Seladelpar improved measures of pruritus, sleep, and fatigue and decreased serum bile acids in patients with primary biliary cholangitis

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.

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.

Relationship between pruritus and sleep in participants with primary biliary cholangitis in the Phase 2b GLIMMER trial

BACKGROUND

Cholestatic pruritus and fatigue are debilitating conditions associated with primary biliary cholangitis (PBC) and can significantly impact patients' quality of life. Pruritus in PBC often worsens at night and patients frequently report sleep disturbance, which contributes to cognitive symptoms and fatigue. Linerixibat is an ileal bile acid transporter inhibitor in clinical development for the treatment of pruritus associated with PBC and was recently assessed versus placebo in the Phase 2b GLIMMER trial. This post-hoc analysis assesses the relationship between pruritus severity and sleep disturbance in participants of GLIMMER regardless of treatment group.

METHODS

GLIMMER (NCT02966834), a multicenter, double-blind, randomized, placebo-controlled trial, recruited 147 patients with PBC and moderate-to-severe pruritus. Following 4 weeks single-blind placebo, patients (randomized 3:1) received linerixibat or placebo for 12 weeks (to Week 16). Participants graded their itch (twice daily) and its interference with sleep (once daily) in an electronic diary using a 0-10 numerical rating scale (NRS). Weekly and monthly itch scores were calculated as the mean of the worst daily itch score over the respective time period. At study visits, participants completed the 5-D itch scale and the PBC-40 quality of life questionnaire, both of which contain an item specific to itch-related sleep disturbance. The impact of pruritus on sleep was assessed post hoc through correlations between the changes in NRS, 5-D itch, and PBC-40.

RESULTS

Strong correlations were found between change from baseline in weekly itch and sleep NRS scores (r = 0.88 [95% confidence interval (CI): 0.83; 0.91]) at the end of treatment (Week 16), as well as in monthly itch and sleep NRS scores (r = 0.84 [95% CI: 0.80; 0.87]). Patients with improved weekly pruritus score severity category demonstrated reduced perceived sleep interference on average. Itch responders (≥2-point improvement in weekly itch score from baseline) displayed larger improvements in weekly sleep NRS score, 5-D itch, and PBC-40 sleep items, than itch non-responders (<2-point improvement).

CONCLUSIONS

A strong correlation exists between changes in pruritus severity and sleep interference in patients with PBC; pruritus reduction could generate concomitant improvement in sleep.

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.

Validation of a Primary Biliary Cholangitis-Specific Version of Chronic Liver Disease Questionnaire: CLDQ-PBC

INTRODUCTION

Primary biliary cholangitis (PBC) is a chronic liver disease, leading to cirrhosis and impairment of patient-reported outcomes. We aimed to develop a PBC-specific version of the Chronic Liver Disease Questionnaire (CLDQ) instrument to assess health-related quality of life of patients with PBC.

METHODS

From our Liver Database, we included patients with PBC who had CLDQ, clinicolaboratory data, and completed Short Form-36 and The Functional Assessment of Chronic Illness Therapy-Fatigue. The 29 items of CLDQ were subjected to item reduction, exploratory factor analysis, and fed into a standard instrument validation pipeline.

RESULTS

Data were available for 108 patients with PBC: 57 ± 11 years, 7% male, 58% cirrhosis, and 24% decompensated cirrhosis (Child B and C). Of 29 CLDQ items, none met the exclusion criteria. Exploratory factor analysis (95% of variance) returned 7 factors. Based on evaluation of factor loadings and face validity, those factors yielded 7 domains (Diet, Emotion, Fatigue, Itch, Symptoms, Sleep, and Worry). Good to excellent internal consistency (Cronbach's α 0.85-0.93) was observed for 5/7 domains. For the remaining 2 domains (Diet and Itch), additional items obtained from patients, experts, and review of the literature were included. For 5 domains, known-group validity tests discriminated between patients with PBC with and without cirrhosis, advanced cirrhosis, and depression ( P < 0.05 for 3-5 domains). The CLDQ-PBC domains were correlated with relevant domains of Short Form-36, CLDQ-PBC Fatigue correlated with Fatigue Scale of Functional Assessment of Chronic Illness Therapy-Fatigue (rho = +0.85), and CLDQ-PBC Worry domain negatively correlated with alkaline phosphatase (rho = -0.38, P = 0.0082).

DISCUSSION

The CLDQ-PBC has been developed based on the original CLDQ. The new instrument has evidence for internal consistency and validity and is being fully validated using an external cohort.

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.

