Seladelpar efficacy and safety at 3 months in patients with primary biliary cholangitis: ENHANCE, a phase 3, randomized, placebo-controlled study

Efficacy and Safety of Novel Oral Anti-Cholestatic Agents for Primary Biliary Cholangitis: Meta-Analyses and Systematic Review

Background: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by progressive bile duct damage and cholestasis. While ursodeoxycholic acid (UDCA) is the first-line therapy, approximately 40% of patients have incomplete responses, necessitating alternative treatments. This systematic review and meta-analysis evaluate the efficacy and safety of novel oral anti-cholestatic agents for PBC. Methods: A systematic literature search was conducted in electronic databases up to September 2024. Randomized controlled trials, cohort studies, and case-control studies evaluating novel oral anti-cholestatic agents in adult PBC patients were included. The primary outcome was a change in alkaline phosphatase (ALP) levels. Safety was assessed by the incidence of serious adverse events. Random-effect meta-analyses were performed. Results: Ten studies involving 878 patients were analyzed. Novel agents included seladelpar, fenofibrate, saroglitazar, bezafibrate, elafibranor, and budesonide. The meta-analysis showed significant reductions in ALP levels with novel agents compared to the controls (SMD -2.80; 95% CI -3.56, -2.03; p < 0.00001), with high heterogeneity (I2 = 93%). Saroglitazar achieved the largest effect size. There was no significant difference in serious adverse events between novel agents and controls (OR 1.21; 95% CI 0.81, 1.83; p = 0.35). Conclusions: Novel oral anti-cholestatic agents show promise in improving biochemical markers in PBC patients with suboptimal UDCA responses, with a safety profile comparable to controls. However, study heterogeneity and limited long-term data restrict direct comparisons. Larger standardized trials with extended follow-up are needed to confirm long-term efficacy and safety.

Long-Term Outcomes of Fenofibrate for Treatment of Ischemic Cholangiopathy in Donation After Circulatory Death Liver Transplantation

The incidence of ischemic cholangiopathy (IC) is expected to remain significant due to rising rates of transplants performed with livers donated after circulatory death (DCD), despite the use of machine perfusion. Absent established pharmacologic interventions against this progressive etiology of allograft dysfunction and failure, we describe the use of fenofibrate-a cheap and widely-accessible peroxisome proliferator-activated receptor agonist that downregulates bile acid production-to impede IC progression in 15 DCD liver recipients who were not responding to reactive, standard-of-care management. All patients were undergoing serial endoscopic retrograde cholangiopathy (ERC) to maintain biliary patency but demonstrated progressive cholestasis, with serum alkaline phosphatase (ALP) rising 70.3% over the 90 days preceding fenofibrate. Cholestasis improved in all patients after fenofibrate initiation, with a 63.9% reduction in mean ALP at 90 days, maintained at 270 days (p = 0.02) and 360 days (p = 0.06). ALP improvement was associated with reduced ERC frequency during and after fenofibrate treatment, and this improvement was independent of concurrent ERC or ursodeoxycholic acid use during fenofibrate treatment. In patients who stopped treatment, ALP increased. No fenofibrate-associated adverse events were seen. These preliminary data support the further study of agents that downregulate bile acid production as a means of impeding IC in DCD livers.

Risk factors and prediction for DILI in clinical practice

INTRODUCTION

Drug-induced liver injury is an important adverse effect and can be caused by various medications, including novel therapeutic agents. The risk stratification of patients susceptible to DILI is a growing field.

AREAS COVERED

The current article highlights new studies on risk stratification regarding risk factors of DILI, prediction of liver injury, and predictors of severe outcomes. Studies on patient demographic and genetic risk factors are discussed, in addition to the potential role of concomitant medications that may affect the risk of DILI.

EXPERT OPINION

Although much is known about patient risk factors for DILI, a better combination of these factors into risk scores is needed to predict which patients are particularly susceptible. Knowledge of these risk factors might determine drug treatment in the near future, as well as the need for routine monitoring of liver tests.

Validation of PBC-10 in Japanese patients with primary biliary cholangitis

BACKGROUND AND AIM

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease that significantly impairs health-related quality of life (HRQOL). The PBC-10, a short-form HRQOL assessment tool, was developed for rapid screening in clinical settings. This study aimed to verify the reliability and validity of the Japanese version of the PBC-10 in Japanese patients with PBC.

METHODS

We retrospectively analyzed HRQOL data from 496 Japanese outpatients with PBC, collected between 2015 and 2016. Reliability was assessed using Cronbach's alpha, item-total score correlations, and ceiling and floor effects. Validity was evaluated by examining correlations between PBC-10 scores and the total and subdomain scores of the Japanese version of the PBC-40, a validated PBC-specific HRQOL questionnaire.

RESULTS

Cronbach's alpha for the PBC-10 was 0.872, demonstrating high internal consistency. Strong item-total score correlations were observed for all items. No ceiling effects were noted, but floor effects were present across all items. The PBC-10 total score showed a very strong positive correlation with the PBC-40 total score (ρ = 0.964, p < 0.001). Strong correlations were also found between most PBC-10 items and the PBC-40 subdomains, supporting validity.

CONCLUSION

The Japanese version of the PBC-10 is a reliable and valid tool for rapidly assessing HRQOL in Japanese PBC outpatients. It has potential utility for identifying patients who may benefit from emerging treatments targeting symptom relief.

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.

The role of Seladelpar in primary biliary cholangitis: a systematic review and meta-analysis

INTRODUCTION

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by progressive bile duct destruction, leading to cholestasis and, if untreated, liver failure. Although ursodeoxycholic acid (UDCA) remains the first-line treatment, many patients exhibit an inadequate response, necessitating alternative therapeutic options. Seladelpar, a peroxisome proliferator-activated receptor delta (PPAR-δ) agonist, has emerged as a promising alternative due to its anti-inflammatory and anti-fibrotic properties.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to evaluate the efficacy and safety of Seladelpar in patients with PBC. A comprehensive database search was performed to identify studies comparing Seladelpar with placebo. Primary and secondary outcomes, including alkaline phosphatase (ALP) normalization, biochemical response, and adverse events, were analyzed.

RESULTS

Three RCTs, comprising 496 patients, were included. Seladelpar significantly improved ALP normalization and biochemical response compared to placebo. Additionally, it effectively reduced ALP and ALT levels from baseline to follow-up. Adverse events, including abdominal pain and headache, were reported, with a higher incidence observed in the Seladelpar group, while other adverse events showed no significant differences between groups.

CONCLUSION

Seladelpar appears to be an effective treatment for PBC, demonstrating significant improvements in key liver function markers. While it has shown therapeutic benefits, further research is warranted to evaluate its long-term safety, particularly regarding adverse event incidence, and to determine its efficacy across different dosages.

