Non-invasive evaluation of response to obeticholic acid in patients with NASH: Results from the REGENERATE study.

BACKGROUND & AIMS: Non-alcoholic steatohepatitis (NASH) is a chronic, progressive fibrotic liver disease that can lead to cirrhosis. While liver biopsy is considered the reference standard for the histologic diagnosis of NASH and staging of fibrosis, its use in clinical practice is limited. Non-invasive tests (NITs) are increasingly being used to identify and stage liver fibrosis in patients with NASH, and several can assess liver-related outcomes. We report changes in various NITs in patients treated with obeticholic acid (OCA) or placebo in the phase III REGENERATE study. METHODS: Patients with NASH and fibrosis stage F2 or F3 (n = 931) were randomized (1:1:1) to receive placebo, OCA 10 mg, or OCA 25 mg once daily. Various NITs based on clinical chemistry and/or imaging were evaluated at baseline and throughout the study. RESULTS: Rapid, sustained reductions from baseline in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase levels, as well as in Fibrosis-4 (FIB-4), FibroTest, FibroMeter, and FibroScan-AST scores were observed in OCA-treated vs. placebo-treated patients. Reduction in liver stiffness by vibration-controlled transient elastography was observed in the OCA 25 mg group vs. the placebo group at Month 18. NIT changes were associated with shifts in histologic fibrosis stage. The greatest improvements were observed in patients with ≥1-stage fibrosis improvement; however, improvements in ALT, AST, FIB-4, and FibroTest were also observed in OCA-treated patients whose histologic fibrosis remained stable. CONCLUSIONS: Based on the REGENERATE Month 18 interim analysis, rapid and sustained improvements in various NITs were observed with OCA treatment. Dynamic changes in selected NITs separated histologic responders from non-responders. These results suggest that NITs may be useful in assessing histologic response to OCA therapy. CLINICALTRIALS. GOV NUMBER: NCT02548351 LAY SUMMARY: Non-alcoholic steatohepatitis (NASH) is a chronic, progressive liver disease that can lead to cirrhosis. To diagnose and assess liver fibrosis (scarring) in patients with NASH, non-invasive tests (NITs) are increasingly being used rather than liver biopsy, which is invasive, expensive, and can be risky. In the REGENERATE study, which is evaluating the effects of obeticholic acid vs. placebo in patients with NASH, various NITs were also evaluated. This analysis shows that improvements in levels of certain blood components, as well as favorable results of ultrasound imaging and proprietary tests of liver function, were associated with improvements in liver fibrosis after treatment with obeticholic acid, suggesting that NITs may be useful alternatives to liver biopsy in assessing NASH patients' response to therapy.

Development of an orally delivered GLP-1 receptor agonist through peptide engineering and drug delivery to treat chronic disease.

Peptide therapeutics are increasingly used in the treatment of disease, but their administration by injection reduces patient compliance and convenience, especially for chronic diseases. Thus, oral administration of a peptide therapeutic represents a significant advance in medicine, but is challenged by gastrointestinal instability and ineffective uptake into the circulation. Here, we have used glucagon-like peptide-1 (GLP-1) as a model peptide therapeutic for treating obesity-linked type 2 diabetes, a common chronic disease. We describe a comprehensive multidisciplinary approach leading to the development of MEDI7219, a GLP-1 receptor agonist (GLP-1RA) specifically engineered for oral delivery. Sites of protease/peptidase vulnerabilities in GLP-1 were removed by amino acid substitution and the peptide backbone was bis-lipidated to promote MEDI7219 reversible plasma protein binding without affecting potency. A combination of sodium chenodeoxycholate and propyl gallate was used to enhance bioavailability of MEDI7219 at the site of maximal gastrointestinal absorption, targeted by enteric-coated tablets. This synergistic approach resulted in MEDI7219 bioavailability of ~ 6% in dogs receiving oral tablets. In a dog model of obesity and insulin resistance, MEDI7219 oral tablets significantly decreased food intake, body weight and glucose excursions, validating the approach. This novel approach to the development of MEDI7219 provides a template for the development of other oral peptide therapeutics.

