Fenofibrate Improves Liver Function and Reduces the Toxicity of the Bile Acid Pool in Patients With Primary Biliary Cholangitis and Primary Sclerosing Cholangitis Who Are Partial Responders to Ursodiol

Navigating the liver landscape: upcoming pharmacotherapies for primary sclerosing cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a bile duct disorder characterized by ductular reaction, hepatic inflammation, and liver fibrosis. The pathogenesis of PSC is still undefined, and treatment options for patients are limited. Previous clinical trials evaluated drug candidates targeting various cellular functions and pathways, such as bile acid signaling and absorption, gut bacteria and permeability, and lipid metabolisms. However, most of phase III clinical trials for PSC were disappointing, except vancomycin therapy, and there are still no established medications for PSC with efficacy and safety confirmed by phase IV clinical trials.

AREAS COVERED

This review summarizes the currently ongoing or completed clinical studies for PSC, which are phase II or further, and discusses therapeutic targets and strategies, limitations, and future directions and possibilities of PSC treatments. A literature search was conducted in PubMed and ClinicalTrials.gov utilizing the combination of the searched term 'primary sclerosing cholangitis' with other keywords, such as 'clinical trials,' 'antibiotics,' or drug names. Clinical trials at phase II or further were included for consideration.

EXPERT OPINION

Only vancomycin demonstrated promising therapeutic effects in the phase III clinical trial. Other drug candidates showed futility or inconsistent results, and the search for novel PSC treatments is still ongoing.

Novel preclinical developments of the primary sclerosing cholangitis treatment landscape

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease associated with inflammation, fibrosis, and destruction of intra- and extrahepatic bile ducts. Despite substantial recent advances in our understanding of PSC, the only proven treatment of PSC is liver transplantation. There is an urgent unmet need to find medical therapies for this disorder.

AREAS COVERED

Multiple drugs are currently under evaluation as therapeutic options for this disease. This article summarizes the literature on the various novel therapeutic options that have been investigated and are currently under development for the treatment of PSC.

EXPERT OPINION

In the next decade, more than one drug will likely be approved for the treatment of the disease, and we will be looking at combination therapies for the optimal management of the disease.

The role of peroxisome proliferator-activated receptors in the regulation of bile acid metabolism

Bile acids are synthesized from cholesterol in the liver. Dysregulation of bile acid homeostasis, characterized by excessive accumulation in the liver, gallbladder and blood, can lead to hepatocellular damage and the development of cholestatic liver disease. Nuclear receptors play a crucial role in the control of bile acid metabolism by efficiently regulating bile acid synthesis and transport in the liver. Among these receptors, peroxisome proliferator-activated receptor (PPAR), a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily, controls the expression of genes involved in adipogenesis, lipid metabolism, inflammation and glucose homeostasis and has emerged as a potential therapeutic target for the treatment of the metabolic syndrome in the past two decades. Emerging evidence suggests that PPAR activation holds promise as a therapeutic target for cholestatic liver disease, as it affects both bile acid production and transport. This review provides a comprehensive overview of recent advances in elucidating the role of PPAR in the regulation of bile acid metabolism, highlighting the current position of PPAR agonists in the treatment of primary biliary cholangitis. By summarizing the specific regulatory effects of PPAR on bile acids, this review contributes to the exploration of novel therapeutic strategies for cholestatic liver diseases.

Treatment of Primary Sclerosing Cholangitis Including Transplantation

Primary sclerosing cholangitis is a progressive cholestatic liver disease that causes stricturing of the intra and extrahepatic bile ducts that can lead to cirrhosis and end stage liver disease. Effective medical therapy has been elusive, but a course of ursodeoxycholic acid may be prescribed at doses of 17-23 mg/kg/day for up to a year to determine if a reduction in serum alkaline phosphatase is observed. A number of drugs are under investigation, including FXR agonists with choleretic and antimicrobial properties. Liver transplantation for PSC has one of the highest survival rates, but recurrent PSC is seen in up to 25% of recipients.

Therapeutic potential of berberine in attenuating cholestatic liver injury: insights from a PSC mouse model

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic liver disease characterized by progressive biliary inflammation and bile duct injury. Berberine (BBR) is a bioactive isoquinoline alkaloid found in various herbs and has multiple beneficial effects on metabolic and inflammatory diseases, including liver diseases. This study aimed to examine the therapeutic effect of BBR on cholestatic liver injury in a PSC mouse model (Mdr2-/- mice) and elucidate the underlying mechanisms.

