Anticholestatic effects of bezafibrate in patients with primary biliary cirrhosis treated with ursodeoxycholic acid

A Phase 3 Trial of Seladelpar in Primary Biliary Cholangitis

BACKGROUND

Effective treatments for patients with primary biliary cholangitis are limited. Seladelpar, a peroxisome proliferator-activated receptor delta agonist, has potential benefits.

METHODS

In this phase 3, 12-month, double-blind, placebo-controlled trial, we randomly assigned (in a 2:1 ratio) patients who had had an inadequate response to or who had a history of unacceptable side effects with ursodeoxycholic acid to receive oral seladelpar at a dose of 10 mg daily or placebo. The primary end point was a biochemical response, which was defined as an alkaline phosphatase level less than 1.67 times the upper limit of the normal range, with a decrease of 15% or more from baseline, and a normal total bilirubin level at month 12. Key secondary end points were normalization of the alkaline phosphatase level at month 12 and a change in the score on the pruritus numerical rating scale (range, 0 [no itch] to 10 [worst itch imaginable]) from baseline to month 6 among patients with a baseline score of at least 4 (indicating moderate-to-severe pruritus).

RESULTS

Of the 193 patients who underwent randomization and treatment, 93.8% received ursodeoxycholic acid as standard-of-care background therapy. A greater percentage of the patients in the seladelpar group than in the placebo group had a biochemical response (61.7% vs. 20.0%; difference, 41.7 percentage points; 95% confidence interval [CI], 27.7 to 53.4, P<0.001). Normalization of the alkaline phosphatase level also occurred in a greater percentage of patients who received seladelpar than of those who received placebo (25.0% vs. 0%; difference, 25.0 percentage points; 95% CI, 18.3 to 33.2, P<0.001). Seladelpar resulted in a greater reduction in the score on the pruritus numerical rating scale than placebo (least-squares mean change from baseline, -3.2 vs. -1.7; least-squares mean difference, -1.5; 95% CI, -2.5 to -0.5, P = 0.005). Adverse events were reported in 86.7% of the patients in the seladelpar group and in 84.6% in the placebo group, and serious adverse events in 7.0% and 6.2%, respectively.

CONCLUSIONS

In this trial involving patients with primary biliary cholangitis, the percentage of patients who had a biochemical response and alkaline phosphatase normalization was significantly greater with seladelpar than with placebo. Seladelpar also significantly reduced pruritus among patients who had moderate-to-severe pruritus at baseline. The incidence and severity of adverse events were similar in the two groups. (Funded by CymaBay Therapeutics; RESPONSE ClinicalTrials.gov number, NCT04620733; EudraCT number, 2020-004348-27.).

New Therapies on the Horizon for Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that can progress to cirrhosis and hepatic failure if left untreated. Ursodeoxycholic acid (UDCA) was introduced as a first-line drug for PBC around 1990; it remarkably improved patient outcomes, leading to the nomenclature change of PBC in 2015, from primary biliary "cirrhosis" to primary biliary "cholangitis." Nevertheless, 20-30% of patients exhibit an incomplete response to UDCA, resulting in significantly worse outcomes compared to those with a complete response. Therefore, improving the long-term outcomes of patients with an incomplete response to UDCA has been recognized as an unmet need. In addition, patients with PBC often suffer from a variety of debilitating symptoms, such as pruritus, fatigue and sicca syndrome, which significantly impair their health-related quality of life. Thus, appropriate management of these symptoms is currently regarded as another unmet need for PBC treatment. In this review, several compounds and drugs under clinical trials that can potentially solve these unmet needs are comprehensively discussed, and future directions of treatment policy of PBC are proposed for significantly improving long-term outcome as well as health-related quality of life of patients.

Study of the effect of bezafibrate with ginkgo biloba extracts in an animal model of hepatotoxicity induced by doxorubicin

This study aimed to evaluate the hepatoprotective effect of combining bezafibrate with ginkgo biloba in doxorubicin-induced hepatotoxicity in rats. Thirty Wister albino rats were allocated into five groups: The negative control group, the positive control group, both received 1 ml of D.W, bezafibrate group received (100 mg/kg), ginkgo biloba group received (60 mg/kg) and the fifth group received bezafibrate + ginkgo biloba. All the treatments were for 14 days along with doxorubicin on days 11-14 except for the negative control. Blood samples were used for the measurement of ALT, AST, ALP, total protein, total bilirubin, albumin, globulin, GSH, catalase, and IL-6. Liver tissue was sent for histopathological examination. The combination of ginkgo biloba and bezafibrate significantly decreased AST, ALP, AST/ALT ratio, albumin/globulin ratio, and IL-6 with significant elevations of catalase, and GSH. The combination group produced more hepatoprotection. This could be attributed to the additive anti-inflammatory and antioxidant effects of the combination.

Determinants of the effectiveness of bezafibrate combined with ursodeoxycholic acid in patients with primary biliary cholangitis

BACKGROUND AND AIMS

For patients with primary biliary cholangitis (PBC) exhibiting suboptimal responses to ursodeoxycholic acid (UDCA), obeticholic acid (OCA), and bezafibrate (BZF) are currently used and shown to improve long-term outcomes. Nevertheless, we encounter patients who die or undergo liver transplantation (LT) even with combination treatment. In this study, we explored prognostic indicators in patients receiving combination treatment of UDCA and BZF.

METHODS

We took advantage of the Japanese PBC registry and enrolled patients who received both UDCA and BZF therapy in 2000 or later. The covariates investigated included baseline covariates as well as treatment covariates. Two main outcomes (all-cause death or LT and liver-related death or LT) were assessed using multivariable-adjusted Cox proportional hazards models.

RESULTS

In total, 772 patients were included. The median follow-up was 7.1 years. Using the Cox regression model, bilirubin (hazard ratio [HR] 6.85, 95% confidence interval [CI] 1.73-27.1, p = 0.006), alkaline phosphatase (HR 5.46, 95% CI 1.32-22.6, p = 0.019), and histological stage (HR 4.87, 95% CI 1.16-20.5, p = 0.031) were found associated with LT-free survival. For survival free from liver disease-related death or LT, albumin (HR 7.72, 95% CI 1.48-40.4, p = 0.016) and bilirubin (HR 14.5, 95% CI 2.37-88.5, p = 0.004) were found significantly associated.

CONCLUSION

In patients with PBC receiving combination therapy, prognostic variables were similar to those in patients receiving UDCA monotherapy. These results indicate the importance of diagnosing patients with PBC at an earlier stage because of the reduced effectiveness of BZF at advanced stages.

