A dose escalating, placebo controlled, double blind, single dose and multidose, safety and tolerability study of fontolizumab, a humanised anti-interferon gamma antibody, in patients with moderate to severe Crohn's disease

Meta-analysis: remission and response from control arms of randomized trials of biological therapies for active luminal Crohn's disease

BACKGROUND

Remission and response are the main outcomes to evaluate the efficacy of new treatments for Crohn's disease (CD).

AIM

To explain variation of remission and response rates in active luminal CD.

METHODS

We studied control patients from trials of biological therapies through articles retrieved by MEDLINE search (from 1997 to 2007) and by bibliography review. Thousand nine hundred and thirteen control patients from 28 trials were identified; data were extracted by three independent observers and pooled by DerSimonian and Laird random effect model; factors influencing remission and clinical response were explored by metaregression for aggregated data.

RESULTS

The pooled control rates of remission and response were 17% and 33%, respectively, both with significant heterogeneity among studies (P < 0.0001). At metaregression, the time of primary outcome evaluation was associated with remission, whereas the trial's criteria for defining response and publication year were predictors of response. CDAI score, CRP levels or other clinical variables related with disease activity or concomitant medications were not significant factors.

CONCLUSIONS

Populations used as 'add-on' treatment comparator in trials of biological therapies for active luminal CD are poorly characterized and outcomes are heterogeneous. Planning of future trials will require better description of patients and concomitant therapies, blinding of outcome assessors and homogeneous criteria of outcome definition.

Decoy oligodeoxynucleotide targeting activator protein-1 (AP-1) attenuates intestinal inflammation in murine experimental colitis

Various therapies are used for inflammatory bowel diseases (IBD), though none seem to be extremely effective. AP-1 is a major transcription factor that upregulates genes involved in immune and proinflammatory responses. We investigated decoy oligodeoxynucleotide (ODN) targeting AP-1 to prevent dextran sulfate sodium (DSS)-induced colitis in mice. Functional efficacies of synthetic decoy and scrambled ODNs were evaluated in vitro by a reporter gene luciferase assay and measuring flagellin-induced IL-8 expression by HCT-15 cells transfected with ODNs. Experimental colitis was induced in mice with a 2.5% DSS solution in drinking water for 7 days, and decoy or scrambled ODNs were intraperitoneally injected from days 2 to 5. Colitis was assessed by weight loss, colon length, histopathology, and detection of myeloperoxidase (MPO), IL-1beta, and TNF-alpha in colon tissue. Therapeutic effects of AP-1 and NF-kappaB decoy ODNs were compared. Transfection of AP-1 decoy ODN inhibited AP-1 transcriptional activity in reporter assays and flagellin-induced IL-8 production in vitro. In mice, AP-1 decoy ODN, but not scrambled ODN, significantly inhibited weight loss, colon shortening, and histological inflammation induced by DSS. Further, AP-1 decoy ODN decreased MPO, IL-1beta, and TNF-alpha in colonic tissue of mice with DSS-induced colitis. The AP-1 decoy therapeutic effect was comparable to that of NF-kappaB decoy ODN, which also significantly decreased intestinal inflammation. Double-strand decoy ODN targeting AP-1 effectively attenuated intestinal inflammation associated with experimental colitis in mice, indicating the potential of targeting proinflammatory transcription factors in new therapies for IBD.

Cytokines and anticytokines in psoriasis

BACKGROUND

Psoriasis is a chronic autoimmune hyperproliferative skin disease of varying severity affecting approximately 2-3% of the general population in the USA and Europe. Although the pathogenesis of psoriasis has not been fully elucidated, an immunologic-genetic relationship is likely. Cutaneous and systemic overexpression of various proinflammatory cytokines (TNF, interleukins, interferon-gamma) has been demonstrated in psoriatic patients.

METHODS

We reviewed the current database literature and summarized the involvement of cytokines and their receptors in the pathogenesis and treatment of psoriasis.

RESULTS

Although many cytokine/anti-cytokine therapies have been conducted, TNF antagonists in the treatment of both psoriasis arthropatica and vulgaris appear to be the most widely used clinically. Interestingly, the efficacy and tolerability of some cytokines (rhIL-11 or ABX-IL-8,) were found to be much lower than expected.

CONCLUSIONS

Preliminary results obtained with cytokine and anti-cytokine therapies appear promising and as such continued research is clearly indicated.