METHODS

Mdr2-/-mice (12-14 weeks old, both sexes) received either BBR (50 mg/kg) or control solution daily for eight weeks via oral gavage. Histological and serum biochemical analyses were used to assess fibrotic liver injury severity. Total RNAseq and pathway analyses were used to identify the potential signaling pathways modulated by BBR in the liver. The expression levels of key genes involved in regulating hepatic fibrosis, bile duct proliferation, inflammation, and bile acid metabolism were validated by qRT-PCR or Western blot analysis. The bile acid composition and levels in the serum, liver, small intestine, and feces and tissue distribution of BBR were measured by LC-MS/MS. Intestinal inflammation and injury were assessed by gene expression profiling and histological analysis. The impact on the gut microbiome was assessed using 16S rRNA gene sequencing.

RESULTS

BBR treatment significantly ameliorated cholestatic liver injury, evidenced by decreased serum levels of AST, ALT, and ALP, and reduced bile duct proliferation and hepatic fibrosis, as shown by H&E, Picro-Sirius Red, and CK19 IHC staining. RNAseq and qRT-PCR analyses indicated a substantial inhibition of fibrotic and inflammatory gene expression. BBR also mitigated ER stress by downregulating Chop, Atf4 and Xbp-1 expression. In addition, BBR modulated bile acid metabolism by altering key gene expressions in the liver and small intestine, resulting in restored bile acid homeostasis characterized by reduced total bile acids in serum, liver, and small intestine and increased fecal excretion. Furthermore, BBR significantly improved intestinal barrier function and reduced bacterial translocation by modulating the gut microbiota.

CONCLUSION

BBR effectively attenuates cholestatic liver injury, suggesting its potential as a therapeutic agent for PSC and other cholestatic liver diseases.

Inflammatory bowel disease and primary sclerosing cholangitis: One disease or two?

Primary sclerosing cholangitis (PSC) was declared one of the biggest unmet needs in hepatology during International Liver Congress 2016 in Berlin. Since then, not much has changed unfortunately, largely due to the still elusive pathophysiology of the disease. One of the most striking features of PSC is its association with inflammatory bowel disease (IBD), with the majority of patients with PSC being diagnosed with extensive colitis. This review describes the epidemiology of IBD in PSC, its specific phenotype, complications and potential pathophysiological mechanisms connecting the two diseases. Whether PSC is merely an extra-intestinal manifestation of IBD or if PSC and IBD are two distinct diseases that happen to share a common susceptibility that leads to a dual phenotype is debated. Implications for the management of the two diseases together are also discussed. Overall, this review summarises the available data in PSC-IBD and discusses whether PSC and IBD are one or two disease(s).

Effectiveness of Fenofibrate in Treatment-Naive Patients With Primary Biliary Cholangitis: A Randomized Clinical Trial

INTRODUCTION

Primary biliary cholangitis (PBC) is a progressive autoimmune liver disease, and patients with inadequate response to ursodeoxycholic acid (UDCA) treatment show reduced long-term survival. Recent studies have shown that fenofibrate is an effective off-label therapy for PBC. However, prospective studies on biochemical response including the timing of fenofibrate administration are lacking. This study is aimed to evaluate the efficacy and safety of fenofibrate in UDCA treatment-naive patients with PBC.

METHODS

A total of 117 treatment-naive patients with PBC were recruited from the Xijing Hospital for a 12-month randomized, parallel, and open-label clinical trial. Study participants were assigned to receive either UDCA standard dose (UDCA-only group) or fenofibrate at a daily dose of 200 mg in addition to UDCA (UDCA-Fenofibrate group).

RESULTS

The primary outcome was biochemical response percentage in patients according to the Barcelona criterion at 12 months. In the UDCA-Fenofibrate group, 81.4% (69.9%-92.9%) of patients achieved the primary outcome and 64.3% (51.9%-76.8%) in the UDCA-only group achieved the primary outcome ( P = 0.048). There was no difference between the 2 groups in noninvasive measures of liver fibrosis and biochemical markers other than alkaline phosphatase at 12 months. Creatinine and transaminases levels in the UDCA-Fenofibrate group increased within the first month, then returned to normal, and remained stable thereafter until the end of the study, even in patients with cirrhosis.

DISCUSSION

In this randomized clinical trial in treatment-naive patients with PBC, the combination of fenofibrate and UDCA resulted in a significantly higher biochemical response rate. Fenofibrate seemed to be well-tolerated in patients.