Efficacy of fibrates in the treatment of primary biliary cholangitis: a meta-analysis

Patients with primary biliary cholangitis (PBC) who respond poorly to ursodeoxycholic acid (UDCA) are increasingly being trialed using fibrates, showing promising results. To further investigate, we performed a meta-analysis to evaluate the benefit of administrating fibrates to patients with PBC. PubMed, EMBASE, and Cochrane library databases were searched using the keywords "bezafibrate", "fenofibrate", "fibrate", "primary biliary cholangitis" and clinical studies involving the use of fibrates in patients with PBC were included. The primary outcome of this study was the effect of fibrates administration on biochemical markers related to cholestasis in patients with PBC, and the secondary outcome was the incidence of treatment-related adverse events. A total of 20 studies with 4783 participants were included in this study. The results revealed that adding fibrates could significantly reduce the levels of ALP (fibrates vs. placebo, MD: - 370.14, P = 0.04; fibrates + UDCA vs. UDCA, MD: - 184.15, P < 0.01), total cholesterol (MD: - 2.82, P = 0.04), GGT (fibrates vs. placebo, MD: - 140.88, P < 0.01; fibrates + UDCA vs. UDCA, MD: - 130.73, P = 0.04), alleviate pruritus symptoms (RD: - 0.20, 95% CI: - 0.39 ~  - 0.01, P = 0.04), and did not significantly increase the incidence of treatment-related side effects. Fibrates can significantly improve liver biochemical parameters and alleviate pruritus in PBC patients.

[Response to Primary Biliary Cholangitis Treatment: Influencing Factors and the Role in Prognosis Prediction]

Objective

To examine the influencing factors and prognostic features of poor response to ursodeoxycholic acid (UDCA) treatment in primary biliary cholangitis (PBC) patients with dyslipidemia.

Methods

A retrospective study was conducted, covering 512 patients who had a confirmed diagnosis of PBC, and who received treatment at West China Hospital, Sichuan University between January 2009 and March 2022. According to their actual response to UDCA treatment, patients were divided into two groups, UDCA full-response group ( n=305) and UDCA non-responding group ( n=207). The data from the two groups were compared to predict the adverse factors influencing patient response and the area under the curve ( AUC) of the receiver operating characteristic (ROC) curve, identify the cut-off value of total cholesterol (TC), and analyze the differences in baseline laboratory test findings and the rate of responses to treatment. According to the TC cut-off value, patients were divided into a group with TC≥5.415 mmol/L and another group with TC<5.415 mmol/L. In addition, differences in the prognosis of the two groups were assessed by comparing the UK-PBC and GLOBE scores.

Results

The baseline data, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), triglycerides (TG), TC, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), were significantly increased in the UDCA non-responding group compared to those in the full-response group (all P<0.005), while the albumin level of the UDCA non-responding group was decreased compared to that of the full-response group ( P=0.012). Findings of multi-factor logistic regression analysis suggested that TC (odds ratio [ OR]=1.501, 95% confidence interval [ CI]: 1.275-1.767, P<0.01) and ALP ( OR=1.005, 95% CI: 1.003-1.006, P<0.01) were independent risk factors influencing patient response. The ROC curve analysis suggested worse prognosis for patients with TC≥5.415 mmol/L ( AUC: 0.727, 95% CI: 0.680-0.775, 63.8% sensitivity, 76.4% specificity). In addition, the UK-PBC risk score at 1 year of treatment was higher in the high-TC group (TC≥5.415 mmol/L) than that in the low-TC group (TC<5.415 mmol/L) ( P<0.05).

Conclusions

Hypercholesterolemia is an independent risk factor for poor response to UDCA in PBC patients. When the baseline TC is equal to or higher than 5.415 mmol/L, PBC patients have a relatively poor response to UDCA and poor prognosis.

Discovery of the First Subnanomolar PPARα/δ Dual Agonist for the Treatment of Cholestatic Liver Diseases

Peroxisome proliferator-activator receptors α/δ (PPARα/δ) are considered as potential drug targets for cholestatic liver diseases (CLD) via ameliorating hepatic cholestasis, inflammation, and fibrosis. In this work, we developed a series of hydantoin derivatives as potent PPARα/δ dual agonists. Representative compound V1 exhibited PPARα/δ dual agonistic activity at the subnanomolar level (PPARα EC₅₀ = 0.7 nM; PPARδ EC₅₀ = 0.4 nM) and showed excellent selectivity over other related nuclear receptors. The crystal structure revealed the binding mode of V1 and PPARδ at 2.1 Å resolution. Importantly, V1 demonstrated excellent pharmacokinetic (PK) properties and a good safety profile. Notably, V1 showed potent anti-CLD and antifibrotic effects in preclinical models at very low doses (0.03 and 0.1 mg/kg). Collectively, this work provides a promising drug candidate for treating CLD and other hepatic fibrosis diseases.

Breach of tolerance versus burden of bile acids: Resolving the conundrum in the immunopathogenesis and natural history of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a classic autoimmune disease due to the loss of tolerance to self-antigens. Bile acids (BA) reportedly play a major role in biliary inflammation and/or in the modulation of dysregulated immune responses in PBC. Several murine models have indicated that molecular mimicry plays a role in autoimmune cholangitis; however, they have all been limited by the relative failure to develop hepatic fibrosis. We hypothesized that species-specific differences in the BA composition between mice and humans were the primary reason for this limited pathology. Here, we aimed to study the impact of human-like hydrophobic BA composition on the development of autoimmune cholangitis and hepatic fibrosis. We took advantage of a unique construct, Cyp2c70/Cyp2a12 double knockout (DKO) mice, which have human-like BA composition, and immunized them with a well-defined mimic of the major mitochondrial autoantigen of PBC, namely 2-octynoic acid (2OA). 2OA-treated DKO mice were significantly exacerbated portal inflammation and bile duct damage with increased Th1 cytokines/chemokines at 8 weeks post-initial immunization. Most importantly, there was clear progression of hepatic fibrosis and increased expression of hepatic fibrosis-related genes. Interestingly, these mice demonstrated increased serum BA concentrations and decreased biliary BA concentrations; hepatic BA levels did not increase because of the upregulation of transporters responsible for the basolateral efflux of BA. Furthermore, cholangitis and hepatic fibrosis were more advanced at 24 weeks post-initial immunization. These results indicate that both the loss of tolerance and the effect of hydrophobic BA are essential for the progression of PBC.

The Pathological Effects of Circulating Hydrophobic Bile Acids in Alzheimer's Disease

Recent clinical studies have revealed that the serum levels of toxic hydrophobic bile acids (deoxy cholic acid, lithocholic acid [LCA], and glycoursodeoxycholic acid) are significantly higher in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) when compared to control subjects. The elevated serum bile acids may be the result of hepatic peroxisomal dysfunction. Circulating hydrophobic bile acids are able to disrupt the blood-brain barrier and promote the formation of amyloid-β plaques through enhancing the oxidation of docosahexaenoic acid. Hydrophobic bile acid may find their ways into the neurons via the apical sodium-dependent bile acid transporter. It has been shown that hydrophobic bile acids impose their pathological effects by activating farnesoid X receptor and suppressing bile acid synthesis in the brain, blocking NMDA receptors, lowering brain oxysterol levels, and interfering with 17β-estradiol actions such as LCA by binding to E2 receptors (molecular modelling data exclusive to this paper). Hydrophobic bile acids may interfere with the sonic hedgehog signaling through alteration of cell membrane rafts and reducing brain 24(S)-hydroxycholesterol. This article will 1) analyze the pathological roles of circulating hydrophobic bile acids in the brain, 2) propose therapeutic approaches, and 3) conclude that consideration be given to reducing/monitoring toxic bile acid levels in patients with AD or aMCI, prior/in combination with other treatments.

