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

Emerging Targets for the Treatment of Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a rare, progressive cholestatic disease of unknown etiology and characterized by inflammation and stricturing of intrahepatic and/or extrahepatic bile ducts. This process leads to bile duct scarring, progressive liver fibrosis, and end-stage liver disease. PSC is often associated with a specific form of inflammatory bowel disease and patients face a significant risk of developing cholangiocarcinoma and colorectal cancer. The clinical course of PSC can differ significantly between subtypes and affected individuals, representing a major obstacle to successful medical treatment trials. Numerous innovative therapeutic targets have been identified and, at least in part, explored, including nuclear and membrane receptors regulating bile acid metabolism and transport, modulation of gut microbiota, and signaling molecules involved in liver inflammation and fibrosis. Successful drug testing in preclinical PSC models as well as positive signals from some clinical studies justify hope. However, no medical treatment has so far been proven to improve transplant-free survival or overall survival in PSC patients. Disease-modifying drugs are urgently awaited. Despite ongoing efforts to improve study designs and implement treatment trials for novel drug targets, a central breakthrough has not yet been convincingly achieved. This situation might change in the near future. This article summarizes current research efforts aimed at developing medical treatments for PSC.

Mechanism-guided drug development and treatment for liver fibrosis: a clinical perspective

Liver fibrosis is a common response to chronic liver injury due to multiple etiologies and plays a crucial in the progression of chronic liver disease to cirrhosis, hepatocellular carcinoma, and other liver-related clinical outcomes. Currently, available treatments to block liver fibrosis are designed to eliminate the underlying causes of liver disease. The lack of truly effective drugs to regress or reverse fibrosis is a major unmet clinical need. In this context, this article briefly describes the pathological process of hepatic fibrosis and focuses on reviewing the progress of clinical studies on mechanism-based anti-fibrotic drug development and therapy, highlighting that the positive effect of thyroid hormone receptor-β (THR-β) analogs, fibroblast growth factor 21 (FGF21) analogues, Glucagon-like peptide 1 receptor (GLP-1R) agonists, pan-peroxisome proliferator-activated receptor (pan-PPAR) agonists, fatty acid synthase (FASN) inhibitors, and hydronidone in reducing liver fibrosis caused by specific etiologies. Moreover, multi-pathway guided combination therapy or traditional Chinese medicine demonstrate significant advantages in combating liver fibrosis. Finally, new technologies and approaches affecting the clinical development of anti-hepatic fibrosis drugs were discussed.

Enteronephrohepatic Circulation of Bile Acids and Therapeutic Potential of Systemic Bile Acid Transporter Inhibitors

Together with carriers in liver and small intestine, kidney transporters function to conserve and compartmentalize bile acids in the enteronephrohepatic circulation. In patients with liver disease, systemic bile acid levels are elevated, undergo increased renal glomerular filtration, and contribute to the pathogenesis of cholemic nephropathy and acute kidney injury. In this review, we describe mechanisms for renal bile acid transport and highlight very recent discoveries that challenge current paradigms for the pathogenesis of cholemic nephropathy and renal tubule cast formation. We also discuss the therapeutic potential of inhibiting the kidney apical sodium-dependent bile acid transporter (ASBT) to redirect bile acids into urine for elimination, reduce hepatobiliary accumulation and systemic levels of bile acids, and treat cholemic nephropathy. In conclusion, a deeper understanding of the enteronephrohepatic bile acid axis is providing insights into novel strategies to protect both liver and kidney in patients with liver disease.

Iqirvo for primary biliary cholangitis - efficacy, safety, and future directions

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by progressive bile duct destruction, leading to cirrhosis and liver failure. Recent advancements in treatment have focused on targeting specific molecular pathways involved in the disease's pathogenesis. Iqirvo, a dual peroxisome proliferator-activated receptor alpha and delta agonist, has shown promise in addressing the unmet medical needs of PBC patients. This review examines the clinical development and efficacy of Iqirvo, which recently received accelerated approval from the U.S. Food and Drug Administration. The approval was based on data demonstrating improvements in biochemical markers associated with liver function and bile acid metabolism. We also discuss the safety profile, potential side effects, and future implications for the management of PBC. The expedited approval of Iqirvo represents a significant advancement in PBC therapy, offering new hope for patients unresponsive to existing treatments.