Current Therapeutics in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is an orphan, cholestatic liver disease that is characterized by inflammatory biliary strictures with variable progression to end-stage liver disease. Its pathophysiology is poorly understood. Chronic biliary inflammation is likely driven by immune dysregulation, gut dysbiosis, and environmental exposures resulting in gut-liver crosstalk and bile acid metabolism disturbances. There is no proven medical therapy that alters disease progression in PSC, with the commonly prescribed ursodeoxycholic acid being shown to improve liver biochemistry at low-moderate doses (15-23 mg/kg/day) but not alter transplant-free survival or liver-related outcomes. Liver transplantation is the only option for patients who develop end-stage liver disease or refractory complications of PSC. Immunosuppressive and antifibrotic agents have not proven to be effective, but there is promise for manipulation of the gut microbiome with fecal microbiota transplantation and antibiotics. Bile acid manipulation via alternate synthetic bile acids such as norursodeoxycholic acid, or interaction at a transcriptional level via nuclear receptor agonists and fibrates have shown potential in phase II trials in PSC with several leading to larger phase III trials. In view of the enhanced malignancy risk, statins, and aspirin show potential for reducing the risk of colorectal cancer and cholangiocarcinoma in PSC patients. For patients who develop clinically relevant strictures with cholestatic symptoms and worsening liver function, balloon dilatation is safer compared with biliary stent insertion with equivalent clinical efficacy.

Noninvasive prognostic models, imaging, and elastography to predict clinical events in primary sclerosing cholangitis: A review

Surrogate endpoints are needed to estimate clinical outcomes in primary sclerosing cholangitis (PSC). Serum alkaline phosphatase was among the first markers studied, but there is substantial variability in alkaline phosphatase levels during the natural history of PSC without intervention. The Mayo risk score incorporates noninvasive variables and has served as a surrogate endpoint for survival for more than two decades. Newer models have better test performance than the Mayo risk score, including the primary sclerosing risk estimate tool (PREsTo) model and UK-PSC score that estimate hepatic decompensation and transplant free survival, respectively. The c-statistics for transplant-free survival for the Mayo risk model and the long-term UK-PSC model are 0.68 and 0.85, respectively. The c-statistics for hepatic decompensation for the Mayo risk model and PREsTo model are 0.85 and 0.90, respectively. The Amsterdam-Oxford model included patients with large duct and small duct PSC and patients with PSC-autoimmune hepatitis overlap and had a c-statistic of 0.68 for transplant-free survival. Other noninvasive tests that warrant further validation include magnetic resonance imaging, elastography and the enhanced liver fibrosis score. Prognostic models, noninvasive tests or a combination of these surrogate endpoints may not only serve to be useful in clinical trials of investigational agents, but also serve to inform our patients about their prognosis.

Recent Advances in the Management of Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by fibroinflammatory damage to the biliary tree, typically in the setting of inflammatory bowel disease, with an increased risk of liver failure and cholangiocarcinoma. A complex pathophysiology, heterogeneity in clinical features, and the rare nature of the disease have contributed to the lack of effective therapy to date. However, recent innovations in the characterization and prognostication of patients with PSC, in addition to new tools for medical management and emerging pharmacologic agents, give rise to the potential for meaningful progress in the next several years. This review summarizes current concepts in PSC and highlights particular areas in need of further study.

Implications of gut microbiota in autoimmune liver diseases

Autoimmune liver diseases (AILD) are a group of immune-mediated liver inflammatory diseases with three major forms including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). Interaction of both genetic and environmental factors leads to the breakdown of self-tolerance, hence resulting in hyper-responsive of autoantibodies and aggressive autoreactive immune cells. Genetic studies have identified dozens of risk loci associated with initiation and development of AILD. However, the role of exogenous factors remains unclear. Recently, both infectious and inflammatory diseases have been associated with microbiota, which colonizes multiple mucosal surfaces and participates in human physiological process and function in immune system, particularly influencing liver, and biliary system via gut-liver axis. Emerging evidence on the role of gut microbiota has expanded our knowledge of AILD in both pathogenesis and potential therapeutic targets, along with putative diagnosis biomarkers. Herein we review the relationship between host and gut microbiota, discuss their potential roles in disease onset and progression, and summarize the compositional and functional alterations of the microbiota in AILD. We also highlighted the microbiota-based therapeutics such as antibiotics and fecal microbiota transplantation (FMT).

Application of the Latest Advances in Evidence-Based Medicine in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic, cholestatic, autoimmune liver disease that can progress to end-stage liver disease and its complications. A previous expert review panel collaborated on a consensus document for gastroenterologists and other healthcare professionals regarding the care of patients with PBC. Subsequently, there have been several recent important developments in the diagnosis, treatment, and monitoring of patients with PBC. These include updates to prognostic models on risk stratification, new noninvasive tools for staging of disease, updates to the appropriate use of and long-term treatment results with obeticholic acid as a second-line treatment, the emerging therapeutic role of fibrates, and the advancement of investigational agents for managing PBC. In this updated expert consensus document, we provide updates on staging, the use of noninvasive prognostic tools, and a treatment algorithm to provide evidence-based and practical tools for clinicians who manage PBC, with the ultimate goal to improve the long-term outcomes for patients with this chronic liver disease.

