Impact of patient characteristics on the clinical efficacy of mongersen (GED-0301), an oral Smad7 antisense oligonucleotide, in active Crohn's disease.

BACKGROUND: In a phase 2 study, mongersen, an oral antisense oligonucleotide targeting Smad7, was effective in inducing clinical remission in approximately 60% of patients with active Crohn's disease (CD). AIM: In a post hoc analysis to evaluate those patient disease characteristics that may have influenced the efficacy and safety of mongersen therapy. METHODS: Patients with steroid-dependent/resistant, active CD were randomised to mongersen 10, 40 or 160 mg/day or placebo for 2 weeks; patients were followed for 10 weeks. Clinical remission [Crohn's Disease Activity Index (CDAI) score <150] and clinical response (CDAI score reduction ≥100 points) were assessed at weeks 2, 4 and 12 for these subgroups: disease duration <5/≥5 years, human serum C-reactive protein (hsCRP) <3/≥3 mg/L, and CDAI at baseline ≤260/>260. Additional patient baseline and disease characteristics were explored. RESULTS: Clinical remission and response rates were significantly higher in patients receiving mongersen 40 and 160 mg/day but not 10 mg/day vs. placebo and independent of disease duration and hsCRP. Patients with baseline CDAI ≤260 had significantly higher remission rates with 40 and 160 mg/day. In patients with baseline CDAI >260, remission rates were statistically greater with 160 mg/day and numerically better with 40 mg/day vs. placebo. Adverse event rates were similar across treatment groups. Mongersen was safe and well tolerated. CONCLUSIONS: Patients with higher CDAI scores achieved clinical remission most frequently with the highest mongersen dose. Disease duration and baseline human serum C-reactive protein did not appear to significantly impact efficacy of mongersen in this study (EudraCT Number: 2011-002640-27.).

Th17-type cytokines, IL-6 and TNF-α synergistically activate STAT3 and NF-kB to promote colorectal cancer cell growth.

Colorectal cancers (CRCs) often show a dense infiltrate of cytokine-producing immune/inflammatory cells. The exact contribution of each immune cell subset and cytokine in the activation of the intracellular pathways sustaining CRC cell growth is not understood. Herein, we isolate tumor-infiltrating leukocytes (TILs) and lamina propria mononuclear cells (LPMCs) from the tumor area and the macroscopically unaffected, adjacent, colonic mucosa of patients who underwent resection for sporadic CRC and show that the culture supernatants of TILs, but not of LPMCs, potently enhance the growth of human CRC cell lines through the activation of the oncogenic transcription factors signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-kB). Characterization of immune cell complexity of TILs and LPMCs reveals no differences in the percentages of T cells, natural killer T cells, natural killer (NK) cells, macrophages and B cells. However, T cells from TILs show a functional switch compared with those from LPMCs to produce large amounts of T helper type 17 (Th17)-related cytokines (that is, interleukin-17A (IL-17A), IL-17F, IL-21 and IL-22), tumor necrosis factor-α (TNF-α) and IL-6. Individual neutralization of IL-17A, IL-17F, IL-21, IL-22, TNF-α or IL-6 does not change TIL-derived supernatant-driven STAT3 and NF-kB activation, as well as their proproliferative effect in CRC cells. In contrast, simultaneous neutralization of both IL-17A and TNF-α, which abrogates NF-kB signaling, and IL-22 and IL-6, which abrogates STAT3 signaling, reduces the mitogenic effect of supernatants in CRC cells. IL-17A, IL-21, IL-22, TNF-α and IL-6 are also produced in excess in the early colonic lesions in a mouse model of sporadic CRC, associated with enhanced STAT3/NF-kB activation. Mice therapeutically given BP-1-102, an orally bioavailable compound targeting STAT3/NF-kB activation and cross-talk, exhibit reduced colon tumorigenesis and diminished expression of STAT3/NF-kB-activating cytokines in the neoplastic areas. These data suggest that strategies aimed at the cotargeting of STAT3/NF-kB activation and interaction between them might represent an attractive and novel approach to combat CRC.

