia is delivering higher amounts of oxygen to the intestinal mucosa. In this review, we summarize the evidence in support of hyperbaric oxygen therapy (HBOT), a mechanism to deliver high amounts of oxygen to tissue, for treating IBD. RECENT FINDINGS: Two phase 2 clinical trials in hospitalized ulcerative colitis patients suffering from moderate-to-severe flares have demonstrated that HBOT improves responsiveness to steroids and avoidance of rescue medical and surgical therapy. Outpatient cohort studies in perianal fistulizing Crohn's disease and fistulizing complications of the pouch have demonstrated improved healing, particularly for complex fistulae. Several systematic reviews have now been completed, and HBOT has been observed to be well tolerated with low rates of adverse events. SUMMARY: HBOT may be considered as an adjunctive treatment for hospitalized ulcerative colitis flares and Crohn's disease-related fistulae. Higher quality trials are needed to confirm efficacy.

Effectiveness and Safety of Biologic Therapy in Hispanic Vs Non-Hispanic Patients With Inflammatory Bowel Diseases: A CA-IBD Cohort Study.

BACKGROUND & AIMS: There are limited data on outcomes of biologic therapy in Hispanic patients with inflammatory bowel diseases (IBDs). We compared risk of hospitalization, surgery, and serious infections in Hispanic vs non-Hispanic patients with IBD in a multicenter, electronic health record-based cohort of biologic-treated patients. METHODS: We identified adult patients with IBD who were new users of biologic agents (tumor necrosis factor α [TNF-α] antagonists, ustekinumab, vedolizumab) from 5 academic institutions in California between 2010 and 2017. We compared the risk of all-cause hospitalization, IBD-related surgery, and serious infections in Hispanic vs non-Hispanic patients using 1:4 propensity score matching and survival analysis. RESULTS: We compared 240 Hispanic patients (53% male; 45% with ulcerative colitis; 73% TNF-α antagonist-treated; 20% with prior biologic exposure) with 960 non-Hispanic patients (51% male; 44% with ulcerative colitis; 67% TNF-α antagonist-treated; 27% with prior biologic exposure). After propensity score matching, Hispanic patients were younger (37 ± 15 vs 40 ± 16 y; P = .02) and had a higher burden of comorbidities (Elixhauser index, >0; 37% vs 26%; P < .01), without any differences in patterns of medication use, burden of inflammation, and hospitalizations. Within 1 year of biologic initiation, Hispanic patients had higher rates of hospitalizations (31% vs 23%; adjusted hazard ratio [aHR], 1.32; 95% CI, 1.01-1.74) and IBD-related surgery (7.1% vs 4.6%; aHR, 2.00; 95% CI, 1.07-3.72), with a trend toward higher risk of serious infections (8.8% vs 4.9%; aHR, 1.74; 95% CI, 0.99-3.05). CONCLUSIONS: In a multicenter, propensity score-matched cohort of biologic-treated patients with IBD, Hispanic patients experienced higher rates of hospitalization, surgery, and serious infections. Future studies are needed to investigate the biological, social, and environmental drivers of these differences.

Comparative Safety and Effectiveness of Biologic Therapy for Crohn's Disease: A CA-IBD Cohort Study.

