Drug Insight: antagonists of tumor-necrosis factor-α in the treatment of inflammatory bowel disease

Validation of a de-immunization strategy for monoclonal antibodies using cynomolgus macaque as a surrogate for human

The immunogenicity of biotherapeutics presents a major challenge during the clinical development of new protein drugs including monoclonal antibodies. To address this, multiple humanization and de-immunization techniques that employ in silico algorithms and in vitro test systems have been proposed and implemented. However, the success of these approaches has been variable and to date, the ability of these techniques to predict immunogenicity has not been systematically tested in humans or other primates. This study tested whether antibody humanization and de-immunization strategies reduce the risk of anti-drug antibody (ADA) development using cynomolgus macaque as a surrogate for human. First human-cyno chimeric antibodies were constructed by grafting the variable domains of the adalimumab and golimumab monoclonal antibodies onto cynomolgus macaque IgG1 and Igκ constant domains followed by framework germlining to cyno to reduce the xenogenic content. Next, B and T cell epitopes and aggregation-prone regions were identified using common in silico methods to select domains with an ADA risk for additional modification. The resultant engineered antibodies had a comparable affinity for TNFα, demonstrated similar biophysical properties, and exhibited significantly reduced ADA levels in cynomolgus macaque compared with the parental antibodies, with a corresponding improvement in the pharmacokinetic profile. Notably, plasma concentrations of the engineered antibodies were quantifiable through 504 hours (chimeric) and 840 hours (germlined/de-immunized), compared with only 336 hours (adalimumab) or 336-672 hours (golimumab). The results point to the significant value in the investment in these engineering strategies as an important guide for monoclonal antibody optimization that can contribute to improved clinical outcomes.

Antitumor evaluation of carboxymethyl chitosan based norcantharidin conjugates against gastric cancer as novel polymer therapeutics

Novel polymer-drug conjugates (CNC) were prepared from carboxymethyl chitosan (CMCS) and norcantharidin (NCTD) via amidation reaction and characterized by FTIR and ¹H NMR spectroscopy. The aim of this study was to elucidate the antitumor efficacy of CNC on gastric cancer and the possible underlying mechanisms. The CNC conjugates possessed significant inhibitory effects on the proliferation of SGC-7901 cells and suppressed the migration as well as tube formation of HUVECs. Besides, Hoechst 33258 staining and Annexin V-FITC/PI detection suggested that the conjugates were more effective in triggering apoptosis of SGC-7901 cells compared with free NCTD. Moreover, CNC remarkably reduced systemic toxicity and enhanced the antitumor efficacy in vivo with a tumor suppression rate of 59.57% against SGC-7901 gastric tumor in BALB/c nude mice. Further investigation about the underlying mechanisms indicated that CNC could upregulate expressions of TNF-α and Bax, and downregulate expressions of VEGF, Bcl-2, MMP-2 and MMP-9, thereby inhibiting tumor metastasis and inducing apoptosis in vivo. Overall, our results demonstrated that CNC might be a promising and feasible polymer therapeutics for gastrointestinal tumor therapy.

Repurposing the anti-malarial drug, quinacrine: new anti-colitis properties

Background

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is associated with an increased risk of colorectal cancer in 8-10 years after disease onset. Current colitis treatment strategies do not offer a cure for the disease, but only treat the symptoms with limited success and dangerous side-effects. Also, there is no preventive treatment for either UC or colorectal cancer. Quinacrine is an anti-malarial drug with versatile use in the treatment of diseases involving inflammatory response such as rheumatoid arthritis and lupus erythematosus. It also has putative anti-cancer effect. Quinacrine's anti-inflammatory, anti-oxidant properties, and anti-tumorigenic properties make it a potential small molecule preventive agent for both UC and associated colorectal cancer.

Results

There were obvious changes in the CDI, histology, and inflammatory load in quinacrine-treated groups in a dose and time dependent manner in both models of UC, induced by chemical or haptenating agent.

Methods

We tested quinacrine at two different doses as a colitis treatment agent in two mouse models of UC - the dextran sulfate sodium and oxazolone. The clinical disease index (CDI), histological changes of the colon, levels of inflammatory markers (Cox-2, iNOS, p53) and overall health vitals were evaluated.

Conclusions

We demonstrate that quinacrine successfully suppresses colitis without any indication of toxicity or side-effects in two mouse models of UC.

Certolizumab pegol (CDP870) for rheumatoid arthritis in adults

BACKGROUND

Tumour necrosis factor (TNF)-alpha inhibitors are beneficial for the treatment of rheumatoid arthritis (RA) in terms of reducing the risk of joint damage, improving physical function and improving quality of life. This Cochrane review is an update of a review of the treatment of RA with certolizumab pegol that was first published in 2011.

OBJECTIVES

To assess the clinical benefits and harms of certolizumab pegol (CDP870) in patients with RA who have not responded well to conventional disease-modifying anti-rheumatic drugs (DMARDs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2014, Issue 5), MEDLINE, EMBASE, Scopus, TOXLINE, Web of Knowledge; websites of the US Food and Drug Administration (FDA) and European Medicines Evaluation Agency (EMEA); reference lists of articles; and searched http/clinicaltrials.gov. The searches were updated from 2009 (date of last search for the original review) to 5 June 2014.