Serum regenerating islet-derived 3-alpha is a biomarker of mucosal enteropathies.

BACKGROUND: The clinical presentation of organic and functional intestinal disorders can overlap and clinicians often rely on invasive and time-consuming procedures to make a final diagnosis. Regenerating islet-derived 3-alpha (Reg3α) is detectable in the circulation of patients with intestinal graft-versus host disease and patients with inflammatory bowel disease (IBD). AIM: To determine whether serum Reg3α testing is useful for discriminating mucosal enteropathies from functional intestinal disorders. METHODS: We prospectively included 47 patients with active coeliac disease (ACD), 13 patients with refractory coeliac disease (RCD), seven patients with common variable immunodeficiency (CVID), 72 patients with active Crohn's disease, 22 patients with active ulcerative colitis (UC) and 28 patients with irritable bowel syndrome (IBS)-related diarrhoea. Sera were also taken from 10 CD patients before and after 6-12 months of a gluten-free diet (GFD) and from 14 patients with IBD before and after induction therapy with Infliximab (IFX). Sera of 119 healthy volunteers were used to determine the cut-off value. Reg3α levels were measured by a commercial ELISA kit. RESULTS: Levels of Reg3α exceeded the cut-off value of the assay in 43/47(91%) ACD patients, 13/13(100%) RCD patients, 7/7(100%) CVID patients, 65/72(90%) Crohn's disease patients, 17/22(77%) UC patients and one patient with IBS(4%). Reg3α levels distinguished mucosal enteropathies from IBS with a sensitivity of 90% and a specificity of 96%. Reg3α levels significantly decreased in CD patients following a GFD and in IBD patients after treatment with IFX. CONCLUSION: Reg3α is a serum biomarker of intestinal damage that, combined with clinical data, identifies patients who should undergo invasive tests for diagnosing enteropathies.

Defective expression of SIRT1 contributes to sustain inflammatory pathways in the gut.

In inflammatory bowel disease (IBD), tissue damage is driven by an excessive immune response, poorly controlled by counter-regulatory mechanisms. SIRT1, a class III NAD+-dependent deacetylase, regulates negatively the expression of various proteins involved in the control of immune-inflammatory pathways, such as Stat3, Smad7, and NF-κB. Here we examined the expression, regulation, and function of SIRT1 in IBD. SIRT1 RNA and protein expression was less pronounced in whole biopsies and lamina propria mononuclear cells (LPMCs) of IBD patients in comparison with normal controls. SIRT1 expression was downregulated in control LPMC by tumor necrosis factor (TNF)-α and interleukin (IL)-21, and upregulated in IBD LPMC by neutralizing TNF-α and IL-21antibodies. Consistently, SIRT1 expression was increased in mucosal samples taken from IBD patients successfully treated with Infliximab. Treatment of IBD LPMC with Cay10591, a specific SIRT1 activator, reduced NF-κB activation and inhibited inflammatory cytokine synthesis, whereas Ex527, an inhibitor of SIRT1, increased interferon (IFN)-γ in control LPMC. SIRT1 was also reduced in mice with colitis induced by 2,4,6-trinitrobenzenesulphonic acid or oxazolone. Cay10591 prevented and cured experimental colitis whereas Ex527 exacerbated disease by modulating T cell-derived cytokine response. Data indicate that SIRT1 is downregulated in IBD patients and colitic mice and suggest that SIRT1 activation can help attenuate inflammatory signals in the gut.

A functional role for Smad7 in sustaining colon cancer cell growth and survival.