Fenofibrate Downregulates NF-κB Signaling to Inhibit Pro-inflammatory Cytokine Secretion in Human THP-1 Macrophages and During Primary Biliary Cholangitis

Chronic liver diseases, e.g., cholestasis, are negatively impacted by inflammation, which further aggravates liver injury. Pharmacotherapy targeting the peroxisome proliferator-activated receptor alpha (PPARα), e.g., fenofibrate, has recently become an off-label therapeutic option for patients with refractory cholestasis. Clinical studies show that fibrates can reduce some pro-inflammatory cytokines in primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC); however, its anti-inflammatory mechanisms have not been established. Numerous cytokines are regulated by the transcription factor nuclear receptor kappa B (NF-κB), and PPARα has been shown to interfere with NF-κB signaling. This study investigates the anti-inflammatory mechanism of fenofibrate by inhibiting NF-κB signaling in human macrophages and clinical outcomes in patients with PBC. For adult patients with PBC and an incomplete biochemical response to ursodiol (13-15 mg/kg/day), the addition of fenofibrate (145-160 mg/day) reduced serum levels of TNF-α, IL-17A, IL-1β, IL-6, IL-8, and MCP-1 and increased IL-10. In THP-1 cells, pretreatment with fenofibrate (125 μM) reduced LPS-stimulated peak concentrations of IL-1β (- 63%), TNF-α (- 88%), and IL-8 (- 54%), in a PPARα-dependent manner. Treatment with fenofibrate prior to LPS significantly decreased nuclear NF-κB p50 and p65 subunit binding by 49% and 31%, respectively. Additionally, fenofibrate decreased nuclear NF-κB p50 and p65 protein expression by 66% and 55% and increased cytoplasmic levels by 53% and 54% versus LPS alone, respectively. Lastly, fenofibrate increased IκBα levels by 2.7-fold (p < 0.001) vs. LPS. These data demonstrate that fenofibrate reduces pro-inflammatory cytokines section by inhibiting in NF-κB signaling, which likely contribute to its anti-inflammatory effects during chronic liver diseases.

Efficacy and safety of fenofibrate add-on therapy in patients with primary biliary cholangitis refractory to ursodeoxycholic acid: A retrospective study and updated meta-analysis

Background: Ursodeoxycholic acid (UDCA) is currently used for the treatment of primary biliary cholangitis (PBC), but some people do not respond well to UDCA. It reported that the combination of fenofibrate and UDCA can improve the clinical indices in these patients. However, more high-quality evidence is needed to improve guideline recommendations.

Methods: Through an updated meta-analysis, studies included were valued by the Cochrane Evaluation Manual and Robins-I. Biochemical and clinical indicator changes in UDCA-refractory PBC patients receiving combination therapy were analyzed by Revman 5.42. Then, we explored the influence of fenofibrate dose and the effectiveness and safety of long-term application by retrospective cohort study.

Results: Our meta-analysis included nine publications with a total of 389 patients, including 216 treated with UDCA alone and 173 who received combination therapy. The meta-analysis showed that combination therapy was more effective than UDCA monotherapy in decreasing biochemical parameters, such as ALP, GGT, IgM, and TG. However, the occurrence of pruritus and adverse events was slightly higher with combination therapy than with UDCA monotherapy. A total of 156 patients were included in our cohort study: 68 patients underwent UDCA monotherapy, and 88 patients underwent combination therapy. Among UDCA-refractory patients, fenofibrate add-on therapy significantly improved the ALP normalization rate.

Conclusion: The combination of fenofibrate and UDCA can decrease biochemical parameters, of UDCA-refractory PBC patient. Furthermore, the efficacy and safety of long-term combination therapy were also confirmed in our cohort study.