Small Molecule Rescue of ATXN3 Toxicity in C. elegans via TFEB/HLH-30.

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), is a polyglutamine expansion disease arising from a trinucleotide CAG repeat expansion in exon 10 of the gene ATXN3. There are no effective pharmacological treatments for MJD, thus the identification of new pathogenic mechanisms, and the development of novel therapeutics is urgently needed. In this study, we performed a comprehensive, blind drug screen of 3942 compounds (many FDA approved) and identified small molecules that rescued the motor-deficient phenotype in transgenic ATXN3 Caenorhabditis elegans strain. Out of this screen, five lead compounds restoring motility, protecting against neurodegeneration, and increasing the lifespan in ATXN3-CAG89 mutant worms were identified. These compounds were alfacalcidol, chenodiol, cyclophosphamide, fenbufen, and sulfaphenazole. We then investigated how these molecules might exert their neuroprotective properties. We found that three of these compounds, chenodiol, fenbufen, and sulfaphenazole, act as modulators for TFEB/HLH-30, a key transcriptional regulator of the autophagy process, and require this gene for their neuroprotective activities. These genetic-chemical approaches, using genetic C. elegans models for MJD and the screening, are promising tools to understand the mechanisms and pathways causing neurodegeneration, leading to MJD. Positively acting compounds may be promising candidates for investigation in mammalian models of MJD and preclinical applications in the treatment of this disease.

A novel LC-MS/MS method for simultaneous estimation of obeticholic acid, glyco-obeticholic acid, tauro-obeticholic acid in human plasma and its application to a pharmacokinetic study.

A rapid, robust, simple, selective, and sensitive liquid chromatography-tandem mass spectrometry method was developed for the simultaneous estimation of obeticholic acid and its two pharmacologically active metabolites, glyco-obeticholic acid, and tauro-obeticholic acid in human plasma. The analytes and their heavy stable isotope-labeled internal standards were extracted from 250 µL human plasma by a solid-phase extraction technique. The method linearity was established over a concentration range of 0.410 to 120.466 ng/mL for obeticholic acid, 0.414 to 121.708 ng/mL for glyco-obeticholic acid, and 0.255 to 75.101 ng/mL for tauro-obeticholic acid. The method was fully validated as per current guidelines on bioanalytical method validation of "United States of Food and Drug Administration" and "European Medicines Agency." The method was successfully applied to study the pharmacokinetics of obeticholic acid, glyco-obeticholic acid, and tauro-obeticholic acid following oral administration of obeticholic acid tablets to healthy male volunteers. All the measured concentrations were within calibration curve ranges.

Comparison of the Pharmacokinetics of Generic Versus Branded Obeticholic Acid in a Chinese Population: Effects of Food and Sex.

The present study assessed the pharmacokinetics and bioequivalence of a single 10-mg dose of a generic and the branded formulation (Ocaliva) of obeticholic acid (OCA) in healthy Chinese subjects under fasting and fed conditions. The possible effects of food and sex on the pharmacokinetics of OCA and its 2 active metabolites (glyco-OCA and tauro-OCA) were evaluated. Plasma concentrations of OCA and its 2 active metabolites were measured by liquid chromatography-tandem mass spectrometry. The 90%CIs of the ratios of the test and reference formulations for Cmax , AUC0-t , and AUC0-∞ of OCA, glyco-OCA, and tauro-OCA were contained entirely within the 80% to 125% range required for bioequivalence under fasting and fed conditions. Plasma exposure of OCA was 30% to 36% higher under fed compared with fasting conditions. Plasma exposure of OCA, glyco-OCA, and tauro-OCA was 39% to 66%, 22% to 58%, and 37% to 84% higher, respectively, in women compared with men under fasting and fed conditions. In conclusion, OCA was well tolerated in healthy Chinese subjects under fasting and fed conditions. The single 10-mg dose of a generic OCA formulation was bioequivalent to Ocaliva. Food and sex impacted the pharmacokinetics of OCA and/or its 2 active metabolites. Further studies are required to determine if these effects are clinically relevant.