Pemafibrate improves liver biochemistry and GLOBE scores in patients with primary biliary cholangitis: Nationwide, multicenter study by the Japanese Red Cross Liver Study Group

AIM

We aimed to evaluate the effect of pemafibrate, a selective peroxisome proliferator-activated receptor-α modulator, on patients with primary biliary cholangitis (PBC) complicated by dyslipidemia.

METHODS

In total, 61 patients with PBC (Add-on group: 33 patients on ursodeoxycholic acid [UDCA] + pemafibrate combination therapy; Switch group: 28 patients who switched from UDCA + other fibrates to UDCA + pemafibrate combination therapy) were included in the study. Changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), and GLOBE scores were retrospectively analyzed from 6 months before to 12 months after treatment. The POISE criteria were also used to evaluate the treatment efficacy after 12 months.

RESULTS

After 12 months of UDCA + pemafibrate combination therapy, AST significantly decreased from 45 ± 3 to 28 ± 3 U/L (p < 0.05), ALT from 49 ± 5 to 32 ± 5 U/L (p < 0.005), GGT from 155 ± 223 to 91 ± 182 U/L (p < 0.005), and ALP from 1.4 ± 0.9 to 0.9 ± 0.8 × upper limit of normal (p < 0.0005) in all patients. ALT, GGT, and ALP levels were significantly lower after 12 months of UDCA + pemafibrate combination therapy in both the Add-on and Switch groups. After 12 months of combination therapy, the mean GLOBE score of all patients significantly decreased from 0.37 to 0.01 (p < 0.05) and the percentage of patients with a GLOBE score of 0.3 or higher decreased.

CONCLUSIONS

In patients with PBC who showed an inadequate response to prior therapy, pemafibrate add-on or switch therapy improved liver biochemistry and GLOBE scores. Pemafibrate may be useful as a second-line drug when UDCA alone is inadequate, or as an alternative after combination therapy with other fibrates.

Efficacy and safety of PPAR agonists in primary biliary cholangitis: a systematic review and meta-analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Primary biliary cholangitis (PBC) is a chronic, progressive autoimmune liver disease. Some patients with PBC do not adequately respond to Ursodeoxycholic acid (UDCA) as a first-line treatment, putting them at an increased risk of disease progression. Peroxisome Proliferator-Activated Receptor (PPAR) agonists are emerging as promising therapeutic options for PBC. We aim to investigate the efficacy and safety of PPAR agonists in treating PBC patients.

METHODS

PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched for Randomized Controlled Trials (RCTs) investigating the use of PPAR agonists in combination with UDCA in patients with PBC, compared to UDCA alone. Mean differences (MD) for continuous variables and risk ratios (RR) for dichotomous variables were calculated to compare treatment response endpoints.

RESULTS

A total of 17 studies with 1219 PBC cases were included in the current review. Alkaline phosphatase (ALP) levels had a significantly greater decline in PPAR and UDCA arms than in UDCA alone (MD - 131.15, 95% CI - 155.95 to - 106.36). Furthermore, in combination therapy arms, gamma-glutamyl transferase (GGT) (MD - 55.69, 95% CI - 76.26 to - 35.13) and total bilirubin (MD - 0.08, 95% CI - 0.14 to - 0.03) were significantly lower than in the UDCA alone group.

CONCLUSIONS

The current study demonstrates that combining UDCA and PPAR agonists effectively reduces ALP, GGT, and Bilirubin levels, crucial markers for effective therapy in PBC patients.

Design, synthesis, and biological evaluation of imidazolidinone derivatives as potent PPARα/δ agonists for the treatment of cholestatic liver diseases

Cholestatic liver disease (CLD) represents a significant and growing public health concern, and there is a lack of effective therapeutic drug in clinical practice. Peroxisome proliferator-activator receptors α/δ (PPARα/δ) are regarded as potential therapeutic targets for CLD. In this study, a series of novel imidazolidinone PPARα/δ agonists were developed, and the preferred compound 8 displayed potent and well-balanced agonistic activity. Compound 8 showed high selectivity over other related nuclear receptors and effectively regulated the PPARα/δ target genes expression in mice. Notably, compound 8 demonstrated good pharmacokinetic profiles and potent in vivo anti-CLD effects. Collectively, compound 8 holds promise for developing an anti-CLD agent.