Assessment of fatigue and its impact in chronic liver disease

Patient-reported outcomes (PROs), such as health-related quality of life (HRQL), are important outcome measures for patients with chronic liver diseases (CLDs). Presence of cirrhosis and advanced liver disease have been associated with worsened HRQL and fatigue. On the other hand, some patients with earlier stages of CLD also experience fatigue, causing PRO impairment. Treatment for some CLDs may improve HRQL and, sometimes, levels of fatigue. We aimed to provide an in-depth expert review of concepts related to fatigue and HRQL in patients with primary biliary cholangitis, hepatitis C virus and MASLD (metabolic dysfunction-associated steatotic liver disease). A panel of experts in fatigue and CLD reviewed and discussed the literature and collaborated to provide this expert review of fatigue in CLD. Herein, we review and report on the complexity of fatigue, highlighting that it is comprised of peripheral (neuromuscular failure, often in conjunction with submaximal cardiorespiratory function) and central (central nervous system dysfunction) causes. Fatigue and HRQL are measured using validated self-report instruments. Additionally, fatigue can be measured through objective tests (e.g. grip strength). Fatigue has deleterious effects on HRQL and one's ability to be physically active and socially engaged but does not always correlate with CLD severity. Treatments for hepatitis C virus and MASLD can improve levels of fatigue and HRQL, but current treatments for primary biliary cholangitis do not seem to affect levels of fatigue. We conclude that obtaining PRO data, including on HRQL and fatigue, is essential for determining the comprehensive burden of CLD and its potential treatments.

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.

High-dose oral thiamine versus placebo for chronic fatigue in patients with primary biliary cholangitis: A crossover randomized clinical trial

BACKGROUND & AIMS

Fatigue has high negative impact on many patients with primary biliary cholangitis (PBC) and treatment options are limited. Recently we showed favorable effects of four weeks of high-dose thiamine treatment on fatigue in patients with inflammatory bowel disease. We aimed to investigate the effect and safety of high-dose (600-1800 mg daily) oral thiamine treatment on chronic fatigue in patients with PBC.

METHODS

Randomized, double-blinded, placebo-controlled crossover trial including patients with severe PBC-related fatigue. Participants were allocated 1:1 to either group 1) 4 weeks of high-dose thiamine, 4 weeks of washout, and 4 weeks of placebo; or group 2) 4 weeks of placebo, washout, and high-dose thiamine, respectively. Fatigue severity was quantified using the fatigue subscale of the PBC-40 questionnaire. The primary outcome was a fatigue reduction of ≥ 5 points after 4 weeks of high-dose thiamine treatment.

RESULTS

We enrolled 36 patients; 34 completed the study. The overall mean reduction in fatigue was 5.0 points (95% CI: 2.5 to 7.5; p < 0.001) for the combined group 1 and group 2. Crossover analysis showed a mean increase in fatigue of 0.3 points (95% CI: -4.2 to 3.8) after high-dose thiamine treatment compared to a 1.4 points (95% CI: 6.2 to -3.4) mean reduction after placebo (p = 0.55). Only mild and transient adverse events were recorded.

CONCLUSION

Four weeks of high-dose oral thiamine treatment in patients with PBC was well tolerated and safe. However, high-dose thiamine was not superior to placebo in reducing PBC-related fatigue.

TRIAL REGISTRATION

The trial was registered in the ClinicalTrials.gov (NCT04893993) and EudraCT (2020-004935-26).

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.

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.).

Open-label, clinical trial extension: Two-year safety and efficacy results of seladelpar in patients with primary biliary cholangitis

BACKGROUND

Seladelpar is a potent and selective peroxisome proliferator-activated receptor-δ agonist that targets multiple cell types involved in primary biliary cholangitis (PBC), leading to anti-cholestatic, anti-inflammatory and anti-pruritic effects.

AIMS

To evaluate the long-term safety and efficacy of seladelpar in patients with PBC.

METHODS

In an open-label, international, long-term extension study, patients with PBC completing seladelpar lead-in studies continued treatment. Seladelpar was taken orally once daily at doses of 5 or 10 mg with dose adjustment permitted for safety or tolerability. The primary analysis was for safety and the secondary efficacy analysis examined biochemical markers of cholestasis and liver injury. The study was terminated early due to the unexpected histological findings in a concurrent study for non-alcoholic steatohepatitis, which were subsequently found to predate treatment. Safety and efficacy data were analysed through 2 years.

