Infliximab plus azathioprine for steroid-dependent Crohn's disease patients: a randomized placebo-controlled trial

Are we ready for top-down therapy for inflammatory bowel diseases: con

The main goal of the therapy of inflammatory bowel diseases is the induction and maintenance of disease remission. Whereas the standard medical approach is guided by the clinical symptoms and concurrent therapy of the patients ('step-up' approach), a new evolving concept for patients with Crohn's disease is trying to modify the disease course by treating intestinal inflammation early and very aggressively with anti-TNF therapy and immunosuppressive agents, such as azathioprine ('top-down' approach). This review discusses the background of this new approach in Crohn's disease and places the first available clinical results of 'top-down' therapy into perspective with available data on potential adverse effects, the natural course and the therapeutic goal of mucosal healing in Crohn's disease.

Biothérapies et MICI: anti-TNF et nouvelles cibles thérapeutiques

PURPOSE

Advances in the understanding of inflammatory bowel disease (IBD) pathophysiological mechanisms in the last few years have allowed the development of novel therapies such as biologic therapies. Theoretically, biologic therapies represent a more specific management of IBD with fewer effects.

CURRENT KNOWLEDGE AND KEY POINTS

Currently, infliximab is the only effective and widely accepted biologic therapy for the treatment of Crohn disease after the conventional therapies. Others anti-TNF therapies such as adalimumab or certolizumab will be soon an alternative treatment notably for patients with allergic reactions to infliximab and for those with lost of response because of anti-infliximab antibody development. Anti-integrin alpha4 therapies have been delayed by three progressive multifocal leukoencephalopathy cases. Immunostimulating therapy may be highly relevant in the future with granulocyte-monocyte colony-stimulating factor.

PERSPECTIVES

Efficacy of these new therapies will modify therapeutics of Crohn's disease and ulcerative colitis and in particular decrease the use of corticosteroids, which are not well tolerated by the patients.

Are we ready for top-down therapy for inflammatory bowel diseases: pro

Until the 1990s, inflammatory bowel diseases (IBD) were treated with conventional drugs, such as mesalazine, corticosteroids and thiopurines, which are effective in a proportion of IBD patients. Despite the introduction of immunosuppressive drugs, a significant number of IBD patients have a disabling disease course and, on average, a poor quality of life. The discovery of anti-TNF strategies and the development of biologics targeting several other pathways, important in the pathogenesis of ulcerative colitis and Crohn's disease, introduced a pivotal discussion. Central to this discussion is the question of whether these new therapies should be introduced early or late in the course of the disease. Important factors that are relevant for this discussion are quality of life, need for corticosteroids and surgery. This article aims to explore whether we are indeed ready for a top-down approach toward biologics.

Positioning biologic therapy for Crohn's disease and ulcerative colitis

Over the past decade, the introduction of biologic agents such as tumor necrosis factor-alpha and alpha4 integrin leukocyte adhesion molecule inhibitors has provided new and effective treatment options for patients with inflammatory bowel disease (IBD). Recent debates have centered on where biologics should be positioned within the current treatment strategy so as to maximize efficacy while balancing risk. This review highlights the current position biologics hold relative to conventional therapies within the current "step-up" treatment strategy. It also critically appraises emerging data, testing the hypothesis that positioning biologics early in the IBD treatment algorithm ("top-down" strategy) results in superior outcomes compared with the current step-up strategy, in which biologics are used only in patients failing conventional therapies or who are steroid dependent.

Estado actual del tratamiento de la enfermedad inflamatoria intestinal

Treatment of inflammatory bowel disease should take some general considerations into account, standing out among them the importance of nutrition, antithrombotic prophylaxis in certain situations, prevention of osteoporosis and prevention of colorectal cancer by endoscopic screening in extensive ulcerous colitis or Crohn's colitis. Ulcerous colitis is still effectively treated with salicylates and steroids in its mild and moderate forms. Severe forms require parenteral steroids, cyclosporine or infliximab, and these are successfully used with immunosuppressants (azathioprine or mercaptopurine) in steroid dependence. Maintenance with salicylates, that should be adequately complied with, is an important point. Crohn's disease is treated with steroids in its mild and moderate forms, and again in corticodependent ones with immunosuppressants, which we are using increasingly sooner. Refractory forms or fistulous forms benefit from the use of biological treatments (infliximab) generally accompanied by immunosuppressants.

Predictive model for the outcome of infliximab therapy in Crohn's disease based on apoptotic pharmacogenetic index and clinical predictors

BACKGROUND

Infliximab (IFX) is an effective therapy for refractory luminal and fistulizing Crohn's disease (CD). Predictors of response could improve selection of patients with a higher probability of favorable outcomes and could improve the safety profile. We aimed to develop a predictive model for the response to infliximab in CD.

METHODS

Genetic and clinical data collected in a previous pharmacogenetic study of apoptosis genes were analyzed using SAS Enterprise miner modeling software and SPSS 12.0. We proposed a novel apoptotic pharmacogenetic index (API) with a score ranging from 0 (low apoptotic response) to 3 (high apoptotic response) and subsequently developed a decision tree model.

RESULTS

Response and remission rates significantly increased with API score (P = 0.005 in the group of patients with luminal CD, P = 0.02 in the group of patients with fistulizing CD). Patients with an API < or = 1 (n = 59) had the lowest response and remission rates in both the luminal CD (50% and 39.5%, respectively) and fistulizing CD (61.9% and 28.6%, respectively) groups, compared to those with an API of 2 (n = 158), whose response and remission rates were 73.8% and 56.1%, respectively, in the luminal CD group and 85.7% and 44.9%, respectively, in the fistulizing CD group; and those with an API of 3 (n = 10), whose response and remission rates were 100% and 85.7%, respectively, in the luminal CD group and 100% and 0% in the fistulizing CD group. Response in patients with an API < or = 1 was significantly influenced by concurrent azathioprine therapy in the luminal CD (21.4% versus 78.9%, P < 0.001) and in the fistulizing CD (46.6% versus 100%, P = 0.04) groups. In patients with an API of 2, we saw an interaction with age older than 40 years and location of disease (response 52.2% versus 83.9%, P = 0.008) in the luminal CD group and with baseline CRP greater than 5 mg/L (73.9% versus 93.9%, P = 0.04) in the fistulizing CD group.

CONCLUSIONS

From our newly proposed apoptotic pharmacogenetic index and clinical predictors, we developed a model for prediction of low, medium, and high responses to the first infusion of IFX in patients with CD. Further studies are needed to confirm the hypothesis generated by our study.

Insights in immunomodulatory therapies for ulcerative colitis and Crohn's disease

Immunomodulators are a class of drugs that attenuate the underlying inflammatory processes of Crohn's disease (CD) and ulcerative colitis (UC), the two major inflammatory bowel diseases (IBD). These agents play a prominent role in the management of refractory and steroid-dependent IBD. The immunomodulatory drugs in the IBD arsenal include azathioprine, 6-mercaptopurine, methotrexate, cyclosporine, and tacrolimus. Azathioprine and 6-mercaptopurine are considered first-line immunosuppressants due to their proven efficacy in both CD and UC and their safety profile, whereas cyclosporine occupies a niche as a surgery-sparing agent in the acute management of severe, steroid-refractory UC. Immunomodulators also appear to have a role as adjunctive therapy when used with infliximab or other biologic agents to reduce immunogenicity. Although data have been limited to observational studies, azathioprine and 6-mercaptopurine may be used during pregnancy.