BACKGROUND & AIMS: We compared the safety and effectiveness of tumor necrosis factor α (TNF-α) antagonists vs vedolizumab vs ustekinumab in patients with Crohn's disease (CD) in a multicenter cohort (CA-IBD). METHODS: We created an electronic health record-based cohort of adult patients with CD who were initiating a new biologic agent (TNF-α antagonists, ustekinumab, vedolizumab) from 5 health systems in California between 2010 and 2017. We compared the risk of serious infections (safety) and all-cause hospitalization and inflammatory bowel disease-related surgery (effectiveness) between different biologic classes using propensity score (PS) matching. RESULTS: As compared with TNF-α antagonists (n = 1030), 2:1 PS-matched, ustekinumab-treated patients with CD (n = 515) experienced a lower risk of serious infections (hazard ratio [HR], 0.36; 95% CI, 0.20-0.64), without any difference in the risk of hospitalization (HR, 0.99; 95% CI, 0.89-1.21) or surgery (HR, 1.08; 95% CI, 0.69-1.70). Compared with vedolizumab (n = 221), 1:1 PS-matched, ustekinumab-treated patients with CD (n = 221) experienced a lower risk of serious infections (HR, 0.20; 95% CI, 0.07-0.60), without significant differences in risk of hospitalization (HR, 0.76; 95% CI, 0.54-1.07) or surgery (HR, 1.42; 95% CI, 0.54-3.72). Compared with TNF-α antagonists (n = 442), 2:1 PS-matched, vedolizumab-treated patients with CD (n = 221) had a similar risk of serious infections (HR, 1.53; 95% CI, 0.84-2.78), hospitalization (HR, 1.32; 95% CI, 0.98-1.77), and surgery (HR, 0.63; 95% CI, 0.27-1.47). High comorbidity burden, concomitant opiate use, and prior hospitalization were associated with serious infections and hospitalization in biologic-treated patients with CD. CONCLUSION: In a multicenter cohort of biologic-treated patients with CD, ustekinumab was associated with a lower risk of serious infections compared with TNF-α antagonists and vedolizumab, without any differences in risk of hospitalization or surgery. The risk of serious infections was similar for TNF-α antagonists vs vedolizumab.

The Host-Microbiome Response to Hyperbaric Oxygen Therapy in Ulcerative Colitis Patients.

BACKGROUND & AIMS: Hyperbaric oxygen therapy (HBOT) is a promising treatment for moderate-to-severe ulcerative colitis. However, our current understanding of the host and microbial response to HBOT remains unclear. This study examined the molecular mechanisms underpinning HBOT using a multi-omic strategy. METHODS: Pre- and post-intervention mucosal biopsies, tissue, and fecal samples were collected from HBOT phase 2 clinical trials. Biopsies and fecal samples were subjected to shotgun metaproteomics, metabolomics, 16s rRNA sequencing, and metagenomics. Tissue was subjected to bulk RNA sequencing and digital spatial profiling (DSP) for single-cell RNA and protein analysis, and immunohistochemistry was performed. Fecal samples were also used for colonization experiments in IL10-/- germ-free UC mouse models. RESULTS: Proteomics identified negative associations between HBOT response and neutrophil azurophilic granule abundance. DSP identified an HBOT-specific reduction of neutrophil STAT3, which was confirmed by immunohistochemistry. HBOT decreased microbial diversity with a proportional increase in Firmicutes and a secondary bile acid lithocholic acid. A major source of the reduction in diversity was the loss of mucus-adherent taxa, resulting in increased MUC2 levels post-HBOT. Targeted database searching revealed strain-level associations between Akkermansia muciniphila and HBOT response status. Colonization of IL10-/- with stool obtained from HBOT responders resulted in lower colitis activity compared with non-responders, with no differences in STAT3 expression, suggesting complementary but independent host and microbial responses. CONCLUSIONS: HBOT reduces host neutrophil STAT3 and azurophilic granule activity in UC patients and changes in microbial composition and metabolism in ways that improve colitis activity. Intestinal microbiota, especially strain level variations in A muciniphila, may contribute to HBOT non-response.

Early Reduction in MM-SES-CD Score After Initiation of Biologic Therapy is Highly Specific for 1-year Endoscopic Remission in Moderate to Severe Crohn's Disease.