Schisandrol B alleviates depression-like behavior in mice by regulating bile acid homeostasis in the brain-liver-gut axis via the pregnane X receptor

BACKGROUND

Depression is a widely recognized neuropsychiatric disorder. Recent studies have shown a potential correlation between bile acid disorders and depression, highlighting the importance of maintaining bile acid balance for effective antidepressant treatment. Schisandrol B (SolB), a primary bioactive compound from Schisandra chinensis (Turcz.) Baill. or Schisandra sphenanthera Rehd.etWils, is pivotal in regulating bile acid homeostasis via pregnane X receptor (PXR) in cholestasis. However, the potential of SolB in alleviating depression-like symptoms, its pharmacological effects, and the underlying mechanisms remain to be fully elucidated.

METHODS

We confirmed the effect of SolB against depression induced by chronic restraint stress (CRS) and chronic unpredictable mild stress (CUMS) in mice. The role of SolB in bile acid homeostasis in depression was analyzed using the metabolomic. Gene analyses and 16S rRNA sequencing were employed to investigate the involvement of PXR. Experiments with Pxr-/- mice were conducted to confirm the essential role of the PXR pathway in SolB's antidepressant effects.

RESULTS

SolB treatment significantly increased sucrose consumption in the SPT and the locomotor activity in the OFT, while decreasing immobility time in the FST and TST in mice exposed to CRS and CUMS. Additionally, SolB treatment significantly preserved the integrity of the dendritic spine, elevated synaptic protein PSD95 levels, and augmented CREB/BDNF expression. Metabolomic and gene analyses indicated that SolB treatment significantly facilitated bile acid metabolism, promoted intestinal bile acid efflux, decreased hippocampal levels of the secondary bile acids DCA and TLCA, and upregulated expression of the PXR target proteins CYP3A11, SULT2A1, MRP2, and OATP1B1 in the liver, and MRP2 and MDR1 in hippocampus, which are integral to bile acid homeostasis. 16S rRNA sequencing revealed that SolB reduced the abundance of the bile salt hydrolase (BSH)-producing bacteria Lactobacillus johnsonii and Bacteroides fragilis and subsequently decreased the production of TLCA and DCA. Moreover, SolB failed to protect against depression induced by CRS in Pxr-null mice, suggesting that the antidepressant effect of SolB was PXR-dependent.

CONCLUSIONS

These results provide direct evidence of the antidepressant effect of SolB via activation of PXR to regulate bile acid homeostasis in the brain-liver-gut axis, suggesting that SolB may serve as a novel potential target for preventing and treating depression.

PPAR agonists for the treatment of cholestatic liver diseases: Over a decade of clinical progress

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are characterized by the destruction of the small bile ducts and the formation of multifocal biliary strictures, respectively, impairing bile flow. This leads to the hepatic accumulation of bile acids, causing liver injury and the risk of progression to cirrhosis and liver failure. First-line therapy for PBC is ursodeoxycholic acid, although up to 40% of treated individuals are incomplete responders, and there is no effective therapy for PSC, highlighting the need for better therapeutic options in these diseases. In addition, pruritus is a common symptom of cholestasis that has severe consequences for quality of life and is often undertreated or untreated. Nuclear receptors are pharmacological targets to treat cholestasis due to their multifactorial regulation of hepatic enzymatic pathways, particularly in bile acid metabolism. The peroxisome proliferator-activated receptor (PPAR) is of significant clinical interest due to its role in regulating bile acid synthesis and detoxification pathways. PPAR agonism by fibrates has traditionally been explored due to PPARα's expression in the liver; however, recent interest has expanded to focus on newer PPAR agonists that activate other PPAR isoforms, for example, δ, γ, alone or in combination. Several PPAR agonists have been investigated as second-line therapy for people living with PBC, including the recent accelerated United States Food and Drug Administration approval of elafibranor and seladelpar. This review evaluates available data on the efficacy and safety of the five PPAR agonists investigated for the treatment of cholestasis and associated pruritus in PBC and PSC, namely fenofibrate, bezafibrate, saroglitazar, elafibranor, and seladelpar.