Initially identified as an inhibitor of transforming growth factor (TGF)-ß mainly owing to its ability to bind TGF-ß receptor type I and abrogate TGF-ß-driven signaling, Smad7 can interact with additional intracellular proteins and regulate TGF-ß-independent pathways, thus having a key role in the control of neoplastic processes in various organs. Genome-wide association studies have shown that common alleles of Smad7 influence the risk of colorectal cancer (CRC), even though the contribution of Smad7 in colon carcinogenesis is not fully understood. In this study, we assessed the expression and role of Smad7 in human and mouse models of sporadic CRC. We document a significant increase of Smad7 in human CRC relative to the surrounding nontumor tissues and show that silencing of Smad7 inhibits the growth of CRC cell lines both in vitro and in vivo after transplantation into immunodeficient mice. Knockdown of Smad7 results in enhanced phosphorylation of the cyclin-dependent kinase (CDK)2, accumulation of CRC cells in S phase and enhanced cell death. Smad7-deficient CRC cells have lower levels of CDC25A, a phosphatase that dephosphorylates CDK2, and hyperphosphorylated eukaryotic initiation factor 2 (eIF2)α, a negative regulator of CDC25 protein translation. Consistently, knockdown of Smad7 associates with inactivation of eIF2α, lower CDC25A expression and diminished fraction of proliferating cells in human CRC explants, and reduces the number of intestinal tumors in Apc(min/+) mice. Altogether, these data support a role for Smad7 in sustaining colon tumorigenesis.

Adenoma, advanced adenoma and colorectal cancer prevalence in asymptomatic 40- to 49-year-old subjects with a first-degree family history of colorectal cancer.

AIM: First-degree relatives (FDRs) of patients with colorectal cancer (CRC) have an increased CRC risk. Few studies have addressed if adenoma and advanced adenoma risk is increased among individuals, 40-49 years of age, with a family history of CRC. Therefore, the aim of the study was to define the prevalence and location of adenoma, advanced adenoma and CRC, according to age, in asymptomatic individuals with a family history of CRC. METHOD: Retrospective study of asymptomatic FDRs, 40 to ≥70 years of age undergoing first screening colonoscopy over a 3-year period, of CRC patients. RESULTS: Among 464 individuals studied, the prevalence of adenoma and advanced adenoma was 18.1% and 6.4%, respectively. According to age intervals, the prevalences of adenoma and advanced adenoma were 14% and 3.5%, respectively, in subjects 40-49 years of age; 14.4% and 6.3%, respectively, in subjects 50-59 years of age; 27% and 8%, respectively, in subjects 60-69 years of age; and 25% and 14%, respectively, in subjects ≥70 years of age; no significant difference was found among the four groups. No difference in lesion location was found, with similar numbers of preneoplastic lesions being present in the right colon and the left colon. CRC was diagnosed in three (0.64%) subjects, one of whom was in the 40-49 years age group. CONCLUSION: In our population of FDRs of CRC patients, 40-49 years of age, the prevalences of adenoma and advanced adenoma were similar to those observed in older subjects with the same CRC risk. Our data support the current indication to perform screening colonoscopy earlier than 45 years of age in subjects at high CRC risk.

IL-15 positively regulates IL-21 production in celiac disease mucosa.

Celiac disease (CD)-associated inflammation is characterized by high interleukin- 21 (IL-21), but the mechanisms that control IL-21 production are not fully understood. Here we analyzed IL-21 cell sources and examined how IL-21 production is regulated in CD. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs), isolated from CD patients and non-CD controls, were analyzed for cell markers, cytokines, and transcription factors by flow cytometry. IL-21 was highly produced by CD4+ and CD4+/CD8+ IELs and LPLs in active CD. IL-21-producing cells coexpressed interferon-γ (IFN-γ) and to a lesser extent T helper type 17 (Th17) cytokines. Treatment of control LPLs with IL-15, a cytokine overproduced in CD, activated Akt and STAT3 (signal transducer and activator of transcription 3), thus enhancing IL-21 synthesis. Active CD biopsies contained elevated levels of Akt, and blockade of IL-15 in those samples reduced IL-21. Similarly, neutralization of IL-15 in biopsies of inactive CD patients inhibited peptic-tryptic digest of gliadin-induced IL-21 expression. These findings indicate that in CD, IL-15 positively regulates IL-21 production.