Differential effects of bile acids on the postprandial secretion of gut hormones: a randomized crossover study.

Bile acids (BA) regulate postprandial metabolism directly and indirectly by affecting the secretion of gut hormones like glucagon-like peptide-1 (GLP-1). The postprandial effects of BA on the secretion of other metabolically active hormones are not well understood. The objective of this study was to investigate the effects of oral ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) on postprandial secretion of GLP-1, oxyntomodulin (OXM), peptide YY (PYY), glucose-dependent insulinotropic peptide (GIP), glucagon, and ghrelin. Twelve healthy volunteers underwent a mixed meal test 60 min after ingestion of UDCA (12-16 mg/kg), CDCA (13-16 mg/kg), or no BA in a randomized crossover study. Glucose, insulin, GLP-1, OXM, PYY, GIP, glucagon, ghrelin, and fibroblast growth factor 19 were measured prior to BA administration at -60 and 0 min (just prior to mixed meal) and 15, 30, 60, 120, 180, and 240 min after the meal. UDCA and CDCA provoked differential gut hormone responses; UDCA did not have any significant effects, but CDCA provoked significant increases in GLP-1 and OXM and a profound reduction in GIP. CDCA increased fasting GLP-1 and OXM secretion in parallel with an increase in insulin. On the other hand, CDCA reduced postprandial secretion of GIP, with an associated reduction in postprandial insulin secretion. Exogenous CDCA can exert multiple salutary effects on the secretion of gut hormones; if these effects are confirmed in obesity and type 2 diabetes, CDCA may be a potential therapy for these conditions.NEW & NOTEWORTHY Oral CDCA and UDCA have different effects on gut and pancreatic hormone secretion. A single dose of CDCA increased fasting secretion of the hormones GLP-1 and OXM with an accompanying increase in insulin secretion. CDCA also reduced postprandial GIP secretion, which was associated with reduced insulin. In contrast, UDCA did not change gut hormone secretion fasting or postprandially. Oral CDCA could be beneficial to patients with obesity and diabetes.

Evolving Role for Pharmacotherapy in NAFLD/NASH.

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent, dynamic disease that occurs across the age spectrum and can lead to cirrhosis and hepatocellular carcinoma. There are currently no US Food and Drug Administration (FDA) approved treatments for NAFLD; however, this is a field of active research. This review summarizes emerging pharmacotherapies for the treatment of adult and pediatric NAFLD. Investigated pharmacotherapies predominantly target bile acid signaling, insulin resistance, and lipid handling within the liver. Three drugs have gone on to phase III trials for which results are available. Of those, obeticholic acid is the single agent that demonstrates promise according to the interim analyses of the REGENERATE trial. Obeticholic acid showed reduction of fibrosis in adults with nonalcoholic steatohepatitis (NASH) taking 25 mg daily for 18 months (n = 931, reduction in fibrosis in 25% vs. 12% placebo, P < 0.01). Ongoing phase III trials include REGENERATE and MAESTRO-NASH, which investigates thyroid hormone receptor-ß agonist MGL-3196. Outcomes of promising phase II trials in adults with NASH are also available and those have investigated agents, including the fibroblast growth factor (FGF)19 analogue NGM282, the GLP1 agonist liraglutide, the FGF21 analogue Pegbelfermin, the sodium glucose co-transporter 2 inhibitor Empagliflozin, the ketohexokinase inhibitor PF-06835919, the acetyl-coenzyme A carboxylase inhibitor GS-0976, and the chemokine receptor antagonist Cenicriviroc. Completed and ongoing clinical trials emphasize the need for a more nuanced understanding of the phenotypes of subgroups within NAFLD that may respond to an individualized approach to pharmacotherapy.

Obeticholic acid improves hepatic bile acid excretion in patients with primary biliary cholangitis.