RESULTS

There were no serious treatment-related adverse events observed among 106 patients treated with seladelpar for up to 2 years. There were four discontinuations for safety, one possibly related to seladelpar. Among 53 patients who completed 2 years of seladelpar, response rates increased from years 1 to 2 for the composite endpoint (alkaline phosphatase [ALP] <1.67 × ULN, ≥15% decrease in ALP, and total bilirubin ≤ULN) and ALP normalisation from 66% to 79% and from 26% to 42%, respectively. In those with elevated bilirubin at baseline, 43% achieved normalisation at year 2.

CONCLUSIONS

Seladelpar was safe, and markedly improved biochemical markers of cholestasis and liver injury in patients with PBC. These effects were maintained or improved throughout the second year.

CLINICALTRIALS

gov: NCT03301506; Clinicaltrialsregister.eu: 2017-003910-16.

New insights into the pathogenesis of primary biliary cholangitis asymptomatic stage

Primary biliary cholangitis (PBC) is a chronic cholestatic progressive liver disease and one of the most important progressive cholangiopathies in adults. Damage to cholangiocytes triggers the development of intrahepatic cholestasis, which progresses to cirrhosis in the terminal stage of the disease. Accumulating data indicate that damage to biliary epithelial cells [(BECs), cholangiocytes] is most likely associated with the intracellular accumulation of bile acids, which have potent detergent properties and damaging effects on cell membranes. The mechanisms underlying uncontrolled bile acid intake into BECs in PBC are associated with pH change in the bile duct lumen, which is controlled by the bicarbonate (HCO3-) buffer system "biliary HCO3- umbrella". The impaired production and entry of HCO3- from BECs into the bile duct lumen is due to epigenetic changes in expression of the X-linked microRNA 506. Based on the growing body of knowledge on the molecular mechanisms of cholangiocyte damage in patients with PBC, we propose a hypothesis explaining the pathogenesis of the first morphologic (ductulopenia), immunologic (antimitochondrial autoantibodies) and clinical (weakness, malaise, rapid fatigue) signs of the disease in the asymptomatic stage. This review focuses on the consideration of these mechanisms.

Emerging Therapeutic Strategies in The Fight Against Primary Biliary Cholangitis

The liver has a vital role in many metabolic and regulatory processes in the body. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is a chronic cholestatic autoimmune disease of the intrahepatic bile ducts associated with loss of tolerance to mitochondrial antigens. At this time there is no definitive cure for PBC; however, ursodeoxycholic acid (UDCA) has been shown to reduce injury when administered as the first line of treatment. Additional therapeutics can be given concurrently or as an alternative to UDCA to manage the symptoms and further curb disease progression. Currently, a liver transplant is the only potentially curative option when the patient has developed end-stage liver disease or intractable pruritus. This review aims to delineate the pathogenesis of primary biliary cholangitis and shed light on current therapeutic strategies in the treatment of PBC.

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

BACKGROUND AND AIMS

ENHANCE was a phase 3 study that evaluated efficacy and safety of seladelpar, a selective peroxisome proliferator-activated receptor-δ (PPAR) agonist, versus placebo in patients with primary biliary cholangitis with inadequate response or intolerance to ursodeoxycholic acid (UDCA).

APPROACH AND RESULTS

Patients were randomized 1:1:1 to oral seladelpar 5 mg (n=89), 10 mg (n=89), placebo (n=87) daily (with UDCA, as appropriate). Primary end point was a composite biochemical response [alkaline phosphatase (ALP) < 1.67×upper limit of normal (ULN), ≥15% ALP decrease from baseline, and total bilirubin ≤ ULN] at month 12. Key secondary end points were ALP normalization at month 12 and change in pruritus numerical rating scale (NRS) at month 6 in patients with baseline score ≥4. Aminotransferases were assessed. ENHANCE was terminated early following an erroneous safety signal in a concurrent, NASH trial. While blinded, primary and secondary efficacy end points were amended to month 3. Significantly more patients receiving seladelpar met the primary end point (seladelpar 5 mg: 57.1%, 10 mg: 78.2%) versus placebo (12.5%) ( p < 0.0001). ALP normalization occurred in 5.4% ( p =0.08) and 27.3% ( p < 0.0001) of patients receiving 5 and 10 mg seladelpar, respectively, versus 0% receiving placebo. Seladelpar 10 mg significantly reduced mean pruritus NRS versus placebo [10 mg: -3.14 ( p =0.02); placebo: -1.55]. Alanine aminotransferase decreased significantly with seladelpar versus placebo [5 mg: 23.4% ( p =0.0008); 10 mg: 16.7% ( p =0.03); placebo: 4%]. There were no serious treatment-related adverse events.