BACKGROUND AND AIMS: This study evaluated the minimal clinically important short-term improvement in the Modified Multiplier Simple Endoscopic Score for crohn's Disease [MM-SES-CD], a novel modified scoring system of the SES-CD, which reliably predicted 1-year endoscopic remission [ER]. METHODS: This post-hoc analysis of two CD clinical trial programmes pooled data of 198 participants with baseline ulcers and SES-CD ≥3, who had baseline, post-induction [8-12 weeks], and 1-year endoscopic assessments. Different cut-off values for endoscopic response were evaluated using receiver operating characteristic [ROC] curves, positive likelihood ratios [PLR], and negative likelihood ratios [NLR]. ER [SES-CD <3] was the binary classifier in all cases. A distribution of cut-offs minimising NLR and maximising PLR was created with 10 000 bootstrapped resamples. An optimal cut-point for low and high probability of 1-year ER was determined based on the maximum Youden Index. RESULTS: MM-SES-CD ≥40% reduction from baseline was selected as the cut-off maximising PLR and minimising NLR. Among 7.6% [15/198] participants achieving this cut-off post-induction, 1-year ER was 46.7%. One-year ER was 16.9% among those not achieving this cut-off. This threshold predicted 1-year ER with 95.0% (95% confidence interval [CI] 90.4%-97.8%) specificity and a PLR of 3.7 [95% CI 1.4-9.5], which was higher than traditional endoscopic response criteria of SES-CD ≥50% reduction [specificity 62.5%, 95% CI 54.5%-70.0%; PLR 1.9, 95% CI 1.4-2.5]. Lower thresholds of MM-SES-CD reduction also were highly specific for 1-year ER [e.g., MM-SES-CD ≥20% reduction was achieved in 19.7% of patients with 83.1% specificity]. CONCLUSIONS: In CD patients, post-induction endoscopic response defined by MM-SES-CD ≥40% reduction from baseline identified patients most likely to achieve 1-year ER.

Hyperbaric Oxygen Therapy Is Effective in the Treatment of Inflammatory and Fistulizing Pouch Complications.

Ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for medically refractory ulcerative colitis. Pouch-related complications, such as pouchitis, cuffitis, or fistulae, occur in up to 50% of patients. Nearly 1 in 5 patients develop pouch-related complications refractory to medical therapy, including biologics. Hypoxia has been suggested as a trigger for these chronic refractory complications, and treating hypoxia may be of therapeutic benefit in this patient population. We investigated the effectiveness of hyperbaric oxygen therapy (HBOT) for patients with medically refractory pouch-related complications.

A Microsimulation Model to Project the 5-Year Impact of Using Hyperbaric Oxygen Therapy for Ulcerative Colitis Patients Hospitalized for Acute Flares.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) improves short-term outcomes for ulcerative colitis (UC) patients hospitalized for acute flares. Longer-term impacts and cost-effectiveness are unknown. METHODS: We compared disease outcomes and cost-effectiveness of HBOT in addition to standard of care versus standard of care alone for UC patients hospitalized for acute flares using a microsimulation model. Published literature was used for transition probabilities, costs, and quality-adjusted life year (QALY) estimates. We modeled 100,000 individuals in each group over a 5-year horizon and compared rates of re-hospitalization, rescue medical therapy, colectomy, death, and cost-effectiveness at a willingness-to-pay of $100,000/QALY. Probabilistic sensitivity analyses were performed with 500 samples and 250 trials, in addition to multiple microsimulation sensitivity analyses. RESULTS: The use of HBOT at the time of index hospitalization for an acute UC flare is projected to reduce the risk of re-hospitalization, inpatient rescue medical therapy, and inpatient emergent colectomy by over 60% (p < 0.001) and mortality by over 30% (p <0.001), during a 5-year horizon. The HBOT strategy costs more ($5600 incremental cost) but also yielded higher QALYs (0.13 incremental yield), resulting in this strategy being cost-effective ($43,000/QALY). Results were sensitive to HBOT costs and rates of endoscopic improvement with HBOT. Probabilistic sensitivity analyses observed HBOT to be more cost-effective than standard of care in 95% of iterations. CONCLUSION: The use of HBOT to optimize response to steroids during the index hospitalization for an acute UC flare is cost-effective and is projected to result in significant reductions in disease-related complications in the long term.

A phase 2B randomised trial of hyperbaric oxygen therapy for ulcerative colitis patients hospitalised for moderate to severe flares.