A phase 1 open-label trial shows that smad7 antisense oligonucleotide (GED0301) does not increase the risk of small bowel strictures in Crohn's disease.

BACKGROUND: In Crohn's disease (CD), knockdown of Smad7, an inhibitor of Transforming Growth Factor (TGF)-ß1 activity, with a specific antisense oligonucleotide (GED0301) seems to be safe and tolerable and associates with TGF-ß1-mediated suppression of inflammatory pathways. AIM: Since TGF-ß1 has pro-fibrogenic effects in many organs, we evaluated whether GED0301 treatment associates with the formation of small bowel strictures. METHODS: Fifteen patients with active, inflammatory CD, receiving oral GED0301 once daily for 7 days, were monitored for the formation of small bowel strictures by Small Intestine Contrast Ultrasonography (SICUS). Serum basic fibroblast growth factor (bFGF) and human chitinase 3-like 1 (also known as YKL-40), two markers of CD-related intestinal strictures, and matrix metalloproteinases (MMP) and tissue inhibitor 1 of MMPs (TIMP1) were analysed at day 0 and day 180 by ELISA. Crohn's disease activity index (CDAI) changes were also monitored. RESULTS: Fourteen patients completed the 6-month study; the remaining underwent intestinal resection for a severe relapse not responsive to medical treatment. No patient developed small bowel stricture and none experienced obstructive symptoms during the study period. GED0301 treatment induced no significant change in the circulating levels of bFGF, YKL-40, MMPs and TIMP1. Seven of 12 patients who reached clinical remission following GED0301 treatment maintained a CDAI < 150 at day 180. CONCLUSION: Short-term treatment of patients with Crohn's disease using GED0301 is not associated with the development of small bowel stricture, thus reinforcing the concept that this drug is safe at least at early time points.

Th17-related cytokines in inflammatory bowel diseases: friends or foes?

T helper (Th)17 cells and other interleukin (IL)-17-producing cells are supposed to play critical roles in several human immune-mediated diseases, including Crohn's disease (CD) and ulcerative colitis (UC), the main forms of inflammatory bowel diseases (IBD) in man. Th17 cells infiltrate massively the inflamed intestine of IBD patients and in vitro and in vivo studies have shown that Th17-type cytokines may trigger and amplify multiple inflammatory pathways. Nonetheless, some Th17-related cytokines, such as interleukin (IL)-17A and IL-22, may target gut epithelial cells and promote the activation of counter-regulatory mechanisms. This observation together with the demonstration that Th17 cells are not stable and can be converted into either regulatory T cells or Th1 cells if stimulated by immune-suppressive (e.g. TGF-ß1) or inflammatory (e.g. IL-12, IL-23) cytokines have contributed to advance our understanding of mechanisms that regulate mucosal homeostasis and inflammation in the gut.

Efficacy and safety of infliximab and adalimumab in Crohn's disease: a single centre study.