Itching for Answers: A Comprehensive Review of Cholestatic Pruritus Treatments

Cholestasis is a clinical and laboratory syndrome indicating impaired bile production or excretion. One of the hallmark symptoms of cholestasis is pruritus. Itch can be severe and debilitating for patients, impacting their quality of life similarly to pain, and, in some cases, it can be refractory. Current therapies like anion exchange resins and rifampicin, offer partial relief but with side effects. Effective, well-tolerated treatments are urgently needed. This literature review examines existing options (bile acid sequestrants, antihistamines, opioid antagonists, sertraline, and rifampicin) and explores novel therapies (monoclonal antibodies, PPAR agonists, and bile-acid-based therapies). We analyze mechanisms, limitations, and adverse effects to aid clinicians and researchers. Novel approaches include monoclonal antibodies to inhibit bile recirculation and PPAR agonists targeting pruritus signaling. Despite the limited current options, ongoing research promises better treatments for cholestatic pruritus, addressing its distressing impact. In summary, cholestasis-associated pruritus poses a significant challenge with limited treatments. Advancements in understanding its pathophysiology offer hope for more effective therapies in the future.

Targeting NTCP for liver disease treatment: A promising strategy

The sodium taurocholate co-transporting polypeptide (NTCP), a bile acids transporter, has been identified as a new therapeutic target for the treatment of liver disease. This paper thoroughly investigates the function of NTCP for regulating bile acid regulation, its correlation with hepatitis B and D infections, and its association with various liver diseases. Additionally, in this review we examine recent breakthroughs in creating NTCP inhibitors and their prospective applications in liver disease treatment. While this review emphasizes the promising potential of targeting NTCP, it concurrently underscores the need for broader and more detailed research to fully understand the long-term implications and potential side effects associated with NTCP inhibition.

PPAR-Mediated Bile Acid Glucuronidation: Therapeutic Targets for the Treatment of Cholestatic Liver Diseases

Cholestatic liver diseases, including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), result from an impairment of bile flow that leads to the hepatic retention of bile acids, causing liver injury. Until recently, the only approved treatments for PBC were ursodeoxycholic acid (UDCA) and obeticholic acid (OCA). While these therapies slow the progression of PBC in the early stage of the disease, approximately 40% of patients respond incompletely to UDCA, and advanced cases do not respond. UDCA does not improve survival in patients with PSC, and patients often have dose-limiting pruritus reactions to OCA. Left untreated, these diseases can progress to fibrosis and cirrhosis, resulting in liver failure and the need for transplantation. These shortcomings emphasize the urgent need for alternative treatment strategies. Recently, nuclear hormone receptors have been explored as pharmacological targets for adjunct therapy because they regulate enzymes involved in bile acid metabolism and detoxification. In particular, the peroxisome proliferator-activated receptor (PPAR) has emerged as a therapeutic target for patients with PBC or PSC who experience an incomplete response to UDCA. PPARα is predominantly expressed in the liver, and it plays an essential role in the regulation of cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, both of which are critical enzyme families involved in the regulation of bile acid metabolism and glucuronidation, respectively. Importantly, PPARα agonists, e.g., fenofibrate, have shown therapeutic benefits in reducing elevated markers of cholestasis in patients with PBC and PSC, and elafibranor, the first PPAR (dual α, β/δ) agonist, has been FDA-approved for the second-line treatment of PBC. Additionally, newer PPAR agonists that target various PPAR isoforms (β/δ, γ) are under development as an adjunct therapy for PBC or PSC, although their impact on glucuronidation pathways are less characterized. This review will focus on PPAR-mediated bile acid glucuronidation as a therapeutic pathway to improve outcomes for patients with PBC and PSC.

Evaluating the safety and efficacy of seladelpar for adults with primary biliary cholangitis

INTRODUCTION

Seladelpar (MBX-8025) is a once-daily administered highly specific PPAR-δ agonist in Phase 3 and extension trials for use in patients with primary biliary cholangitis (PBC).

AREAS COVERED

This review provides background on current treatment options for PBC, and summarizes clinical trial data regarding the safety and effectiveness of seladelpar within the context of these treatments.

EXPERT OPINION

Clinical trials results demonstrate the safety and tolerability of seladelpar use for PBC, including in patients with cirrhosis. The primary composite endpoint (ALP <1.67 times ULN, decrease ≥ 15% from baseline, and TB ≤ULN) was met in 61.7% of the patients treated with seladelpar and in 20% receiving placebo (p < 0.001). Moreover, pruritus - a cardinal and often intractable symptom of PBC - was improved with seladelpar treatment, as were overall quality of life measurements. Improvements in markers of inflammation were likewise observed. These biochemical and clinical findings therefore represent landmark developments in PBC treatment and offer a therapeutic option for PBC.

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.

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.

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.

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.