Management of patients with inflammatory bowel disease and spondyloarthritis

Introduction: More than half of the patients with inflammatory bowel disease (IBD) experience at least one extra-intestinal manifestation (EIM). The most common EIM in patients with IBD is spondyloarthritis (SpA). Microscopic intestinal inflammation is documented in almost 50% of the patients with SpA.

Areas covered: We give an overview of the classification, the epidemiology and the diagnosis of IBD and SpA. The treatment goals, the pharmacologic management options and the available treatment guidelines in IBD patients with SpA are discussed.

Expert commentary: The coexistence of IBD and SpA generates challenges and opportunities for both the gastroenterologist and the rheumatologist. The potential of drugs with a gut-specific mode of action in the treatment of IBD-related arthritis warrants further exploration.     

Biological therapies for inflammatory bowel disease: controversies and future options

Over the last few years, advances in understanding the pathogenesis of inflammatory bowel disease, together with progress in biotechnology, have led to the availability of several biological drugs that have dramatically changed the therapeutic approach to these disorders. Indeed, several molecules targeting crucial inflammatory cytokines, blocking T-cell activation/proliferation or the recruitment of inflammatory cells into the inflamed bowel, have been discovered and commercialized. However, the increasing use of biological agents has raised some concerns regarding their short- and long-term safety. This review offers a critical evaluation of the efficacy and safety of biological agents in the management of both Crohn’s disease and ulcerative colitis. In addition, promising therapeutic options are discussed.     

Evaluation of new therapies for inflammatory bowel disease

The pathophysiology of inflammatory bowel disease (IBD) is gradually being unravelled and new therapies are being developed to target the disturbed biological processes. This article outlines the clinical features of IBD, its current therapy and pathogenesis. The difficulties for clinical pharmacologists and gastroenterologists associated with designing, executing and interpreting clinical trials in IBD are then discussed. The final section reviews methods that can used to demonstrate the pharmacological actions of new treatments in patients with IBD. It is emphasized that proof of the therapeutic efficacy of a novel agent with a specific mechanism of action yields not only clinical benefit to patients with IBD, but also indicates the importance of the targeted biochemical pathway in the pathogenesis of the disease.     

From model to mechanism: lessons of mice and men in the discovery of protein biologicals for the treatment of inflammatory bowel disease

Successful therapeutics for inflammatory bowel disease (IBD) must be able to reverse effectively the complex processes involved in the manifestation of inflammatory pathology in intact tissues. Although studies of human tissue samples are important to confirm the biological rationale for developing a particular therapeutic, in vivo rodent models of IBD provide a biological ‘flask’ in which therapeutics can be tested in a more representative setting. Moreover, gene targeting and transgenic technologies in rodents have exponentially increased the repertoire of available IBD models and provided insight into possible contributions that certain genes may have in the pathogenesis of disease. These models have been key in generating the current arsenal of biological therapeutics that are available, or are presently under investigation, for the treatment of IBD patients.     

Safety of infliximab for the treatment of inflammatory bowel disease: current understanding of the potential for serious adverse events

Introduction: Infliximab, a chimeric monoclonal antibody directed towards TNF-α, has revolutionized the treatment of inflammatory bowel disease (IBD). Since this therapy suppresses the immune system by neutralizing the immunological activity of TNF, concerns exist regarding the potential for infection, malignancy and immune disorders.

Areas covered: Comprehensive data from randomized controlled trials, meta-analyses and cohort studies have defined the risk of infection and malignancy with infliximab. Additional data regarding associations with immune disorders, such as drug-induced lupus, demyelinating syndromes and psoriaform skin disease have emerged, primarily from case reports. We report evidence from the most robust data sources that have examined these adverse events.

Expert opinion: A modest increase in the incidence of serious infection with infliximab and TNF-antagonists has been observed in methodologically rigorous studies. Combination therapy with an immunosuppressant does not confer a higher risk of serious infection than infliximab monotherapy. TNF-antagonist therapy alone with an immunosuppressant is not associated with higher rates of malignancy. Additional data are required to define causality, the magnitude and determinants of risk for other immune-related complications. Available data suggest the therapeutic index of infliximab is favorable for treatment of moderate-to-severe IBD.     