PPAR agonists for the treatment of primary biliary cholangitis: Old and new tales

Introduction

Primary biliary cholangitis (PBC) is an autoimmune liver disease involving the small intrahepatic bile ducts; when untreated or undertreated, it may evolve to liver fibrosis and cirrhosis. Ursodeoxycholic Acid (UDCA) is the standard of care treatment, Obeticholic Acid (OCA) has been approved as second-line therapy for those non responder or intolerant to UDCA. However, due to moderate rate of UDCA-non responders and to warnings recently issued against OCA use in patients with cirrhosis, further therapies are needed.Areas covered. Deep investigations into the pathogenesis of PBC is leading to proposal of new therapeutic agents, among which peroxisome proliferator-activated receptor (PPAR) ligands seem to be highly promising given the preliminary, positive results in Phase 2 and 3 trials. Bezafibrate, the most evaluated, is currently used in clinical practice in combination with UDCA in referral centers. We herein describe completed and ongoing trials involving PPAR agonists use in PBC, analyzing pits and falls.

Expert opinion

Testing new therapeutic opportunities in PBC is challenging due to its low prevalence and slow progression. However, new drugs including PPAR agonists, are currently under investigation and should be considered for at-risk PBC patients.

Treatment of Primary Biliary Cholangitis: First-Line and Second-Line Therapies

Primary biliary cholangitis (PBC) is an autoimmune disease of the interlobular bile ducts leading to secondary damage of hepatocytes and may progress to cirrhosis and liver failure. The first-line treatment is ursodeoxycholic acid; up to 40% of patients do not have an adequate response and remain at risk of disease progression. Obeticholic acid has been conditionally approved for the treatment of PBC as add-on therapy and bezafibrate has shown similar efficacy in this group of patients. Several new therapies are in development and may further add to the treatment options available to patients with PBC.

Ursodeoxycholic acid is associated with improved long-term outcome in patients with primary sclerosing cholangitis

BACKGROUND

It remains unclear whether ursodeoxycholic acid (UDCA) treatment improves long-term outcomes in patients with primary sclerosing cholangitis (PSC). In this study, we investigated whether UDCA treatment is associated with improved liver transplantation (LT)-free survival in a cohort of Japanese patients with PSC.Journal instruction requires a city and country for affiliations; however, these are missing in affiliation [6]. Please verify if the provided city and country are correct and amend if necessary.'Tokyo, Japan' is correct.

METHODS

We used retrospective data from the Japanese PSC registry that included 435 patients with PSC. In this study, we enrolled patients with a complete dataset at diagnosis, along with the diagnosis year, treatment protocol, follow-up period, and outcome data. The association between UDCA treatment and all-cause death or LT was analyzed using Cox regression and inverse probability of UDCA treatment weighting (IPTW)-adjusted Cox regression models adjusted for covariates.

RESULTS

Among 435 patients with PSC, 110 were excluded due to insufficient or missing data, and the remaining 325 patients (male, 187 (58%); mean age at diagnosis, 45.8 years) were enrolled. The mean follow-up period was 5.1 years, and 57 deaths and 24 LTs occurred during observation. UDCA was administered to 278 patients (86%). The Cox regression model demonstrated that UDCA treatment was associated with an improvement in LT-free survival [adjusted hazard ratio (aHR) 0.47, 95% confidence interval (CI) 0.28-0.78, p = 0.003]. In addition, the IPTW-adjusted model indicated a significant association between UDCA and LT-free survival (aHR 0.43, 95% CI 0.25-0.75, p = 0.020). Sensitivity analysis excluding patients treated with bezafibrate indicated a similarly significant association between UDCA treatment and LT-free survival.

CONCLUSION

In this Japanese PSC cohort, UDCA treatment was significantly associated with improved LT-free survival.

Obeticholic Acid for Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease that may progress to fibrosis and/or cirrhosis. Treatment options are currently limited. The first-line therapy for this disease is the drug ursodeoxycholic acid (UDCA), which has been proven to normalize serum markers of liver dysfunction, halt histologic disease progression, and lead to a prolongation of transplant-free survival. However, 30–40% of patients unfortunately do not respond to this first-line therapy. Obeticholic acid (OCA) is the only registered agent for second-line treatment in UDCA-non responders. In this review, we focus on the pharmacological features of OCA, describing its mechanism of action of and its tolerability and efficacy in PBC patients. We also highlight current perspectives on future therapies for this condition.

Efficacy and Safety of Bezafibrate Alone or in Combination with Ursodeoxycholic Acid in Primary Biliary Cholangitis: Systematic Review and Meta-Analysis

BACKGROUND

Bezafibrate (BZF) alone or in combination with ursodeoxycholic acid (UDCA) has been used to slow disease progression in patients with primary biliary cholangitis (PBC). We performed a systematic review and meta-analysis to assess the efficacy and harms of BZF monotherapy or combination therapy.

METHODS

We performed a systematic search of PubMed, EMBASE, Cochrane Library, Scopus, ClinicalTrials.gov, and WHO ICTRP from inception until January 2020, for randomized controlled clinical trials assessing BZF + UDCA versus UDCA monotherapy or BZF monotherapy versus UDCA monotherapy in PBC patients. Additionally, we systematically evaluated data on harms using seven observational studies. Pooled effect estimates were calculated for the outcomes of interest. The certainty of evidence was assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

RESULTS

We identified 7 randomized controlled trials with a total of 279 participants. Comparing BZF + UDCA to UDCA alone, a clinically significant improvement was observed in serum ALP with a mean difference (MD) of - 159.04 U/L (95% CI - 186.45 to - 131.62) and a reduction in gamma-glutamyltransferase (GGT) (MD - 106.94 IU/L; 95% CI - 151.99 to - 61.89), but not in total bilirubin (TB) or IgM levels. A statistically significant reduction in ALP levels was also noticed with BZF monotherapy compared to UDCA monotherapy. The effect of BZF + UDCA versus UDCA on mortality remains unclear. Across 5 observational studies including 106 patients, one death was reported due to advanced liver disease in an incomplete responder getting treatment with BZF + UDCA. Analysis of observational studies demonstrated improvement in pruritus intensity with BZF.

CONCLUSIONS

Use of BZF alone or in combination with UDCA improved liver biochemistries in patients with PBC, but its effect on mortality, liver-related complications or quality of life remains unknown.