Fenofibrate in primary sclerosing cholangitis; a randomized, double-blind, placebo-controlled trial

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease with no medical treatment proven to improve survival and postpone liver transplantation. Previous studies have shown the effectiveness of fibrates in primary biliary cholangitis. The current study prospectively evaluated the effect of fenofibrate on PSC patients. We administered 200 mg of fenofibrate to PSC patients in the intervention arm and a placebo in the control arm once per day for 6 months and evaluated liver biochemistries (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, bilirubin, and albumin) and the Mayo Risk Score at the start and end of the study. The primary endpoint was defined as a reduction greater than 50% or normalization of ALP levels. Secondary endpoints were an improvement in the Mayo Risk Score and serum bilirubin levels. Thirty patients were included (19 female, 11 male, 40.2 ± 9.2 years old), all under treatment with Ursodeoxycholic acid prior to this study. ALP and ALT levels significantly decreased in the fenofibrate group, by 64.7% (mean difference = 557, p = 0.004, 95% CI = 208.72, 905.27) and 52.78%, (p = 0.006), respectively. The primary endpoint was achieved in 66.7% of patients (10 in 15) in the fenofibrate group versus 20% of patients (3 in 15) in the placebo group (p = 0.009). Other endpoints were not met. As studies have demonstrated lower levels of ALP may improve outcomes for PSC, our study resulted in significantly lower levels of ALP in the fenofibrate group, which could translate into better disease prognosis in PSC.

Pretransplant Evaluation and Liver Transplantation Outcome in PBC Patients

Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic liver disease characterized by progressive cholangiocyte and bile duct destruction leading to fibrosis and finally to liver cirrhosis. The presence of disease-specific serological antimitochondrial antibody (AMA) together with elevated alkaline phosphatase (ALP) as a biomarker of cholestasis is sufficient for diagnosis. Ursodeoxycholic acid (UDCA) is the first treatment option for PBC. Up to 40% of patients have an incomplete response to therapy, and over time disease progresses to liver cirrhosis. Several risk scores are proposed for better evaluation of patients before and during treatment to stratify patients at increased risk of disease progression. GLOBE score and UK PBC risk score are used for the evaluation of UDCA treatment and Mayo risk score for transplant-free survival. Liver transplantation (LT) is the only treatment option for end-stage liver disease. More than 10 years after LT, 40% of patients experience recurrence of the disease. A liver biopsy is required to establish rPBC (recurrent primary biliary cholangitis). The only treatment option for rPBC is UDCA, and data show biochemical and clinical improvement, plus potential beneficial effects for use after transplantation for the prevention of rPBC development. Additional studies are required to assess the full impact of rPBC on graft and recipient survival and for treatment options for rPBC.

PPARα: A potential therapeutic target of cholestasis

The accumulation of bile acids in the liver leads to the development of cholestasis and hepatocyte injury. Nuclear receptors control the synthesis and transport of bile acids in the liver. Among them, the farnesoid X receptor (FXR) is the most common receptor studied in treating cholestasis. The activation of this receptor can reduce the amount of bile acid synthesis and decrease the bile acid content in the liver, alleviating cholestasis. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) have a FXR excitatory effect, but the unresponsiveness of some patients and the side effect of pruritus seriously affect the results of UDCA or OCA treatment. The activator of peroxisome proliferator-activated receptor alpha (PPARα) has emerged as a new target for controlling the synthesis and transport of bile acids during cholestasis. Moreover, the anti-inflammatory effect of PPARα can effectively reduce cholestatic liver injury, thereby improving patients’ physiological status. Here, we will focus on the function of PPARα and its involvement in the regulation of bile acid transport and metabolism. In addition, the anti-inflammatory effects of PPARα will be discussed in some detail. Finally, we will discuss the application of PPARα agonists for cholestatic liver disorders.

Peroxisome Proliferator-Activated Receptors Regulate Hepatic Immunity and Assist in the Treatment of Primary Biliary Cholangitis

Fibrates, which are agonists of peroxisome proliferator-activated receptor alpha, have received increasing attention in the treatment of primary biliary cholangitis. Reduced alkaline phosphatase levels and improved clinical outcomes were observed in patients with primary biliary cholangitis with an inadequate response to ursodeoxycholic acid (UDCA) monotherapy4 when treated with bezafibrate or fenofibrate combined with UDCA. In contrast to obeticholic acid, which exacerbates pruritus in patients, fibrates have been shown to relieve pruritus. Clinical trial outcomes show potential for the treatment of primary biliary cholangitis by targeting peroxisome proliferator-activated receptors. It is currently agreed that primary biliary cholangitis is an autoimmune-mediated cholestatic liver disease, and peroxisome proliferator-activated receptor is a nuclear receptor that regulates the functions of multiple immune cells, thus playing an important role in regulating innate and adaptive immunity. Therefore, this review focuses on the immune disorder of primary biliary cholangitis and summarizes the regulation of hepatic immunity when peroxisome proliferator-activated receptors are targeted for treating primary biliary cholangitis.