SELECTION CRITERIA

Randomised controlled trials that compared certolizumab pegol with any other agent including placebo or methotrexate (MTX) in adult patients with active RA despite current or prior treatment with conventional disease-modifying anti-rheumatic drugs (DMARDs), such as MTX.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results, trial quality and extracted data. Disagreements were resolved by discussion or referral to a third author.

MAIN RESULTS

Eleven trials were included in this update. Ten (4324 patients) were included in the pooled analysis for benefits, five more than previously, and 10 (3711 patients) in the pooled analysis for harms, four more trials (1930 patients) than previously. The duration of follow-up varied from 12 to 52 weeks and the range of doses of certolizumab pegol varied from 50 to 400 mg given subcutaneously (sc). In phase III trials, the control was placebo plus MTX in five trials and placebo in four trials. The risk of bias of the included studies was assessed as low but there may have been a risk of attrition bias.Statistically significant improvements were observed at 24 weeks with the approved dose of 200 mg certolizumab pegol every other week, in 1) American College of Rheumatology (ACR) 50% improvement: 27% absolute improvement (95% CI 20% to 33%), NNT of 4 (95% CI 3 to 8), risk ratio (RR) 3.80 (95% CI 2.42 to 5.95); 2) the Health Assessment Questionnaire (HAQ): -12% absolute improvement (95% CI -9% to -14%), NNT of 6 (95% CI 5 to 8), mean difference (MD) - 0.35 (95% CI -0.43 to -0.26) (scale 0 to 3); 3) Disease Activity Score (DAS) remission improvement: absolute improvement 11% (95% CI 8% to 15%), NNT of 9 (95% CI 4 to 20), RR 8.47 (95% CI 4.15-17.28); and 4) radiological changes: erosion score (ES) absolute improvement -0.29% (95% CI -0.42% to -0.17%), NNT of 6 (95% CI 4 to 10), MD -0.67 (95% CI -0.96 to -0.38) (scale 0 to 230). Serious adverse events were statistically significantly more frequent for certolizumab pegol (200 mg every other week) with an absolute rate difference of 4% (95% CI 2% to 6%), NNTH of 32 (95% CI 17 to 88), Peto odds ratio (OR) 1.77 (95% CI 1.27 to 2.46). There was a statistically significant increase in all withdrawals in the placebo groups (for all doses and all follow-ups) with an absolute rate difference of -34% (95% CI -18% to -50%), NNTH of 4 (95% CI 3 to 5), NNTH of 4 (95% CI 3 to 5), RR 0.42 (95% CI 0.36 to 0.50); and there was a statistically significant increase in all withdrawals due to adverse events in the certolizumab groups (for all doses and all follow-up) with an absolute rate difference of 2% (95% CI 1% to 3%), NNTH of 55 (95% CI 27 to 238), Peto OR 1.66 (95% CI 1.15 to 2.37).The risk of bias was low and the quality of evidence was downgraded to moderate because of high rates of dropouts (> 20%) in most of the trials. We did not find any problems with inconsistency, indirectness, imprecision or publication bias.

AUTHORS' CONCLUSIONS

The results and conclusions did not change from the previous review. There is moderate-level evidence from randomised controlled trials that certolizumab pegol alone or combined with methotrexate is beneficial in the treatment of RA. Adverse events were more frequent with active treatment. We found a potential risk of serious adverse events.

Chronic inflammatory diseases: do immunological patterns drive the choice of biotechnology drugs? A critical review

Chronic inflammatory diseases represent a heterogeneous group of conditions that can affect practically any organ or system. An increasing number of biologic agents have been developed to selectively target the cell populations and signaling pathways involved in chronic inflammation, including cytokines, monoclonal antibodies and engineered receptors. This approach has been remarkably successful in alleviating some of the signs and symptoms of refractory autoimmune diseases. The use of this therapeutic strategy is likely to increase with the introduction of biosimilar agents. The different nature of these biological products makes the comparison of their pharmaceutical and clinical characteristics difficult, including safety and potency and these issues may be particularly relevant in the case of biosimilars. In addition, the heterogeneity of autoimmune diseases and of autoimmune patients, further adds to the complexity of choosing the right drug for each patient and predicting efficacy and safety of the treatment. In this review, we summarize actual knowledge about current biological agents and their use in autoimmune diseases, with a special emphasis for rheumatoid arthritis, inflammatory bowel diseases and psoriasis. The purpose of this analysis is to address the most critical issues raised by the rapid advancements in this field over recent years, and to acknowledge the potentially valuable gains brought about by the increasing availability of these new biologic agents.

Adverse effects of golimumab in the treatment of rheumatologic diseases

INTRODUCTION

A number of new biological immune modulators have become available as treatments for inflammatory diseases over the past two decades. Most prominent among them are TNF-α inhibitors (TNFi) which have been available in the clinic since the late 1990s. TNFi have demonstrated efficacy in various rheumatologic diseases as well as in inflammatory bowel disease and psoriasis. Golimumab is one of the most recently introduced TNFi.

AREAS COVERED

Although golimumab is generally well tolerated, as is the case with other TNFi and indeed with most of the marketed immunomodulatory drugs, potential adverse events may be associated with its use. Herein, we the potential adverse effects associated with golimumab therapy are reviewed. Adverse effects are divided into target-related and agent-related categories.

EXPERT OPINION

Golimumab has been demonstrated to be generally safe and well tolerated. Its safety profile seems to be very comparable to the other available TNFi. Long-term studies of golimumab and other TNFi will help establish the durability of response to golimumab as well as identify any potential delayed or cumulative adverse effects.