BACKGROUND: Infliximab and adalimumab are highly effective in Crohn's Disease (CD). This is supported by clinical trials and open-label studies using either infliximab or adalimumab, thus not allowing a proper comparison between these anti-TNFs in CD. AIM: To evaluate the efficacy and safety of infliximab and adalimumab in active CD. METHODS: In a longitudinal study, CD patients with indication for anti-TNFs were treated with infliximab or adalimumab. RESULTS: Ninety-three patients were treated with infliximab (n = 44) or adalimumab (n = 49). In the infliximab group, the induction was completed by 77.3% of patients, due to no response (n = 2), delayed hypersensitivity reactions (DHR) or infusion reactions (n = 8). Maintenance with infliximab was completed by 60% of patients, due to clinical worsening or loss of efficacy (n = 5), DHR or infusion reactions (n = 5). In the adalimumab group, all patients completed the induction, while maintenance was completed by 67% of patients, due to clinical worsening or loss of efficacy (n = 8), DHR (n = 1), other causes (n = 7). In both groups, the CDAI significantly reduced at baseline vs. each visit (P < 0.04). The Kaplan-Meier survival analysis performed to evaluate the risk of steroid-free remission in patients treated with infliximab vs. adalimumab detected no differences (log-rank test P = 0.4). Cox proportional-hazards regression identified two predictors of steroid-free remission using anti-TNFs: no smokers [HR = 2.94 (1.52-5.70), P = 0.001] and non stricturing non penetrating behaviour [HR = 3.116 (1.06-9.13), P = 0.03826]. CONCLUSIONS: Infliximab and adalimumab showed a similar efficacy. No smoking and non-stricturing non-penetrating behaviour were predictors of steroid-free remission.

Epigenetically silenced miR-34b/c as a novel faecal-based screening marker for colorectal cancer.

BACKGROUND: MicroRNAs are tiny non-coding small endogenous RNAs that regulate gene expression by translational repression, mRNA cleavage and mRNA inhibition. The aim of this study was to investigate the hypermethylation of miR-34b/c and miR-148a in colorectal cancer, and correlate this data to clinicopathological features. We also aimed to evaluate the hypermethylation of miR-34b/c in faeces specimens as a novel non-invasive faecal-DNA-based screening marker. METHODS: The 5-aza-2'-deoxycytidine treatment and methylation-specific PCR were carried out to detect the hypermethylation of miR-34b/c and miR-148a. RESULTS: The miR-34b/c hypermethylation was found in 97.5% (79 out of 82) of primary colorectal tumours, P=0.0110. In 75% (21 out of 28) of faecal specimens we found a hypermethylation of miR-34b/c while only in 16% (2 out of 12) of high-grade dysplasia. In addition, miR-148a was found to be hypermethylated in 65% (51 out of 78) of colorectal tumour tissues with no significant correlation to clinicopathological features. However, a trend with female gender and advanced age was found, P=0.083. We also observed a trend to lower survival rate in patients with miR-148a hypermethylation with 10-year survival probability: 48 vs 65%, P=0.561. CONCLUSIONS: These findings show that aberrant hypermethylation of miR-34b/c could be an ideal class of early screening marker, whereas miR-148a could serve as a disease progression follow-up marker.

Frataxin participates to the hypoxia-induced response in tumors.

Defective expression of frataxin is responsible for the degenerative disease Friedreich's ataxia. Frataxin is a protein required for cell survival since complete knockout is lethal. Frataxin protects tumor cells against oxidative stress and apoptosis but also acts as a tumor suppressor. The molecular bases of this apparent paradox are missing. We therefore sought to investigate the pathways through which frataxin enhances stress resistance in tumor cells. We found that frataxin expression is upregulated in several tumor cell lines in response to hypoxic stress, a condition often associated with tumor progression. Moreover, frataxin upregulation in response to hypoxia is dependent on hypoxia-inducible factors expression and modulates the activation of the tumor-suppressor p53. Importantly, we show for the first time that frataxin is in fact increased in human tumors in vivo. These results show that frataxin participates to the hypoxia-induced stress response in tumors, thus implying that modulation of its expression could have a critical role in tumor cell survival and/or progression.

Interleukin-25 production is differently regulated by TNF-α and TGF-ß1 in the human gut.