BACKGROUND: Hyperbaric oxygen has been reported to improve disease activity in hospitalised ulcerative colitis (UC) patients. AIM: To evaluate dosing strategies with hyperbaric oxygen for hospitalised UC patients. METHODS: We enrolled UC patients hospitalised for acute flares (Mayo score 6-12). Initially, all patients received 3 days of hyperbaric oxygen at 2.4 atmospheres (90 minutes with two air breaks) in addition to intravenous steroids. Day 3 responders (reduction of partial Mayo score ≥ 2 points and rectal bleeding score ≥ 1 point) were randomised to receive a total of 5 days vs 3 days of hyperbaric oxygen. RESULTS: We treated 20 patients with hyperbaric oxygen (75% prior biologic failure). Day 3 response was achieved in 55% (n = 11/20), with significant reductions in stool frequency, rectal bleeding and CRP (P < 0.01). A more significant reduction in disease activity was observed with 5 days vs 3 days of hyperbaric oxygen (P = 0.03). Infliximab or colectomy was required in only three patients (15%) despite a predicted probability of 80% for second-line therapy. Day 3 hyperbaric oxygen responders were less likely to require re-hospitalisation or colectomy by 3 months vs non-responders (0% vs 66%, P = 0.002). No treatment-related adverse events were observed. CONCLUSION: Hyperbaric oxygen appears to be effective for optimising response to intravenous steroids in UC patients hospitalised for acute flares, with low rates of re-hospitalisation or colectomy at 3 months. An optimal clinical response is achieved with 5 days of hyperbaric oxygen. Larger phase 3 trials are needed to confirm efficacy and obtain labelled approval.

No benefit of continuing vs stopping 5-aminosalicylates in patients with ulcerative colitis escalated to anti-metabolite therapy.

BACKGROUND: Whilst continuation of 5-aminosalicylates (5-ASA) after escalation to biologic therapy is considered ineffective in patients with ulcerative colitis (UC), their role in patients escalated to anti-metabolites is unclear. AIM: To compared patterns and outcomes of continuing vs stopping 5-ASA in patients with UC who escalated to anti-metabolite monotherapy, using a de-identified administrative claims database. METHODS: We identified patients with UC who were new users of anti-metabolite monotherapy who were receiving 5-ASA, and were followed for at least 12 months after starting anti-metabolite therapy. We evaluated patterns of 5-ASA use (stopped 5-ASA, short-term 5-ASA use for <6 months after starting anti-metabolites, persistent 5-ASA use for >6 months after starting anti-metabolites). We compared outcomes (risk of UC-related hospitalisation and/or surgery, need for corticosteroids, treatment escalation to biologic therapy) by pattern of 5-ASA use, using Cox proportional hazard analysis adjusting for age, sex, race, comorbidity burden, and hospitalisation or emergency department visit, abdominal surgery and corticosteroid use in the previous 12 months (as measures of disease severity), with a 12-month immortal time period. RESULTS: Of 4068 patients with UC who were new-users of anti-metabolite monotherapy, 578 (14.2%), 782 (19.2%) and 2708 (66.6%) stopped 5-ASA, used 5-ASA transiently or persistently, respectively. Compared to patients who stopped 5-ASA after starting anti-metabolites, persistent 5-ASA use was associated with a higher risk of UC-related hospitalisation (HR, 1.40 [1.07-1.83]) and corticosteroid use (HR, 1.48 [1.28-1.70]), without an increase in risk of UC-related surgery (HR, 1.32 [0.86-2.00]) or treatment escalation (HR, 0.80 [0.53-1.20]). Sensitivity analyses using a 3 months window after initiation of anti-metabolites to classify patients as continuing vs stopping 5-ASA showed similar results. Residual confounding by disease severity could not be excluded. CONCLUSION: 5-ASA are usually continued long-term even after escalating to anti-metabolite therapy in patients with UC without clinical benefit.