Paraoxonase-1 suppresses experimental colitis via the inhibition of IFN-γ production from CD4 T cells

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, where excessive Th1 cell responses are observed. We performed experiments to identify immunologically bioactive proteins in human plasma and found that paraoxonase (PON)-1, which has esterase activity and is associated with high-density lipoproteins, inhibited the IFN-γ production by both murine and human differentiating Th1 cells. Trinitrobenzene sulfonic acid-induced colitis was attenuated by the administration of PON-1. The beneficial effects of PON-1 were associated with a reduced ratio of IFN-γ-producing CD4 T cells in the mesenteric lymph nodes and decreased production of T cell-related cytokines in the colon. PON-1 inhibited the TCR-induced activation of ERK-MAPK signaling and the nuclear translocation of NF-κB in CD4 T cells. Interestingly, an excessive CD4 T cell response was observed in PON-1-deficient mice under physiological and pathological conditions. Additionally, the efficacy of PON-1 or G3C9-C284A (G3C9), which shows a higher esterase activity than PON-1, on colitis was similar to that of an anti-TNF-α mAb, which is a clinically used CD treatment. Moreover, G3C9 more effectively suppressed CD4(+)CD45RB(high) cell transfer-induced chronic colitis in mice than did PON-1, and the efficacy of G3C9 against the colitis was similar to that of the anti-TNF-α mAb. Therefore, PON-1 (or G3C9) administration may be clinically beneficial for CD patients.

Fc gamma receptor CD64 modulates the inhibitory activity of infliximab

Background

Tumor necrosis factor (TNF) is an important cytokine in the pathogenesis of inflammatory bowel disease (IBD). Anti-TNF antibodies have been successfully implemented in IBD therapy, however their efficacies differ among IBD patients. Here we investigate the influence of CD64 Fc receptor on the inhibitory activity of anti-TNFs in cells of intestinal wall.

Methods

Intestinal cell lines, monocytes/macrophages and peripheral blood mononuclear cells (PBMCs) were used as models. The efficacies of adalimumab, infliximab and certolizumab-pegol were assessed by RT-PCR for target genes. Protein levels and localizations were examined by Western blotting and immunofluorescence. Antibody fragments were obtained by proteolytic digestion, immunoprecipitation and protein chip analysis. Knock-down of specific gene expression was performed using siRNAs.

Results

Infliximab had limited efficacy towards soluble TNF in cell types expressing Fc gamma receptor CD64. Both adalimumab and infliximab had lower efficacies in PBMCs of IBD patients, which express elevated levels of CD64. Infliximab-TNF complexes were more potent in activating CD64 in THP-1 cells than adalimumab, which was accompanied by distinct phospho-tyrosine signals. Blocking Fc parts and isolation of Fab fragments of infliximab improved its efficacy. IFN-γ-induced expression of CD64 correlated with a loss of efficacy of infliximab, whereas reduction of CD64 expression by either siRNA or PMA treatment improved inhibitory activity of this drug. Colonic mRNA expression levels of CD64 and other Fc gamma receptors were significantly increased in the inflamed tissues of infliximab non-responders.

Conclusions

CD64 modulates the efficacy of infliximab both in vitro and ex vivo, whereas the presence of this receptor has no impact on the inhibitory activity of certolizumab-pegol, which lacks Fc fragment. These data could be helpful in both predicting and evaluating the outcome of anti-TNF therapy in IBD patients with elevated systemic and local levels of Fc receptors.

Apoptosis as a mechanism of action of tumor necrosis factor antagonists in rheumatoid arthritis

Tumor necrosis factor (TNF) antagonists are drugs developed to block endogenous TNF, an essential proinflammatory molecule with a central role in the pathogenesis of rheumatoid arthritis (RA). Although extensive studies have been performed concerning the mode of action of TNF-blocking agents, there are still many unresolved questions and potential differences between different TNF-blocking drugs. One unresolved issue is to what extent apoptosis is affected by TNF blockade in RA. We provide an overview of studies that have investigated the proapoptotic effect of different anti-TNF drugs in RA, searching for a unified interpretation of somewhat contradictory data.

Early versus late surgery in patients with intestinal Behçet disease

BACKGROUND

To date, no studies have been conducted to evaluate the potential benefits of early surgery in patients with intestinal Behçet disease.

OBJECTIVE

We investigated the long-term clinical outcomes in patients with intestinal Behçet disease first diagnosed at surgery ("early surgery") compared with those requiring surgical resection during the course of the disease ("late surgery").

DESIGN

This is a retrospective cohort study.

SETTINGS

This study was conducted at a single tertiary academic medical center.

PATIENTS

We reviewed the medical records of 272 consecutive patients with intestinal Behçet disease between March 1986 and August 2010.

MAIN OUTCOME MEASURES

The cumulative probabilities of clinical recurrence and reoperation after operation were the main outcomes measures.

RESULTS

Forty of 272 patients were first diagnosed with intestinal Behçet disease at surgery (early surgery); the remaining 232 were diagnosed clinically, with 62 undergoing surgery during their follow-up after clinical diagnosis (late surgery). The cumulative probabilities of postoperative clinical recurrence and reoperation were significantly lower in the early-surgery group than in the late-surgery group (p = 0.045 and p = 0.003). In multivariate analysis, early surgery was the only independent factor significantly associated with a reduced probability of reoperation (HR 0.26; 95% CI 0.10-0.71; p = 0.008). However, when we analyzed only the patients who underwent surgery because of chronic symptoms, early surgery was not associated with lower cumulative clinical recurrence and reoperation rates (p = 0.896 and p = 0.492).