Novel therapies based on enhancement of gut innate immunity in inflammatory bowel disease

Inflammatory bowel disease (IBD), in particular Crohn's disease (CD) and ulcerative colitis (UC), results from several known and unknown genetic and environmental factors, altering the gut innate immunity and the gut adaptive immunity. The first genetic discoveries pointed to dysfunctions of the sensing systems in the intestinal tract towards dangerous as well as innumerable commensal bacteria of the gut lumen, confirming their role as main environmental factors. Recent advances in the pathophysiology of innate immunity are reviewed, concerning chiefly microbial–epithelial interactions, with the role of the mucus barrier (mucins, trefoil factors), the localisation of the microbiota normally absent beneath the mucus layer and present and invasive in IBD, the numerous defensive functions of the epithelial barrier that could be altered in IBD (tight junction proteins, defence receptors: Toll-like receptors, NOD2/CARD15, peroxysome proliferator activated receptor-γ (PPAR- γ), secretion of microcidal β-defensins, release of exosomes, autophagocytosis etc.). In the lamina propria, natural killer cells, macrophages and dendritic cells play an important role in innate immunity, particularly the dendritic cells, potent sensing and antigen- presenting cells, triggering either adaptive immunity with its potentially serious inflammatory consequences or inducing immunotolerance through T regulatory cells. By studying in-depth innate immunity, including the role of mesenteric fat in CD, it may be possible to discover the aetiological primary events of IBD and also to design more therapies based on enhancement of innate immunity. These therapies are reviewed with the impetus of various patented drugs and the still-too-rare randomised clinical trials: agents reinforcing the mucus barrier, the epithelial barrier and the lamina propria cell functions for innate immunity. As recent studies confirmed dysfunctions of granulocytes, particularly neutrophils in IBD, trials aimed at stimulating granulocytes and macrophages were interesting and gave encouraging results. PPAR-γ agonists are also effective in UC patients and may explain one of the modes of actions of sulfasalazine, beside its inhibition of the NF-κB. Many studies underlined the role of some probiotics in enhancement of the intestinal epithelial barrier function, but so far randomised clinical trials were positive only for the prevention and treatment of UC and pouchitis. Genetically modified probiotics delivering trefoil factor or IL-10 are very promising. Finally, treatments based on the enhancement of innate immunity might lower the risks of treatments based on reduction of adaptive immunity (immmunosuppressants and biologicals).     

Current pharmacotherapy for inflammatory bowel disease

Ulcerative colitis (UC) and Crohn’s disease (CD), collectively termed inflammatory bowel disease (IBD), are chronic spontaneously relapsing enteropathies of unknown aetiology. Pharmacotherapy for IBD has essentially been unchanged for over twenty years, with therapy based around 5-aminosalicylic acid (5-ASA) preparations, corticosteroids, antibiotics and immunosuppression. Much of the controversy surrounding optimal use of these drugs in IBD arises as a consequence of methodological deficiencies in many of the early trials combined with the difficulty in consistent patient selection due to the heterogeneous nature of both UC and CD. More recently, well-designed clinical trials have attempted to provide an ‘evidence based’ approach to managing IBD which, in time, will allow optimisation of current therapies and accurate evaluation of novel agents. Over the past two decades, improved research methodology has considerably increased our molecular understanding of the aetiopathogenesis of IBD which has ultimately lead to the development of specific mediator directed or ‘designer’ drug therapy for IBD. This review evaluates the literature on current IBD therapy, summarises the important recent studies which have made an impact on clinical practice, and examines the risks and benefits of the novel agents which are currently under investigation in clinical trials of IBD therapy.     

New developments in the treatment of inflammatory bowel disease

Therapy of inflammatory bowel disease (IBD) is rapidly changing with the advent of new discoveries in disease pathogenesis. The need for targeted therapies against the uncontrolled immuno-inflammatory reaction in IBD together with a prerequisite for minimal side effects is driving improvement in old medicines and is leading to the development of new drugs. This review introduces emerging changes in IBD treatment, such as improvements in conventional IBD medications or their use. Balsalazide, budesonide and changes in the use of 5-aminosalicylate (5-ASA) products and purine analogues, such as azathioprine, are discussed. Additionally, studies examining the role of drugs newly introduced into IBD therapy, such as mycophenolate mofetil (MMF), thalidomide and heparin, are stated. Emerging biological therapies, such as therapies against TNF, therapies to enhance anti-inflammatory cytokines, therapeutic manoeuvres to disrupt immune cell trafficking, anti-oxidant therapies, as well as non-conventional treatments, such as diet therapies, prebiotics and probiotics, and helminth therapies are discussed.     

Novel drug delivery strategies for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses two idiopathic inflammatory diseases of the intestinal tract: Crohn’s disease and ulcerative colitis. Existing therapy for IBD consists mainly of orally or rectally administered small drug molecules, such as 5-aminosalicylates and corticosteroids, or potent systemic immune suppressants. IBD presents a challenging target for drug delivery, particularly by the oral route, as, contrary to most therapeutic regimens, minimal systemic absorption and maximal intestinal wall drug levels are desired. Several delivery strategies are employed to achieve this goal, including the chemical modification of the drug molecules, the use of controlled- and delayed-release formulations and the use of bioadhesive particles. The goal of this review is to summarise existing IBD therapy and examine novel approaches in intestinal drug delivery.     

