New treatments/targets for primary biliary cholangitis

Setanaxib, a first-in-class selective NADPH oxidase 1/4 inhibitor for primary biliary cholangitis: A randomized, placebo-controlled, phase 2 trial

BACKGROUND

Primary biliary cholangitis (PBC) is a rare liver disease with significant unmet need for second-line/add-on treatments. Setanaxib, a NOX1/4 inhibitor, has shown anti-fibrotic effects in in vitro and animal studies. This phase 2, randomized, multicentre study investigated the efficacy and safety of setanaxib in patients with PBC.

METHODS

Patients with ≥6 months of ursodeoxycholic acid (UDCA) treatment were randomized 1:1:1 to oral setanaxib 400 mg once daily (OD), twice daily (BID), or placebo, in addition to UDCA for 24 weeks. Other inclusion criteria included alkaline phosphatase (ALP) ≥1.5 × ULN and gamma-glutamyl transferase (GGT) ≥1.5 × ULN. The primary endpoint was percentage change from baseline in GGT at Week 24; secondary endpoints included change from baseline in ALP, liver stiffness (LS; via transient elastography), fatigue at Week 24, and safety outcomes. p values compare setanaxib 400 mg BID and placebo groups.

RESULTS

Of patients randomized (setanaxib 400 mg OD and BID: 38, and 36; placebo: 37), 104/111 completed Week 24. Mean (standard deviation [SD]) change in GGT to Week 24 was -4.9% (59.6%) for setanaxib 400 mg OD, -19.0% (28.9%) for setanaxib 400 mg BID, and -8.4% (21.5%) for placebo; p = .31. Patients treated with setanaxib 400 mg OD and BID showed decreased serum ALP levels from baseline to Week 24 (p = .002: setanaxib BID versus placebo). Patients treated with setanaxib 400 mg OD and BID showed mean (SD) percentage increases in LS to Week 24 of 3.3% (35.0%) and 7.9% (43.7%), versus 10.1% (33.1%) for placebo (p = .65). Changes in mean (SD) PBC-40 fatigue domain scores to Week 24 were +0.3% (24.9%) for setanaxib 400 mg OD, -9.9% (19.8%) for setanaxib 400 mg BID and +2.4% (23.1%) for placebo, p = .027. Two patients (one placebo, one setanaxib 400 mg BID) experienced serious treatment-emergent adverse events, deemed unrelated to study drug.

CONCLUSIONS

The primary endpoint was not met. However, the secondary endpoints provide preliminary evidence for potential anti-cholestatic and anti-fibrotic effects in PBC, supporting the further evaluation of setanaxib in a future phase 2b/3 trial.

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

Introduction

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

Expert opinion

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

Feasibility, safety and tolerability of the CREB-binding protein/β-catenin inhibitor OP-724 in patients with advanced primary biliary cholangitis: an investigator-initiated, open-label, non-randomised, two-centre, phase 1 study

Objective

This study aimed to evaluate the safety and tolerability of OP-724, a CREB-binding protein/β-catenin inhibitor, in patients with advanced primary biliary cholangitis (PBC).

Design

An open-label, non-randomised, phase 1 trial was conducted at two hospitals in Japan. Patients with advanced PBC classified as stage III or higher according to the Scheuer classification by liver biopsy between 4 September 2019 and 21 September 2021 were enrolled. Seven patients received intravenous OP-724 infusions at escalating dosages of 280 and 380 mg/m2/4 hours two times weekly for 12 weeks. The primary endpoint was the incidence of serious adverse events (SAEs). The secondary endpoints were the incidence of AEs and the improvement in the modified Histological Activity Index (mHAI) score.

Results

Seven patients (median age, 68 years) were enrolled. Of these seven patients, five completed twelve cycles of treatment, one discontinued prematurely for personal reasons in the 280 mg/m2/4 hours cohort, and one in the 380 mg/m2/4 hours cohort was withdrawn from the study due to drug-induced liver injury (grade 2). Consequently, the recommended dosage was determined to be 280 mg/m2/4 hours. SAEs did not occur. The most common AEs were abdominal discomfort (29%) and abnormal hepatic function (43%). OP-724 treatment was associated with histological improvements in the fibrosis stage (2/5 (40%)) and mHAI score (3/5 (60%)) on histological analysis.