Single and Multiple Doses of Seladelpar Decrease Diurnal Markers of Bile Acid Synthesis in Mice

Peroxisome proliferator-activated receptors (PPARs) modulate bile metabolism and are important therapeutic options in cholestatic diseases. This study was aimed at understanding the effects of single and multiple doses of seladelpar, a PPARδ (peroxisome proliferator-activated receptor delta) agonist, on plasma C4 (a freely diffusible metabolite accepted as a proxy for de novo bile acid biosynthesis), Fibroblast Growth Factor 21 (Fgf21), and gene expression changes in the liver of male and female mice. C57BL/6 mice were treated with seladelpar 10 mg/kg/day or vehicle through oral gavage before lights out on Day 1 (single dose) or from Day 1 to Day 7 (multiple doses). Liver samples were obtained at 0, 1, 2, 4, 8, 12, 16, and 24 h postdosing, and plasma C4 and Fgf21 levels were measured. In vehicle-treated mice, C4 levels were higher in the dark cycle compared to the light cycle, with higher levels in females than in males. Plasma Fgf21 did not vary substantially over the dark-light cycle or show a sex-specific expression pattern. Seladelpar treatment significantly reduced plasma C4 and increased Fgf21 levels in both sexes, which coincided with a decrease in cholesterol 7α-hydroxylase mRNA and an increase in Fgf21 mRNA in the livers. Untargeted RNA sequencing revealed a strong correlation between the genes differentially expressed after single- and multiple-dose seladelpar treatment. PPAR-responsive genes, including pyruvate dehydrogenase kinase 4, acyl-CoA thioesterase 2, and angiopoietin-like 4, were upregulated. No changes in nuclear receptors, clock genes, and sex-specific genes were observed. Overall, these results are consistent with a model where seladelpar treatment reduces bile acid synthesis by upregulating Fgf21 and modulating other PPAR-responsive genes.

Drug-Induced Liver Injury in Patients With Chronic Liver Disease

OBJECTIVE

Drug-induced liver injury (DILI) is a global problem and can develop from exposure to prescription or over-the-counter medications as well as herbal and dietary supplements. The diagnosis of DILI is clinically challenging, and liver injury can be severe leading to liver failure, death, or liver transplantation. Patients with underlying chronic liver diseases (CLD) may be at increased risk for DILI, which is associated with factors related to drug or liver disease.

METHODS

This review summarises current knowledge on the risk and outcomes of DILI in patients with CLD.

RESULTS

Patients with CLD may be at an increased risk for DILI. Additionally patients with underlying CLD are at risk for more severe liver injury and worse outcomes after DILI.

DISCUSSION

The risk for and poor outcomes from DILI are accentuated in patients with CLD and potentially leading to the worst-case scenario of acute-on-chronic liver failure. We highlight the key observations on DILI with a broad range of underlying liver diseases and the high-DILI risk agents implicated in those populations.

Primary biliary cholangitis: a summary of pathogenesis and therapies

Primary biliary cholangitis (PBC) is a progressive autoimmune liver disease characterized by chronic inflammation and destruction of interlobular bile ducts. Its pathogenesis involves a complex interplay of genetic predisposition, environmental triggers, and immune-mediated mechanisms, particularly T-helper cell activity, leading to bile duct damage. First-line therapy includes ursodeoxycholic acid (UDCA), which improves liver biochemistry and slows disease progression, with obeticholic acid (OCA) as an option for non-responders. Double and/or triple therapy, including UDCA, OCA, and fibrates, appears to be superior in achieving therapeutic benefits in UDCA-nonresponsive PBC patients. Emerging therapies, such as peroxisome proliferator-activated receptor-α agonists, biologics such as dacetuzumab and rituximab, and experimental approaches such as stem-cell therapy, offer promising advances in managing PBC. Liver transplantation remains a final treatment option for advanced cases.

Pruritus in Chronic Cholestatic Liver Diseases, Especially in Primary Biliary Cholangitis: A Narrative Review

Patients with chronic cholestatic liver diseases often experience itch and struggle with this symptom. We discuss the mechanism of itch in patients with chronic cholestatic liver diseases, such as primary biliary cholangitis (PBC) and others, and their therapies, including ileal bile acid transporter (IBAT) inhibitors. In patients with PBC, there are high serum/plasma concentrations of multiple factors, including bile salts, bilirubin, endogenous opioids, lysophosphatidic acid (LPA), autotaxin, and histamine. Bile salts, bilirubin, LPA, and autotaxin affect itch mediators in the skin and sensory nerves, while the endogenous opioid balance affects mediators in the spinal cord. Itch is sensitized by both the peripheral and central nervous systems. Both mechanisms are involved in itch in patients with chronic cholestatic liver disease. Although IBAT inhibitors have been approved for use in pediatric cholestatic conditions, such as progressive familial intrahepatic cholestasis and Alagille syndrome, IBAT inhibition seems to be a promising treatment for chronic refractory itch in patients with PBC. A traditional non-systematic review results in this narrative review. Multidisciplinary cooperation, involving hepatologists, dermatologists, and pharmacists, could provide better treatment for PBC patients suffering from refractory itch. In conclusion, we summarized the existing knowledge on itch caused by chronic cholestatic liver diseases, especially in PBC with a focus on the mechanisms and therapies. This narrative review provides the mechanisms and therapeutic options for itch in patients with chronic cholestatic liver diseases.

Peroxisome proliferator-activated receptor delta and liver diseases

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors involved in transcriptional regulation and play an important role in many physiological and metabolic processes. Unlike PPAR-alpha and PPAR-gamma, PPAR-delta is ubiquitously expressed, and its activity is key to maintaining proper metabolic homeostasis within the liver. PPAR-delta not only regulates physiologic processes of lipid, glucose, and bile acid metabolism but also attenuates pathologic responses to alcohol metabolism, inflammation, fibrosis, and carcinogenesis, and is considered an important therapeutic target in liver diseases. Promising results have been reported in clinical trials for PPAR-delta agonists in liver disease, and the selective agonist seladelpar was recently conditionally approved in the United States as a new treatment option for primary biliary cholangitis. This review provides an overview of PPAR-delta's function and biology in the liver, examines its kinetics and therapeutic potential across different liver diseases, and discusses the current status of clinical trials involving its agonists.

COBALT: A Confirmatory Trial of Obeticholic Acid in Primary Biliary Cholangitis With Placebo and External Controls

INTRODUCTION

Obeticholic acid (OCA) treatment for primary biliary cholangitis (PBC) was conditionally approved in the phase 3 POISE trial. The COBALT confirmatory trial assessed whether clinical outcomes in patients with PBC improve with OCA therapy.

METHODS

Patients randomized to OCA (5-10 mg) were compared with placebo (randomized controlled trial [RCT]) or external control (EC). The primary composite endpoint was time to death, liver transplant, model for end-stage liver disease score ≥15, uncontrolled ascites, or hospitalization for hepatic decompensation. A prespecified propensity score-weighted EC group was derived from a US healthcare claims database.

RESULTS

In the RCT, the primary endpoint occurred in 28.6% of OCA (n = 168) and 28.9% of placebo patients (n = 166; intent-to-treat analysis hazard ratio [HR] = 1.01, 95% confidence interval = 0.68-1.51), but functional unblinding and crossover to commercial therapy occurred, especially in the placebo arm. Correcting for these using inverse probability of censoring weighting and as-treated analyses shifted the HR to favor OCA. In the EC (n = 1,051), the weighted primary endpoint occurred in 10.1% of OCA and 21.5% of non-OCA patients (HR = 0.39; 95% confidence interval = 0.22-0.69; P = 0.001). No new safety signals were identified in the RCT.

