Butyrate functions in concert with myeloid-derived suppressor cells recruited by CCR9 to alleviate DSS-induced murine colitis

Ulcerative colitis (UC) is a precancerous disease caused mainly by a combination of genetic susceptibility, environmental factors and microbiota dysbiosis. As a kind of short-chain fatty acid (SCFA), butyrate has been shown to be closely related to the progression of colitis. However, the exact regulatory mechanism of butyrate in colitis needs to be further elucidated. In our current research, the effects of butyrate were examined in a dextran sulfate sodium (DSS)-induced murine colitis model, which simulates human UC. The administration of butyrate significantly reversed the signs of colitis and alleviated colonic histological damage in DSS‑induced colitis. The transcription levels of the main proinflammatory mediators, including tumor necrosis factor-α, interleukin-6 and interleukin-12, were also reduced, as determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). This indicates that butyrate could alleviate DSS-induced colitis by inhibiting proinflammatory mediators. In addition, we found that myeloid-derived suppressor cells (MDSCs), which have an inflammation-relieving effect, did not effectively alleviate DSS‑induced colitis but showed a compensatory increase in the DSS group. However, the compensatory increase in MDSCs in the DSS group significantly decreased after butyrate treatment. Moreover, the chemokine receptor CCR9, which mediates the homing of intestinal immune cells, also showed consistent changes similar to MDSCs. Butyrate alone did not have the aforementioned effects on mice. Thus, butyrate may effectively relieve DSS‑induced colitis by synergistic regulatory effects with MDSCs, which migrate and gather through CCR9 recruitment.

Cenicriviroc for the treatment of liver fibrosis in adults with nonalcoholic steatohepatitis: AURORA Phase 3 study design

INTRODUCTION

Nonalcoholic steatohepatitis (NASH) is a sub-classification of nonalcoholic fatty liver disease (NAFLD) characterized by increased risk of progressive liver fibrosis. Cenicriviroc (CVC) is a novel, orally administered, potent chemokine 2 and 5 receptor antagonist currently in development for the treatment of liver fibrosis in adults with NASH.

METHODS AND ANALYSIS

Efficacy and safety of CVC will be comprehensively evaluated in a global, Phase 3, multicenter, randomized, double-blind, placebo-controlled study (AURORA, NCT03028740) of subjects with NASH and Stage F2 or F3 fibrosis. Approximately 2000 adults (Part 1, 1200 subjects; Part 2, 800 additional subjects) aged 18-75 years with histological evidence of NASH with Stage F2 or F3 fibrosis (NASH Clinical Research Network classification system) will be randomized 2:1 to CVC 150 mg or placebo orally once daily. Primary efficacy endpoints will include the proportion of subjects with ≥1-stage improvement in liver fibrosis and no worsening of steatohepatitis at Month 12 relative to screening (Part 1), and time to first occurrence of any adjudicated event: death; histopathologic progression to cirrhosis; liver transplant; Model of End-Stage Liver Disease score ≥ 15; ascites; hospitalization due to liver decompensation (Part 2). Patient-reported outcomes will assess changes in health outcomes from baseline (Chronic Liver Disease Questionnaire - NAFLD; Work Productivity and Activity Impairment in NASH; 36-Item Short Form Health Survey version 2). Adverse events will be assessed throughout the study. As there are currently no approved treatments indicated for NASH, the AURORA CVC Phase 3 study addresses an unmet medical need.

Chemokines and Chemokine Receptors as Therapeutic Targets in Inflammatory Bowel Disease; Pitfalls and Promise

The principal targets for anti-chemokine therapy in inflammatory bowel disease (IBD) have been the receptors CCR9 and CXCR3 and their respective ligands CCL25 and CXCL10. More recently CCR6 and its ligand CCL20 have also received attention, the expression of the latter in enterocytes being manipulated through Smad7 signalling. These pathways, selected based on their fundamental role in regulating mucosal immunity, have led to the development of several therapeutic candidates that have been tested in early phase clinical trials with variable clinical efficacy. In this article, we appraise the status of chemokine-directed therapy in IBD, review recent developments, and nominate future areas for therapeutic focus.