Proof-of-concept study to evaluate the safety and efficacy of saroglitazar in patients with primary biliary cholangitis

BACKGROUND & AIM

Saroglitazar is a novel peroxisome proliferator-activated receptor (PPAR) agonist with dual agonistic properties (α/γ). Due to a strong mechanistic rationale, we aimed to test the safety and efficacy of saroglitazar in patients with primary biliary cholangitis (PBC) who were either ursodeoxycholic acid (UDCA) resistant or intolerant.

METHODS

In this double-blind, phase II proof-of-concept trial, 37 patients with PBC were randomized to saroglitazar 4 mg (n = 13), saroglitazar 2 mg (n = 14), or placebo (n = 10) daily for 16 weeks. The primary efficacy endpoint was the reduction in alkaline phosphatase (ALP) level at Week 16.

RESULTS

A significant reduction of mean ALP levels was observed at Week 16 relative to baseline in both the saroglitazar 4 mg (least-squares [LS] mean =-163.3 U/L, SE = 25.1, p <0.001) and 2 mg (LS mean =-155.8 U/L, SE = 24.4, p <0.001) groups, compared with placebo (LS mean =-21.1 U/L, SE = 28.9). Treatment with saroglitazar resulted in a rapid reduction of ALP concentration at Week 4 that was sustained through the study duration. At least 1 treatment-emergent adverse event occurred in 11 (84.6%) patients in the saroglitazar 4 mg group, in 12 (85.7%) patients in the 2 mg group and in 8 (80%) patients in the placebo group. Study drug was discontinued in 4 patients (3 patients in the 4 mg group and 1 patient in the 2 mg group) due to aminotransferase increases that promptly returned to baseline values after drug discontinuation.

CONCLUSIONS

Saroglitazar at 2 mg and 4 mg daily was tolerated and resulted in rapid and sustained improvements in ALP. Further studies are underway at a daily dose of 2 mg and 1 mg due to the higher incidence of elevated liver enzymes observed with the 4 mg dose. CLINICALTRIALS.

GOV IDENTIFIER

NCT03112681 LAY SUMMARY: Saroglitazar resulted in a rapid and sustained improvement in alkaline phosphatase levels in patients with primary biliary cholangitis. The mean percentage reductions in alkaline phosphatase levels were 49% and 51% in the saroglitazar 4 mg and 2 mg groups compared to 3% in the placebo group.

Adjunct Fenofibrate Up-regulates Bile Acid Glucuronidation and Improves Treatment Response For Patients With Cholestasis

Accumulation of cytotoxic bile acids (BAs) during cholestasis can result in liver failure. Glucuronidation, a phase II metabolism pathway responsible for BA detoxification, is regulated by peroxisome proliferator-activated receptor alpha (PPARα). This study investigates the efficacy of adjunct fenofibrate therapy to up-regulate BA-glucuronidation and reduce serum BA toxicity during cholestasis. Adult patients with primary biliary cholangitis (PBC, n = 32) and primary sclerosing cholangitis (PSC, n = 23), who experienced an incomplete response while receiving ursodiol monotherapy (13-15 mg/kg/day), defined as serum alkaline phosphatase (ALP) ≥ 1.5 times the upper limit of normal, received additional fenofibrate (145-160 mg/day) as standard of care. Serum BA and BA-glucuronide concentrations were measured by liquid chromatography-mass spectrometry. Combination therapy with fenofibrate significantly decreased elevated serum ALP (-76%, P < 0.001), aspartate transaminase, alanine aminotransferase, bilirubin, total serum BAs (-54%), and increased serum BA-glucuronides (+2.1-fold, P < 0.01) versus ursodiol monotherapy. The major serum BA-glucuronides that were favorably altered following adjunct fenofibrate include hyodeoxycholic acid-6G (+3.7-fold, P < 0.01), hyocholic acid-6G (+2.6-fold, P < 0.05), chenodeoxycholic acid (CDCA)-3G (-36%), and lithocholic acid (LCA)-3G (-42%) versus ursodiol monotherapy. Fenofibrate also up-regulated the expression of uridine 5'-diphospho-glucuronosyltransferases and multidrug resistance-associated protein 3 messenger RNA in primary human hepatocytes. Pearson's correlation coefficients identified strong associations between serum ALP and metabolic ratios of CDCA-3G (r2  = 0.62, P < 0.0001), deoxycholic acid (DCA)-3G (r2  = 0.48, P < 0.0001), and LCA-3G (r2  = 0.40, P < 0.001), in ursodiol monotherapy versus control. Receiver operating characteristic analysis identified serum BA-glucuronides as measures of response to therapy. Conclusion: Fenofibrate favorably alters major serum BA-glucuronides, which correlate with reduced serum ALP levels and improved outcomes. A PPARα-mediated anti-cholestatic mechanism is involved in detoxifying serum BAs in patients with PBC and PSC who have an incomplete response on ursodiol monotherapy and receive adjunct fenofibrate. Serum BA-glucuronides may serve as a noninvasive measure of treatment response in PBC and PSC.