LIMITATIONS

We analyzed the clinical characteristics retrospectively, and the number of patients was insufficient to reach a decisive conclusion.

CONCLUSIONS

: According to the current study, the patients with intestinal Behçet disease undergoing early surgery showed better prognoses in comparison with those undergoing late surgery. Early surgery may represent a valid approach in the initial management of the patients with intestinal Behçet disease, at least in the subset of the patients with acute symptoms.

A humanized monoclonal antibody targeting the β7 integrin selectively blocks intestinal homing of T lymphocytes

BACKGROUND AND PURPOSE

rhuMAb Beta7 is a humanized anti-human β7 monoclonal antibody currently in phase I in inflammatory bowel disease. rhuMAb Beta7 binds the β7 subunit of the integrins α4β7 and αEβ7, blocking interaction with their ligands. These integrins play key roles in immune cell homing to and retention in mucosal sites, and are associated with chronic inflammatory diseases of the gastrointestinal tract. The goal of this study was to evaluate the mucosal specificity of rhuMAb Beta7.

EXPERIMENTAL APPROACH

We assessed the effect of murine anti-Beta7 on lymphocyte homing in mouse models of autoimmune disease. We also compared the effect of rhuMAb Beta7 on circulating mucosal-homing versus peripheral-homing T cells in naïve non-human primates.

KEY RESULTS

In cynomolgus monkeys, occupancy of β7 integrin receptors by rhuMAb Beta7 correlated with an increase in circulating β7(+) mucosal-homing lymphocytes, with no apparent effect on levels of circulating β7(-) peripheral-homing lymphocytes. rhuMAb Beta7 also inhibited lymphocyte homing to the inflamed colons of severe combined immunodeficient mice in CD45RB(high) CD4(+) T-cell transfer models. Consistent with a lack of effect on peripheral homing, in a mouse model of experimental autoimmune encephalomyelitis, anti-β7 treatment resulted in no amelioration of CNS inflammation.

CONCLUSIONS AND IMPLICATIONS

The results presented here suggest that rhuMAb Beta7 selectively blocks lymphocyte homing to the gastrointestinal tract without affecting lymphocyte trafficking to non-mucosal tissues. rhuMAb Beta7 provides a targeted therapeutic approach with the potential for a more attractive benefit:risk ratio than currently available inflammatory bowel disease therapies.

Certolizumab pegol (CDP870) for rheumatoid arthritis in adults

BACKGROUND

TNF-alpha inhibitors have been shown to reduce the risk of joint damage and improve physical function and quality of life in people with rheumatoid arthritis (RA). This is the first Cochrane review of certolizumab pegol, a new TNF-alpha inhibitor.

OBJECTIVES

To assess the effectiveness and safety of certolizumab pegol (CDP870) in patients with RA who have not responded well to conventional disease modifying anti-rheumatic drugs (DMARDs).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 3),  MEDLINE (1966 to November 2009), EMBASE (1966 to November 2009), Scopus (January 2004 to November 2009), TOXLINE (until November 2009), Web of Knowledge (until November 2009); websites of the US Food and Drug Administration (FDA) and European Medicines Evaluation Agency (EMEA) (until November 2009), and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials that compared certolizumab pegol with any other agent including placebo or methotrexate (MTX) in adult RA patients with active rheumatoid arthritis despite current or prior treatment with conventional DMARDs, such as methotrexate (MTX).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results, trial quality and extracted data.

MAIN RESULTS

Five trials were included. We included in the analysis 2394 people for effectiveness and 2094 people for safety. The duration of follow-up was from 12 to 52 weeks, and the range of doses of certolizumab pegol were from 50 to 400 mg subcutaneously (sc). In three trials the control was placebo plus methotrexate (MTX) and in two trials it was just placebo. Significant improvements were observed at 24 weeks with the approved dose of 200 mg certolizumab pegol: American College of Rheumatology (ACR) 50% improvement: risk ratio (RR) 6.01 (95% CI 3.84 to 9.40) with an absolute benefit of 29% (95% CI 25% to 34%), number needed to treat to benefit (NNTB) of 4 (3 to 5) and the Health Assessment Questionnaire (HAQ) mean difference (MD) - 0.39 (95% CI -0.45 to -0.32) (scale 0 to 3). At 52 weeks the results were quite similar: ACR 50% improvement RR 5.27 (95% CI 3.19 to 8.71), HAQ mean difference (MD) - 0.42 (95% CI -0.52 to -0.32). Serious adverse events were more frequent for certolizumab pegol 200 mg, Peto OR 2.02 (95% CI 1.24 to 3.30). The most common adverse events with certolizumab pegol 200 mg were: upper respiratory tract infections, Peto OR 2.21 (95% CI 1.15 to 4.25); hypertension, Peto OR 2.81 (95% CI 1.38 to 5.75); and nasopharyngitis, Peto OR 2.71 (95% CI 1.30 to 5.66).