DISCUSSION

Functional unblinding and treatment crossover, particularly in the placebo arm, confounded the intent-to-treat estimate of outcomes associated with OCA in the RCT. Comparison with the real-world EC showed that OCA treatment significantly reduced the risk of negative clinical outcomes. These analyses demonstrate the value of EC data in confirmatory trials and suggest that treatment with OCA improves clinical outcomes in patients with PBC.

Pharmacokinetic, Safety, and Pharmacodynamic Profiles of Saroglitazar Magnesium in Cholestatic Cirrhosis With Hepatic Impairment and Participants With Renal Impairment

Saroglitazar magnesium, a dual PPAR α/γ agonist, currently in Phase III for treating primary biliary cholangitis (PBC), was evaluated for its pharmacokinetic (PK) profile, safety, and pharmacodynamics in participants with cholestatic liver disease (CLD) across different levels of hepatic impairment (HI) and participants with severe renal impairment (RI). Three PK studies comparing saroglitazar with healthy controls were conducted: Study 1 involved daily oral doses of 1 or 2 mg for 4 weeks in 12 PBC cirrhosis participants with mild or moderate HI; Study 2 assessed single-dose PK (2 or 4 mg) in eight non-cirrhotic CLD participants; Study 3 evaluated single-dose PK (2 mg) in eight participants with severe RI. On day 1, saroglitazar exposure increased by 14.6-42% in mild HI vs. normal, but by day 28, levels were similar, indicating no accumulation. In moderate HI, exposure was significantly increased by 50.4-85% on days 1 and 28, with 34-46% lower clearance despite a similar half-life. The moderate HI group had a 59% higher exposure than the non-cirrhotic group. Saroglitazar (1 and 2 mg) reduced alkaline phosphatase (ALP) levels by 17-40% after 4 weeks in participants with abnormal baseline ALP. Single-dose PK in non-cirrhotic CLD (2 and 4 mg) and severe RI (2 mg) was comparable to matched controls without significant safety issues. Overall, saroglitazar (1 and 2 mg) was safe and well-tolerated in cholestatic cirrhosis with mild HI and participants with severe RI without major PK changes. Moderate HI increased exposure and decreased clearance without any safety concerns.

Second-Line Treatment for Patients With Primary Biliary Cholangitis: A Systematic Review With Network Meta-Analysis

BACKGROUND & AIMS

Approximately 40% of patients with Primary Biliary Cholangitis (PBC) show incomplete response to ursodeoxycholic acid, thus needing second-line treatment to prevent disease progression. As no head-to-head comparison study is available, we used a network meta-analysis (NMA) to compare efficacy and safety of available second-line therapies.

METHODS

We performed a systematic literature review including randomised, placebo-controlled trials of patients with PBC and incomplete response, or intolerance, to ursodeoxycholic acid, and compared relative risks (RRs) for primary (biochemical response at 52-week) and secondary outcomes [incidence of new-onset pruritus and serious adverse events (SAEs)].

RESULTS

The NMA included three studies, each testing obeticholic acid (OCA), seladelpar or elafibranor versus placebo (active therapy/placebo: 379/191 patients). All treatments significantly increased the RR for biochemical response with an advantage of elafibranor versus seladelpar (RR: 4.37, 95% CI: 1.01-18.87). OCA 5-10 mg/10 mg was associated with a higher risk of new-onset pruritus compared to placebo (RR: 1.43; 95% CI: 1.09-1.88/RR: 1.79; 95% CI: 1.37-2.33), while seladelpar decreased this risk (RR: 0.30; 95% CI: 0.12-0.80). Compared to placebo, OCA 5-10 mg/10 mg was associated with an increased risk of SAE (RR: 3.82; 95% CI: 1.46-10.02/RR 2.67; 95% CI: 1.00-7.08).

CONCLUSIONS

Among second line therapies for patients with PBC, elafibranor is slightly more effective in obtaining biochemical response than seladelpar that, on the other hand, is the only drug associated with a lower incidence of pruritus. While of similar efficacy, OCA was associated with increased pruritus and SAEs. These findings may help personalise second-line treatment in patients with PBC.

Review of Current and Upcoming Second-Line Treatments for Primary Biliary Cholangitis

BACKGROUND

Treatment for primary biliary cholangitis (PBC) was defined by its singular relationship with ursodeoxycholic acid (UDCA) for decades. However, nearly 40% of patients fail to achieve adequate biochemical response with UDCA, necessitating second-line therapies.

AIMS

The aim of our review was to assess the efficacy and safety of second-line therapies for PBC from phase three trials.

METHODS

We conducted a systematic review of PubMed, Medline, and ClinicalTrials.gov for published phase three trial data of second-line PBC therapies.

RESULTS

Four phase three clinical trial evaluating obeticholic acid, bezafibrate, seladelpar, and elafibranor, were identified. All trials but one defined the treatment endpoints of an alkaline phosphatase (ALP) less than 1.67 times the upper limit of normal (ULN), a 15% decrease of ALP from baseline, and normal total bilirubin (TB) after 12 months. All therapies demonstrated statistically significant achievement of primary endpoints relative to placebo. Reduction in ALP from baseline ranged from 113 to 133.9 U/L (- 34.6% to - 50%) across all trials. Primary endpoint treatment differences relative to placebo ranged between 31 and 47%. ALP normalization rates were described for three treatments and varied between 15 and 67% in treatment cohorts,compared to 0% to 2% of placebo cohorts. Only elafibranor and seladelpar demonstrated significant reduction in total 5D itch scale scores. Discontinuation rates across studies ranged from 1 to 14% due to adverse effects.

CONCLUSION

All reviewed therapies met their respective study endpoints. Effective second-line therapies area available and continue to receive long-term evaluation in patients with PBC.

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.

Up-to-Date Snapshot of Current and Emerging Medical Therapies in Primary Biliary Cholangitis

Background/Objectives: Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic disease of the liver that symptomatically can present with pruritus and fatigue. Its established first- and second-line therapies are ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) although they provide limited symptom management. Liver transplantation offers a potentially curative therapeutic option in refractory cases progressing to cirrhosis. Novel research published after the current guidelines highlights the importance of providing an up-to-date analysis of treatment options available. Methods: In this study, we conducted a literature search using Pubmed, Ovid Medline, and SCOPUS to provide a narrative review of first-line, second-line, and emerging therapies in PBC. Results: UDCA has been well established as a long-term, safe therapy within the literature although it is possible that treatment dosage can be further optimised in refractory patients. It has a favourable side effect profile. Despite improving biochemical markers, histopathological profile, and overall outcomes, up to 30-40% of patients are refractory to it. Age and sex are highlighted as independent indicators of non-responsiveness. This necessitates effective second-line therapies. Future trials could aim to investigate UDCA as a co-first-line therapy. Further supporting results for OCA were found in the interim extension trial of the seminal POISE study. The long-term phase 4 COBOLT trial is still awaiting results to further assess the complications, adherence, and potential adverse effects. It is a viable option in UDCA-refractory patients. The high incidence rate of dose-related pruritis indicates that alternative second-line options are needed. Bezafibrate is an off-label antilipemic agent that shows promise as a prospective second-line therapy option. The landmark BEZURSO trial alleviated some efficacy and safety concerns, but it remains associated with elevated serum creatinine; thus, it should be considered with caution. Other prospective second-line therapies are budesonide, triple therapy, and novel agents such as seladelpar and elafibranor. Conclusions: UDCA should remain the treatment of choice for PBC, though perhaps not as monotherapy. With further investigation, BF shows promise as a new second-line therapy alongside OCA, which it may outperform.