Metabolomic Analysis Reveals the Therapeutic Effects of MBT1805, a Novel Pan-Peroxisome Proliferator-Activated Receptor Agonist, on α-Naphthylisothiocyanate-Induced Cholestasis in Mice

Background and Aims: Therapeutic drugs that are used to treat cholestatic liver disease are limited; however, the results of clinical trials on primary biliary cholangitis treatment targeting peroxisome proliferator-activated receptors (PPARs) are encouraging. In this study, we aimed to identify the effects of MBT1805, a novel balanced PPARα/γ/δ agonist, on cholestasis induced by α-naphthylisothiocyanate (ANIT) and elucidate the underlying mechanisms through untargeted and bile acid-targeted metabolomic analysis.

Methods: Levels of serum biochemical indicators (transaminase, aspartate transaminase, alkaline phosphatase, and total bilirubin) and liver histopathology were analyzed to evaluate the therapeutic effects of MBT1805 on ANIT-induced cholestasis in C57BL/6 mice. Untargeted and bile acid-targeted metabolomic analysis of liver tissues was performed using ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MC/MC). qRT-PCR and Western blot analysis were carried out to measure the expression of key enzymes and transporters regulating bile acid synthesis, biotransformation, and transport.

Results: MBT1805 significantly improved abnormal levels of liver biochemical indicators and gallbladder enlargement induced by ANIT. Histopathological analysis showed that MBT1805 effectively relieved ANIT-induced necrosis, vacuolation, and inflammatory infiltration. Untargeted metabolomic analysis identified 27 metabolites that were involved in the primary biliary acid biosynthesis pathway. In addition, bile acid-targeted metabolomics showed that MBT1805 could alleviate the abnormal bile acid content and composition induced by ANIT. Furthermore, qRT-PCR and Western blot results confirmed that MBT1805 could effectively regulate bile acid synthesis, biotransformation, and transport which helps relieve cholestasis.

Conclusions: MBT1805 is a potential candidate drug for cholestasis, with a balanced PPARα/γ/δ activation effect.

Effects of Switching from Fenofibrate to Pemafibrate for Asymptomatic Primary Biliary Cholangitis

Background/Aims

The addition of a fibrate to ursodeoxycholic acid (UDCA) is the standard treatment for asymptomatic primary biliary cholangitis (aPBC) with an incomplete response to UDCA. Among the fibrates, bezafibrate and fenofibrate increase the serum creatinine level and reduce the estimated glomerular filtration rate (eGFR). Pemafibrate is an selective peroxisome proliferator-activated receptor alpha modulator (SPPARM-α) mainly metabolized by the liver that was recently approved to treat dyslipidemia. This study confirmed the changes in the biochemical markers after switching from fenofibrate to pemafibrate in aPBC patients.

Methods

This study examined the effects of switching treatment from fenofibrate to pemafibrate in 16 aPBC patients. The biological parameters of these patients were examined at the initiation of fenofibrate and after switching to pemafibrate, then at 24 and 48 weeks later, respectively.

Results

Among patients with aPBC treated with UDCA and fenofibrate, the ALP, GGT, and serum IgM levels decreased significantly (p<0.0001) over 48 weeks. On the other hand, serum creatinine levels increased significantly, and eGFR decreased significantly (p<0.0001). After switching to pemafibrate plus UDCA, patients with aPBC exhibited significantly lower serum creatinine levels (p=0.007) and significantly higher eGFR levels (p=0.014).

Conclusions

Pemafibrate has therapeutic efficacy for aPBC patients with an inadequate response to UDCA. Pemafibrate might be another option for aPBC patients given its beneficial effects on renal function, but larger, multicenter studies with a longer follow-up are needed.