Approaches to Integrating Biomarkers Into Clinical Trials and Care Pathways as Targets for the Treatment of Inflammatory Bowel Diseases.

BACKGROUND & AIMS: There is no consensus on the best way to integrate biomarkers into inflammatory bowel disease (IBD) research and clinical practice. The International Organization for the Study of Inflammatory Bowel Disease aimed to outline biomarker definitions, categories, and operating properties required for their use in registration trials and clinical practice. Using fecal calprotectin as an example, we provide a framework for biomarker development and validation in patients with IBD. METHODS: We reviewed international society guidelines, regulatory agency guidance documents, and standardized reporting guidelines for biomarkers, in combination with publications on fecal calprotectin levels in patients with IBD. We assessed the validity of fecal calprotectin to serve as a surrogate biomarker of IBD activity and outlined a framework for further validation and development of biomarkers. RESULTS: No endpoints have been fully validated as surrogates of risk of disease complications; mucosal healing is the most valid endpoint used to determine risk of disease complications. Fecal level of calprotectin has not been validated as a biomarker for IBD activity because of lack of technical and clinical reliability, assessment of performance when used as a replacement for endoscopy, and assessment of responsiveness to changes in disease states. The level of fecal calprotectin can be used only as a prognostic factor for disease recurrence in patients in remission after medical or surgical treatment. CONCLUSIONS: We reviewed guidelines, regulatory documents, and publications to identify properties required for the development of biomarkers of IBD activity and areas in need of clarification from regulatory agencies and societies. We propose a path forward for research of biomarkers for IBD.

No Benefit of Concomitant 5-Aminosalicylates in Patients With Ulcerative Colitis Escalated to Biologic Therapy: Pooled Analysis of Individual Participant Data From Clinical Trials.

OBJECTIVES: 5-aminosalicylates (5-ASA) are frequently continued in patients with moderate-severe ulcerative colitis (UC), even after escalation to biologic agents, without evaluation of the benefit of this approach. We conducted an individual participant data (IPD) pooled analysis of trials of infliximab and golimumab in UC, to evaluate whether concomitant use of 5-ASA modifies clinical outcomes among anti-tumor necrosis factor (TNF)-α-treated patients. METHODS: We included IPD from five trials of infliximab and golimumab in patients with moderate-severe UC (ACT-1 and -2, PURSUIT-SC, PURSUIT-M, NCT00336492). Patients treated with infliximab or golimumab were categorized as receiving concomitant 5-ASA or not at time of trial entry. Primary outcome was clinical remission (Mayo Clinic Score < 3) at last follow-up for each trial; secondary outcomes were clinical response and mucosal healing. Using multivariable logistic regression analysis, we evaluated association between concomitant 5-ASA and clinical remission, after adjusting for sex, smoking, baseline disease activity, disease extent, biochemical variables (C-reactive protein, albumin, hemoglobin), and concomitant prednisone and immunomodulators. RESULTS: We included 2183 infliximab-treated or golimumab-treated patients (1715 [78.6%] on 5-ASA). Concomitant use of 5-ASA was not associated with odds of achieving clinical remission (adjusted OR, 0.67 [95% CI, 0.45-1.01], p = 0.06), clinical response (aOR, 0.89 [0.60-1.33], p = 0.58) or mucosal healing (aOR, 1.12 [0.82-1.51], p = 0.48). These results were consistent in trials of induction and maintenance therapy, and in trials of infliximab and golimumab. CONCLUSIONS: Based on IPD pooled analysis, in patients with moderate-severe UC who are escalated to anti-TNF therapy, continuing 5-ASA does not improve clinical outcomes.

