What is left when anti-tumour necrosis factor therapy in inflammatory bowel diseases fails?

Stem cell transplantation for induction of remission in medically refractory Crohn's disease

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease that causes inflammation and stricture, of any part of the mucosa and the gut wall. It forms skip lesions, sparing the areas in between the affected parts of the gastrointestinal tract. Crohn's disease could have one of three complications; fistula, intestinal obstruction due to stricture, or gastrointestinal inflammation presenting as severe diarrhoea. Stem cell therapy (SCT) is an innovative treatment that has been recently used in CD. The exact role of SCT in CD is still unclear. Stem cells modify the immunity of the patients or act as a "reset tool" for the immune system as in the case of systemically-injected stem cells, or regenerate the affected area of necrotic and inflammatory tissue as in the case of local injection into the lesion. Stem cells are a wide variety of cells including pluripotent stem cells or differentiated stem cells. The hazards range from rejection to symptomatic manifestations as fever or increase infection.  OBJECTIVES: The objective of this Cochrane systematic review is to assess the effects of stem cell transplantation compared to standard of care alone or with placebo on efficacy and safety outcomes in patients with refractory CD.

SEARCH METHODS

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and clinical trial registries (Clinicaltrials.gov, World Health Organization-International Clinical Trials Registry Platform WHO ICTRP) from inception to 19 March 2021, without any language, publication year, or publication status restrictions. In addition, we searched references of included studies and review articles for further references. An update of the published studies was done during the writing of the review.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) that assessed the effectiveness and safety of SCT in refractory CD versus standard care alone (control) or with placebo.

DATA COLLECTION AND ANALYSIS

Two review authors (SEN and SFA) independently screened the studies retrieved from the search results for inclusion, extracted data and assessed the risk of bias. Any disagreement was resolved through a consensus between the authors. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We conducted our search on 19 March 2021 and identified 639 records. We added two records by a manual search of the published reviews on the topic to a total of 641 records. The Covidence program removed 125 duplicates making a total of 516 reports. Two review authors (SEN and SFA) screened titles and abstracts and excluded 451 records with the remaining 65 for full-text records screened independently by the two authors; only 18 studies were considered for inclusion.  We included seven RCTs with a total of 442 participants for the meta-analysis. The intervention group included 234 patients, and the control group included 208 patients. Nine trials are ongoing and, two abstracts are awaiting classification. All patients in the control and intervention groups received the standard therapy for CD. Only three studies used blinding methods for the control group in the form of a placebo, with one study of the three stated that the blinding method was inefficient. The patients and personnel were aware of the intervention in the rest of the four studies as they were open-label trials. However, the effect of unblinding was balanced by the low risk of detection bias in five of the included studies. The evidence is uncertain about the effect of SCT on achieving clinical remission as compared to control/placebo (risk ratio (RR) 1.88, 95% Confidence Interval (CI) 0.80 to 4.41; 3 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT on achieving Crohn's Disease Activity Index (CDAI) <150 at 24 weeks compared to control (RR1.02 95% CI 0.67 to 1.56; 4 studies; very-low certainty evidence). SCT is likely to achieve fistula closure as compared to the control/placebo both in the short term (RR 1.48, 95% CI 1.12 to 1.96); low-certainty evidence) and in the long term (RR 1.42, 95% CI 1.09 to 1.87; 4 studies; low-certainty evidence) follow-up. The evidence is very uncertain about the effect of SCT to cause no difference in the number of total adverse events as compared to the control/placebo (RR 0.99, 95% CI [0.88 to  1.13); 4 studies; very-low-certainty evidence). However, SCT is likely to increase the number of serious adverse events as compared to the control/placebo (RR 1.22, 95% CI 0.88 to 1.67; 7 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT to decrease the withdrawal due to adverse events as compared to the control/placebo (RR 0.78, 95% CI 0.32 to 1.89; 3 studies; very-low certainty evidence). Funding by pharmaceutical companies was found in three studies, with one including more than 50% of our studied population.