Primary biliary cholangitis drug evaluation and regulatory approval: Where do we go from here?

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease. The management landscape was transformed 20 years ago with the advent of ursodeoxycholic acid. Up to 40% of patients do not, however, respond adequately to ursodeoxycholic acid and therefore still remain at risk of disease progression to cirrhosis. The introduction of obeticholic acid as a second-line therapy for patients failing ursodeoxycholic acid has improved outcomes for patients with PBC. There remains, however, a need for better treatment for patients at higher risk. The greatest threat facing our efforts to improve treatment in PBC is, paradoxically, the regulatory approval model providing conditional marketing authorization for new drugs based on biochemical markers on the condition that long-term, randomized placebo-controlled outcome trials are performed to confirm efficacy. As demonstrated by the COBALT confirmatory study with obeticholic acid, it is difficult to retain patients in the required follow-on confirmatory placebo-controlled PBC outcome trials when a licensed drug is commercially available. New PBC therapies in development, such as the peroxisome proliferator-activated receptor agonists, face even greater challenges in demonstrating outcome benefit through randomized placebo-controlled studies once following conditional marketing authorization, as there will be even more treatment options available. A recently published EMA Reflection Paper provides some guidance on the regulatory pathway to full approval but fails to recognize the importance of real-world data in providing evidence of outcome benefit in rare diseases. Here we explore the impact of the EMA reflection paper on PBC therapy and offer pragmatic solutions for generating evidence of long-term outcomes through real-world data collection.

Seladelpar: First Approval

Seladelpar (LIVDELZI®) is an oral delpar [i.e. a selective peroxisome proliferator-activated receptor (PPAR)δ agonist] being developed by Gilead Sciences for the treatment of primary biliary cholangitis (PBC). On 14 August 2024, based on a reduction in alkaline phosphatase (ALP), it received accelerated approval in the USA for the treatment of PBC in combination with ursodeoxycholic acid (UDCA) in adults who have an inadequate response to UDCA, or as monotherapy in patients unable to tolerate UDCA. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory studies. A regulatory assessment for seladelpar for the treatment of PBC is underway in the EU and the UK. This article summarizes the milestones in the development of seladelpar leading to this first approval.

A Comparative Analysis of ADRs under Obeticholic Acid and Ursodeoxycholic Acid in Cholestatic Liver Diseases Using the FAERS Database

BACKGROUND

The objective of this study was to compare the safety profiles of OCA and UDCA for the treatment of PBC using the FDA Adverse Event Reporting System database.

METHODS

We extracted reports for OCA from 2016 to 2023 and UDCA from 2004 to 2023. Demographic details, adverse events (AEs), and concomitant medications were analyzed using descriptive statistics and signal detection methods.

RESULTS

The most common for OCA were pruritus (1345 cases, ROR 20.96) and fatigue (528 cases, ROR 3.46). UDCA was more frequently associated with hepatocellular carcinoma (22 cases, ROR 16.37) and type I hypersensitivity reactions (11 cases, ROR 12.77). OCA was also linked to a higher frequency of constipation (161 cases, ROR 3.92) and increased blood alkaline phosphatase levels (145 cases, ROR 44.27).

CONCLUSION

This study reveals distinct safety profiles for OCA and UDCA in the treatment of PBC. OCA is associated with a higher frequency of pruritus, fatigue, constipation, and increased blood alkaline phosphatase levels, while UDCA is linked to hepatocellular carcinoma and type I hypersensitivity reactions. These findings support personalized treatment approaches based on individual patient characteristics.

Bile Acid Signaling in Metabolic and Inflammatory Diseases and Drug Development

Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates biliary secretion of lipids, endogenous metabolites, and xenobiotics. In intestine, bile acids facilitate the digestion and absorption of dietary lipids and fat-soluble vitamins. Through activation of nuclear receptors and G protein-coupled receptors and interaction with gut microbiome, bile acids critically regulate host metabolism and innate and adaptive immunity and are involved in the pathogenesis of cholestasis, metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, type-2 diabetes, and inflammatory bowel diseases. Bile acids and their derivatives have been developed as potential therapeutic agents for treating chronic metabolic and inflammatory liver diseases and gastrointestinal disorders. SIGNIFICANCE STATEMENT: Bile acids facilitate biliary cholesterol solubilization and dietary lipid absorption, regulate host metabolism and immunity, and modulate gut microbiome. Targeting bile acid metabolism and signaling holds promise for treating metabolic and inflammatory diseases.

The Versatile Role of Peroxisome Proliferator-Activated Receptors in Immune-Mediated Intestinal Diseases

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that sense lipophilic molecules and act as transcription factors to regulate target genes. PPARs have been implicated in the regulation of innate immunity, glucose and lipid metabolism, cell proliferation, wound healing, and fibrotic processes. Some synthetic PPAR ligands are promising molecules for the treatment of inflammatory and fibrotic processes in immune-mediated intestinal diseases. Some of these are currently undergoing or have previously undergone clinical trials. Dietary PPAR ligands and changes in microbiota composition could modulate PPARs' activation to reduce inflammatory responses in these immune-mediated diseases, based on animal models and clinical trials. This narrative review aims to summarize the role of PPARs in immune-mediated bowel diseases and their potential therapeutic use.

AI-based automation of enrollment criteria and endpoint assessment in clinical trials in liver diseases

Clinical trials in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis) require histologic scoring for assessment of inclusion criteria and endpoints. However, variability in interpretation has impacted clinical trial outcomes. We developed an artificial intelligence-based measurement (AIM) tool for scoring MASH histology (AIM-MASH). AIM-MASH predictions for MASH Clinical Research Network necroinflammation grades and fibrosis stages were reproducible (κ = 1) and aligned with expert pathologist consensus scores (κ = 0.62-0.74). The AIM-MASH versus consensus agreements were comparable to average pathologists for MASH Clinical Research Network scores (82% versus 81%) and fibrosis (97% versus 96%). Continuous scores produced by AIM-MASH for key histological features of MASH correlated with mean pathologist scores and noninvasive biomarkers and strongly predicted progression-free survival in patients with stage 3 (P < 0.0001) and stage 4 (P = 0.03) fibrosis. In a retrospective analysis of the ATLAS trial (NCT03449446), responders receiving study treatment showed a greater continuous change in fibrosis compared with placebo (P = 0.02). Overall, these results suggest that AIM-MASH may assist pathologists in histologic review of MASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient responses.