Crohn's disease: a review of current treatment with a focus on biologics

Crohn's disease is a debilitating and expensive disease that is growing in incidence in both developing and developed countries. While conventional therapies, such as corticosteroids and immunosuppressants, continue to play a vital role in treating this condition, it is evident that many affected individuals do not respond to therapy or develop intolerable adverse effects. The addition of modern biological therapies to the Crohn's disease armamentarium is providing a change in expectations for disease outcome. Infliximab and adalimumab are currently the only biological agents approved for induction and maintenance treatment in adults (infliximab and adalimumab) and children (infliximab) with Crohn's disease. Furthermore, infliximab has a beneficial effect on perianal fistulas. Other tumour necrosis factor (TNF)-alpha inhibitors, such as certolizumab pegol, also demonstrate promising results in adults with moderate to severe active disease. In addition, adalimumab and certolizumab pegol have shown clinical efficacy in patients who are intolerant to or lose response to infliximab, suggesting that switching between agents may allow response to be maintained over time. The primary safety concerns with TNFalpha inhibitors include increased risk of serious infection (including reactivation of tuberculosis), malignancy (particularly lymphoma) and demyelinating disease. Other agents in development include recombinant human anti-inflammatory cytokines, agents that target pro-inflammatory cytokines and granulocyte-macrophage colony-stimulating factors. Further prospective studies will provide interesting insight into different mechanisms by which factors involved in the pathophysiology of Crohn's disease can be modulated.

Novel therapeutic options in the inflammatory bowel disease world

Advances in the understanding of the pathogenesis of inflammatory bowel disease have encouraged the development of many new therapies targeted at specific and non-specific mediators of the inflammatory bowel disease inflammatory pathway. The role of these therapies, including novel anti-tumour necrosis factor-alpha agents, anti-adhesion molecules, recombinant cytokines, myeloid growth factors, helminths, and probiotics, in the management of paediatric onset inflammatory bowel disease is promising and warrants further investigation.

Clinical pharmacokinetics and use of infliximab

Tumor necrosis factor-alpha (TNFalpha) is a key proinflammatory cytokine involved in chronic inflammatory diseases. Infliximab, a chimeric (human-murine) monoclonal IgG1 anti-TNFalpha antibody, is used in the treatment of Crohn's disease (including fistulising disease) and rheumatoid arthritis (in combination with methotrexate) if standard treatments have failed. The indications for infliximab have recently been expanded to include ankylosing spondylitis, psoriatic arthritis, psoriasis and ulcerative colitis. The biological agent infliximab is given by multiple intravenous infusions in a dosage of 3-5 mg/kg (initially at weeks 0, 2 and 6; subsequently in intervals of 4-8 weeks). In controlled trials, clinical response rates of 20-40% have been achieved with such regimens in Crohn's disease and rheumatoid arthritis. However, the therapeutic benefits must be balanced against the risks of a variety of severe adverse events (e.g. severe infections including tuberculosis, hepatotoxicity, infusion reactions, serum sickness-like disease and lymphoma). Following single and multiple infusions of infliximab, no relevant differences in median concentration-time profiles have been observed between patients with Crohn's disease, patients with rheumatoid arthritis and patients with psoriasis. The apparent volume of distribution of the high-molecular-weight infliximab (149.1 kDa) is low (3-6L) and represents the intravascular space. The long persistence in this compartment (elimination half-life 7-12 days, mean residence time 12-17 days) is due to the very low systemic clearance of about 11-15 mL/hour (0.18-0.25 mL/minute). Elimination of infliximab is most probably accomplished through degradation by unspecific proteases. During multiple infusions (every 4-8 weeks), no accumulation was observed, and serum concentrations and the area under the plasma concentration-time curve of infliximab increased in proportion to the infused dose, indicating linear pharmacokinetics. Co-medication with methotrexate delayed the decline in the serum concentrations of infliximab. When relating serum concentrations to the clinical response in patients with rheumatoid arthritis and patients with Crohn's disease, it can be assumed that trough concentrations above 1 microg/mL could be used as a kind of therapeutic target. In the future, identification of biomarkers for (non-)response and risk factors for adverse drug reactions would be very helpful. Furthermore, combined biological, pharmacokinetic, pharmacogenomic and clinical studies have not yet been performed and are needed to optimise the therapeutic potential of infliximab, which is currently established as a rescue treatment in refractory patients.

Biologics in Crohn's disease: searching indicators for outcome

New insights into the underlying mechanism of Crohn's disease is enabling the development of new therapies. Even though the mechanisms of these drugs have been studied extensively, reliable indicators for implementation of new biologic drugs are still needed. This review presents biologics in Crohn's disease focusing on efficacy, steroid sparing, mucosal healing and safety, including immunogenicity.

Inflammatory bowel disease diagnosis, evaluation and classification: state-of-the art approach

PURPOSE OF REVIEW

Progress in inflammatory bowel disease, aided by use of animal models, and focused on pathways leading to inflammation and the relationship between the innate and adaptive immune systems, is identifying target pathogenic mechanisms for therapeutic intervention. This review will describe the most recent advances and discuss promising pathways for therapeutic discovery.

RECENT FINDINGS

Identification and testing of immune and genetic markers to distinguish subgroups of patients with inflammatory bowel disease have surged over the last decade. What was limited to a few serum antibodies is now complemented with a number of genetic associations. Recent years have seen renewed interest, with additional evidence on the relationship between intestinal commensal bacteria and the inflammatory process in Inflammatory bowel disease.