AUTHORS' CONCLUSIONS

With an overall high grade of evidence this review revealed an improvement of clinical results (ACR50, 28 joint disease activity score (DAS-28) remission and HAQ scores) with certolizumab pegol. Adverse events were more frequent with certolizumab; there was a statistically significant increase in the number of serious adverse events, infections and hypertension.

Comparative analysis of the effects of anti-IL-6 receptor mAb and anti-TNF mAb treatment on CD4+ T-cell responses in murine colitis

BACKGROUND

The efficacy of anti-tumor necrosis factor monoclonal antibody (anti-TNF mAb) for Crohn's disease (CD) is well established, and anti-interleukin-6 receptor (anti-IL-6R) mAb has also been reported to be effective in CD. It is, however, unclear if the efficacy and mechanisms of both agents are different in CD therapy.

METHODS

Using an adoptive transfer colitis model, we compared the efficacy of anti-IL-6R mAb, anti-TNF mAb, and TNF receptor-Fc fusion protein (TNFR-Fc), and their modes of action on CD4+ T cells. We also investigated the role of Th1 and Th17 cells in colitis using the same model.

RESULTS

The histological scores for the anti-IL-6R mAb and anti-TNF mAb groups but not for TNFR-Fc group were much lower than that for the control group, and the score was the lowest for the anti-IL-6R mAb group. The frequency of proliferating CD4+ T cells was reduced in anti-IL-6R mAb and anti-TNF mAb groups, but not in the TNFR-Fc group, whereas the frequency of apoptotic CD4+ T cells was similar in all groups. Anti-IL-6R mAb suppressed the induction of Th17 cells and increased the frequency of lamina propria regulatory T cells, whereas anti-TNF mAb exerted no influence on CD4+ T-cell differentiation. A deficiency in interferon-γ and/or IL-17 in CD4+ T cells reduced the severity of colitis.

CONCLUSIONS

Our findings suggest that suppression of the proliferation of pathogenic CD4+ T cells is the major mode of action of biological agents for colitis therapy. Anti-IL-6R mAb might have benefits in CD patients with Th17 dominance and impaired Treg frequency.

Mast cell hyperplasia, B-cell malignancy, and intestinal inflammation in mice with conditional expression of a constitutively active kit

Signaling through the receptor tyrosine kinase kit controls proliferation and differentiation of hematopoietic precursor cells and mast cells. Somatic point mutations of the receptor that constitutively activate kit signaling are associated with mastocytosis and various hematopoietic malignancies. We generated a Cre/loxP-based bacterial artificial chromosome transgenic mouse model that allows conditional expression of a kit gene carrying the kitD814V mutation (the murine homolog of the most common mutation in human mastocytosis, kitD816V) driven by the kit promoter. Expression of the mutant kit in cells of adult mice, including hematopoietic precursors, caused severe mastocytosis with 100% penetrance at young age frequently associated with additional hematopoietic (mostly B lineage-derived) neoplasms and focal colitis. Restriction of transgene expression to mature mast cells resulted in a similar mast cell disease developing with slower kinetics. Embryonic expression led to a hyperproliferative dysregulation of the erythroid lineage with a high rate of perinatal lethality. In addition, most adult animals developed colitis associated with mucosal mast cell accumulation. Our findings demonstrate that the effects of constitutive kit signaling critically depend on the developmental stage and the state of differentiation of the cell hit by the gain-of-function mutation.

Drug targeting strategies for the treatment of inflammatory bowel disease: a mechanistic update

The therapeutic management of inflammatory bowel disease (IBD) represents the perfect scenario for drug targeting to the site(s) of action. While existing formulation-based targeting strategies include rectal dosage forms and oral systems that target the colon by pH-, time-, microflora- and pressure-triggered drug release, novel approaches for site-specific delivery in IBD therapy will target the inflamed intestine per se rather than intestinal region. The purpose of this article is to present a mechanistic update on the strategies employed to achieve minimal systemic exposure accompanied by maximal drug levels in the inflamed intestinal tissue. The introduction of biological agents, micro/nanoparticulate carriers including liposomes, transgenic bacteria, and gene therapy opportunities are discussed, as well as the challenges remaining to be achieved in the targeted treatment of IBD.

Characterization of golimumab, a human monoclonal antibody specific for human tumor necrosis factor α

We prepared and characterized golimumab (CNTO148), a human IgG1 tumor necrosis factor alpha (TNFα) antagonist monoclonal antibody chosen for clinical development based on its molecular properties. Golimumab was compared with infliximab, adalimumab and etanercept for affinity and in vitro TNFα neutralization. The affinity of golimumab for soluble human TNFα, as determined by surface plasmon resonance, was similar to that of etanercept (18 pM versus 11 pM), greater than that of infliximab (44 pM) and significantly greater than that of adalimumab (127 pM, p=0.018).  The concentration of golimumab necessary to neutralize TNFα-induced E-selectin expression on human endothelial cells by 50% was significantly less than those for infliximab (3.2 fold; p=0.017) and adalimumab (3.3-fold; p=0.008) and comparable to that for etanercept. The conformational stability of golimumab was greater than that of infliximab (primary melting temperature [Tm] 74.8 °C vs. 69.5 °C) as assessed by differential scanning calorimetry.  In addition, golimumab showed minimal aggregation over the intended shelf life when formulated as a high concentration liquid product (100 mg/mL) for subcutaneous administration.  In vivo, golimumab at doses of 1 and 10 mg/kg significantly delayed disease progression in a mouse model of human TNFα-induced arthritis when compared with untreated mice, while infliximab was effective only at 10 mg/kg. Golimumab also significantly reduced histological scores for arthritis severity and cartilage damage, as well as serum levels of pro-inflammatory cytokines and chemokines associated with arthritis. Thus, we have demonstrated that golimumab is a highly stable human monoclonal antibody with high affinity and capacity to neutralize human TNFα in vitro and in vivo.