Update on the Pharmacological Treatment of Primary Biliary Cholangitis

Ursodeoxycholic acid (UDCA) is the first-line therapy used for the treatment of PBC. In recent years, new pharmacological agents have been proposed for PBC therapy to cure UDCA-non-responders. Obeticholic acid (OCA) is registered in many countries for PBC, and fibrates also seem to be effective in ameliorating biochemistry alteration and symptoms typical of PBC. Moreover, a variety of new agents, acting with different mechanisms of action, are under clinical evaluation for PBC treatment, including PPAR agonists, anti-NOX agents, immunomodulators, and mesenchymal stem cell transplantation. Since an insufficient amount of data is currently available about the effect of these novel approaches on robust clinical endpoints, such as transplant-free survival, their clinical approval needs to be supported by the consistent improvement of these parameters. The intensive research in this field will hopefully lead to a novel treatment landscape for PBC in the near future, with innovative therapies based on the combination of multiple agents acting on different pathogenetic mechanisms.

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.

Clinically Relevant Dose of Pemafibrate, a Novel Selective Peroxisome Proliferator-Activated Receptor α Modulator (SPPARMα), Lowers Serum Triglyceride Levels by Targeting Hepatic PPARα in Mice

Pemafibrate (PEM) is a novel lipid-lowering drug classified as a selective peroxisome proliferator-activated receptor α (PPARα) modulator whose binding efficiency to PPARα is superior to that of fibrates. This agent is also useful for non-alcoholic fatty liver disease and primary biliary cholangitis with dyslipidemia. The dose of PEM used in some previous mouse experiments is often much higher than the clinical dose in humans; however, the precise mechanism of reduced serum triglyceride (TG) for the clinical dose of PEM has not been fully evaluated. To address this issue, PEM at a clinically relevant dose (0.1 mg/kg/day) or relatively high dose (0.3 mg/kg/day) was administered to male C57BL/6J mice for 14 days. Clinical dose PEM sufficiently lowered circulating TG levels without apparent hepatotoxicity in mice, likely due to hepatic PPARα stimulation and the enhancement of fatty acid uptake and β-oxidation. Interestingly, PPARα was activated only in the liver by PEM and not in other tissues. The clinical dose of PEM also increased serum/hepatic fibroblast growth factor 21 (FGF21) without enhancing hepatic lipid peroxide 4-hydroxynonenal or inflammatory signaling. In conclusion, a clinically relevant dose of PEM in mice efficiently and safely reduced serum TG and increased FGF21 targeting hepatic PPARα. These findings may help explain the multiple beneficial effects of PEM observed in the clinical setting.

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.

Effects of pemafibrate on primary biliary cholangitis with dyslipidemia

AIM

The purpose of this study was to examine the effect of pemafibrate (PEM) in primary biliary cholangitis (PBC) patients with dyslipidemia.

METHODS

Patients who were diagnosed with PBC between June 2018 and December 31, 2020 were included in the study if they also had dyslipidemia and their alkaline phosphatase (ALP) or gamma-glutamyl transferase (GGT) levels remained above the normal range despite taking 600 mg/day ursodeoxycholic acid (UDCA) for at least 6 months. Patients who were treated with UDCA alone were administered PEM as an add-on (PEM-add group), and patients who were treated with UDCA and bezafibrate (BEZ) for at least 6 months were given PEM instead of BEZ (PEM-switch group). Clinical parameters were compared in all patients, and the levels of ALP, GGT, the estimated glomerular filtration rate (eGFR), and creatinine (Cr) were compared between the PEM-add and PEM-switch groups. Improvement in cholangitis was also evaluated.

RESULTS

In the PEM-add group, both ALP and GGT improved in 40 of 46 patients (87.0%). In the PEM-switch group, both ALP and GGT improved in 15 of 29 patients (51.7%). In the PEM-switch group, however, significant improvement was seen in eGFR and Cr.

CONCLUSIONS

Administration of PEM is effective in PBC patients with dyslipidemia who are refractory to UDCA monotherapy. In patients using both UDCA and BEZ, there was an advantage in switching to PEM if they had renal damage; however, improvement of ALP and GGT occurred in about 50%.

The Nuclear Receptor PXR in Chronic Liver Disease

Pregnane X receptor (PXR), a nuclear receptor known for modulating the transcription of drug metabolizing enzymes and transporters (DMETs), such as cytochrome P450 3A4 and P-glycoprotein, is functionally involved in chronic liver diseases of different etiologies. Furthermore, PXR activity relates to that of other NRs, such as constitutive androstane receptor (CAR), through a crosstalk that in turn orchestrates a complex network of responses. Thus, besides regulating DMETs, PXR signaling is involved in both liver damage progression and repair and in the neoplastic transition to hepatocellular carcinoma. We here summarize the present knowledge about PXR expression and function in chronic liver diseases characterized by different etiologies and clinical outcome, focusing on the molecular pathways involved in PXR activity. Although many molecular details of these finely tuned networks still need to be fully understood, we conclude that PXR and its modulation could represent a promising pharmacological target for the identification of novel therapeutical approaches to chronic liver diseases.

Emerging drugs for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare immune-mediated cholestatic disease for which no medical therapy has been shown to slow disease progression. Consequently, liver transplantation is the only lifesaving intervention for patients, and despite being a rare disease, PSC is the lead indication for transplantation across several European countries. The vast majority of patients (>70%) also develop inflammatory bowel disease (IBD) at some point in their lifetime, which imparts added lifetime risks of hepatobiliary malignancy and colorectal cancer. The rare disease nature, variable and often slow rates of disease progression (years rather than months), and lack of robust surrogate biomarkers for early stage yet high risk disease, represent critical challenges in trial design that have long precluded the development of effective medical treatment. However, the horizon for new treatments is encouraging, given innovative clinical trial programmes led by industry, alongside several investigator-initiated studies. Herein, we outline the current platform of interventional trials in PSC, before discussing emerging areas of therapeutic interest.

Treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by progressive fibro-stenotic strictures and destruction of the biliary tree. Currently, there is no effective treatment which can delay its progression or ameliorate the transplant-free survival. Moreover, a major chontroversy in PSC is whether to use UDCA. More recently, novel pharmacological agents emerged aiming at: i) modulation of bile composition; ii) immunomodulation; iii) targeting the gut microbiome; iv) targeting fibrosis. Successful PSC therapy, however, will be most likely a personalized combination of different drugs plus endoscopic treatment. This review aims at offering an overview on the experimental pharmacological strategies currently exploited for PSC treatment.

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.

Obeticholic Acid and Fibrates in Primary Biliary Cholangitis: Comparative Effects in a Multicentric Observational Study

INTRODUCTION

Obeticholic acid (OCA) and fibrates therapy results in biochemical improvement in placebo-controlled trials in patients with primary biliary cholangitis and insufficient response to ursodeoxycholic acid. There is scarce information outside of clinical trials. Therefore, we have assessed the effectiveness and adverse events of these treatments.

METHODS

Data from patients included in the ColHai registry treated with OCA, fibrates, or both were recorded during a year, as well as adverse events and treatment discontinuation.