BACKGROUND & AIMS: Obeticholic acid (OCA) is an agonist of the nuclear bile acid receptor farnesoid X receptor, which regulates hepatic bile acid metabolism. We tested whether OCA treatment would influence hepatic transport of conjugated bile acids in patients with primary biliary cholangitis (PBC) who responded inadequately to treatment with ursodeoxycholic acid (UDCA). METHODS: Eight UDCA-treated patients with PBC with alkaline phosphatase ≥1.5 times the upper limit of normal range participated in a double-blind, placebo-controlled study. While continuing on UDCA, the patients were randomised to two 3-month crossover treatment periods with placebo and OCA, in random order, separated by a 1-month washout period without study treatment. After each of the two treatment periods, we determined rate constants for transport of conjugated bile acids between blood, hepatocytes, biliary canaliculi, and bile ducts by positron emission tomography of the liver using the conjugated bile acid tracer [N-methyl-11C]cholylsarcosine (11C-CSar). The hepatic blood perfusion was measured using infusion of indocyanine green and Fick's principle. RESULTS: Compared with placebo, OCA increased hepatic blood perfusion by a median of 11% (p = 0.045), the unidirectional uptake clearance of 11C-CSar from blood into hepatocytes by a median of 11% (p = 0.01), and the rate constant for secretion of 11C-CSar from hepatocytes into biliary canaliculi by a median of 73% (p = 0.03). This resulted in an OCA-induced decrease in the hepatocyte residence time of 11C-CSar by a median of 30% (p = 0.01), from group median 11 min to 8 min. CONCLUSIONS: This study of UDCA-treated patients with PBC showed that, compared with placebo, OCA increased the hepatic transport of the conjugated bile acid tracer 11C-CSar, and thus endogenous conjugated bile acids, from hepatocytes into biliary canaliculi. As a result, OCA reduced the time hepatocytes are exposed to potentially cytotoxic bile acids. LAY SUMMARY: Primary biliary cholangitis is a chronic liver disease in which the small bile ducts are progressively destroyed. We tested whether the treatment with obeticholic acid (OCA) would improve liver excretion of bile acids compared with placebo in 8 patients with primary biliary cholangitis. A special scanning technique (PET scan) showed that OCA increased the transport of bile acids from blood to bile. OCA thereby reduced the time that potentially toxic bile acids reside in the liver by approximately one-third.

Double trouble: a case of an ataxic young man with coeliac disease and cerebrotendinous xanthomatosis.

We present the case of a 29-year-old south Asian man born of consanguineous marriage, presenting with ataxia, peripheral neuropathy and cognitive impairment. An initial diagnosis of coeliac disease was thought to explain the pertinent clinical features; however, further investigation led to an additional diagnosis of the rare yet treatable autosomal recessive condition, cerebrotendinous xanthomatosis. With both conditions employing highly diverse and overlapping clinical phenotypes, this contributed to a delay in diagnosis. Our report highlights the importance of paying close attention to both the clinical phenotype and family history.

BRD4 inhibition and FXR activation, individually beneficial in cholestasis, are antagonistic in combination.

Activation of farnesoid X receptor (FXR) by obeticholic acid (OCA) reduces hepatic inflammation and fibrosis in patients with primary biliary cholangitis (PBC), a life-threatening cholestatic liver failure. Inhibition of bromodomain-containing protein 4 (BRD4) also has antiinflammatory, antifibrotic effects in mice. We determined the role of BRD4 in FXR function in bile acid (BA) regulation and examined whether the known beneficial effects of OCA are enhanced by inhibiting BRD4 in cholestatic mice. Liver-specific downregulation of BRD4 disrupted BA homeostasis in mice, and FXR-mediated regulation of BA-related genes, including small heterodimer partner and cholesterol 7 alpha-hydroxylase, was BRD4 dependent. In cholestatic mice, JQ1 or OCA treatment ameliorated hepatotoxicity, inflammation, and fibrosis, but surprisingly, was antagonistic in combination. Mechanistically, OCA increased binding of FXR, and the corepressor silencing mediator of retinoid and thyroid hormone receptor (SMRT) decreased NF-κB binding at inflammatory genes and repressed the genes in a BRD4-dependent manner. In patients with PBC, hepatic expression of FXR and BRD4 was significantly reduced. In conclusion, BRD4 is a potentially novel cofactor of FXR for maintaining BA homeostasis and hepatoprotection. Although BRD4 promotes hepatic inflammation and fibrosis in cholestasis, paradoxically, BRD4 is required for the antiinflammatory, antifibrotic actions of OCA-activated FXR. Cotreatment with OCA and JQ1, individually beneficial, may be antagonistic in treatment of liver disease patients with inflammation and fibrosis complications.