Clinical course of Crohn's disease first diagnosed at surgery for acute abdomen

BACKGROUND

The severity of clinical activity of Crohn's disease is high during the first year after diagnosis and decreases thereafter. Approximately 50% of patients require steroids and immunosuppressants and 75% need surgery during their lifetime. The clinical course of patients with Crohn's disease first diagnosed at surgery has never been investigated.

AIM

To assess the clinical course of Crohn's disease first diagnosed at surgery for acute abdomen and to evaluate the need for medical and surgical treatment in this subset of patients.

PATIENTS AND METHODS

Hospital clinical records of 490 consecutive Crohn's disease patients were reviewed. Patients were classified according to the Vienna criteria. Sex, extraintestinal manifestations, family history of inflammatory bowel diseases, appendectomy, smoking habit and medical/surgical treatments performed during the follow-up period were assessed.

STATISTICAL ANALYSIS

Kaplan-Meier survival method and Cox proportional hazards regression model.

RESULTS

Of the 490 Crohn's disease patients, 115 had diagnosis of Crohn's disease at surgery for acute abdomen (Group A) and 375 by conventional clinical, radiological, endoscopic and histologic criteria (Group B). Patients in Group A showed a low risk of further surgery (Log Rank test p<0.001) and a longer time interval between diagnosis and first operation compared to Group B (10.8 years vs. 5.8 years, p<0.01, respectively). Furthermore, patients in Group A used less steroids and immunosuppressants (OR 0.3, p<0.0001; OR 0.6, p<0.004, respectively).

CONCLUSIONS

Crohn's disease patients first diagnosed at surgery for acute abdomen showed a low risk for reintervention and less use of steroids and immunosuppressants during follow-up than those not operated upon at diagnosis. Early surgery may represent a valid approach in the initial management of patients with Crohn's disease, at least in the subset of patients with ileal and complicated disease.

Efficacy and safety of TNF-blocker therapy in systemic lupus erythematosus

BACKGROUND

There is still unmet medical need in the therapy of severe organ manifestations of patients with systemic lupus erythematosus (SLE). Therapeutic agents targeting pro-inflammatory cytokines may be an interesting option.

OBJECTIVE

To review available data on the efficacy and safety of tumour necrosis factor (TNF) blockade in SLE.

METHODS

A review of the literature was conducted.

RESULTS/CONCLUSIONS

Open-label experience suggests that TNF blockade is effective in SLE patients with arthritis, nephritis and skin disease. In particular, nephritis may remain in long-term remission after just four infusions of infliximab administered. Despite the induction of lupus-specific autoantibodies, short-term therapy with infliximab in combination with azathioprine appears feasible and relatively safe. The data call for controlled clinical trials, at least one of which has been initiated.

Infliximab restores glucose homeostasis in an animal model of diet-induced obesity and diabetes

TNF-alpha plays an important role in obesity-linked insulin resistance and diabetes mellitus by activating at least two serine kinases capable of promoting negative regulation of key elements of the insulin signaling pathway. Pharmacological inhibition of TNF-alpha is currently in use for the treatment of rheumatoid and psoriatic arthritis, and some case reports have shown clinical improvement of diabetes in patients treated with the TNF-alpha blocking monoclonal antibody infliximab. The objective of this study was to evaluate the effect of infliximab on glucose homeostasis and insulin signal transduction in an animal model of diabetes. Diabetes was induced in Swiss mice by a fat-rich diet. Glucose and insulin homeostasis were evaluated by glucose and insulin tolerance tests and by the hyperinsulinemic-euglycemic clamp. Signal transduction was evaluated by immunoprecipitation and immunoblotting assays. Short-term treatment with infliximab rapidly reduced blood glucose and insulin levels and glucose and insulin areas under the curve during a glucose tolerance test. Furthermore, infliximab increased the glucose decay constant during an insulin tolerance test and promoted a significant increase in glucose infusion rate during a hyperinsulinemic-euglycemic clamp. In addition, the clinical outcomes were accompanied by improved insulin signal transduction in muscle, liver, and hypothalamus, as determined by the evaluation of insulin-induced insulin receptor, insulin receptor substrate-1, and receptor substrate-2 tyrosine phosphorylation and Akt and forkhead box protein O1 serine phosphorylation. Thus, pharmacological inhibition of TNF-alpha may be an attractive approach to treat severely insulin-resistant patients with type 2 diabetes mellitus.

Fatal miliary Coccidioidomycosis in a patient receiving infliximab therapy: a case report

A 78-year-old white male from Iowa in the United States of America receiving the anti- tumor necrois factor (TNF) agent infliximab therapy for rheumatoid arthritis developed a cheek ulcer which failed to respond to empiric antibiotic therapy. He subsequently presented with progressive respiratory failure from miliary coccidioidomycosis which proved fatal. The patient vacationed in Arizona 6 months previously and likely contracted the organism there as Iowa is not an endemic area for coccidioidomycosis. Respiratory failure from miliary infiltration is an uncommon presentation of coccidioidomycosis. Physicians should be aware of the importance of travel history and potential for life-threatening coccidioidomycosis in patients receiving tumor necrosis factor inhibitors.