RESULTS

Eighty-six patients were treated with OCA, 250 with fibrates (81% bezafibrate; 19% fenofibrate), and 15 with OCA plus fibrates. OCA group had baseline significantly higher alkaline phosphatase (ALP) (P = 0.01) and lower platelets (P = 0.03) than fibrates. Both treatments significantly decreased ALP, gamma-glutamyl transferase (GGT), and transaminases and improved Globe score. Albumin and immunoglobulin type M improved in the fibrates group. ALP decrease was higher under fibrates, whereas alanine aminotransferase decline was higher under OCA. Although baseline transaminases and GGT were higher in patients with OCA plus fibrates, significant ALP, GGT, alanine aminotransferase, and Globe score improvement were observed during triple therapy. Adverse events were reported in 14.7% of patients (21.3% OCA; 17.6% fenofibrate; 10.7% bezafibrate), mainly pruritus (10.1% with OCA). Discontinuation was more frequent in fenofibrate treatment mainly because of intolerance or adverse events.

DISCUSSION

Second-line therapy with OCA or fibrates improves hepatic biochemistry and the GLOBE score in primary biliary cholangitis patients with suboptimal response to ursodeoxycholic acid. Simultaneous treatment with OCA and fibrates improved ALP as well.

Bezafibrate therapy in primary biliary cholangitis refractory to ursodeoxycholic acid: a longitudinal study of paired liver biopsies at 5 years of follow up

BACKGROUND

Ursodeoxycholic acid (UDCA) is the first-line therapy for primary biliary cholangitis (PBC). However, nearly 40% of patients have an incomplete response to UDCA. The addition of bezafibrate has shown biochemical benefit in this group of patients.

AIM

To evaluate the long-term effects of UDCA in combination with bezafibrate on histological outcomes in patients with UDCA-refractory PBC.

METHODS

Fifty-nine patients refractory to UDCA were included. Clinical parameters were monitored and paired liver biopsy (PLB) was performed after 5 years of follow-up.

RESULTS

Of the total cohort, 49 subjects were analysed and 31 had PLB at 5 years. Values for serum ALP, AST, ALT and GGT significantly improved with UDCA-bezafibrate. This beneficial effect was observed at 12 months where 86% achieved ALP at normal levels. Analyses of PLB showed a significant decrease in liver damage as reflected by Ludwig (baseline 2.29 ± 1.2, to 1.84 ± 1 at year 5, P = 0.0242) and Ishak (baseline 6.19 ± 2.2 to 4.77 ± 2.2 at year 5, P = 0.0008) scores. Overall, regression of fibrosis was attained in 48% of patients. Furthermore, we observed a significant reduction in the proportion with cirrhosis from 19% at baseline to 3% at 5 years (P < 0.001). These beneficial effects were associated with better predictive risk scores using the GLOBE and UK-PBC prognosis models.

CONCLUSIONS

Adding bezafibrate to UDCA in patients with UDCA-refractory PBC showed a significant decrease in fibrosis and inflammatory histological scores at 5 years. These beneficial effects warrant further evaluation in long-term cohort studies and controlled trials.

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.

Association of bezafibrate with transplant-free survival in patients with primary biliary cholangitis

BACKGROUND & AIMS

A beneficial effect of bezafibrate (BZF) on symptoms and biochemical features of primary biliary cholangitis (PBC) has been reported in patients with an incomplete response to ursodeoxycholic acid (UDCA), but long-term effects on survival remain unknown. In Japan, BZF has been used as a de facto second-line therapy for PBC since 2000. Herein, we compared the survival rates between patients treated with and those without BZF in a large nationwide Japanese PBC cohort.

METHODS

All consecutively registered patients of this cohort who started UDCA therapy from 2000 onwards and had a follow-up ≥1 year were included. Association between BZF exposure and mortality or need for liver transplantation (LT) was assessed using time-dependent, multivariable-and propensity score-adjusted Cox proportional hazards models. Clinical benefit was quantified using the number needed to treat (NNT).

RESULTS

Of 3,908 eligible patients, 3,162 (81%) received UDCA only and 746 (19%) UDCA and BZF over 17,360 and 3,932 patient-years, respectively. During follow-up, 183 deaths (89 liver-related) and 21 LT were registered. Exposure to combination therapy was associated with a significant decrease in all-cause and liver-related mortality or need for LT (adjusted hazard ratios: 0.3253, 95% CI 0.1936-0.5466 and 0.2748, 95% CI 0.1336-0.5655, respectively; p <0.001 for both). This association was consistent across various risk groups at baseline. The NNTs with combination therapy to prevent 1 additional death or LT over 5, 10, and 15 years were 29 (95% CI 22-46), 14 (10-22), and 8 (6-15), respectively.

CONCLUSIONS

In a large retrospective cohort study of treatment effects in patients with PBC, the addition of BZF to UDCA was associated with improved prognosis.

LAY SUMMARY

The long-term efficacy of bezafibrate (BZF) on liver transplantation (LT) - free survival in patients with PBC and an incomplete response to ursodeoxycholic acid (UDCA) remains to be determined. In this Japanese nationwide retrospective cohort study, the use of UDCA-BZF combination therapy, compared to UDCA alone, was associated with a lower risk of all-cause and liver-related mortality or need for LT. These results indicate that BZF is so far the only drug in PBC to have demonstrated efficacy in improving symptoms, biochemical markers, and long-term outcomes.

Safety of fibrates in cholestatic liver diseases

BACKGROUND AND AIM

Off-label use of fibrates in patients with cholestatic liver diseases results in improved biochemical parameters and pruritus; however, their safety in this population has been a concern. This study summarizes safety data for fibrates when used for treatment of cholestatic liver diseases.

METHODS

A systematic review of published studies evaluating the use of fibrates for treatment of primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) was performed. Electronic databases were searched up to December 2019 for published studies evaluating treatment outcomes associated to fibrates for these 2 diseases.

RESULTS

A total of 37 studies were identified, including 31 for PBC and 6 for PSC, with a total of 1107 unique patients treated with fibrates ± ursodeoxycholic acid (UDCA). Most studies evaluated fenofibrate and bezafibrate, and only 1 study evaluated pemafibrate. There were no studies evaluating gemfibrozil or clofibrate. The most commonly reported adverse events (AEs) were gastrointestinal and musculoskeletal. Elevations of aminotransferases and serum creatinine were reported more commonly in patients treated with UDCA plus fibrates versus UDCA monotherapy.

CONCLUSIONS

Fibrates appear to be safe and well tolerated in patients with PBC, with a low frequency of AEs. There are scarce data about the safety of these agents for treatment of PSC.

The ursodeoxycholic acid response score predicts pathological features in primary biliary cholangitis

AIM

The ursodeoxycholic acid response score (URS) can predict the biochemical response to 12 months of ursodeoxycholic acid (UDCA) treatment in patients with primary biliary cholangitis (PBC). We investigated the relationship between the URS and the histopathological features before and after UDCA treatment.

METHODS

Patients with PBC (n = 126) were examined for the association between the probability of response (POR) to UDCA based on the URS formulas and clinicopathological features. Furthermore, 30 patients were examined for the association between the POR and pathological changes.