Primary biliary cholangitis.

Primary biliary cholangitis is an autoimmune liver disease that predominantly affects women. It is characterised by a chronic and destructive, small bile duct, granulomatous lymphocytic cholangitis, with typical seroreactivity for antimitochondrial antibodies. Patients have variable risks of progressive ductopenia, cholestasis, and biliary fibrosis. Considerations for the cause of this disease emphasise an interaction of chronic immune damage with biliary epithelial cell responses and encompass complex, poorly understood genetic risks and environmental triggers. Licensed disease-modifying treatment focuses on amelioration of cholestasis, with weight-dosed oral ursodeoxycholic acid. For patients who do not respond sufficiently, or patients with ursodeoxycholic acid intolerance, conditionally licensed add-on therapy is with the FXR (NR1H4) agonist, obeticholic acid. Off-label therapy is recognised as an alternative, notably with the pan-PPAR agonist bezafibrate; clinical trial agents are also under development. Baseline characteristics, such as young age, male sex, and advanced disease, and serum markers of liver injury, particularly bilirubin and ALP, are used to stratify risk and assess treatment responsiveness. Parallel attention to the burden of patient symptoms is paramount, including pruritus and fatigue.

Downregulation of Cyp7a1 by Cholic Acid and Chenodeoxycholic Acid in Cyp27a1/ApoE Double Knockout Mice: Differential Cardiovascular Outcome.

Sterol 27-hydroxylase (CYP27A1) is a key enzyme in bile acids (BAs) biosynthesis and a regulator of cholesterol metabolism. Cyp27a1/Apolipoprotein E double knockout (DKO) mice fed with western diet (WD) are protected from atherosclerosis via up-regulation of hepatic Cyp7a1 and Cyp3a11. Since feeding BAs ameliorates metabolic changes in Cyp27a1 KO mice, we tested BAs feeding on the development of atherosclerosis in DKO mice. DKO mice were fed for 8 weeks with WD containing 0.1% cholic acid (CA) (WD-CA) or chenodeoxycholic acid (CDCA) (WD-CDCA). Atherosclerotic lesions, plasma lipoprotein composition and functionality, hepatic lipid content, BAs amount and composition, expression of genes involved in lipid metabolism and BA signaling in liver and intestine as well as intestinal cholesterol absorption were assessed. Hepatic Cyp7a1 and Cyp3a11 expression were reduced by 60% after feeding with both WD-CA and WD-CDCA. After feeding with WD-CA we observed a 40-fold increase in the abundance of atherosclerotic lesions in the aortic valve, doubling of the levels of plasma total and low density lipoprotein cholesterol and halving of the level of high density lipoprotein cholesterol. Furthermore, in these mice plasma cholesterol efflux capacity decreased by 30%, hepatic BA content increased 10-fold, intestinal cholesterol absorption increased 6-fold. No such changes were observed in mice fed with WD-CDCA. Despite similar reduction on Cyp7a1 and Cyp3a11 hepatic expression, CA and CDCA have a drastically different impact on development of atherosclerosis, plasma and hepatic lipids, BAs composition and intestinal absorption. Reduced cholesterol absorption contributes largely to athero-protection in DKO mice.

Vitamin D Receptor Deletion Changes Bile Acid Composition in Mice Orally Administered Chenodeoxycholic Acid.