An altered balance between effector and regulatory factors is supposed to sustain the tissue-damaging immune response in inflammatory bowel disease (IBD). We have recently shown that in IBD, there is a defective synthesis of the counter-regulatory cytokine, interleukin (IL)-25. In this study we investigated factors that control IL-25 production in the gut. IBD patients produced less IL-25 when compared with normal controls. Stimulation of normal intestinal explants with tumor necrosis factor-α (TNF-α), but not interferon-γ (IFN-γ) or IL-21, reduced IL-25 synthesis. Consistently, IL-25 production was enhanced by anti-TNF-α both in vitro and in vivo. Upregulation of IL-25 was also seen in normal colonic explants stimulated with transforming growth factor-ß1 (TGF-ß1). As in IBD, TGF-ß1 activity is abrogated by Smad7, we next assessed whether inhibition of Smad7 with an antisense oligonucleotide enhanced IL-25 expression. Knockdown of Smad7 was accompanied by an increase in IL-25 production. Data show that IL-25 production is differently regulated by TNF-α and TGF-ß1 in the human gut.

The dual role of interleukin-25 in the control of immune-mediated pathologies.

Interleukin-25 (IL-25) plays a key role in the initiation and expansion of T helper (Th) 2 cell-mediated immune responses, thereby contributing to allergic diseases and host defense against helminthic parasites. More recent studies have however shown that IL-25 can also control the function of non-T cells, such as antigen presenting cells and endothelial cells, and reduces Th1/Th17-mediated pathologies. These new and exciting observations reveal a broader role for IL-25 than previously anticipated, and delineate various scenarios where therapeutic interventions around IL-25 activity can be imagined.

Endoscopic vs ultrasonographic findings related to Crohn's disease recurrence: a prospective longitudinal study at 3 years.

BACKGROUND AND AIMS: Ileocolonoscopy (IC) is the gold standard for assessing Crohn's Disease (CD) recurrence after ileo-colonic resection. In a prospective longitudinal study we compared findings related to CD recurrence when using techniques visualizing either the luminal or the extraluminal surface (IC and small bowel follow through, SBFT vs Small Intestine Contrast Ultrasonography, SICUS). METHODS: From 2003 to 2008, 25 CD patients undergoing ileo-colonic resection were enrolled. Clinical assessment (CDAI) was performed at 1, 2 and 3 years. IC was performed at 1 (n=25) and 3 years (n=15), SBFT at 2 years (n=21) and SICUS at 1 (n=25), 2 (n=21) and 3 years (n=15). Recurrence was assessed by SBFT and SICUS (bowel wall thickness, BWT) when using IC as gold standard. RESULTS: At 1 year, all patients were inactive and recurrence was detected by IC in 24/25 (96%) and by SICUS in 25/25 patients. At 2 years, 6/21 patients (29%) were active and recurrence was detected by SBFT in 12/21 (57%) and by SICUS in 21/21 patients. At 3 years, 5/15 patients (33%) were active, IC showed recurrence in 14/15 (93%), and SICUS in 15/15 patients. The endoscopic score at 1 year was higher in patients developing relapse at 2 years (n=5) than in patients maintaining remission (n=10) (median: 4, range 3-4 vs 2, range 0-3; p=0.003). The same finding was not observed by using SICUS (median BWT at 1 year: 5, range 4-7 vs 3.7, range 3.5-6; p=0.19). CONCLUSIONS: Although IC and SICUS provide a different view of the bowel wall, in experienced hands SICUS provides findings compatible with endoscopic recurrence after ileo-colonic resection for CD. Discrepant findings may be observed in a low proportion of patients with minor lesions related to CD recurrence.

Role of CA19.9 in predicting bevacizumab efficacy for metastatic colorectal cancer patients.