Mechanism for Covalent Binding of MLN3126, an Oral Chemokine C-C Motif Receptor 9 Antagonist, to Serum Albumins

N-{4-Chloro-2-[(1-oxidopyridin-4-yl)carbonyl]phenyl}-4-(propan-2-yloxy)benzenesulfonamide (MLN3126) is an orally available chemokine C-C motif receptor 9 selective antagonist. In nonclinical pharmacokinetic studies of MLN3126, nonextractable radioactivity was observed in plasma after oral administration of 14C-labeled MLN3126 ([14C]MLN3126) to Sprague-Dawley (SD) rats. In this study, the nonextractable radioactive component was digested with trypsin or a nonspecific protease, pronase, after chemical reduction to obtain drug-peptide adducts or drug-amino acid adducts. The chemical structure of these adducts was characterized by liquid chromatography/mass spectrometry. The results demonstrated that the major part of the nonextractable radioactivity was accounted for by covalent binding via the Schiff base formed specifically between the ε-amino group of lysine residue 199 in rat serum albumin and the carbonyl group of MLN3126. The half-life (t1/2) of the total radioactivity in plasma during and after 21 daily multiple oral administrations of [14C]MLN3126 to SD rats was approximately 5-fold shorter than the reported t1/2 of albumin in rats. The data indicated that the covalent binding was reversible under physiologic conditions. The formation of the covalent binding was also confirmed in in vitro incubations with serum albumins from rats, humans, and dogs in the same manner, indicating that there are no qualitative interspecies differences in the formation of the Schiff base.

Effects of vercirnon on the activity of CYP3A4, CYP2C19 and CYP2C8 enzymes and BCRP and OATP1B1 transporters using probe substrates

PURPOSE

Vercirnon is a CCR9 chemokine receptor antagonist being developed for the treatment of Crohn's disease. As a variety of concomitant medications are often required for the treatment of Crohn's disease, it is important to characterise the drug interaction profile of vercirnon. To confirm the results of previous in vitro inhibition studies, this study assessed the in vivo effect of vercirnon on the activity of cytochrome P450 enzymes (CYP3A4, CYP2C19 and CYP2C8) and drug transport proteins (BCRP and OATP1B1) using probe substrates.

METHODS

This was an open-label, single-sequence, repeat-dose study conducted in 24 healthy adult subjects. On days 1-4, subjects received probe substrates (midazolam, pioglitazone, omeprazole and rosuvastatin; in that order), followed by administration of vercirnon 500 mg twice daily (BID) on days 5-14. On days 11-14, in addition to vercirnon 500 mg BID, subjects also received probe substrates as on days 1-4. Blood samples were collected for pharmacokinetic analysis of probe substrates, vercirnon and two of its metabolites.

RESULTS

Geometric least-squares mean ratios (90 % confidence interval) of area under the concentration-time curve from time zero to infinity for probe administered with vercirnon (test) compared with probe alone (reference) for midazolam, pioglitazone, omeprazole and rosuvastatin were 0.92 (0.85, 0.99), 1.01 (0.95, 1.07), 0.99 (0.76,1.31) and 0.98 (0.88, 1.09), respectively.

CONCLUSIONS

Co-administration of probe substrates midazolam, pioglitazone, omeprazole, and rosuvastatin following repeat dosing of vercirnon 500 mg BID demonstrated vercirnon had no clinically significant effect on CYP3A4, CYP2C8, CYP2C19 enzyme activity or BCRP or OATP1B1 transporter activity.