The vitamin D receptor (VDR) is a nuclear receptor for the active form of vitamin D3 and also for the secondary bile acid lithocholic acid (LCA). The in vivo role of VDR in bile acid metabolism remains largely uncharacterized. We previously reported that pharmacological VDR activation enhances urinary bile acid excretion, particularly in mice fed chow supplemented with chenodeoxycholic acid (CDCA), which is metabolized to muricholic acid in mouse liver and is also converted to LCA by intestinal bacteria. In this study, we examined the effect of VDR deletion on bile acid composition utilizing VDR-knockout (VDR-KO) mice. VDR deletion did not change total bile acid levels in liver or feces of mice when fed standard chow supplemented with calcium, needed to prevent hypocalcemia in VDR-KO mice. Total bile acid levels in plasma and urine tended to be higher and lower, respectively, in VDR-KO mice. After feeding CDCA-supplemented chow, VDR-KO mice showed decreased hepatic, fecal and urinary total bile acid and CDCA levels compared to wild-type mice. Plasma total bile acids and LCA were relatively high in these mice. These results indicate that VDR deletion influences CDCA metabolism. VDR may play a role in the excretion of excess bile acids.

Activation of the Farnesoid X Receptor (FXR) Suppresses Linoleic Acid-Induced Inflammation in the Large Yellow Croaker (Larimichthys crocea).

BACKGROUND: High linoleic acid (LA) intake leads to inflammation that adversely influences health in fish. However, whether the farnesoid X receptor (FXR) could be an effective target for regulating LA-induced inflammation remains unknown. OBJECTIVE: The purpose of this study was to investigate the role of FXR in the regulation of LA-induced inflammation in large yellow croakers. METHODS: Large yellow croakers (initial weight of 10.03 ± 0.02 g) were allocated to 4 groups and fed a fish oil diet (6% FO), a soybean oil diet (6% SO), or the SO diet supplemented with 300 or 900 mg chenodeoxycholic acid (CDCA)/kg for 10 wk. The cultured kidney cell line PCK and primary hepatocytes from large yellow croakers were stimulated by LA (50 µM) after pretreatment with an FXR ligand (GW4064 or CDCA) or transfection with fxr-small interfering RNA (siFXR). mRNA expression of proinflammatory genes in the head kidney and liver tissues, PCK cells, and primary hepatocytes was determined by qPCR. The luciferase reporter assay, electrophoretic mobility shift assay, and immunoprecipitation assay were conducted in HEK 293T cells to determine the transcriptional activity of P65 and protein interactions between P65 and FXR or the small heterodimer partner (SHP). RESULTS: Proinflammatory genes were 93-1180% higher in the SO group compared with the FO group. CDCA supplementation decreased mRNA expression of proinflammatory genes by 17-87% while increasing fxr and shp expression by 120-460%. In PCK cells and primary hepatocytes, ligand-mediated activation of FXR decreased the LA-induced expression of proinflammatory genes by 18-67%, whereas siRNA-mediated knockdown of FXR increased the LA-induced expression of proinflammatory genes by 64-96%. FXR bound to the promoter of shp and regulated its mRNA expression. Both FXR and SHP could bind to P65 to suppress the transcriptional activity of P65. CONCLUSIONS: These results indicate that FXR has anti-inflammatory properties in large yellow croakers by directly and indirectly suppressing NFκB activity.

Current and new pharmacotherapy options for non-alcoholic steatohepatitis.