Ferric maltol (ST10): a novel oral iron supplement for the treatment of iron deficiency anemia in inflammatory bowel disease

Introduction: Iron deficiency anemia affects up to three quarters of patients with inflammatory bowel disease (IBD). It can significantly impact the quality of life and the ability to work by impairing physical, emotional, and cognitive functioning. The etiology of iron deficiency anemia is multifactorial and oral or intravenous iron replacement is necessary. However, oral iron supplements are often discontinued prematurely due to poor tolerability or insufficient efficacy. Moreover, intravenous supplementation is inconvenient, associated with potentially serious safety risks, and a burden on healthcare resources.

Areas covered: Ferric maltol is a novel ferric iron compound with potential use as an oral therapy for iron deficiency anemia. This overview explains how the molecule’s design impacts clinical outcomes and summarizes available clinical data (ranging from early comparisons with ferrous sulfate to randomized, placebo-controlled, Phase III data in patients with IBD known to be intolerant of oral ferrous products).

Expert opinion: Ferric maltol offers the ability to treat iron deficiency anemia in mild-to-moderate IBD without resorting to intravenous therapy, even in those who are intolerant of oral ferrous products. This clinical benefit has the potential to change treatment pathways and increase choice, not only in IBD but also perhaps in many areas beyond gastroenterology.     

Micro/nano-particulate drug delivery systems: a boon for the treatment of inflammatory bowel disease

Enzyme therapies for lysosomal storage diseases have developed over the past decade into the standard-of-care for affected patients. Such therapy for Gaucher disease has been the prototype, using natural source or recombinant forms of human acid β-glucosidase (GCase). In Gaucher disease, macrophages are the repository for the pathological lipid and the target for delivery of GCase. The macrophage mannose receptor provides a Trojan horse for intracellular delivery of intravenously administered GCase (man-GCase) with mannosyl-terminated oligosaccharide chains. Passage through several hostile compartments (e.g., plasma) leads to inefficient delivery of man-GCase to macrophage lysosomes. However, regular infusions of man-GCase re-establishes health in affected patients. Similar results are being obtained in several other lysosomal storage diseases. Evolving gene and chaperone approaches provide alternative treatment strategies.     

炎症性肠病的药物治疗现状

炎症性肠病（inflammatory bowel disease,IBD）目前是消化系统疾病的研究热点之一,主要包括溃疡性结肠炎（ulcerative colitis,UC）和克罗恩病（Crohn''s disease,CD）,其发病机制尚未完全阐明,也尚无针对IBD的有效治疗药物。随着对IBD发病机制的深入研究,出现了一些新型药物和制剂。笔者就IBD及其药物治疗的研究现状作一简要综述。     

化学诱导型结肠炎动物模型的研究进展

实验动物模型对于发现抗炎症性肠病的药物及探讨其发病机制具有重要作用。通过文献查阅,综述了目前用于炎症性肠病药理学研究的化学诱导型结肠炎动物模型的研究进展,从制备方法、模型特征、可能的致病机制和用途等方面进行了详细的论述。对于认知和了解炎症性肠病的发病机制及在实验中对IBD实验动物模型的选择提供一定的依据。     

PF-00547659 for the treatment of Crohn’s disease and ulcerative colitis

Introduction: Gut-specific homing is mainly mediated by the expression of MAdCAM-1 on endothelial cells.

An increase in MAdCAM-1 expression has been shown in patients with inflammatory bowel disease (IBD).

Areas covered: PF-00547659 is a fully human monoclonal antibody (mAb) toward MAdCAM-1 on endothelial cells, blocking its binding with the α4β7 integrin on leukocytes. This review discusses the available data on effectiveness and safety of PF-00547659 in IBD.

Expert opinion: A phase II study in moderate-to-severe ulcerative colitis (UC) patients, both naïve and previously exposed to anti-tumor necrosis factors, showed that PF-00547659 was superior to placebo for induction of remission, response, and mucosal healing at week 12. In contrast, preliminary results in a similar study in Crohn’s disease (CD) did not show a superiority of PF-00547659, suggesting that PF-00547659 may have limited impact over CD outcomes. However, the time frame needed to evaluate clinical effectiveness of PF-00547659 may be longer in CD patients, given its transmural characteristic. In addition, it should be taken into consideration the possibility of incorporating new tools and more objective parameters in disease assessment that are proven to better correlate with inflammation. Future randomized-controlled trials are needed to confirm the efficacy of PF-00547659 in CD.     