RESULTS

The POR area under the receiver operating characteristic curve (AUROC) for predicting the biochemical response to UDCA was 0.861. The PORs of stage 1 in the Nakanuma system and grade 0 in the CK7 grading in hepatocytes were significantly higher than those of stage 3 and grade 3, respectively. The AUROCs for the prediction of stage ≥2, stage ≥3 and stage 4 in the Nakanuma system at pretreatment were 0.592, 0.710 and 0.817, respectively. The AUROCs for the prediction of grade ≥1, grade ≥2 and grade 3 in the CK7 hepatocyte grading were 0.741, 0.824 and 0.970, respectively. Furthermore, the AUROC for predicting the histological stage progression after UDCA treatment in the Scheuer classification and the Nakanuma system were 0.712 and 0.799, respectively.

CONCLUSIONS

The URS not only predicts the biochemical response, but also reflects the Nakanuma system and the CK7 hepatocyte grading at pretreatment. This scoring system can identify an inadequate histological response to UDCA treatment in the Scheuer classification and the Nakanuma system.

Experimental Pharmacological Agents for the Treatment of Primary Biliary Cholangitis

The standard therapy for primary biliary cholangitis (PBC) is ursodeoxycholic acid (UDCA) which has shown to improve hepatic biochemistry, delay histological progression and improve transplant-free survival. Approximately 30-40% of patients do not respond or are intolerant to UDCA. Obeticholic acid, a farnesoid X receptor (FXR) agonist is the only agent approved by the Food and Drug Administration for patients who do not respond to UDCA. Recently, combination therapy with UDCA and bezafibrate has been shown to improve biochemistry and both GLOBE and UK-PBC score in patients with an inadequate response to UDCA. More recently, new pharmacological agents have been included in Phase 2 and Phase 3 trials: PPAR agonists, non-bile acid FXR agonists, anti-NOX agents, immunomodulators and mesenchymal stem cells transplantation. This review gives an overview on the current experimental pharmacological agents employed in the treatment of PBC.

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.

Current understanding of primary biliary cholangitis

Primary biliary cholangitis (PBC) causes chronic and persistent cholestasis in the liver, eventually resulting in cirrhosis and hepatic failure without appropriate treatment. PBC mainly develops in middle-aged women, but it is also common in young women and men. PBC is considered a model of autoimmune disease because of the presence of disease-specific autoantibodies, that is, antimitochondrial antibodies (AMAs), intense infiltration of mononuclear cells into the bile ducts, and a high prevalence of autoimmune diseases such as comorbidities. Histologically, PBC is characterized by degeneration and necrosis of intrahepatic biliary epithelial cells surrounded by a dense infiltration of mononuclear cells, coined as chronic non-suppurative destructive cholangitis, which leads to destructive changes and the disappearance of small- or medium-sized bile ducts. Since 1990, early diagnosis with the detection of AMAs and introduction of ursodeoxycholic acid as first-line treatment has greatly altered the clinical course of PBC, and liver transplantation-free survival of patients with PBC is now comparable to that of the general population.

Regulation of CAR and PXR Expression in Health and Disease

Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.

Primary Sclerosing Cholangitis and Primary Biliary Cirrhosis Overlap Syndrome: A Review

Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) are slow progressive diseases which have been increasing in prevalence. The pathogeneses of PBC and PSC are incompletely understood but the underlying mechanisms appear to be fundamentally autoimmune in origin. Although PBC and PSC appear to be separate entities, overlap has been described. Diagnosis depends on a combination of serological markers, imaging, and pathological criteria. The mainstay of treatment has been ursodeoxycholic acid and in some cases of extrahepatic biliary obstruction and overlap disorder, endoscopic retrograde cholangiopancreatography has been useful.

A validation study of the Ursodeoxycholic Acid Response Score in Japanese patients with primary biliary cholangitis

BACKGROUND/PURPOSE

Although ursodeoxycholic acid (UDCA) is a first-line treatment for primary biliary cholangitis (PBC), 20%-30% of patients with PBC exhibit an incomplete response to UDCA. Recently, the UDCA Response Score was proposed for predicting response to UDCA using pretreatment parameters in patients with PBC. We aimed to validate the UDCA Response Score in Japanese patients with PBC.

METHODS

Registry data of Japanese patients (n = 873) were collected. Patients with data on all clinical parameters required for calculating the UDCA Response Score were selected. The endpoint was UDCA response, defined as alkaline phosphatase <1.67 times the upper limit of the normal value after 12 months of UDCA treatment.

RESULTS

All parameters were available in 804 patients (male/female = 120/684, age 58.9 [interquartile range 51.1-66.9] years). Bezafibrate was commenced within 12 months of UDCA in 78 patients (9.7%) because of the lack of an early response. We found that the endpoint was not reached in these 78 patients, and the area under the receiver operating characteristic curve (AUROC) of the score was 0.74 (95% confidence interval [CI] 0.70-0.79). The AUROC was 0.77 (95% CI 0.70-0.83) in patients undergoing UDCA monotherapy (n = 726). Finally, the AUROC of the modified UDCA Response Score using only data from the treatment start date was 0.80 (95% CI 0.70-0.90) in patients receiving a combination therapy of UDCA and bezafibrate (n = 160).

CONCLUSION

The validity of the UDCA Response Score was acceptable in Japanese patients; this score will be informative in patients treated with a combination therapy of UDCA and bezafibrate.

Update on Emerging Treatment Options for Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease that may progress to fibrosis or cirrhosis. Treatment options are currently limited. Ursodeoxycholic acid (UDCA) remains first-line therapy and has been proven to normalize serum biochemistries, halt histologic disease progression, and lead to patient survival comparable to the general population. Obeticholic acid (OCA) was recently approved as adjunct therapy in PBC patients with inadequate response or intolerance to UDCA. However, OCA has been associated with worsening pruritus in clinical studies which may limit its use in this patient population. Several studies are currently underway to address the lack of treatment options for PBC. Of these, fibrates, which have been used in Japan for over a decade, have produced promising results. Furthermore, as currently approved therapies for PBC do not address the potentially debilitating clinical symptoms of PBC such as pruritus and fatigue, supplemental therapy is often required for symptom control.

IgM response is a prognostic biomarker of primary biliary cholangitis treated with ursodeoxycholic acid and bezafibrate

BACKGROUND AND AIM

Primary biliary cholangitis (PBC) patients who are refractory to ursodeoxycholic acid (UDCA) are at risk for progression to cirrhosis and liver failure. Bezafibrate could be an alternative second-line therapeutic option in these patients. This study aimed to evaluate the long-term outcome(s) of combined UDCA and bezafibrate therapy in UDCA-refractory PBC patients and identify prognostic factors.

METHODS

Among 445 patients treated with UDCA, 150 patients inadequately responded to UDCA monotherapy and received long-term UDCA plus bezafibrate (median, 15 years). Data from these patients were used for this retrospective analysis.

RESULTS

Combination therapy resulted in significant improvements in serum biochemistry and liver transplantation risk estimated using the UK-PBC-risk and the GLOBE scores. The cumulative normalization rates of alkaline phosphatase, gamma-glutamyltransferase, and immunoglobulin M (IgM) were significantly higher in patients without cirrhosis-related symptoms or liver-related events than in those with them. Overall, IgM constantly emerged as a significant factor associated with cirrhosis-related symptoms and liver-related events at all time points. Cumulative survival rates were significantly lower in patients with IgM ≥ 240 mg/dL than in patients with IgM < 240 mg/dL. Thus, normalization of IgM levels was a good surrogate predictor of long-term prognosis. None of the patients discontinued combination therapy due to any adverse events during the follow-up period.