INTRODUCTION: There is an unmet medical need for an effective anti-fibrotic treatment for NASH with advanced fibrosis. AREAS COVERED: The authors review the current and novel agents for the treatment of NASH with fibrosis. They also consider the potential future strategies of combination therapies. EXPERT OPINION: Farnesoid X receptor (FXR) agonist (obeticholic acid [OCA]) significantly ameliorated hepatic fibrosis in NASH stage 2/3 fibrosis in an interim analysis of phase 3 trial. Because OCA has several drawbacks such as itching and elevated low-density lipoprotein-cholesterol (LDL-C), non-bile acid FXR agonists are now under development. Selonsertib (apoptosis signaling kinase 1 inhibitor), emricasan (an irreversible pan-caspase inhibitor), and simtsuzumab (a monoclonal antibody against lysyl oxidase-like 2) were discontinued because of no efficacy over placebo. Peroxisome proliferator-activator receptor α/δ agonists, C-C motif chemokine receptor-2/5 antagonists, and thyroid ß receptor agonist are ongoing in phase 3 trials. A variety of agents including fibroblast growth factor (FGF)-21 and FGF-19 agonists, as well as acetyl-CoA carboxylase inhibitors, are also expected. Among antidiabetic agents, semaglutide, a novel GLP-1 RA, is ongoing for NASH stage 1-3 fibrosis in a phase 2 trial. Furthermore, the combination of GLP-RA/glucagon receptor agonist and GLP-RA/gastrointestinal peptide agonist are promising future options.

A randomized, placebo-controlled, phase II study of obeticholic acid for primary sclerosing cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is a rare, cholestatic liver disease with no currently approved therapies. Obeticholic acid (OCA) is a potent farnesoid X receptor (FXR) agonist approved for the treatment of primary biliary cholangitis. We investigated the efficacy and safety of OCA in patients with PSC. METHODS: AESOP was a phase II, randomized, double-blind, placebo-controlled, dose-finding study. Eligible patients were 18 to 75 years of age with a diagnosis of PSC and serum alkaline phosphatase (ALP) ≥2× the upper limit of normal (ULN) and total bilirubin <2.5× ULN. Patients were randomized 1:1:1 to receive placebo, OCA 1.5-3.0 mg, or OCA 5-10 mg once daily for a 24-week, double-blind phase followed by a 2-year, long-term safety extension (LTSE). Primary endpoints were change in ALP from baseline to week 24, and safety. RESULTS: The intent-to-treat population comprised 76 patients randomized to placebo (n = 25), OCA 1.5-3.0 mg (n = 25), and OCA 5-10 mg (n = 26). At week 24, serum ALP was significantly reduced with OCA 5-10 mg vs. placebo (least-square [LS] mean difference = -83.4 [SE = 40.3] U/L; 95% CI -164.28 to -2.57; p = 0.043). Serum ALP was not significantly reduced with OCA 1.5-3.0 mg vs. placebo at week 24 (LS mean [SE] difference = -78.29 [41.81] U/L; 95% CI -162.08 to 5.50; p = 0.067). Total bilirubin remained comparable to baseline in all groups. The most common treatment-emergent adverse event was dose-related pruritus (placebo 46%; OCA 1.5-3.0 mg 60%; OCA 5-10 mg 67%). Reductions in ALP were maintained during the LTSE, and no new safety signals emerged. CONCLUSIONS: Treatment with OCA 5-10 mg reduced serum ALP in patients with PSC. Mild to moderate dose-related pruritus was the most common adverse event. REGISTRATION: ClinicalTrials.gov: NCT02177136; EudraCT: 2014-002205-38. LAY SUMMARY: Primary sclerosing cholangitis (PSC) is a long-term disease that damages the bile ducts in the liver over time. In the AESOP clinical study in patients with PSC, obeticholic acid reduced serum alkaline phosphatase (a potential marker of disease severity) during an initial 24-week treatment period. The result was sustained during the 2-year, long-term extension of the study. The most common side effect of obeticholic acid in the study was itchy skin, which is consistent with earlier clinical studies.

FXR activation promotes intestinal cholesterol excretion and attenuates hyperlipidemia in SR-B1-deficient mice fed a high-fat and high-cholesterol diet.