Late-breaking news from the "4th International Meeting on Inflammatory Bowel Diseases" Capri, 2006

At the "4th International Meeting on Inflammatory Bowel Diseases: on the Way to New Therapies," Capri, 2006, genetics, bacteria-host interactions, immunomodulation, and tissue response were discussed deeply in order to understand, rationalize, and develop novel therapies. About genetics, the importance of a better understanding of the nature of known loci and of the putative associations was stressed. It was confirmed that genotype-phenotype associations in inflammatory bowel disease (IBD) have important clinical and therapeutic implications. The importance of the search for dominant bacterial antigens in chronic immune-mediated intestinal inflammation emerged, as well as knowledge of cellular and molecular mechanisms of bacterial-host interactions. It was discussed how innate and adaptive immunity signaling events can perpetuate chronic inflammation. Signal transduction pathways provide an intracellular mechanism by which cells respond and adapt to environmental stress. The identification of these signals have led to a greater understanding of the pathogenesis of IBD and pointed to potential therapeutic targets. It was shown that immune homeostasis is lost in IBD, resulting in a complex tissue response involving the action of immune and nonimmune cells. The nonimmune tissue response in IBD could be regarded as a new target for control of chronic intestinal inflammation. The changing role of biotherapy in IBD was widely discussed and in particular the anti-TNF-alpha monoclonal antibodies. Granulocyte-colony stimulating factor (GM-CSF) and stem cells therapies were also discussed. The risk-to-benefit ratio of the novel therapies was analyzed in detail. Finally, future directions for basic science and the unmet needs for clinical practice were presented.

Mode of function of biological anti-TNF agents in the treatment of inflammatory bowel diseases

TNF-alpha has been identified as a major mediator in the pathophysiology of inflammation. Anti-TNF agents, either as a neutralising antibody or a soluble TNF receptor, have markedly influenced the clinical management of several chronic inflammatory disorders. Whereas it seems likely that neutralisation of soluble and membrane-bound TNF might be a key mechanism of any anti-TNF agent, the potential of the anti-TNF antibody infliximab to induce lymphocyte/monocyte apoptosis in Crohn's disease has been considered an additional important mechanism. Other potential mode of actions include induction of the anti-inflammatory cytokines IL-10 or TGF-beta via retrograde signalling or induction of a certain subset of regulatory T cells. Certolizumab, a pegylated fully human anti-TNF monoclonal antibody also effective in Crohn's disease, lacks the capacity to induce apoptosis. Therefore, the capacity to induce apoptosis and neutralisation of TNF alone are insufficient to explain clinical efficacy of anti-TNF agents in human inflammatory bowel diseases.

Adalimumab in patients with Crohn's disease--safety and efficacy in an open-label single centre study

AIM

To evaluate the efficacy and safety of adalimumab, a human antitumour necrosis factor-alpha antibody, in induction and maintenance of remission in patients with Crohn's disease either refractory or intolerant to infliximab in a single centre cohort.

METHODS

Sixteen Crohn's disease patients received 160 mg adalimumab subcutaneously in week 0, followed by 80 mg every other week. Clinical response was assessed based on Crohn's disease activity index and laboratory parameters (leukocyte count, C-reactive protein). In all patients genotyping for CARD15 variants and the +1059G/C polymorphism in the C-reactive protein gene was performed.

RESULTS

In 10 of 16 patients (63%) treated with adalimumab, remission (CDAI score <150) was induced for at least 8 weeks independent of CARD15 or +1059G/C CRP status. In six of these 10 patients ongoing remission is observed now for more than 24 weeks. Adalimumab significantly decreased C-reactive protein serum levels and Crohn's disease activity index. There was one serious complication (fungal pneumonia). Six patients intermittently developed minor dermatological problems resolving after topical therapy. Otherwise, treatment was generally well tolerated.

CONCLUSION

Adalimumab can induce and maintain remission in patients with moderate to severe Crohn's disease intolerant or refractory to infliximab. Further experience from larger cohorts is required to evaluate dose regimen and safety profiles in Crohn's disease therapy.

The inhibition of TNF-alpha anti-tumoral properties by blocking antibodies promotes tumor growth in a rat model

Tumor necrosis factor (TNF) antagonists represent a milestone in the therapy of autoimmune conditions. Anti-TNF antibodies have been approved for clinical use and during the last eight years thousands of patients have been treated. However, the long-term sequelae of anti-TNF agents in promoting carcinogenesis remain unclear. This study sought to define the role of intra-tumor TNF-alpha production on cancer cell progression and to determine whether TNF-alpha antibodies can suppress anti-tumoral immunity. Using an experimental animal tumor model we demonstrate that anti-TNF-alpha antibodies hinder anti-tumor immune responses and promote growth of immunogenic rat colon tumors (REG) that are always rejected by immunocompetent untreated rats. The major role of TNF-alpha in the anti-tumoral immune response was confirmed by transfecting progressive and tolerogenic rat colon tumor cells (PRO) with the TNF-alpha gene. PRO tumor cells secreting TNF-alpha induce tumor-infiltrating dendritic cell (DC) activation. This triggers a potent immune response leading to tumor rejection and long-lasting immunity. Therefore, the prominent role of TNF-alpha in anti-tumoral immune responses underscores the need for caution and close surveillance following the administration of TNF inhibitors.