AUTHORS' CONCLUSIONS

SCT shows an uncertain effect on clinical remission with low certainty of evidence. SCT shows an uncertain effect on CDAI score to reach <150 after 24 weeks of treatment, with very low certainty evidence. SCT shows beneficial effects on fistula-closure during short and long-term follow-up with low-certainty evidence in both outcomes. There was no change in the total number of adverse events with SCT as compared to control, with very low certainty evidence. While there was a moderate effect on increasing the number of serious adverse events in the SCT group, as compared to the control with low-certainty evidence. Withdrawal due to adverse events was slightly higher in the control group with very low certainty evidence. All the participants were refractory to standard medical treatment, but the number of participants was small, this may limit the generalizability of the results. Further research is needed for validation. More objective outcomes are needed in the assessment of stem cell effectiveness in the treatment of Crohn's disease, especially the intestinal CD subtype; with standardization of the dose, methods of stem cell preparation, route of administration, and inclusion criteria to the studies to achieve clear results.

Advances in research of tacrolimus for treatment of inflammatory bowel disease

Traditional drugs for inflammatory bowel disease (IBD) include aminosalicylic acid preparations, glucocorticoids, and immunosuppressive agents such as thiopurine and cyclosporine. In recent ten years, the application of anti-tumor necrosis factor (anti-TNF) drugs has greatly improved the clinical remission of patients with IBD, but there are still some problems, such as no response, intolerance, and recurrence after withdrawal. In recent years, tacrolimus, as a new powerful immunosuppressive agent, has been used as a second-line therapeutic drug for IBD. At present, the tacrolimus induced short-term remission effect in IBD is relatively obvious, and it has been gradually used for treatment of IBD refractory to traditional drugs or anti-TNF drugs. A few studies have found that tacrolimus can be used safely for a long time under proper monitoring. However, there is little evidence of long-term efficacy and safety. In this paper, we review the latest advances in the treatment of IBD with tacrolimus and make a comparison with anti-TNF drugs.

Diterpenoid alkaloids of Aconitum laciniatum and mitigation of inflammation by 14-O-acetylneoline in a murine model of ulcerative colitis

Aconitum laciniatum is used in Bhutanese traditional medicine for treating various chronic infections and inflammatory conditions. We carried out in-depth isolation and characterization of the phytochemicals from the root component and determined the anti-inflammatory effects of the isolated compounds against chemically-induced colitis in mice. Five diterpenoid alkaloids - pseudaconitine, 14-veratroylpseudaconine, 14-O-acetylneoline, neoline, and senbusine A - were isolated from A. laciniatum for the first time. Two of the alkaloids were tested for anti-inflammatory properties in the TNBS-induced colitis model in mice. Various parameters were measured to assess pathology including weight loss, clinical and macroscopic scores, histological structure and IFN-γ production in the gut. Of the two alkaloids tested, 14-O-acetylneoline showed significant protection against different parameters of colitic inflammation. Compared to control mice that received TNBS alone, mice treated with 14-O-acetylneoline experienced significantly less weight loss and had significantly lower clinical scores, macroscopic pathology and grades of histological inflammation. Moreover, colonic IFN-γ mRNA levels were significantly reduced in mice that received 14-O-acetylneoline compared to control mice that received TNBS alone. This alkaloid is now considered a novel anti-colitis drug lead compound.

Characterizing unmet medical need and the potential role of new biologic treatment options in patients with ulcerative colitis and Crohn's disease: a systematic review and clinician surveys

OBJECTIVES

Comparative outcomes of patients with ulcerative colitis (UC) and Crohn's disease (CD) prescribed a biologic therapy are inconclusive. The aim of this research was to characterize the degree of unmet medical need in patients with UC or CD and to identify the potential role for new therapies.