Safety of vedolizumab in the treatment of Crohn’s disease and ulcerative colitis

Introduction: Vedolizumab is the latest FDA-approved anti-integrin therapy for treatment of moderate-to-severe inflammatory bowel disease (IBD). The safety and efficacy of vedolizumab have been studied in short-term clinical trials.

Areas covered: This paper reviews the safety profile of vedolizumab compared with other biologics. It also highlights the mechanism of action of the medication. We discuss the current position of vedolizumab in our current algorithm for IBD management and comment on future prospects of the drug.

Expert opinion: Vedolizumab appears to be a safe and effective option in the treatment of moderate-to-severe IBD in the short term. Long-term observational studies and post-marketing safety data are needed to ascertain the long-term efficacy and side effect profile.     

Will novel oral formulations change the management of inflammatory bowel disease?

Introduction: The traditional management of inflammatory bowel disease (IBD) with sulphasalazine/5-aminosalicylic acid, glucocorticoids and immunomodulators (i.e., thiopurines and methotrexate) was nearly two decades ago extended with intravenously or subcutaneously administered biologics (i.e., tumor necrosis factor inhibitors and later gut-selective integrin antagonists). However, recently, orally administered treatments with simple, well-characterized, and stable structures consisting of either small molecules or anti-sense therapy have been devised.

Areas covered: This review discusses the current approaches with promising new oral drugs with distinct modes of action, including: the Janus kinase inhibitors (i.e., tofacitinib, filgotinib and peficitinib); the immunomodulatory drug (laquinimod); a small α4 antagonist (AJM300); agonists for sphingosine-phosphate receptors (i.e., ozanimod, APD334, and amiselimod), as well as anti-sense therapy (mongersen) targeting SMAD7, drugs which directly target intracellular pathways of relevance for intestinal inflammation.

Expert opinion: A new avenue using easily administered oral therapies for the management of IBD is being introduced. While their place in the clinical armamentarium remains to be proven, it is likely that many of these drugs will find their place in the treatment algorithm of IBD in the next few years. Thus, we will face times in which IBD therapy will be based on significantly more tablets than prescribed today.     

Long-term treatment with infliximab in inflammatory bowel disease: safety and tolerability issues

Crohn's disease and ulcerative colitis represent the most common forms of inflammatory bowel disease (IBD), clinical conditions affecting the small and/or large bowel. It is well known that IBD is an immune-mediated condition and that TNF-α plays a pivotal role in the pathogenesis of the disease. TNF-α has been scrupulously studied as a target for therapeutic intervention in this setting. A number of biologic compounds have been developed, including the European Medicine Agency (EMEA)-approved agents, infliximab and adalimumab. Although their efficacy in induction and maintenance of remission has been established by several clinical trials, many issues regarding safety remain to be elucidated. In fact, anti-TNF treatment may be associated with a number of rare, but serious, adverse events, including infusion reactions, infections, lymphomas and other malignancies. A black-box warning has to be taken into consideration when looking at potential serious infections such as tuberculosis. Active infections, demyelinating disorders and severe heart failure are contraindications for anti-TNF treatment. This review focuses on drug toxicity and adverse events related to infliximab treatment in IBD.     

Expert opinion on interleukin-12/23 and interleukin-23 antagonists as potential therapeutic options for the treatment of inflammatory bowel disease

Introduction: Blockade of interleukin (IL)-12 and IL-23 is a novel therapeutic target for inflammatory bowel disease (IBD). The monoclonal antibody targeting the shared p40 subunit of IL-12 and IL23, namely ustekinumab, has been approved for Crohn’s disease (CD) and has demonstrated promising results in the treatment of ulcerative colitis. Several agents targeting the IL-23-specific p19 subunit are currently in various stages of development. These newer agents have the potential to provide safety benefits.

Areas covered: This review discusses the current state of IL-12/23 and IL-23 antagonists for the treatment of IBD. With multiple biologic classes available, we make recommendations for positioning of these agents in clinical practice.

Expert opinion: While tumor necrosis factor (TNF) antagonists remain the biologic of choice for majority of patients with moderate-to-severe IBD, IL-12/23, and IL-23 antagonists should be considered for first- or second-line therapy because of their efficacy in biologic-naïve and experienced patients. Additionally, IL-12/23 and IL-23 antagonists may be preferred over anti-TNF therapy in older patients who are at increased risk for infections and malignancy. The safety compared to anti-TNF may be even greater when one considers that concurrent immunosuppression is probably not necessary when using this class of drug, owing to the low rates of immunogenicity.