CONCLUSIONS

Patients with primary biliary cholangitis (PBC) with inadequate response or intolerance to UDCA who were treated with seladelpar 10 mg had significant improvements in liver biochemistry and pruritus. Seladelpar appeared safe and well tolerated.

Functional and Structural Insights into the Human PPARα/δ/γ Targeting Preferences of Anti-NASH Investigational Drugs, Lanifibranor, Seladelpar, and Elafibranor

No therapeutic drugs are currently available for nonalcoholic steatohepatitis (NASH) that progresses from nonalcoholic fatty liver via oxidative stress-involved pathways. Three cognate peroxisome proliferator-activated receptor (PPAR) subtypes (PPARα/δ/γ) are considered as attractive targets. Although lanifibranor (PPARα/δ/γ pan agonist) and saroglitazar (PPARα/γ dual agonist) are currently under investigation in clinical trials for NASH, the development of seladelpar (PPARδ-selective agonist), elafibranor (PPARα/δ dual agonist), and many other dual/pan agonists has been discontinued due to serious side effects or little/no efficacies. This study aimed to obtain functional and structural insights into the potency, efficacy, and selectivity against PPARα/δ/γ of three current and past anti-NASH investigational drugs: lanifibranor, seladelpar, and elafibranor. Ligand activities were evaluated by three assays to detect different facets of the PPAR activation: transactivation assay, coactivator recruitment assay, and thermal stability assay. Seven high-resolution cocrystal structures (namely, those of the PPARα/δ/γ-ligand-binding domain (LBD)-lanifibranor, PPARα/δ/γ-LBD-seladelpar, and PPARα-LBD-elafibranor) were obtained through X-ray diffraction analyses, six of which represent the first deposit in the Protein Data Bank. Lanifibranor and seladelpar were found to bind to different regions of the PPARα/δ/γ-ligand-binding pockets and activated all PPAR subtypes with different potencies and efficacies in the three assays. In contrast, elafibranor induced transactivation and coactivator recruitment (not thermal stability) of all PPAR subtypes, but the PPARδ/γ-LBD-elafibranor cocrystals were not obtained. These results illustrate the highly variable PPARα/δ/γ activation profiles and binding modes of these PPAR ligands that define their pharmacological actions.

New Treatment Paradigms in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an archetypal autoimmune disease. Chronic lymphocytic cholangitis is associated with interface hepatitis, ductopenia, cholestasis, and progressive biliary fibrosis. People living with PBC are frequently symptomatic, experiencing a quality-of-life burden dominated by fatigue, itch, abdominal pain, and sicca complex. Although the female predominance, specific serum autoantibodies, immune-mediated cellular injury, as well as genetic (HLA and non-HLA) risk factors, identify PBC as autoimmune, to date treatment has focused on cholestatic consequences. Biliary epithelial homeostasis is abnormal and contributes to disease. The impact of cholangiocyte senescence, apoptosis, and impaired bicarbonate secretion enhances chronic inflammation and bile acid retention. First-line therapy is a non-specific anti-cholestatic agent, ursodeoxycholic acid. For those with residual cholestasis biochemically, obeticholic acid is introduced, and this semisynthetic farnesoid X receptor agonist adds choleretic, anti-fibrotic, and anti-inflammatory activity. Future PBC licensed therapy will likely include peroxisome proliferator activated receptor (PPAR) pathway agonists, including specific PPAR-delta agonism (seladelpar), as well as elafibrinor and saroglitazar (both with broader PPAR agonism). These agents dovetail the clinical and trial experience for off-label bezafibrate and fenofibrate use. Symptom management is essential, and encouragingly, PPAR agonists reduce itch; IBAT inhibition (eg, linerixibat) also appears promising for pruritus. For those where liver fibrosis is the target, NOX inhibition is being evaluated. Earlier stage therapies in development include therapy to impact immunoregulation in patients, as well other approaches to treating pruritus (eg, antagonists of MrgprX4). Collectively the PBC therapeutic landscape is exciting. Therapy goals are increasingly proactive and individualized and aspire to rapidly achieve normal serum tests and quality of life with prevention of end-stage liver disease.