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.

Primary biliary cholangitis

Primary biliary cholangitis is a chronic, autoimmune, cholestatic disease that mainly affects women aged 40-70 years. Recent epidemiological studies have shown an increasing incidence worldwide despite geographical heterogeneity and a decrease in the female-to-male ratio of those the disease affects. Similar to other autoimmune diseases, primary biliary cholangitis occurs in genetically predisposed individuals upon exposure to environmental triggers, specifically xenobiotics, smoking, and the gut microbiome. Notably, the diversity of the intestinal microbiome is diminished in individuals with primary biliary cholangitis. The intricate interplay among immune cells, cytokines, chemokines, and biliary epithelial cells is postulated as the underlying pathogenic mechanism involved in the development and progression of primary biliary cholangitis, and extensive research has been dedicated to comprehending these complex interactions. Following the official approval of obeticholic acid as second-line treatment for patients with an incomplete response or intolerance to ursodeoxycholic acid, clinical trials have indicated that peroxisome proliferator activator receptor agonists are promising additional second-line drugs. Future dual or triple drug regimens might reach a new treatment goal of normalisation of alkaline phosphatase levels, rather than a decrease to less than 1·67 times the upper limit of normal levels, and potentially improve long-term outcomes. Improvement of health-related quality of life with better recognition and care of subjective symptoms, such as pruritus and fatigue, is also an important treatment goal. Promising clinical investigations are underway to alleviate these symptoms. Efforts to facilitate better access to medical care and dissemination of current knowledge should enable diagnosis at an earlier stage of primary biliary cholangitis and ensure access to treatments based on risk stratification for all patients.

Serum bile acid change correlates with improvement in pruritus in patients with primary biliary cholangitis receiving linerixibat

BACKGROUND & AIMS

Total serum bile acid (TSBA) levels are elevated in patients with primary biliary cholangitis (PBC) and may mediate cholestatic pruritus. Linerixibat, an ileal bile acid transporter inhibitor, improved pruritus in patients with PBC. We explored the relationship between linerixibat dose, TSBA concentration, and pruritus.

METHODS

Data from Phase 1/2 trials were used to develop a population kinetic-pharmacodynamic model to characterize the linerixibat dose-TSBA relationship. Individual Bayesian parameter estimates for participants in the GLIMMER study were used to derive the area under the TSBA concentration curve over 24 h (AUC0-24). Time-matched post hoc estimates of AUC0-24 were correlated with pruritus reported on a 0-10 numerical rating scale. Baseline TSBA concentration was correlated with change from baseline (ΔBL) in monthly itch score (MIS). ΔBL in model-estimated TSBA AUC0-24 was correlated with time-matched ΔBL in weekly itch score (WIS) or MIS.

RESULTS

Linerixibat dose dependently reduced TSBA AUC0-24, reaching steady state after 5 days. Baseline TSBA levels in GLIMMER did not correlate with ΔBL in MIS. ΔBL in TSBA AUC0-24 correlated with improved WIS over 12 weeks of treatment (r = 0.52, p < 0.0001). Of participants with a ≥30% decrease in TSBA AUC0-24, 60% were pruritus responders (≥2-point improvement in WIS from baseline).

CONCLUSIONS

Linerixibat treatment leads to rapid, dose-dependent TSBA reductions. Baseline TSBA levels do not correlate with on-treatment pruritus change, suggesting they do not predict linerixibat response. Change in TSBA AUC0-24 correlates significantly with, and can be predictive of, pruritus improvement in patients with PBC.

ACAD9 treatment with bezafibrate and nicotinamide riboside temporarily stabilizes cardiomyopathy and lactic acidosis

Pathogenic ACAD9 variants cause complex I deficiency. Patients presenting in infancy unresponsive to riboflavin have high mortality. A six-month-old infant presented with riboflavin unresponsive lactic acidosis and life-threatening cardiomyopathy. Treatment with high dose bezafibrate and nicotinamide riboside resulted in marked clinical improvement including reduced lactate and NT-pro-brain type natriuretic peptide levels, with stabilized echocardiographic measures. After a long stable period, the child succumbed from cardiac failure with infection at 10.5 months. Therapy was well tolerated. Peak bezafibrate levels exceeded its EC50. The clinical improvement with this treatment illustrates its potential, but weak PPAR agonist activity of bezafibrate limited its efficacy.

Revisiting PPAR agonists: novel perspectives in the treatment of primary biliary cholangitis

INTRODUCTION

In primary biliary cholangitis (PBC), approximately 40% of the patients respond incompletely to first-line treatment with ursodeoxycholic acid (UDCA), resulting in a poorer prognosis. Although obeticholic acid (OCA) is approved as a second-line therapy, it is not well-tolerated by patients with significant itching or advanced cirrhosis. Peroxisome proliferator-activated receptor (PPAR) agonists, including fibrates traditionally known as antihyperlipidemic agents, have emerged as potent alternatives for treating PBC patients with an incomplete response to UDCA.

AREAS COVERED

This article provides a detailed overview of the mechanisms of PPAR agonists and evaluates their efficacy and adverse events, focusing on findings from recent phase III clinical trials.

EXPERT OPINION

PPAR agonists are significant alternatives in the treatment of PBC, showing the potential to enhance biochemical responses, reduce mortality, and alleviate pruritus. Long-term outcomes for PBC patients, particularly those with advanced disease, and longitudinal data on the antipruritic effects of PPAR agonists require further investigation. Combining PPAR agonists with other treatments and advancing personalized approaches may enhance therapeutic efficacy and patient outcomes. This study provides future perspectives on the roles of PPAR agonists in PBC management.

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.

The treatment of primary biliary cholangitis: from shadow to light

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic disease characterized by the destruction of the small intrahepatic bile ducts, which can progress to liver cirrhosis. The gold standard in the treatment of PBC is ursodeoxycholic acid (UDCA), which is indicated in all patients with PBC because it improves not only biochemical parameters but also patients' survival. An important milestone in the identification of patients at risk is the assessment of biochemical response to UDCA. Patients who respond to treatment have a lower incidence of hepatic events and better prognosis than patients who do not. Several scoring systems can be used to assess the response and identify non-responders who will benefit from second-line treatment. Obeticholic acid (OCA) is currently the only approved second-line treatment for PBC, which is effective for non-responders to UDCA therapy or patients, who have not tolerated UDCA therapy. However, OCA is contraindicated in advanced liver cirrhosis and portal hypertension. Moreover, pruritus may be a limiting factor for the administration of OCA. Fibrates have shown promising data supporting their use in non-responders to UDCA because they improve the biochemical parameters and elastographic findings and have possible antipruritic effects. Therefore, the idea of a triple treatment seems interesting. Clinical research is focusing on several other groups of drugs: peroxisome proliferator-activated receptor (PPAR) δ- and α/δ agonists, non-steroidal farnesoid X receptor agonists, fibroblast growth factor 19 modulators, and inhibitors of nicotinamide adenine dinucleotide phosphate oxidase 1 and 4.