CONCLUSIONS

Our findings point to the beneficial effects of long-term UDCA plus bezafibrate combination therapy for UDCA-refractory PBC patients, and IgM response can be a useful predictive biomarker of long-term clinical outcomes.

Drug Therapies for Chronic Cholestatic Liver Diseases

Though ursodeoxycholic acid (UDCA) remains the baseline treatment for most cholestatic liver diseases, UDCA treatment leaves approximately one-third of patients with primary biliary cholangitis (PBC) and all patients with primary sclerosing cholangitis (PSC) at risk for disease progression. New anticholestatic agents, including nuclear receptor agonists, choleretics, and bile acid synthesis suppressors, will likely increase response rates to therapy in PBC and PSC. Strategies that target early immune-mediated injury have so far been disappointing, hampered by the lack of biomarkers to detect early disease states, which then could profit from immunomodulatory therapy. Future concepts need to personalize treatments according to disease stage, progression, and phase, and to combine multiple drugs to target different pathogenic pathways.

Emerging therapies in primary sclerosing cholangitis: pathophysiological basis and clinical opportunities

Primary sclerosing cholangitis (PSC) is a progressive liver disease, histologically characterized by inflammation and fibrosis of the bile ducts, and clinically leading to multi-focal biliary strictures and with time cirrhosis and liver failure. Patients bear a significant risk of cholangiocarcinoma and colorectal cancer, and frequently have concomitant inflammatory bowel disease and autoimmune disease manifestations. To date, no medical therapy has proven significant impact on clinical outcomes and most patients ultimately need liver transplantation. Several treatment strategies have failed in the past and whilst prescription of ursodeoxycholic acid (UDCA) prevails, controversy regarding benefits remains. Lack of statistical power, slow and variable disease progression, lack of surrogate biomarkers for disease severity and other challenges in trial design serve as critical obstacles in the development of effective therapy. Advances in our understanding of PSC pathogenesis and biliary physiology over recent years has however led to a surge of clinical trials targeting various mechanistic compartments and currently raising hopes for imminent changes in patient management. Here, in light of pathophysiology, we outline and critically evaluate emerging treatment strategies in PSC, as tested in recent or ongoing phase II and III trials, stratified per a triad of targets of nuclear and membrane receptors regulating bile acid metabolism, immune modulators, and effects on the gut microbiome. Furthermore, we revisit the UDCA trials of the past and critically discuss relevant aspects of clinical trial design, including how the choice of endpoints, alkaline phosphatase in particular, may affect the future path to novel, effective PSC therapeutics.

Bezafibrate Improves GLOBE and UK-PBC Scores and Long-Term Outcomes in Patients With Primary Biliary Cholangitis

In Japan, bezafibrate (BF) is a second-line agent for primary biliary cholangitis (PBC) that is refractory to ursodeoxycholic acid (UDCA) treatment. From a retrospective cohort (n = 873) from the Japan PBC Study Group, we enrolled 118 patients who had received UDCA monotherapy for at least 1 year followed by combination therapy with UDCA+BF for at least 1 year. GLOBE and UK-PBC scores after UDCA monotherapy (i.e., immediately before UDCA+BF combination therapy) were compared with those after 1 year of UDCA+BF combination therapy. The real outcomes of enrolled patients estimated by Kaplan-Meier analysis were compared with the predicted outcomes calculated using GLOBE and UK-PBC scores. In addition, the hazard ratio of BF treatment was calculated using propensity score analysis. The mean GLOBE score before the combination therapy was 0.504 ± 0.080, which improved significantly to 0.115 ± 0.085 (P < 0.0001) after 1 year of combination therapy. The real liver transplant-free survival of enrolled patients was significantly better than that predicted by GLOBE score before introducing BF. Combination therapy did not significantly improve the real rates of liver transplantation or liver-related death compared with those predicted by UK-PBC risk score before introducing BF, but the predicted risk was significantly reduced by the addition of BF (P < 0.0001). Cox regression analysis with inverse probability of treatment weighting showed that the addition of BF significantly reduced the hazard of liver transplant or liver-related death in patients who, after 1 year of UDCA monotherapy, had normal serum bilirubin (adjusted hazard ratio 0.09, 95% confidence interval 0.01-0.60, P = 0.013). Conclusion: Addition of BF to UDCA monotherapy improves not only GLOBE and UK-PBC scores but also the long-term prognosis of PBC patients, especially those with early-stage PBC.

ABCB4/MDR3 in health and disease – at the crossroads of biochemistry and medicine

Several ABC transporters of the human liver are responsible for the secretion of bile salts, lipids and cholesterol. Their interplay protects the biliary tree from the harsh detergent activity of bile salts. Among these transporters, ABCB4 is essential for the translocation of phosphatidylcholine (PC) lipids from the inner to the outer leaflet of the canalicular membrane of hepatocytes. ABCB4 deficiency can result in altered PC to bile salt ratios, which led to intrahepatic cholestasis of pregnancy, low phospholipid associated cholelithiasis, drug induced liver injury or even progressive familial intrahepatic cholestasis type 3. Although PC lipids only account for 30–40% of the lipids in the canalicular membrane, 95% of all phospholipids in bile are PC lipids. We discuss this discrepancy in the light of PC synthesis and bile salts favoring certain lipids. Nevertheless, the in vivo extraction of PC lipids from the outer leaflet of the canalicular membrane by bile salts should be considered as a separate step in bile formation. Therefore, methods to characterize disease causing ABCB4 mutations should be considered carefully, but such an analysis represents a crucial point in understanding the currently unknown transport mechanism of this ABC transporter.

Regulation of bile acid metabolism in mouse models with hydrophobic bile acid composition

The bile acid (BA) composition in mice is substantially different from that in humans. Chenodeoxycholic acid (CDCA) is an end product in the human liver; however, mouse Cyp2c70 metabolizes CDCA to hydrophilic muricholic acids (MCAs). Moreover, in humans, the gut microbiota converts the primary BAs, cholic acid and CDCA, into deoxycholic acid (DCA) and lithocholic acid (LCA), respectively. In contrast, the mouse Cyp2a12 reverts this action and converts these secondary BAs to primary BAs. Here, we generated Cyp2a12 KO, Cyp2c70 KO, and Cyp2a12/Cyp2c70 double KO (DKO) mice using the CRISPR-Cas9 system to study the regulation of BA metabolism under hydrophobic BA composition. Cyp2a12 KO mice showed the accumulation of DCAs, whereas Cyp2c70 KO mice lacked MCAs and exhibited markedly increased hepatobiliary proportions of CDCA. In DKO mice, not only DCAs or CDCAs but also DCAs, CDCAs, and LCAs were all elevated. In Cyp2c70 KO and DKO mice, chronic liver inflammation was observed depending on the hepatic unconjugated CDCA concentrations. The BA pool was markedly reduced in Cyp2c70 KO and DKO mice, but the FXR was not activated. It was suggested that the cytokine/c-Jun N-terminal kinase signaling pathway and the pregnane X receptor-mediated pathway are the predominant mechanisms, preferred over the FXR/small heterodimer partner and FXR/fibroblast growth factor 15 pathways, for controlling BA synthesis under hydrophobic BA composition. From our results, we hypothesize that these KO mice can be novel and useful models for investigating the roles of hydrophobic BAs in various human diseases.