Effects of tumour necrosis factor-alpha on human sperm motility and apoptosis

The aim of this study was to evaluate the effects of tumour necrosis factor-alpha (TNF-alpha) on sperm motility, mitochondrial membrane potential (DeltaPsi), phosphatidylserine (PS) externalization, sperm chromatin packaging quality, and DNA fragmentation. Motile spermatozoa, obtained from 10 normozoospermic men, were incubated with increasing concentrations of TNF-alpha and analyzed 1, 3, 6, and 24 h after incubation by flow cytometry. TNF-alpha decreased total motility 24 h after incubation at 10 ng/mL and progressive motility 3 h after incubation. Accordingly, TNF-alpha reduced sperm DeltaPsi in a concentration- and time-dependent manner. TNF-alpha increased the percentage of spermatozoa with PS externalization from the concentration of 1 ng/mL 1 h after incubation. TNF-alpha produced sperm chromatin and DNA damage in a concentration- and time-dependent manner. In conclusion, these findings may explain the reduction of fertility, secondary to upregulated production of TNF-alpha, in men with urogenital infections.

Treatment with biologic therapies and the risk of cancer in patients with IBD

The proven involvement of cytokines in the pathophysiology of IBD has led to the development of powerful, selective, anticytokine drugs--so-called biologics--as a therapy for IBD. Although the efficacy of infliximab, a chimeric monoclonal IgG1 antibody directed against tumor necrosis factor, is proven and the use of biologic agents is growing worldwide, there is concern about their long-term safety, which includes the risk of developing cancer. An increased risk of malignancies, particularly lymphoma, has been reported in some studies of infliximab-treated patients with IBD; however, the increased risk could be caused by the underlying chronic disease, severity of the disease, concomitant medications (e.g. conventional immunomodulators), infliximab itself, or all of these variables. At present, the data do not provide clear evidence for a causal association between infliximab and the increased cancer risk. In appropriately selected patients with severe, refractory Crohn's disease, the benefits of biologic therapy seem to outweigh the cancer risk. Multicenter, case-control studies in large populations, with a long-term follow-up are needed to define the outcome of patients with IBD treated with biologic therapies.

Targeting nanomedicines in the treatment of Crohn's disease: focus on certolizumab pegol (CDP870)

A variety of targets for therapeutic intervention are based upon advances in understanding of the immunopathogenesis of Crohn's disease. Crohn's disease is initiated by an innate immune response, which eventuates in a T-cell driven process, characterized by a T-helper cell 1 type cytokine profile. Several new treatments now focus on suppressing T-cell differentiation or T-cell inflammation. Since inflammatory bowel disease (IBD) represents a state of dysregulated inflammation, drugs that augment the anti-inflammatory response have the potential to downregulate inflammation and thereby hopefully modify the disease. Tumour necrosis factor (TNF) is a major target of research and clinical investigation. TNF has proinflammatory effects in the intestinal mucosa and is a pivotal cytokine in the inflammatory cascade. Certolizumab pegol (CDP870) is a PEGylated, Fab' fragment of a humanized anti-TNF-alpha monoclonal antibody. PEGylation increases the half-life, reduces the requirement for frequent dosing, and possibly reduces antigenicity as well. Certolizumab has been shown in Phase III trials to achieve and maintain clinical response and remission in Crohn's disease patients. It improves the quality of life. Certolizumab pegol will be indicated for moderately to severely active Crohn's disease, but it is not yet licensed in Europe or the US. It is not possible to construct an algorithm for treatment, but when compared with infliximab the two principal advantages are likely to be lower immunogenicity (as shown by anti-drug antibodies, absence of infusion reactions, and low rate of antinuclear antibodies), and a subcutaneous route of administration. These two factors may be sufficient to promote it up the pecking order of anti-TNF agents.

Drug therapy of inflammatory bowel disease in fertile women

Inflammatory bowel disease (IBD) is a disease that affects women of childbearing age. Active disease at conception increases the risk for adverse outcomes and thus postponement of pregnancy until the disease is in remission is the best advice that physicians can give their IBD patients. The majority of medications used to treat IBD are safe in pregnancy and breastfeeding; active, untreated, or undertreated disease is more deleterious than active therapy.

Interleukin-6 trans-signaling in inflammatory bowel disease

The pathogenesis of inflammatory bowel disease (IBD) is complex, involving a wide range of molecules including cytokines. Recent investigations support the important role of an interleukin-6 (IL-6) signaling pathway in the development of IBD. However, the molecular mechanisms of this pathway in the intestine remain incompletely understood. The circulating and intestinal levels of IL-6 as well as soluble IL-6 receptor (sIL-6R) are increased in patients with IBD. It is remarkable that the mucosal T cells of IBD patients are extremely resistant to apoptosis and that a large fraction of these cells express membrane-bound gp130 but not IL-6R. The accumulated evidence strongly supports the hypothesis that the development and perpetuation of IBD relies on the increased formation of IL-6/sIL-6R complexes interacting with membrane-bound gp130 on T cells via trans-signaling. These studies suggest that IL-6 trans-signaling may play a role in the development of IBD; they therefore imply the possibility of a selective therapeutic strategy to target this signaling.