Current Therapies for Cholestatic Diseases

Cholestasis is a condition characterized by decrease in bile flow due to progressive pathological states that lead to chronic cholestatic liver diseases which affect the biliary tree at the intrahepatic level and extrahepatic level. They induce complications such as cirrhosis, liver failure, malignancies, bone disease and nutritional deficiencies that merit close follow-up and specific interventions. Furthermore, as those conditions progress to liver cirrhosis, there will be an increase in mortality but also an important impact in quality of life and economic burden due to comorbidities related with liver failure. Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. With a general view of therapeutic options and their molecular targets, this review addresses the pathophysiology of cholangiopathies. The objective is to provide clinicians with an overview of the safety and efficacy of the treatment of cholangiopathies based on the current evidence.

Primary Biliary Cholangitis: Promising Emerging Innovative Therapies and Their Impact on GLOBE Scores

Primary biliary cholangitis (PBC), previously referred to as primary biliary cirrhosis, is an autoimmune disorder leading to the destruction of intra-hepatic bile ducts. If untreated, progressive bile duct damage and cholestasis can lead to ductopenia and result in cirrhosis. Ursodiol, the first drug approved for PBC, has changed the natural history of this disease and improved patient outcomes. Subsequently, several new prediction models incorporating a response to ursodiol were developed. These include the GLOBE score, which was shown to predict long-term outcomes in patients with PBC. In 2016, obeticholic acid (OCA) became the second drug to be approved by the FDA, predominantly based on improvement in alkaline phosphatase (ALP) levels. This trial has subsequently influenced the design of clinical trials. Several drugs are currently being evaluated as therapeutic options for PBC, with improvement in ALP being a main endpoint. In this review, we will discuss the impact of new therapies on GLOBE scores in patients with PBC.

Primary biliary cholangitis: Epidemiology, prognosis, and treatment

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease characterized by a destructive, small duct, and lymphocytic cholangitis, and marked by the presence of antimitochondrial antibodies. The incidence and prevalence of PBC vary widely in different regions and time periods, and although disproportionally more common among White non-Hispanic females, contemporary data show a higher prevalence in males and racial minorities than previously described. Outcomes largely depend on early recognition of the disease and prompt institution of treatment, which, in turn, are directly influenced by provider bias and socioeconomic factors. Ursodeoxycholic acid remains the initial treatment of choice for PBC, with obeticholic acid and fibrates (off-label therapy) reserved as add-on therapy for the management of inadequate responders or those with ursodeoxycholic acid intolerance. Novel and repurposed drugs are currently at different stages of clinical development not only for the treatment of PBC but also for its symptomatic management. Here, we summarize the most up-to-date data regarding the epidemiology, prognosis, and treatment of PBC, providing clinically useful information for its holistic management.

Cholestatic Pruritus Treatments in Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: A Systematic Literature Review

BACKGROUND AND AIMS

We conducted a systematic literature review to understand the evidence supporting treatment decisions for cholestatic pruritus associated with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC).

METHODS

Studies that enrolled ≥ 75% participants with PBC or PSC and reported ≥ 1 endpoint(s) related to efficacy, safety, health-related quality of life (HRQoL) or other patient-reported outcomes were included. Bias was assessed using the Cochrane risk of bias tool for randomised controlled trials (RCTs) and the Quality of Cohort studies tool for non-RCTs.

RESULTS

Thirty-nine publications were identified, covering 42 studies and six treatment classes (including investigational and approved products): anion-exchange resins, antibiotics (rifampicin/derivatives), opiates, selective serotonin reuptake inhibitors, fibrates, ileal bile acid transporter inhibitors and other agents not categorised in these six classes. Across studies, median sample size was small (n = 18), 20 studies were over 20 years old, 25 followed patients for ≤ 6 weeks, only 25 were RCTs. Pruritus was assessed using several different tools, with inconsistencies in their application. Cholestyramine, considered first-line therapy for moderate-severe cholestatic pruritus, was assessed in six studies (two RCTs) including 56 patients with PBC and 2 with PSC, with evidence of efficacy demonstrated in only three studies, among which, two RCTs were assessed as having a high risk of bias. Findings were similar for other drug classes.

CONCLUSIONS

There is a lack of consistent and reproducible evidence available on efficacy, impact on HRQoL, and safety of cholestatic pruritus treatments, leaving physicians to rely on clinical experience rather than evidence-based medicine for treatment selection.

Impact of setanaxib on quality of life outcomes in primary biliary cholangitis in a phase 2 randomized controlled trial

BACKGROUND

There is a real unmet need for primary biliary cholangitis (PBC) treatments that can improve quality of life impacting symptoms. In this post hoc analysis, we evaluated potential effects of the NADP oxidase 1/4 inhibitor, setanaxib, on patient-reported quality of life from a phase 2 trial in PBC.