Conclusion

Administration of intravenous OP-724 infusion at a dosage of 280 mg/m2/4 hours two times weekly for 12 weeks was well tolerated by patients with advanced PBC. However, further evaluation of antifibrotic effects in patients with PBC is warranted.

Trial registration number

NCT04047160.

Evaluation and Management of Pruritus in Primary Biliary Cholangitis

Chronic pruritus is a classic symptom in patients with primary biliary cholangitis. It affects up to two-thirds of patients in the course of the disease. Efficient therapy consists of topical treatment combined with systemic options such as anion exchangers, rifampicin, bezafibrate, μ-opioid receptor antagonists, selective-serotonin receptor uptake inhibitors, and gabapentinoids. Future therapeutic approaches may contain the selective blockade of the enterohepatic cycle by inhibiting the ileal bile acid transporter, the agonism at κ-opioid receptors, and antagonism of the mas-related G protein-coupled receptor X4. As nondrug treatment, ultraviolet B therapy, albumin dialysis, and biliary drainage are available at specialized centers.

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.

Clinical Patterns of Primary Biliary Cholangitis: Comparison Between Two European Case Series

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic liver disease characterized by progressive destruction of the intrahepatic bile ducts, followed by fibrous substitution of the ducts and potential evolution in cirrhosis. The geographical disparity in the prevalence of PBC suggests a possible role of environmental factors in developing the disease. We analyzed two groups of patients with different geographical prevalence.

METHODS

This study concerned the analysis of 14 Caucasian patients in two groups: ten patients enrolled in the Digestive Diseases Unit, University of Catanzaro (Italy), and four patients enrolled in the Department of Hepatology, University Hospital Kràlovskè Vinohrady of Prague (Czech Republic). The statistical analysis was performed using the software IBM SPSS (v. 20, Windows).

RESULTS

The Italian group showed a statistically significant difference in the total bilirubin values at diagnosis and during the last control (0.74±0.267 vs. 0.56±0.246; p-value: 0.013). Moreover, the comparison between the two groups showed a statistically significant difference in the serum albumin values at the time of the last control (4.6±0.231 vs. 4.15±0.532; p-value: 0.048).

CONCLUSION

Our data indicate an effective difference in the onset and clinical presentation between our two groups. More epidemiologic, prospective, and multicenter research projects are warranted to advance PBC knowledge in Europe.

Future challenges in gastroenterology and hepatology, between innovations and unmet needs: A SIGE Young Editorial Board's perspective

Gastroenterology, Digestive Endoscopy and Hepatology have faced significant improvements in terms of diagnosis and therapy in the last decades. However, many fields still remain poorly explored, and many questions unanswered. Moreover, basic-science, as well as translational and clinical discoveries, together with technology advancement will determine further steps toward a better, refined care for many gastroenterological disorders in the future. Therefore, the Young Investigators of the Italian Society of Gastroenterology (SIGE) joined together, offering a perspective on major future innovations in some hot clinical topics in Gastroenterology, Endoscopy, and Hepatology, as well as the current pitfalls and the grey zones.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LAY SUMMARY

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

Primary biliary cholangitis: pathogenic mechanisms

PURPOSE OF REVIEW

Primary biliary cholangitis (PBC) is characterized by autoimmune damage of intrahepatic bile ducts associated with a loss of tolerance to mitochondrial antigens. PBC etiopathogenesis is intriguing because of different perplexing features, namely: a) although mitochondria are present in all cell types and tissues, the damage is mainly restricted to biliary epithelial cells (BECs); b) despite being an autoimmune disorder, it does not respond to immunosuppressive drugs but rather to ursodeoxycholic acid, a bile salt that induces HCO3- rich choleresis; c) the overwhelming female preponderance of the disease remains unexplained. Here we present an etiopathogenic view of PBC which sheds light on these puzzling facts of the disease.

RECENT FINDINGS

PBC develops in patients with genetic predisposition to autoimmunity in whom epigenetic mechanisms silence the Cl-/HCO3- exchanger AE2 in both cholangiocytes and lymphoid cells. Defective AE2 function can produce BECs damage as a result of decreased biliary HCO3- secretion with disruption of the protective alkaline umbrella that normally prevents the penetration of toxic apolar bile salts into cholangiocytes. AE2 dysfunction also causes increased intracellular pH (pHi) in cholangiocytes, leading to the activation of soluble adenylyl cyclase, which sensitizes BECs to bile salt-induced apoptosis. Recently, mitophagy was found to be inhibited by cytosolic alkalization and stimulated by acidification. Accordingly, we propose that AE2 deficiency may disturb mitophagy in BECs, thus, promoting the accumulation of defective mitochondria, oxidative stress and presentation of mitochondrial antigens to the immune cells. As women possess a more acidic endolysosomal milieu than men, mitophagy might be more affected in women in an AE2-defective background. Apart from affecting BECs function, AE2 downregulation in lymphocytes may also contribute to alter immunoregulation facilitating autoreactive T-cell responses.