Obeticholic acid (OCA) activates the farnesoid X receptor (FXR) to lower circulating total cholesterol (TC) and high density lipoprotein-cholesterol (HDL-C) concentrations and to stimulate fecal cholesterol excretion in mice by increasing hepatic SR-B1 expression. Here we show that hepatic SR-B1 depletion by an adenovirus expressing Sr-b1 shRNA (Ad-shSR-B1) attenuated these beneficial effects of OCA in mice on a chow diet. The mRNA levels of ABC cholesterol transporter genes (Abca1, Abcg1, Abcg5, and Abcg8) were unchanged in the liver of hepatic SR-B1-depleted mice regardless of OCA treatment; however, a modest increase in Abca1, Abcg5, and Abcg8 mRNA levels was observed in the ileum of vehicle-treated control mice and Abca1 and Abcg8 mRNA levels were increased more by OCA administration. OCA treatment of Sr-b1 knock out (KO) mice (Sr-b1-/-) fed a normal chow diet (NCD) displayed a similar lack of transhepatic cholesterol movement, as well as a modest increase in the levels of ileum cholesterol transporter expression. However, OCA treatment of Sr-b1 KO mice fed a cholesterol-enriched diet reduced circulating cholesterol and increased fecal cholesterol output to comparable degrees to that of wild-type (WT) mice, and these effects were accompanied by substantial elevations of mRNA levels of Abca1, Abcg1, Abcg5, and Abcg8 in the ileum of Sr-b1 KO mice. Our studies suggest that FXR activation stimulates intestinal cholesterol excretion and reduces diet-induced hyperlipidemia through increased expression of ileal cholesterol transporters when hepatic SR-B1-mediated cholesterol movement is absent.

SUMOylation inhibitors synergize with FXR agonists in combating liver fibrosis.

Farnesoid X receptor (FXR) is a promising target for nonalcoholic steatohepatitis (NASH) and fibrosis. Although various FXR agonists have shown anti-fibrotic effects in diverse preclinical animal models, the response rate and efficacies in clinical trials were not optimum. Here we report that prophylactic but not therapeutic administration of obeticholic acid (OCA) prevents hepatic stellate cell (HSC) activation and fibrogenesis. Activated HSCs show limited response to OCA and other FXR agonists due to enhanced FXR SUMOylation. SUMOylation inhibitors rescue FXR signaling and thereby increasing the efficacy of OCA against HSC activation and fibrosis. FXR upregulates Perilipin-1, a direct target gene of FXR, to stabilize lipid droplets and thereby prevent HSC activation. Therapeutic coadministration of OCA and SUMOylation inhibitors drastically impedes liver fibrosis induced by CCl4, bile duct ligation, and more importantly NASH. In conclusion, we propose a promising therapeutic approach by combining SUMOylation inhibitors and FXR agonists for liver fibrosis.

Controlled Delivery of Bile Acids to the Colon.

INTRODUCTION: Bile acids, such as chenodeoxycholic acid, play an important role in digestion but are also involved in intestinal motility, fluid homeostasis, and humoral activity. Colonic delivery of sodium chenodeoxycholate (CDC) has demonstrated clinical efficacy in treating irritable bowel syndrome with constipation but was associated with a high frequency of abdominal pain. We hypothesized that these adverse effects were triggered by local super-physiological CDC levels caused by an unfavorable pharmacokinetic profile of the delayed release formulation. METHODS: We developed novel release matrix systems based on hydroxypropyl methylcellulose (HPMC) for sustained release of CDC. These included standard HPMC formulations as well as bi-layered formulations to account for potential delivery failures due to low colonic fluid in constipated patients. We evaluated CDC release profiles in silico (pharmacokinetic modeling), in vitro and in vivo in swine (pharmacokinetics, rectal manometry). RESULTS: For the delayed release formulation in vitro release studies demonstrated pH triggered dose dumping which was associated with giant colonic contractions in vivo. Release from the bi-layered HPMC systems provided controlled release of CDC while minimizing the frequency of giant contractions and providing enhanced exposure as compared to standard HPMC formulations in vivo. DISCUSSION: Bi-phasic CDC release could help treat constipation while mitigating abdominal pain observed in previous clinical trials. Further studies are necessary to demonstrate the therapeutic potential of these systems in humans.