Omega-3 Polyunsaturated Fatty Acid: A Pharmaco-Nutraceutical Approach to Improve the Responsiveness to Ursodeoxycholic Acid

Ursodeoxycholic acid (UDCA) is the first line therapy for the treatment of cholestatic and autoimmune liver diseases. Its clinical use is currently limited by a significant proportion of non-responder patients. Polyunsaturated fatty acids (n-3 PUFAs) possess important anti-inflammatory properties and protect liver cells against bile acid (BA)-induced toxicity. The present study was designed to rapidly evaluate whether combining n-3 PUFAs (i.e., eicosapentaenoic [EPA] and docosahexaenoic [DHA] acids) to UDCA would provide additional benefits when compared to the drug alone. The parameters evaluated were (i) the expression of genes governing BA synthesis, transport, and metabolism; (ii) the prevention of BA-induced apoptosis and endoplasmic reticulum (ER)-stress; and (iii) the control of BA- and LPS-dependent inflammation. In the absence of n-3 PUFAs, most of the parameters investigated were unaffected by UDCA or were only altered by the higher dose (500 µM) of the drug. By contrast, in the presence of EPA/DHA (50/50 µM), all parameters showed a strongly improved response and the lowest UDCA dosage (50 µM) provided equal or better benefits than the highest dose used alone. For example, the combination EPA/DHA + UDCA 50 µM caused comparable down-regulation of the CYP7A1 gene expression and of the BA-induced caspase 3 activity as observed with UDCA 500 µM. In conclusion, these results suggest that the addition of n-3 PUFAs to UDCA may improve the response to the drug, and that such a pharmaco-nutraceutical approach could be used in clinic to open the narrow therapeutic dose of UDCA in cholestatic liver diseases.

Fibrotic Events in the Progression of Cholestatic Liver Disease

Cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are associated with active hepatic fibrogenesis, which can ultimately lead to the development of cirrhosis. However, the exact relationship between the development of liver fibrosis and the progression of cholestatic liver disease remains elusive. Periductular fibroblasts located around the bile ducts seem biologically different from hepatic stellate cells (HSCs). The fibrotic events in these clinical conditions appear to be related to complex crosstalk between immune/inflammatory mechanisms, cytokine signalling, and perturbed homeostasis between cholangiocytes and mesenchymal cells. Several animal models including bile duct ligation (BDL) and the Mdr2-knockout mice have improved our understanding of mechanisms underlying chronic cholestasis. In the present review, we aim to elucidate the mechanisms of fibrosis in order to help to identify potential diagnostic and therapeutic targets.

Primary biliary cholangitis: treatment

PURPOSE OF REVIEW

To discuss the most recent data regarding treatment of patients with primary biliary cholangitis (PBC) with inadequate response to ursodeoxycholic acid (UDCA).

RECENT FINDINGS

Patients with PBC at high-risk of progressive disease are younger, have advanced fibrosis and showed inadequate response to UDCA after 12 months of treatment. These patients need a second-line treatment in addition to UDCA. The goal of therapy should be the normalization of ALP and bilirubin below 0.6 the upper limit of normal. Obeticholic acid (OCA) has proven to be effective in improving surrogate markers of prognosis in PBC, also in real-life cohort. Pruritus is the most frequent adverse event during treatment with OCA. Bezafibrate is another option in patients with inadequate response to UDCA as it was proven to improve surrogate endpoints, pruritus and even, clinical outcome compared with UDCA monotherapy. Finally, budesonide may be considered in patients with marked portal inflammation. Triple therapy with UDCA, OCA and bezafibrate may be considered in patients showing inadequate response to dual therapy.

SUMMARY

Patients with PBC need to be evaluated at baseline, and on-treatment, for the risk of progressive disease and eventually treated with second-line therapies in addition to UDCA.

The association of histological progression with biochemical response to ursodeoxycholic acid in primary biliary cholangitis

Primary biliary cholangitis (PBC) is currently diagnosed at an early stage; therefore, the number of patients with PBC without symptoms at the time of diagnosis is increasing. However, up to 30% of patients with PBC exhibit the suboptimal response to ursodeoxycholic acid (UDCA) and are at high risk of end-stage liver disease. Obeticholic acid is an approved second-line therapy for patients with PBC that are refractory to UDCA. Novel surrogate endpoints are required to identify individuals eligible for second-line therapies. An inadequate biochemical response to UDCA is a useful predictor of poor outcomes in patients with PBC. In addition to UDCA effects on biochemical parameters, histological outcomes could be considered as candidate surrogate endpoints. Alterations in liver histology are used as surrogate endpoints in clinical studies. However, current staging systems are insufficient to determine PBC disease severity and progression because of the pathological heterogeneity of the disease. Histological features at baseline and biochemical response to UDCA treatment can affect the disease course of PBC. Therefore, novel surrogate endpoints must be represented by parameters characterized by histological outcomes and treatment responses in PBC. In this review, we discuss the existing histological parameters and newly created factors to identify patients with PBC who are at a high risk of developing end-stage liver disease and, consequently, the potential need for additional treatments.