PATIENTS AND METHODS

The underpinning double-blind, randomized, placebo-controlled trial (NCT03226067) recruited 111 patients with PBC and inadequate response/intolerance to ursodeoxycholic acid. Patients self-administered oral placebo (n=37), setanaxib 400 mg once daily (OD; n=38), or setanaxib 400 mg twice daily (BID; n=36), in addition to ursodeoxycholic acid for 24 weeks. Quality of life outcomes were assessed using the validated PBC-40 questionnaire. Patients were stratified post hoc by baseline fatigue severity.

RESULTS

At week 24, patients treated with setanaxib 400 mg BID reported greater mean (SE) absolute reductions from baseline in PBC-40 fatigue domain score [-3.6 (1.3)] versus those receiving setanaxib 400 mg OD [-0.8 (1.0)]) or placebo [0.6 (0.9)]. Similar observations were made across all PBC-40 domains except itch. In the setanaxib 400 mg BID arm, patients with moderate-to-severe fatigue at baseline had a greater reduction in mean fatigue score at week 24 [-5.8 (2.1)] versus those with mild fatigue [-0.6 (0.9)]; results were similar across all domains. Reduced fatigue was correlated with emotional, social, symptom, and cognitive improvements.

CONCLUSIONS

These results support further investigation of setanaxib as a treatment for patients with PBC, particularly for those with clinically significant fatigue.

Selected Aspects of the Intricate Background of Immune-Related Cholangiopathies-A Critical Overview

Primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are rare immune-related cholangiopathies with still poorly explained pathogenesis. Although triggers of chronic inflammation with subsequent fibrosis that affect cholangiocytes leading to obliteration of bile ducts and conversion to liver cirrhosis are unclear, both disorders are regarded to be multifactorial. Different factors can contribute to the development of hepatocellular injury in the course of progressive cholestasis, including (1) body accumulation of bile acids and their toxicity, (2) decreased food intake and nutrient absorption, (3) gut microbiota transformation, and (4) reorganized host metabolism. Growing evidence suggests that intestinal microbiome composition not only can be altered by liver dysfunction, but in turn, it actively impacts hepatic conditions. In this review, we highlight the role of key factors such as the gut-liver axis, intestinal barrier integrity, bile acid synthesis and circulation, and microbiome composition, which seem to be strongly related to PBC and PSC outcome. Emerging treatments and future therapeutic strategies are also presented.

Primary biliary cholangitis as a roadmap for the development of novel treatments for cholestatic liver diseases†

The discovery of nuclear receptors and transporters has contributed to the development of new drugs for the treatment of cholestatic liver diseases. Particular progress has been made in the development of second-line therapies for PBC. These new drugs can be separated into compounds primarily targeting cholestasis, molecules targeting fibrogenesis and molecules with immune-mediated action. Finally, drugs aimed at symptom relief (pruritus and fatigue) are also under investigation. Obeticholic acid is currently the only approved second-line therapy for PBC. Drugs in the late phase of clinical development include peroxisome proliferator-activated receptor agonists, norursodeoxycholic acid and NADPH oxidase 1/4 inhibitors.

Incomplete response to ursodeoxycholic acid in primary biliary cholangitis: criteria, epidemiology, and possible mechanisms

INTRODUCTION

As a common autoimmune disease with the characteristic of early complication, primary biliary cholangitis (PBC) leads to an increasing number of mortalities among people with end-stage liver disease (ESLD) waiting for liver transplantation. Ursodeoxycholic acid (UDCA) is the only approved first-line medicine for PBC, and a good response to treatment could acquire an ideal prognosis. Patients with poor UDCA response usually have more adverse outcomes and worse survival, therefore, the management of this group become a major consideration.

AREAS COVERED

Due to the complexity of race and environment for PBC, different criteria for UDCA response exhibit various predictive performances. Factors affecting UDCA response conditions include gender, age, ethnicity, serum indicators, auto-antibodies, and autoimmune comorbidities, while no agreement has been reached. In this review, we mainly focus on cellular senescence, immune-mediated damage, and vitamin D deficiency as possible mechanisms for UDCA non-responders.

EXPERT OPINION

The pathogenesis of PBC has yet to be clarified. Immunology-related mechanisms and therapy targets ought to be the main effort made for further study. Irrespective of the response condition, UDCA is recommended for routine administration in all PBC patients without contraindication. Ongoing clinical trials of second-line and additional therapy exhibit promising prospects.

Novel Therapies in Primary Biliary Cholangitis: What Is in the Pipeline?