A randomized controlled trial of the efficacy and safety of CCX282-B, an orally-administered blocker of chemokine receptor CCR9, for patients with Crohn's disease

CCX282-B, also called vercirnon, is a specific, orally-administered chemokine receptor CCR9 antagonist that regulates migration and activation of inflammatory cells in the intestine. This randomized, placebo-controlled trial was conducted to evaluate the safety and efficacy of CCX282-B in 436 patients with Crohn's disease. Crohn's Disease Activity Index (CDAI) scores were 250-450 and C-reactive protein >7.5 mg/L at study entry. In addition to stable concomitant Crohn's medication (85% of subjects), subjects received placebo or CCX282-B (250 mg once daily, 250 mg twice daily, or 500 mg once daily) for 12 weeks. They then received 250 mg CCX282-B twice daily, open-label, through week 16. Subjects who had a clinical response (a ≥ 70 point drop in CDAI) at week 16 were randomly assigned to groups given placebo or CCX282-B (250 mg, twice daily) for 36 weeks. Primary endpoints were clinical response at Week 8 and sustained clinical response at Week 52. During the 12-week Induction period, the clinical response was highest in the group given 500 mg CCX282-B once daily. Response rates at week 8 were 49% in the placebo group, 52% in the group given CCX282-B 250 mg once daily (odds ratio [OR] = 1.12; p = .667 vs placebo), 48% in the group given CCX282-B 250 mg twice daily (OR = 0.95; p = .833), and 60% in the group given CCX282-B 500 mg once daily (OR = 1.53; p = .111). At week 12, response rates were 47%, 56% (OR = 1.44; p = .168), 49% (OR = 1.07; p = .792), and 61% (OR = 1.74; p = .039), respectively. At the end of the Maintenance period (week 52), 47% of subjects on CCX282-B were in remission, compared to 31% on placebo (OR = 2.01; p = .012); 46% showed sustained clinical responses, compared to 42% on placebo (OR = 1.14; p = .629). CCX282-B was well tolerated. Encouraging results from this clinical trial led to initiation of Phase 3 clinical trials in Crohn's disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00306215.

Met-CCL5 modifies monocyte subpopulations during liver fibrosis regression

Fibrosis or scarring of the liver parenchyma is a mainstay of chronic liver diseases and is associated with increased morbidity and mortality. Since complete scarring of the liver develops over several decades, therapeutic intervention with the aim of ameliorating fibrosis is of great clinical interest. In a recent study, we could identify the chemokine receptor antagonist Met-CCL5 as a potential compound to inhibit fibrosis progression and accelerate its regression. In the current study we characterized immune changes during fibrosis regression associated with the treatment with the CCL5 (RANTES) chemokine receptor antagonist Met-CCL5 in an established mouse model of chronic liver damage. Met-CCL5 or PBS was given after fibrosis induction (8 weeks of CCl(4)) and mice were sacrificed three and seven days after peak fibrosis. Mouse livers were analyzed for immune cell infiltration and cytokine gene expression. The results show that overall monocyte recruitment was not affected by Met-CCL5, but there was a significant shift to a pro-inflammatory Gr1+ monocyte population in the livers of mice treated with Met-CCL5. These monocytes were mostly iNOS +, a phenomenon which was also evident when analyzing the overall gene expression profiles in the livers. Since a shift in monocyte subpopulations has recently been identified to contribute to fibrosis regression, our results help explaining the efficacy of CCL5 chemokine antagonism as a novel treatment option for fibrotic liver diseases.

GSK-1605786, a selective small-molecule antagonist of the CCR9 chemokine receptor for the treatment of Crohn's disease

GSK-1605786 (CCX-282; Traficet-EN), a selective antagonist of the CC chemokine receptor (CCR9), is being developed by GlaxoSmithKline plc under license from ChemoCentryx Inc for the potential treatment of inflammatory bowel disease, including Crohn's disease and celiac disease. CCR9 is a tissue-specific lymphocyte trafficking molecule that selectively attracts both B- and T-cells to the small gut. Inhibition of CCR9 by GSK-1605786 may inhibit B- and T-cell entry to the small gut and ameliorate inflammation while leaving immune function at other anatomical sites unaffected. GSK-1605786 was assessed as a treatment for moderate-to-severe Crohn's disease in the phase II/III PROTECT-1 trial and as a treatment for celiac disease in a phase II trial. Data suggest that GSK-1605786 is efficacious in patients with Crohn's disease with the advantage of being orally bioavailable.