CEA and CA19.9 are biomarkers routinely measured for monitoring treatment response in metastatic colorectal cancer (MCRC) patients, yet their predictive value during therapies containing new antineoplastic drugs (i.e. FOLFIRI/OLFOX/Bevacizumab) has not yet been investigated. Consecutive chemotherapy-naive MCRC patients treated with either standard chemotherapy-alone (FOLFIRI/FOLFOX) or chemotherapy+bevacizumab (FOLFIRI+bevacizumab) were included in the analysis. Patients had to have serial biweekly measurement of CEA and CA19.9 available for at least three months of treatment. Primary study endpoint was Progression Free Survival (PFS). Biomarker levels and type of treatment as well as major demographic and clinical factors were analyzed for their impact on PFS. Out of 243 evaluated MCRC patients, 87 had biomarkers available as per inclusion criteria. Among all evaluated factors only type of treatment (chemotherapy-alone vs chemotherapy+bevacizumab) and baseline CA19.9 (> vs < normal) were independently associated with PFS, whilst neither baseline CEA nor biomarker reduction during therapy reached statistical significance. When patients with different baseline CA19.9 levels were analysed separately, only patients with abnormal CA19.9 benefited significantly from the administration of bevacizumab.The current study demonstrated a significant predictive value of CA19.9, but not of CEA and biomarker reduction, for MCRC patients treated with new antineoplastic drugs. Moreover, only patients with abnormal baseline CA19.9 levels benefited significantly from bevacizumab.

Clinical trial: ulcerative colitis maintenance treatment with 5-ASA: a 1-year, randomized multicentre study comparing MMX with Asacol.

BACKGROUND: 5-ASA-MMX (1.2 g/tablet) is a 5-aminosalicylic acid formulation, designed for once-daily dosing in the treatment of ulcerative colitis. AIM: To evaluate the efficacy and safety of 5-ASA-MMX (2.4 g/day, once daily), compared with Asacol (2.4 g/day, twice daily) in the maintenance of left-sided UC, through a double-blind, double-dummy, parallel-group, randomized, comparator study. METHODS: In all, 331 patients with UC were randomized to receive either 5-ASA-MMX 2.4 g/day, once daily, or Asacol 2.4 g/day, twice daily, for 12 months. All patients were in remission for >or=1 month prior to the trial, with >or=1 documented relapse in the previous year. The co-primary endpoints of this study were the proportion of patients in clinical, and clinical and endoscopic remission following 12 months' treatment. RESULTS: In the intent-to-treat population, excluding those with major protocol deviations, 68.0 and 65.9% patients in the 5-ASA-MMX and Asacol groups, respectively, were in clinical remission (P = 0.69), and 60.9 and 61.7% of patients, respectively, were in clinical and endoscopic remission (P = 0.89). Diary card data revealed statistically significant treatment differences favouring 5-ASA-MMX. Both treatments were similarly tolerated. CONCLUSIONS: Once-daily 5-ASA-MMX is similarly effective with a comparable safety profile to Asacol administered twice daily, for the maintenance treatment of ulcerative colitis.

TGF-beta1 and Smad7 in the regulation of IBD.

Inflammatory bowel diseases (IBDs) are caused by an aberrant and excessive local immune response to components of the bacterial microflora that are: poorly controlled by endogenous counter regulatory mechanisms such as the immunosuppressive cytokine transforming growth factor-beta1 (TGF-beta1). Studies in human IBD tissues have documented a disruption of TGF-beta1 signaling marked by a block in the phosphorylation of the activated TGF-beta receptor-associated signaling molecule, Smad3, caused by the upregulation of the intracellular inhibitor of Smad signaling, Smad7. Inhibition of Smad7 with a specific antisense oligonucleotide restores TGF-beta1/Smad3 signaling, resulting in a marked suppression of inflammatory cytokine production. The functional relevance of Smad7 in gut inflammation was confirmed by studies in murine models of IBD. In inflamed tissues of mice with colitis induced by either the trinitrobenzene sulfonic acid or oxazolone, p-Smad3 was low despite active TGF-beta1 being produced in excess. In vivo administration of Smad7 antisense oligonucleotides to mice with colitis restored TGF-beta1 signaling and decreased the synthesis of inflammatory molecules and the extent of gut damage. These data support a role for Smad7 in maintaining intestinal inflammation, and suggest that blocking Smad7 could be a promising way to dampen the ongoing inflammation in IBD.