Primary biliary cholangitis is a chronic autoimmune disease characterized by inflammation and the progressive destruction of small intrahepatic bile ducts. Current first-line treatment includes ursodeoxycholic acid; however, a significant number of patients have an inadequate response to therapy. These patients are at risk of liver failure requiring liver transplantation and experience a poor quality of life due to refractory symptoms. This manuscript aims to shed light on the current and prospective treatment options that may slow disease progression and improve these patients' symptoms.

Seladelpar: an investigational drug for the treatment of early-stage primary biliary cholangitis (PBC)

INTRODUCTION

Generic fibrates are used off-label as add-in therapy for the management of primary biliary cholangitis (PBC) but with unproven long-term liver-related survival benefits. The recently developed fibrate, seladelpar, has shown promising results in clinical trials, but these outcomes have been previously marred by safety concerns.

AREAS COVERED

We summarize existing treatment options in PBC and evaluate current trial data for seladelpar in relation to liver biochemistry, symptomology, and safety.

EXPERT OPINION

Seladelpar leads to marked improvement in liver biochemistry and may improve symptoms. Safety concerns around liver toxicity appear to have been addressed. With likely increasing evidence compared to existing off-label fibrates, seladelpar has the potential as an attractive future second-line agent in PBC.

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.

A phase II, randomized, open-label, 52-week study of seladelpar in patients with primary biliary cholangitis

BACKGROUND & AIMS

We examined the efficacy and safety of seladelpar, a selective peroxisome proliferator-activated receptor-delta agonist, in adults with primary biliary cholangitis (PBC) at risk of disease progression (alkaline phosphatase [ALP] ≥1.67xupper limit of normal [ULN]) who were receiving or intolerant to ursodeoxycholic acid.

METHODS

In this 52-week, phase II, dose-ranging, open-label study, patients were randomized (1:1) to seladelpar 5 mg/day (n = 53) or 10 mg/day (n = 55) or assigned to 2 mg/day (n = 11; United Kingdom sites after interim analysis) for 12 weeks. Doses could then be uptitrated to 10 mg/day. The primary efficacy endpoint was ALP change from baseline to Week 8.

RESULTS

Mean baseline ALP was 300, 345, and 295 U/L in the 2 mg, 5 mg, and 10 mg cohorts, respectively. Twenty-one percent of patients had cirrhosis, 71% had pruritus. At Week 8, mean ± standard error ALP reductions from baseline were 26 ± 2.8%, 33 ± 2.6%, and 41 ± 1.8% in the 2 mg (n = 11), 5 mg (n = 49), and 10 mg (n = 52) cohorts (all p ≤0.005), respectively. Responses were maintained or improved at Week 52, after dose escalation in 91% and 80% of the 2 mg and 5 mg cohorts, respectively. At Week 52, composite response (ALP <1.67xULN, ≥15% ALP decrease, and normal total bilirubin) rates were 64%, 53%, and 67%, and ALP normalization rates were 9%, 13%, and 33% in the 2 mg, 5 mg, and 10 mg cohorts, respectively. Pruritus visual analog scale score was decreased in the 5 mg and 10 mg cohorts. There were no treatment-related serious adverse events, and 4 patients discontinued due to adverse events.

CONCLUSIONS

Seladelpar demonstrated robust, dose-dependent, clinically significant, and durable improvements in biochemical markers of cholestasis and inflammation in patients with PBC at risk of disease progression. Seladelpar appeared safe and well tolerated and was not associated with any increase in pruritus.

CLINICALTRIALS

GOV NUMBER

NCT02955602 CLINICALTRIALSREGISTER.

EU NUMBER

2016-002996-91 LAY SUMMARY: Current treatment options for patients living with primary biliary cholangitis (PBC) are not optimal due to inadequate effectiveness or undesirable side effects. Patients with PBC who took seladelpar, a new treatment being developed for PBC, at increasing doses (2, 5, or 10 mg/day) for 1 year had clinically significant, dose-dependent improvements in key liver tests. Treatment appeared safe and was not associated with any worsening in patient self-reported itch scores.

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.