Hyperbaric oxygen therapy is well tolerated and effective for ulcerative colitis patients hospitalized for moderate-severe flares: a phase 2A pilot multi-center, randomized, double-blind, sham-controlled trial.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) markedly increases tissue oxygen delivery. Case series suggest it may have a potential therapeutic benefit in ulcerative colitis (UC). We investigated the therapeutic potential of HBOT as an adjunct to steroids for UC flares requiring hospitalization. METHODS: The study was terminated early due to poor recruitment with 18 of the planned 70 patients enrolled. UC patients hospitalized for moderate-severe flares (Mayo score ≥6, endoscopic sub-score ≥2) were block randomized to steroids + daily HBOT (n = 10) or steroids + daily sham hyperbaric air (n = 8). Patients were blinded to study assignment, and assessments were performed by a blinded gastroenterologist. Primary outcome was the clinical remission rate at study day 5 (partial Mayo score ≤2 with no sub-score >1). Key secondary outcomes were: clinical response (reduction in partial Mayo score ≥2, rectal bleeding sub-score of 0-1) and progression to second-line therapy (colectomy or biologic therapy) during the hospitalization. RESULTS: A significantly higher proportion of HBOT-treated patients achieved clinical remission at study day 5 and 10 (50 vs. 0%, p = 0.04). HBOT-treated patients less often required progression to second-line therapy during the hospitalization (10 vs. 63%, p = 0.04). The proportion requiring in-hospital colectomy specifically as second-line therapy for medically refractory UC was lower in the HBOT group compared to sham (0 vs. 38%, p = 0.07). There were no serious adverse events. CONCLUSION: In this small, proof-of-concept, phase 2A trial, the use of HBOT as an adjunctive therapy to steroids for UC patients hospitalized for moderate-severe flares resulted in higher rates of clinical remission, and a reduction in rates of progression to second-line therapy during the hospitalization. Larger well-powered trials are needed, however, to provided definitive evidence of therapeutic benefit.

Chemoprevention of colorectal cancer in individuals with previous colorectal neoplasia: systematic review and network meta-analysis.

OBJECTIVE:  To assess the comparative efficacy and safety of candidate agents (low and high dose aspirin, non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), calcium, vitamin D, folic acid, alone or in combination) for prevention of advanced metachronous neoplasia (that is, occurring at different times after resection of initial neoplasia) in individuals with previous colorectal neoplasia, through a systematic review and network meta-analysis. DATA SOURCES:  Medline, Embase, Web of Science, from inception to 15 October 2015; clinical trial registries. STUDY SELECTION:  Randomized controlled trials in adults with previous colorectal neoplasia, treated with candidate chemoprevention agents, and compared with placebo or another candidate agent. Primary efficacy outcome was risk of advanced metachronous neoplasia; safety outcome was serious adverse events. DATA EXTRACTION:  Two investigators identified studies and abstracted data. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed with surface under the cumulative ranking (SUCRA) probabilities (ranging from 1, indicating that the treatment has a high likelihood to be best, to 0, indicating the treatment has a high likelihood to be worst). Quality of evidence was appraised with GRADE criteria. RESULTS:  15 randomized controlled trials (12 234 patients) comparing 10 different strategies were included. Compared with placebo, non-aspirin NSAIDs were ranked best for preventing advanced metachronous neoplasia (odds ratio 0.37, 95% credible interval 0.24 to 0.53; SUCRA=0.98; high quality evidence), followed by low-dose aspirin (0.71, 0.41 to 1.23; SUCRA=0.67; low quality evidence). Low dose aspirin, however, was ranked the safest among chemoprevention agents (0.78, 0.43 to 1.38; SUCRA=0.84), whereas non-aspirin NSAIDs (1.23, 0.95 to 1.64; SUCRA=0.26) were ranked low for safety. High dose aspirin was comparable with low dose aspirin in efficacy (1.12, 0.59 to 2.10; SUCRA=0.58) but had an inferior safety profile (SUCRA=0.51). Efficacy of agents for reducing metachronous colorectal cancer could not be estimated. CONCLUSIONS:  Among individuals with previous colorectal neoplasia, non-aspirin NSAIDs are the most effective agents for the prevention of advanced metachronous neoplasia, whereas low dose aspirin has the most favorable risk:benefit profile. REGISTRATION:  PROSPERO (CRD42015029598).