Efficacy and safety of peroxisome proliferator-activated receptor agonists for the treatment of primary biliary cholangitis: a meta-analysis of randomized controlled trials

BACKGROUND

Peroxisome proliferator-activated receptor (PPAR) agonists are recognised as a promising treatment for primary biliary cholangitis (PBC). However, the effects and safety of these agonists on PBC remain unexplored. Our study aimed to investigate the efficacy and safety of PPAR agonists in treating PBC.

METHODS

We searched Cochrane Library, and Web of Science, PubMed, and Embase databases from inception to 15 March 2024 for randomised controlled studies (RCTs) that enrolled individuals with PBC treated with PPAR agonists compared with placebo. The primary outcomes were biochemical response and normalization of the alkaline phosphatase (ALP) level.

RESULTS

Eight RCTs involving 869 participants in total were included. The meta-analysis revealed that compared to placebo, PPAR agonists increased the rate of biochemical response (RR: 5.53; 95% CI: 3.79, 8.06) and normalization of the ALP level (RR: 17.18; 95% CI: 5.61, 52.61). In addition, PPAR agonists can also reduce alanine aminotransferase (ALT) (MD: -12.69 U/L; 95% CI: -18.03, -7.35), aspartate aminotransferase (AST) (MD: -4.18 U/L; 95% CI: -7.28, -1.08), ALP (MD: -142.95 U/L; 95% CI: -167.29, -118.60), γ-glutamyltransferase (GGT) (MD: -63.03 U/L; 95% CI: -92.08, -33.98), and total cholesterol (TC) levels (SMD: -0.71; 95% CI: -1.38, -0.04), and there was no significant difference in overall adverse reactions (RR: 0.99; 95% CI: 0.92, 1.05), serious adverse reactions (RR: 1.10; 95% CI: 0.70, 1.72) between the two groups.

CONCLUSION

PPAR agonists are safe and well-tolerated in patients with PBC and are effective in improving the rate of biochemical response and related biomarkers.

Seladelpar treatment reduces IL-31 and pruritus in patients with primary biliary cholangitis

BACKGROUND AND AIMS

Pruritus is a debilitating symptom for many people living with primary biliary cholangitis (PBC). In studies with seladelpar, a selective peroxisome proliferator-activated receptor-delta agonist, patients with PBC experienced significant improvement in pruritus and reduction of serum bile acids. Interleukin-31 (IL-31) is a cytokine known to mediate pruritus, and blocking IL-31 signaling provides relief in pruritic skin diseases. This study examined the connection between seladelpar's antipruritic effects and IL-31 and bile acid levels in patients with PBC.

APPROACH AND RESULTS

IL-31 levels were quantified in serum samples from the ENHANCE study of patients with PBC receiving daily oral doses of placebo (n = 55), seladelpar 5 mg (n = 53) or 10 mg (n = 53) for 3 months, and for healthy volunteers (n = 55). IL-31 levels were compared with pruritus using a numerical rating scale (NRS, 0-10) and with bile acid levels. Baseline IL-31 levels closely correlated with pruritus NRS ( r = 0.54, p < 0.0001), and total ( r = 0.54, p < 0.0001) and conjugated bile acids (up to 0.64, p < 0.0001). Decreases in IL-31 were observed with seladelpar 5 mg (-30%, p = 0.0003) and 10 mg (-52%, p < 0.0001) versus placebo (+31%). Patients with clinically meaningful improvement in pruritus (NRS ≥ 2 decrease) demonstrated greater dose-dependent reductions in IL-31 compared to those without pruritus improvement (NRS < 2 decrease). Strong correlations were observed for the changes between levels of IL-31 and total bile acids ( r = 0.63, p < 0.0001) in the seladelpar 10 mg group.

CONCLUSIONS

Seladelpar decreased serum IL-31 and bile acids in patients with PBC. The reductions of IL-31 and bile acids correlated closely with each other and pruritus improvement, suggesting a mechanism to explain seladelpar's antipruritic effects.

Letter: Fibrates may be safe and effective in patients with primary biliary cholangitis and decompensated cirrhosis

This article is linked to Hofer et al papers. To view these articles, visit https://doi.org/10.1111/apt.17908 and https://doi.org/10.1111/apt.18067.

Mechanistic studies on the alleviation of ANIT-induced cholestatic liver injury by Polygala fallax Hemsl. polysaccharides

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala fallax Hemsl. is a traditional folk medicine commonly used by ethnic minorities in the Guangxi Zhuang Autonomous Region, and has a traditional application in the treatment of liver disease. Polygala fallax Hemsl. polysaccharides (PFPs) are of interest for their potential health benefits.

AIM OF THIS STUDY

This study explored the impact of PFPs on a mouse model of cholestatic liver injury (CLI) induced by alpha-naphthyl isothiocyanate (ANIT), as well as the potential mechanisms.

MATERIALS AND METHODS

A mouse CLI model was constructed using ANIT (80 mg/kg) and intervened with different doses of PFPs or ursodeoxycholic acid. Their serum biochemical indices, hepatic oxidative stress indices, and hepatic pathological characteristics were investigated. Then RNA sequencing was performed on liver tissues to identify differentially expressed genes and signaling pathways and to elucidate the mechanism of liver protection by PFPs. Finally, Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to verify the differentially expressed genes.

RESULTS

Data analyses showed that PFPs reduced the levels of liver function-related biochemical indices, such as ALT, AST, AKP, TBA, DBIL, and TBIL. PFPs up-regulated the activities of SOD and GSH, down-regulated the contents of MDA, inhibited the release of IL-1β, IL-6, and TNF-α, or promoted IL-10. Pathologic characterization of the liver revealed that PFPs reduced hepatocyte apoptosis or necrosis. The RNA sequencing indicated that the genes with differential expression were primarily enriched for the biosynthesis of primary bile acids, secretion or transportation of bile, the reactive oxygen species in chemical carcinogenesis, and the NF-kappa B signaling pathway. In addition, the results of qRT-PCR and Western blotting analysis were consistent with those of RNA sequencing analysis.

CONCLUSIONS

In summary, this study showed that PFPs improved intrahepatic cholestasis and alleviated liver damage through the modulation of primary bile acid production, Control of protein expression related to bile secretion or transportation, decrease in inflammatory reactions, and inhibition of oxidative pressure. As a result, PFPs might offer a hopeful ethnic dietary approach for managing intrahepatic cholestasis.

PPARβ/δ as a promising molecular drug target for liver diseases: A focused review

Various liver diseases pose great threats to humans. Although the etiologies of these liver diseases are quite diverse, they share similar pathologic phenotypes and molecular mechanisms such as oxidative stress, lipid and glucose metabolism disturbance, hepatic Kupffer cell (KC) proinflammatory polarization and inflammation, insulin resistance, and hepatic stellate cell (HSC) activation and proliferation. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is expressed in various types of liver cells with relatively higher expression in KCs and HSCs. Accumulating evidence has revealed the versatile functions of PPARβ/δ such as controlling lipid homeostasis, inhibiting inflammation, regulating glucose metabolism, and restoring insulin sensitivity, suggesting that PPARβ/δ may serve as a potential molecular drug target for various liver diseases. This article aims to provide a concise review of the structure, expression pattern and biological functions of PPARβ/δ in the liver and its roles in various liver diseases, and to discuss potential future research perspectives.