Understanding fatigue in primary biliary cholangitis: From pathophysiology to treatment perspectives

Fatigue is considered one of the most frequent and debilitating symptoms in primary biliary cholangitis (PBC), affecting over 50% of PBC patients. One in five patients with PBC suffer from severe fatigue, which significantly impairs quality of life. Fatigue is made up of a central and a peripheral component, whose pathophysiology is still greatly unresolved. Central fatigue is characterised by a lack of self-motivation and can manifest both in physical and mental activities (lack of intention). Peripheral fatigue includes neuromuscular dysfunction and muscle weakness (lack of ability). Peripheral fatigue could be explained by an excessive deviation from aerobic to anaerobic metabolism leading to excessive lactic acid accumulation and therefore accelerated decline in muscle function and prolonged recovery time. As opposed to itching, and with the exception of end-stage liver disease, fatigue is not related to disease progression. The objective of this review is to outline current understanding regarding the pathophysiology of fatigue, the role of comorbidities and contributing factors, the main tools for fatigue assessment, the failed therapeutic options, and future treatment perspectives for this disabling symptom. Since fatigue is an extremely common and debilitating symptom and there is still no licensed therapy for fatigue in PBC patients, further research is warranted to understand its causative mechanisms and to find an effective treatment.

Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: Current Knowledge of Pathogenesis and Therapeutics

Cholangiopathies encompass various biliary diseases affecting the biliary epithelium, resulting in cholestasis, inflammation, fibrosis, and ultimately liver cirrhosis. Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the most important progressive cholangiopathies in adults. Much research has broadened the scope of disease biology to genetic risk, epigenetic changes, dysregulated mucosal immunity, altered biliary epithelial cell function, and dysbiosis, all of which interact and arise in the context of ill-defined environmental triggers. An in-depth understanding of the molecular pathogenesis of these cholestatic diseases will help clinicians better prevent and treat diseases. In this review, we focus on the main underlying mechanisms of disease initiation and progression, and novel targeted therapeutics beyond currently approved treatments.

Gene Therapy for Acquired and Genetic Cholestasis

Cholestatic diseases can be caused by the dysfunction of transporters involved in hepatobiliary circulation. Although pharmacological treatments constitute the current standard of care for these diseases, none are curative, with liver transplantation being the only long-term solution for severe cholestasis, albeit with many disadvantages. Liver-directed gene therapy has shown promising results in clinical trials for genetic diseases, and it could constitute a potential new therapeutic approach for cholestatic diseases. Many preclinical gene therapy studies have shown positive results in animal models of both acquired and genetic cholestasis. The delivery of genes that reduce apoptosis or fibrosis or improve bile flow has shown therapeutic effects in rodents in which cholestasis was induced by drugs or bile duct ligation. Most studies targeting inherited cholestasis, such as progressive familial intrahepatic cholestasis (PFIC), have focused on supplementing a correct version of a mutated gene to the liver using viral or non-viral vectors in order to achieve expression of the therapeutic protein. These strategies have generated promising results in treating PFIC3 in mouse models of the disease. However, important challenges remain in translating this therapy to the clinic, as well as in developing gene therapy strategies for other types of acquired and genetic cholestasis.

Selective PPARδ agonist seladelpar suppresses bile acid synthesis by reducing hepatocyte CYP7A1 via the fibroblast growth factor 21 signaling pathway

Peroxisome proliferator–activated receptor delta (PPARδ) agonists have been shown to exert beneficial effects in liver disease and reduce total bile acid levels. The mechanism(s) whereby PPARδ agonism reduces bile acid levels are, however, unknown, and therefore the aim of the present study was to investigate the molecular pathways responsible for reducing bile acid synthesis in hepatocytes, following treatment with the selective PPARδ agonist, seladelpar. We show that administration of seladelpar to WT mice repressed the liver expression of cholesterol 7 alpha-hydroxylase (Cyp7a1), the rate-limiting enzyme for bile acid synthesis, and decreased plasma 7α-hydroxy-4-cholesten-3-one (C4), a freely diffusible metabolite downstream of Cyp7a1. In primary mouse hepatocytes, seladelpar significantly reduced the expression of Cyp7a1 independent of the nuclear bile acid receptor, Farnesoid X receptor. In addition, seladelpar upregulated fibroblast growth factor 21 (Fgf21) in mouse liver, serum, and in cultured hepatocytes. We demonstrate that recombinant Fgf21 protein activated the c-Jun N-terminal kinase (JNK) signaling pathway and repressed Cyp7a1 gene expression in primary hepatocytes. The suppressive effect of seladelpar on Cyp7a1 expression was blocked by a JNK inhibitor as well as in the absence of Fgf21, indicating that Fgf21 plays an indispensable role in PPARδ-mediated downregulation of Cyp7a1. Finally, reduction of CYP7A1 expression by seladelpar was confirmed in primary human hepatocytes. In conclusion, we show that seladelpar reduces bile acid synthesis via an FGF21-dependent mechanism that signals at least partially through JNK to repress CYP7A1.