SUMMARY

There is emerging evidence that discriminating pathogenic abnormalities are present in certain clusters of patients, defined by selected immune responses. These traits have been used to identify correlates between relevant mouse models and immunophenotypic clusters of patients. Such approaches will not only help us to more easily define groups of patients for study, but will also enhance our understanding of the interface between various pathways and disease expression, and ultimately, identify the primal therapeutic targets in the appropriate subgroups of patients.

Inflammatory bowel disease: clinical aspects and established and evolving therapies

Crohn's disease and ulcerative colitis are two idiopathic inflammatory bowel disorders. In this paper we discuss the current diagnostic approach, their pathology, natural course, and common complications, the assessment of disease activity, extraintestinal manifestations, and medical and surgical management, and provide diagnostic and therapeutic algorithms. We critically review the evidence for established (5-aminosalicylic acid compounds, corticosteroids, immunomodulators, calcineurin inhibitors) and emerging novel therapies--including biological therapies--directed at cytokines (eg, infliximab, adalimumab, certolizumab pegol) and receptors (eg, visilizumab, abatacept) involved in T-cell activation, selective adhesion molecule blockers (eg, natalizumab, MLN-02, alicaforsen), anti-inflammatory cytokines (eg, interleukin 10), modulation of the intestinal flora (eg, antibiotics, prebiotics, probiotics), leucocyte apheresis and many more monoclonal antibodies, small molecules, recombinant growth factors, and MAP kinase inhibitors targeting various inflammatory cells and pathways. Finally, we summarise the practical aspects of standard therapies including dosing, precautions, and side-effects.

Cytokine therapy for Crohn's disease: advances in translational research

Crohn's disease (CD) and ulcerative colitis (UC), the two idiopathic inflammatory bowel diseases (IBDs), affect almost two million individuals in North America and several million worldwide. Cytokines are important in the pathogenesis of CD, and their manipulation has successfully reduced disease severity and maintained remission. Following the discovery of novel cytokines and the role they may play in gut mucosal immunity, as well as the emergence of new concepts and changing paradigms in CD pathogenesis, the roles of several cytokines have been elucidated and tested in both preclinical animal models and clinical trials of patients with IBD. Complementary to this, proof of concept for new cytokine targets is rapidly developing, with the possibility of future cytokine-based therapies that may offer greater specificity and decreased toxicity for the treatment of CD. This review discusses novel concepts in CD pathogenesis and the roles of cytokines in the initiation and perpetuation of disease. In addition, we review applications of cytokine-based therapies in human clinical trials and preclinical animal studies. Finally, we discuss novel cytokine targets not yet investigated in vivo and describe their potential contribution to CD pathogenesis.

Advances in biologic therapy for ulcerative colitis and Crohn's disease

The medical management of inflammatory bowel disease (IBD) has changed considerably since the advent of biologic treatments. In this review we offer a critical evaluation of controlled studies with biologic agents for the management of both Crohn's disease (CD) and ulcerative colitis (UC). Biologics under evaluation or approved for UC that are discussed include monoclonal antibodies to tumor necrosis factor ([TNF]) infliximab), inhibitors of adhesion molecules (MLN02 and alicaforsen), anti-CD3 antibodies (visilizumab), and anti-interleukin (IL)-2 receptor antibodies (daclizumab). Biologics under evaluation or approved for CD that are reviewed include three monoclonal antibodies to TNF (infliximab, adalimumab, and certolizumab pegol), monoclonal antibodies against IL-12, interferon-chi, and IL-6 receptors, inhibitors of adhesion molecules (natalizumab, alicaforsen), and growth factors. Only the chimeric monoclonal anti-TNF antibody infliximab is currently available worldwide. The potency of this agent in moderate-to-severe UC and CD has been one of the most important advances in the care of IBD in the past decade.

Focus on mechanisms of inflammation in inflammatory bowel disease sites of inhibition: current and future therapies

Anti-TNF antibodies were the first biologic agents registered to treat patients who have CD and, more recently, patients who have UC. The sequence of events underlying the inflammatory reaction in IBD is extremely complex, however, and involves both the innate and antigen-driven adaptive immune system. Novel therapies are directed at several key players of this cascade. Blockade of T-cell proliferation and activation and inhibition of T-cell cytokines has been most extensively targeted by clinical trials in humans. Inhibition of adhesion molecules and the use of selected growth factors seem to have therapeutic potential. Restoration of regulatory T-cell and dendritic-cell function is still waiting to be explored in clinical trials. Although an increasing number of biologic therapies for IBD are being developed, the discovery of the full spectrum of treatment modalities is only beginning. Often, however, the clinical efficacy of biologic agents is investigated, and for some molecules is established, before mechanisms of action are specifically explored. Eight years after the Food and Drug Administration approved infliximab for the treatment of luminal CD, it is not known how this anti-TNF antibody actually dampens inflammation in IBD. The advent of newer anti-TNF agents is only postponing the answer.

Interfering with interferons in inflammatory bowel disease

Early experience of fontolizumab, a humanised anti‐interferon γ antibody, in active Crohn's disease has shown that the drug caused a significant decrease in endoscopic severity scores and CRP and was reasonably well tolerated. Fontolizumab may be worthy of further clinical trials