Hyperlipidaemia in primary biliary cholangitis: treatment, safety and efficacy

Primary biliary cholangitis (PBC) is an autoimmune liver disease associated with altered lipoprotein metabolism, mainly cholesterol. Hypercholesterolaemia, a major modifiable risk factor for cardiovascular disease in the general population, occurs in 75%-95% of individuals with PBC. The impact of hypercholesterolaemia on cardiovascular risk in PBC, however, is controversial. Previous data have shown that hypercholesterolaemia in PBC is not always associated with an increase in cardiovascular events. However, patients with PBC with cardiovascular risk factors may still warrant cholesterol-lowering therapy. Treatment of hypercholesterolaemia in PBC poses unique challenges among primary care providers due to concerns of hepatotoxicity associated with cholesterol-lowering medications. This review summarises the current understanding of the pathophysiology of hypercholesterolaemia in PBC and its pertinent cardiovascular risk. We will also discuss indications for treatment and the efficacy and safety of available agents for hypercholesterolaemia in PBC.

Effectiveness of bezafibrate and ursodeoxycholic acid in patients with primary biliary cholangitis: a meta-analysis of randomized controlled trials

Background

Ursodeoxycholic acid (UDCA) and obeticholic acid are currently approved treatments for primary biliary cholangitis (PBC). Since some patients do not respond adequately to UDCA, other therapies, such as bezafibrate, have been developed. In this meta-analysis we evaluated the efficacy and safety of using both UDCA and bezafibrate in patients with an inadequate response to UDCA.

Methods

We evaluated all randomized controlled trials comparing the combination of UDCA and bezafibrate with UDCA monotherapy. Standardized mean difference (SMD) was used to assess the treatment effect of combination therapy compared with UDCA alone.

Results

Ten trials with a total of 369 patients were analyzed. UDCA and bezafibrate combination therapy was more effective than UDCA monotherapy in improving alanine aminotransferase (SMD -2.04, 95% confidence interval [CI] -3.30 to -0.79), alkaline phosphatase at both less than 12 months (SMD -3.63, 95%CI -6.43 to -0.84) and more than 12 months (SMD -2.33, 95%CI -4.03 to -0.63), gamma-glutamyltransferase (SMD -1.29, 95%CI -2.67 to 0.08), triglyceride (SMD -0.80, 95%CI -1.41 to -0.19), immunoglobulin M (SMD -1.48, 95%CI -2.39 to -0.56), and cholesterol (SMD -4.61, 95%CI -7.34 to -1.89). There was no difference between the 2 groups in bilirubin, aspartate aminotransferase or albumin. None of the adverse effects differed statistically between the 2 groups.

Conclusion

UDCA and bezafibrate combined treatment is superior to UDCA alone in UDCA non-responders with regard to decreasing liver biochemistry markers, without any significant increase in side effects in patients with PBC.

Additional fibrate treatment in UDCA-refractory PBC patients

BACKGROUND & AIMS

There is no proven treatment for ursodeoxycholic acid (UDCA)-refractory primary biliary cholangitis (PBC) other than obeticholic acid. Although fibrates have been reported to improve biochemical parameters, the long-term effects remain unclear. This study evaluated the effect of fibrate on clinical outcomes of UDCA-refractory PBC.

METHODS

Patients whose alkaline phosphatase (ALP) was not normalized with at least 13 mg/kg of UDCA treatment for >1 year were included from two tertiary referral centres. The primary outcome was ALP normalization. Secondary outcomes included the development of cirrhosis and hepatic deterioration. Immortal time bias was adjusted using the Mantel-Byar method.

RESULTS

A total of 100 UDCA-refractory PBC patients were included: 71 patients received UDCA alone (the UDCA group) and 29 patients received UDCA plus additional fibrate treatment of 160 mg/d fenofibrate or 400 mg/d bezafibrate (the fibrate/UDCA group). During the follow-up period, the probability of ALP normalization was significantly higher in the fibrate/UDCA group (hazard ratio [HR] = 5.00, 95% confidence interval = 2.87-8.27, P < 0.001). Among 58 non-cirrhotic patients (43 in the UDCA group and 15 in the fibrate/UDCA group), 19 patients (44.1%) in the UDCA group and none in the fibrate/UDCA group developed cirrhosis (HR = 0.12, P = 0.04). Hepatic deterioration (Child-Pugh score increase or signs of decompensated cirrhosis) occurred in 17 patients (23.9%) of the UDCA group and none in the fibrate/UDCA group in which the difference was significant (HR = 0.12, P = 0.04).

CONCLUSIONS

In patients with UDCA-refractory PBC, additional fibrate treatment is associated with a higher probability of ALP normalization and a lower risk of cirrhosis development and hepatic deterioration.

Bioinformatics‑based identification of key pathways and candidate genes for estrogen‑induced intrahepatic cholestasis using DNA microarray analysis

Estrogen‑induced intrahepatic cholestasis (EIC) has increased incidence during pregnancy, and within women taking oral contraception and postmenopausal hormone replacement therapy. However, the pathology underlying EIC is not well understood. The aim of the present study was to identify key pathways and candidate genes in estrogen‑induced intrahepatic cholestasis (EIC) that may be potential targets for diagnosis and treatment. A whole‑genome microarray (4x44K) analysis of a 17α‑ethinylestradiol (EE)‑induced EIC rat liver model was performed. Bioinformatics‑based methods were used to identify key pathways and candidate genes associated with EIC. The candidate genes were validated using a reverse transcription quantitative polymerase chain reaction assay. A total of 455 genes were differentially expressed (P<0.05 and fold change >2.0) following EE treatment, including 225 downregulated genes and 230 upregulated genes. Sulfotransferase family 1E member 1, cytochrome P450 family 3 subfamily A member 2, carbonic anhydrase 3, leukotriene C4 synthase and ADAM metallopeptidase domain 8 were the 5 candidate genes identified to be differentially expressed and involved in the metabolism of estrogens and bile acids and the regulation of inflammation and oxidative stress. The Analyses of Gene Ontology enrichment, Kyoto Encyclopedia of Genes and Genomes pathways and protein‑protein interaction network associated‑modules identified several key pathways involved in the homeostasis of lipids and bile acids and in AMPK, p53 and Wnt signaling. These key pathways and candidate genes may have critical roles in the pathogenesis of EIC. In addition, reversing the abnormal expression of candidate genes or restoring the dysfunction of key pathways may provide therapeutic opportunities for patients with EIC.

Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits

Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.