SUMMARY

PBC can be considered as a disorder of Cl-/HCO3- exchange in individuals with genetic predisposition to autoimmunity.

Insights Into the Involvement of Circular RNAs in Autoimmune Diseases

Circular RNAs (circRNAs) are single-stranded, endogenous, non-coding RNA (ncRNA) molecules formed by the backsplicing of messenger RNA (mRNA) precursors and have covalently closed circular structures without 5′-end caps and 3′-end polyadenylation [poly(A)] tails. CircRNAs are characterized by abundant species, stable structures, conserved sequences, cell- or tissue-specific expression, and widespread and stable presence in many organisms. Therefore, circRNAs can be used as biomarkers for the prediction, diagnosis, and treatment of a variety of diseases. Autoimmune diseases (AIDs) are caused by defects in immune tolerance or abnormal immune regulation, which leads to damage to host organs. Due to the complexity of the pathophysiological processes of AIDs, clinical therapeutics have been suboptimal. The emergence of circRNAs sheds new light on the treatment of AIDs. In particular, circRNAs mainly participate in the occurrence and development of AIDs by sponging targets. This review systematically explains the formation, function, mechanism, and characteristics of circRNAs in the context of AIDs. With a deeper understanding of the pathophysiological functions of circRNAs in the pathogenesis of AIDs, circRNAs may become reasonable, accurate, and effective biomarkers for the diagnosis and treatment of AIDs in the future.

Comprehensive assessment of ECM turnover using serum biomarkers establishes PBC as a high-turnover autoimmune liver disease

Background & Aims

Primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) are phenotypically distinct autoimmune liver diseases that progress to cirrhosis and liver failure; however, their histological fibrosis distribution differs. We investigated the extracellular matrix (ECM) profiles of patients with PSC, PBC, and AIH to establish whether the diseases display differential patterns of ECM turnover.

Methods

Serum samples were retrospectively collected from the UK (test cohort; PSC n = 78; PBC n = 74; AIH n = 58) and Norway (validation cohort; PSC n = 138; PBC n = 28; AIH n = 27). Patients with ulcerative colitis without liver disease (n = 194) served as controls. We assessed specific serological biomarkers of ECM turnover: type III and V collagen formation (PRO-C3, PRO-C5), degradation of type III and IV collagen (C3M, C4M), biglycan (BGM) and citrullinated vimentin (VICM).

Results

Most of the ECM markers showed elevated serum levels in PBC compared with PSC or AIH (p <0.01). PRO-C3 correlated well with liver stiffness and showed the most striking differences between advanced and non-advanced liver disease; several of the other ECM markers were also associated with stage. PRO-C3 and other ECM markers were inversely associated with ursodeoxycholic acid treatment response in PBC and remission in AIH. All ECM remodelling markers were significantly elevated (p <0.05) in patients with PSC, PBC, or AIH compared with ulcerative colitis.

Conclusions

In this first study comparing ECM turnover in autoimmune liver diseases, we found increased ECM turnover in PBC compared with either PSC or AIH. The study indicates that ECM remodelling is different in PSC, PBC, and AIH, suggesting differing opportunities for therapeutic intervention.

Lay summary

The level of scarring is linked to prognosis in autoimmune liver diseases such as primary sclerosing cholangitis, primary biliary cholangitis, and autoimmune hepatitis; hence, the scarring process is a possible target for novel therapy. Investigating the scarring process using highly specific technology, we show that the scarring process is different between the 3 autoimmune liver diseases, and this may have important implications for the development of medical treatment.

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Serological biomarkers specifically targeting extracellular matrix remodelling enable evaluation of the dynamics of fibrosis evolution.

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ECM turnover was increased in PBC compared with PSC and AIH.

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ECM markers, particularly PRO-C3, were associated with disease stage in the autoimmune liver diseases and with clinical outcome in PSC.