Immunopathogenesis of Primary Biliary Cholangitis, Primary Sclerosing Cholangitis and Autoimmune Hepatitis: Themes and Concepts

Autoimmune liver diseases include primary biliary cholangitis, primary sclerosing cholangitis, and autoimmune hepatitis, a family of chronic immune-mediated disorders that target hepatocytes and cholangiocytes. Treatments remain nonspecific, variably effective, and noncurative, and the need for liver transplantation is disproportionate to their rarity. Development of effective therapies requires better knowledge of pathogenic mechanisms, including the roles of genetic risk, and how the environment and gut dysbiosis cause immune cell dysfunction and aberrant bile acid signaling. This review summarizes key etiologic and pathogenic concepts and themes relevant for clinical practice and how such learning can guide the development of new therapies for people living with autoimmune liver diseases.

Seladelpar: New hope for patients with primary biliary cholangitis

The study by Hirschfield et al.1 demonstrated safety profile and clinically significant effectiveness of the peroxisome proliferator-activated receptor delta (PPARδ) agonist seladelpar in patients with primary biliary cholangitis, highlighting its plausible use as a second-line treatment to reduce disease activity and pruritus.

Sodium/bile acid co-transporter inhibitors currently in preclinical or early clinical development for the treatment of primary biliary cholangitis

INTRODUCTION

Pruritus is common and often undertreated in patients with primary biliary cholangitis (PBC). Existing treatments largely have an aging and low-quality evidence base, and studies included only small numbers of patients. More recent data that has added to our understanding of pruritus treatments has often come from clinical trials where itching was a secondary outcome measure in a trial designed primarily to assess disease-modifying agents. This area represents an unmet clinical need in the management of PBC.

AREAS COVERED

In this manuscript, we first summarize the proposed mechanisms for PBC-related pruritus and the current treatment paradigm. We then present an appraisal of the existing pre-clinical and clinical evidence for the use of ileal bile acid transporter inhibitors (IBATis) for this indication in PBC patients.

EXPERT OPINION

Evidence for the efficacy of IBATis is promising but limited by the currently available volume of data. Furthermore, larger clinical trials with long-term data on efficacy, safety and tolerability are needed to confirm the role of using IBATis in clinical practice and their place on the itch treatment ladder. Additional focus should also be given to exploring the disease-modifying potential of IBATis in PBC.

Exploring Advanced Therapies for Primary Biliary Cholangitis: Insights from the Gut Microbiota-Bile Acid-Immunity Network

Primary biliary cholangitis (PBC) is a cholestatic liver disease characterized by immune-mediated injury to small bile ducts. Although PBC is an autoimmune disease, the effectiveness of conventional immunosuppressive therapy is disappointing. Nearly 40% of PBC patients do not respond to the first-line drug UDCA. Without appropriate intervention, PBC patients eventually progress to liver cirrhosis and even death. There is an urgent need to develop new therapies. The gut-liver axis emphasizes the interconnection between the gut and the liver, and evidence is increasing that gut microbiota and bile acids play an important role in the pathogenesis of cholestatic diseases. Dysbiosis of gut microbiota, imbalance of bile acids, and immune-mediated bile duct injury constitute the triad of pathophysiology in PBC. Autoimmune cholangitis has the potential to be improved through immune system modulation. Considering the failure of conventional immunotherapies and the involvement of gut microbiota and bile acids in the pathogenesis, targeting immune factors associated with them, such as bile acid receptors, microbial-derived molecules, and related specific immune cells, may offer breakthroughs. Understanding the gut microbiota-bile acid network and related immune dysfunctions in PBC provides a new perspective on therapeutic strategies. Therefore, we summarize the latest advances in research of gut microbiota and bile acids in PBC and, for the first time, explore the possibility of related immune factors as novel immunotherapy targets. This article discusses potential therapeutic approaches focusing on regulating gut microbiota, maintaining bile acid homeostasis, their interactions, and related immune factors.

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

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

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

Efficacy and Safety of Elafibranor in Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis is a rare, chronic cholestatic liver disease characterized by the destruction of interlobular bile ducts, leading to cholestasis and liver fibrosis. Whether elafibranor, an oral, dual peroxisome proliferator-activated receptor (PPAR) α and δ agonist, may have benefit as a treatment for primary biliary cholangitis is unknown.

METHODS

In this multinational, phase 3, double-blind, placebo-controlled trial, we randomly assigned (in a 2:1 ratio) patients with primary biliary cholangitis who had had an inadequate response to or unacceptable side effects with ursodeoxycholic acid to receive once-daily elafibranor, at a dose of 80 mg, or placebo. The primary end point was a biochemical response (defined as an alkaline phosphatase level of <1.67 times the upper limit of the normal range, with a reduction of ≥15% from baseline, and normal total bilirubin levels) at week 52. Key secondary end points were normalization of the alkaline phosphatase level at week 52 and a change in pruritus intensity from baseline through week 52 and through week 24, as measured on the Worst Itch Numeric Rating Scale (WI-NRS; scores range from 0 [no itch] to 10 [worst itch imaginable]).

RESULTS

A total of 161 patients underwent randomization. A biochemical response (the primary end point) was observed in 51% of the patients (55 of 108) who received elafibranor and in 4% (2 of 53) who received placebo, for a difference of 47 percentage points (95% confidence interval [CI], 32 to 57; P<0.001). The alkaline phosphatase level normalized in 15% of the patients in the elafibranor group and in none of the patients in the placebo group at week 52 (difference, 15 percentage points; 95% CI, 6 to 23; P = 0.002). Among patients who had moderate-to-severe pruritus (44 patients in the elafibranor group and 22 in the placebo group), the least-squares mean change from baseline through week 52 on the WI-NRS did not differ significantly between the groups (-1.93 vs. -1.15; difference, -0.78; 95% CI, -1.99 to 0.42; P = 0.20). Adverse events that occurred more frequently with elafibranor than with placebo included abdominal pain, diarrhea, nausea, and vomiting.

CONCLUSIONS

Treatment with elafibranor resulted in significantly greater improvements in relevant biochemical indicators of cholestasis than placebo. (Funded by GENFIT and Ipsen; ELATIVE ClinicalTrials.gov number, NCT04526665.).

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.).

Cholestatic Pruritus: Pathophysiology, Current Management Approach, and Emerging Therapies

Purpose of Review

Cholestatic pruritus refers to the sensation of itch experienced by patients with disease processes impairing bile flow. This article aims to illustrate the burden of cholestatic pruritus, review the proposed mechanisms, and summarize its available and emerging therapies.

Recent Findings

Pruritus is experienced by many patients with cholestatic liver diseases. It is underdiagnosed and negatively impacts patients’ quality of life. Its direct cause remains unclear though multiple pathways have been explored. Current therapies are insufficient but newly approved ileal bile acid transporter (IBAT) inhibitors and emerging peroxisome proliferator-activated receptor (PPAR) agonists are promising.