METHODS

A systematic literature review was undertaken of studies reporting outcomes associated with the use of existing biologic therapies in patients with UC or CD, focusing on the nature and rate of treatment failure. To complement the systematic review, contemporaneous data were obtained from a survey of practising gastroenterologists in the UK and France. Data were qualitatively combined in a narrative framework to evaluate the degree of unmet medical need among patients with UC or CD.

RESULTS

Studies identified in the systematic review (n = 120) were heterogeneous, particularly with respect to the definitions of treatment failure; estimates of treatment failure were high but uncertain. On the basis of standardized definitions, estimates of treatment failure provided by clinicians (n = 102) were high, and they were higher for second-line treatment failure (primary: ≤ 37%; secondary: ≤ 41%) compared with first-line treatment failure (primary: ≤ 26%; secondary: ≤ 28%). The majority of the systematic review and survey data were reflective of outcomes with infliximab and adalimumab.

CONCLUSION

High treatment failure rates associated with existing biologics, identified by the review and clinician surveys, indicate a need for other biologic treatment options to improve the management and outcomes for people with UC and CD. Outcomes associated with existing and new biologic treatments should be investigated in head-to-head randomized trials in the context of their likely uses in clinical practice.

Amelioration of trinitrobenzene sulfonic acid-induced colitis in mice by liquiritigenin

BACKGROUND AND AIM

The anti-inflammatory effects of liquiritigenin, a major flavonoid isolated from Glycyrrhizae uralensis, have been reported in many inflammation models. However, its protective effects have not been reported in a colitis model. This study investigated the anti-inflammatory effect and mechanism of liquiritigenin for trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice.

METHODS

Male mice imprinting control regions (ICR) were randomly divided into five groups: normal, TNBS-induced colitis, colitis treated with liquiritigenin at low dose (10 mg/kg) and high dose (20 mg/kg), or mesalazine (10 mg/kg). TNBS colitis induction was performed except for in the normal group, and they were treated with liquiritigenin or mesalazine except control group. The treatment effect was measured after three days treatment, by body weight, colon length, macroscopic score, histological score, levels of cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, and IL-10) in colon tissue as well as the nuclear factor kappa-light-chain-enhancer pathway of activated B cells (NF-κB) activation.

RESULTS

Mice treated with high-dose liquiritigenin showed significant body weight gain, inhibition of colon shortening, protective effect on histological damages, and myeloperoxidase activity of colon tissue compared with the control group. Furthermore, mice treated with high-dose liquiritigenin experienced significantly suppressed tumor necrosis factor-α, IL-1β, and IL-6 as well as enhanced IL-10 expression (all P < 0.05). High-dose liquiritigenin treatment group showed significant decreases in TNBS-induced phosphorylation of IKKβ, p65, and IκB-α.

CONCLUSION

Liquiritigenin may ameliorate TNBS-induced colitis in mice by suppressing expression of pro-inflammatory cytokines through NF-κB pathway.

Early investigational TNF receptor antagonists for the treatment of ulcerative colitis

INTRODUCTION

Ulcerative colitis (UC) is a life-long, immunologically mediated condition that results from an inappropriate activation of the mucosal immune system by intestinal luminal antigens in genetically susceptible individuals. TNF-α is a pro-inflammatory cytokine central to UC pathogenesis.

AREAS COVERED

This review examines the evidence for the use of the anti-TNF (αTNF) medications infliximab, adalimumab, certolizumab and golimumab in the management of UC. It highlights the newer biosimilar agents that are becoming available and the early stage investigation of an orally administered αTNF agent.

EXPERT OPINION

αTNF therapy is effective but only in a proportion of UC patients. As there is now strong evidence that UC is not just a single disease but a series of phenotypes with distinct genetic, serological and environmental aspects, understanding the heterogeneity of the innate immunological response in UC could allow for better targeted patient management. Identifying differences in the efficacy of the various αTNF agents is difficult as there are no head-to-head studies, but only infliximab has proven clinical efficacy in the management of acute severe colitis. Biosimilars to the αTNF agents are now available and with the added competition, medications costs should fall allowing for greater patient access.