Summary

Cholestatic pruritus affects many patients with cholestatic liver diseases and can be debilitating. In moderate to severe cases, current guidelines provide treatment options that are ineffective. Emerging agents such as IBAT inhibitors and PPAR agonists should be considered, including referral to clinical trials. Further exploration into the pathophysiology and effective therapeutic agents is needed.

Persistent pruritus associated with worse quality of life in patients with chronic hepatitis

INTRODUCTION

Prevalence and severity of pruritus among US patients with chronic hepatitis B and C (HBV, HCV) are not well-documented. Chronic Hepatitis Cohort Study (CHeCS) patients were surveyed to examine pruritus prevalence and impact on quality of life (QoL).

METHODS

Patients who reported experiencing pruritus ≥3 on a Numeric Rating Scale (NRS) within the past 30 days were invited to participate in a 6-month study using the SF-36 questionnaire. General regression (univariate followed by multivariable modelling) was used to analyse pruritus intensity and eight QoL dimensions.

RESULTS

Among 1654 patients (HBV = 358, HCV = 1296, HBV/HCV = 6), pruritus prevalence was significantly higher among patients with HCV than those with HBV (44% vs. 35%; p < .05). One hundred and twenty-three patients (21 HBV and 102 HCV) participated in the QoL study (72% ≥60 years; 50% men; 25% Black; 37% with cirrhosis; 66% had BMI > 25). Mean NRS was 4.9-5.3. QoL responses for social functioning and emotional well-being were higher (70-72 points) than responses for energy/fatigue (50-51). Antiviral treatment rates were higher in HCV (92%, SVR 99%) than HBV (71% ever, 43% ongoing). Multivariable analyses showed no significant effect of hepatitis type or antiviral treatments on itch. Antihistamines were associated with severe itch. Higher NRS was associated with significantly reduced QoL. Each unit increase in NRS was associated with a 2-3 unit decline in emotional well-being, general health, physical function, energy/fatigue, social functioning and emotional health.

CONCLUSION

Pruritus negatively affects many viral hepatitis patients, regardless of antiviral treatment status. Improved treatment options are needed to address its impact on QoL.

Seladelpar combined with complementary therapies improves fibrosis, inflammation, and liver injury in a mouse model of nonalcoholic steatohepatitis

Seladelpar, a selective peroxisome proliferator-activated receptor δ (PPARδ) agonist, improves markers of hepatic injury in human liver diseases, but histological improvement of nonalcoholic steatohepatitis (NASH) and liver fibrosis has been challenging with any single agent. To discover how complementary agents could work with seladelpar to achieve optimal outcomes, this study evaluated a variety of therapeutics (alone and in combination) in a mouse model of NASH. Mice on a high-fat amylin liver NASH (AMLN) diet were treated for 12 wk with seladelpar, GLP-1-R (glucagon-like peptide-1 receptor) agonist liraglutide, apoptosis signal-regulating kinase 1 (ASK1) inhibitor selonsertib, farnesoid X receptor (FXR) agonist obeticholic acid, and with seladelpar in combination with liraglutide or selonsertib. Seladelpar treatment markedly improved plasma markers of liver function. Seladelpar alone or in combination resulted in stark reductions in liver fibrosis (hydroxyproline, new collagen synthesis rate, mRNA indices of fibrosis, and fibrosis staining) compared with vehicle and the other single agents. Robust reductions in liver steatosis were also observed. Seladelpar produced a reorganization of metabolic gene expression, particularly for those genes promoting peroxisomal and mitochondrial lipid oxidation. In summary, substantial improvements in NASH and NASH-induced fibrosis were observed with seladelpar alone and in combination with liraglutide in this model. Broad gene expression analysis suggests seladelpar should be effective in concert with diverse mechanisms of action.NEW & NOTEWORTHY NASH is a chronic, progressive, and increasingly problematic liver disease that has been resistant to treatment with individual therapeutics. In this study using a diet-induced mouse model of NASH, we found that the PPARδ agonist seladelpar reduced fibrosis and NASH pathology alone and in combinations with a GLP-1-R agonist (liraglutide) or an ASK1 inhibitor (selonsertib). Liver transcriptome analysis comparing each agent and coadministration suggests seladelpar should be effective in combination with a variety of therapeutics.

Exploring the Relationship between Liver Disease, Bacterial Translocation, and Dysbiosis: Unveiling the Gut-Liver Axis

Background

The global burden of liver disease and cirrhosis has been progressively increasing in the last decade. The interplay between gut microbiota and immune system and the bidirectional relationship with the liver, known as the gut-liver axis, has arisen as a fundamental aspect of liver disease.

Summary

Alterations of the gut microbiome have been described and include both dysbiotic microbial signatures and intestinal bacterial overgrowth. The integrity of the intestinal epithelial barrier is essential for preventing the access of harmful substances and bacterial products into the host. Bacterial translocation due to altered host-microbiota interactions triggers local immune cell activation and facilitates a chronic inflammatory state that can ultimately lead to immune exhaustion, characteristic of cirrhosis. In cirrhosis, breakdown of the gut vascular barrier allows access of bacterial products to portal blood circulation and facilitates their influx into the liver, further contributing to disease progression.

Key Messages

A better understanding of the contributing factors to pathological bacterial translocation and the impact of dysbiosis in liver disease will lead to achieve innovative therapeutic strategies in cirrhosis.

Optimal drug regimens for improving ALP biochemical levels in patients with primary biliary cholangitis refractory to UDCA: a systematic review and Bayesian network meta-analysis

BACKGROUND

Up to 40% of UDCA-treated patients do not have an adequate clinical response. Farnesoid X receptor agonists, peroxisome proliferator-activated receptor agonists, and fibroblast growth factor 19 analogs were developed as adjunctive therapy. The aim of this network meta-analysis was to compare the efficacy of these drugs as add-on therapy for patients with primary biliary cholangitis (PBC) refractory to UDCA in improving ALP levels.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library for eligible studies until 1 December 2023. Randomized controlled trials, cohort studies, and case-control studies comparing the efficacy of different combination treatments and UDCA monotherapy in UDCA-refractory PBC patients were included in the analysis. Cumulative probability was used to rank the included treatments.

RESULTS

A total of 23 articles were eligible for our network meta-analysis. In terms of improving ALP levels, In terms of improving ALP biochemical levels, bezafibrate combined with UDCA (MD 104.49, 95% CI 60.41, 161.92), fenofibrate combined with UDCA (MD 87.81, 95% CI (52.34, 129.79), OCA combined with UDCA (MD 65.21, 95% CI 8.99, 121.80), seladelpar combined with UDCA (MD 117.39, 95% CI 19.97, 213.95), elafibranor combined with UDCA (MD 140.73, 95% CI 74.34, 209.98), saroglitazar combined with UDCA (MD 132.09, 95% CI 13.99, 247.04) was more effective than UDCA monotherapy. Elafibranor in combination with UDCA was the most likely (32%) to be the optimal drug regimen.

CONCLUSION

As second-line therapy for UDCA-refractory PBC, PPAR agonists were more effective than any other drugs with other mechanisms in improving ALP biochemical levels, with elafibranor being the best.