Azathioprine for primary biliary cirrhosis

Update on Emerging Treatment Options for Primary Biliary Cholangitis

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

New Therapeutic Targets in Autoimmune Cholangiopathies

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are autoimmune cholangiopathies characterized by limited treatment options. A more accurate understanding of the several pathways involved in these diseases has fostered the development of novel and promising targeted drugs. For PBC, the characterization of the role of farnesoid X receptor (FXR) and perixosome-proliferator activated receptor (PPAR) has paved the way to several clinical trials including different molecules with choleretic and antinflammatory action. Conversely, different pathogenetic models have been proposed in PSC such as the “leaky gut” hypothesis, a dysbiotic microbiota or a defect in mechanisms protecting against bile acid toxicity. Along these theories, new treatment approaches have been developed, ranging from drugs interfering with trafficking of lymphocytes from the gut to the liver, fecal microbiota transplantation or new biliary acids with possible immunomodulatory potential. Finally, for both diseases, antifibrotic agents are under investigation. In this review, we will illustrate current understanding of molecular mechanisms in PBC and PSC, focusing on actionable biological pathways for which novel treatments are being developed.

Pharmacological interventions for primary biliary cholangitis: an attempted network meta-analysis

BACKGROUND

Primary biliary cholangitis (previously primary biliary cirrhosis) is a chronic liver disease caused by the destruction of small intra-hepatic bile ducts resulting in stasis of bile (cholestasis), liver fibrosis, and liver cirrhosis. The optimal pharmacological treatment of primary biliary cholangitis remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the treatment of primary biliary cholangitis through a network meta-analysis and to generate rankings of the available pharmacological interventions according to their safety and efficacy. However, it was not possible to assess whether the potential effect modifiers were similar across different comparisons. Therefore, we did not perform the network meta-analysis, and instead, assessed the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and randomised controlled trials registers to February 2017 to identify randomised clinical trials on pharmacological interventions for primary biliary cholangitis.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in participants with primary biliary cholangitis. We excluded trials which included participants who had previously undergone liver transplantation. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CI) using both fixed-effect and random-effects models based on available-participant analysis with Review Manager 5. We assessed risk of bias according to Cochrane, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 74 trials including 5902 participants that met the inclusion criteria of this review. A total of 46 trials (4274 participants) provided information for one or more outcomes. All the trials were at high risk of bias in one or more domains. Overall, all the evidence was low or very low quality. The proportion of participants with symptoms varied from 19.9% to 100% in the trials that reported this information. The proportion of participants who were antimitochondrial antibody (AMA) positive ranged from 80.8% to 100% in the trials that reported this information. It appeared that most trials included participants who had not received previous treatments or included participants regardless of the previous treatments received. The follow-up in the trials ranged from 1 to 96 months.The proportion of people with mortality (maximal follow-up) was higher in the methotrexate group versus the no intervention group (OR 8.83, 95% CI 1.01 to 76.96; 60 participants; 1 trial; low quality evidence). The proportion of people with mortality (maximal follow-up) was lower in the azathioprine group versus the no intervention group (OR 0.56, 95% CI 0.32 to 0.98; 224 participants; 2 trials; I² = 0%; low quality evidence). However, it has to be noted that a large proportion of participants (25%) was excluded from the trial that contributed most participants to this analysis and the results were not reliable. There was no evidence of a difference in any of the remaining comparisons. The proportion of people with serious adverse events was higher in the D-penicillamine versus no intervention group (OR 28.77, 95% CI 1.57 to 526.67; 52 participants; 1 trial; low quality evidence). The proportion of people with serious adverse events was higher in the obeticholic acid plus ursodeoxycholic acid (UDCA) group versus the UDCA group (OR 3.58, 95% CI 1.02 to 12.51; 216 participants; 1 trial; low quality evidence). There was no evidence of a difference in any of the remaining comparisons for serious adverse events (proportion) or serious adverse events (number of events). None of the trials reported health-related quality of life at any time point.

FUNDING

nine trials had no special funding or were funded by hospital or charities; 31 trials were funded by pharmaceutical companies; and 34 trials provided no information on source of funding.

AUTHORS' CONCLUSIONS

Based on very low quality evidence, there is currently no evidence that any intervention is beneficial for primary biliary cholangitis. However, the follow-up periods in the trials were short and there is significant uncertainty in this issue. Further well-designed randomised clinical trials are necessary. Future randomised clinical trials ought to be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid post-randomisation dropouts or planned cross-overs; should have sufficient follow-up period (e.g. five or 10 years or more); and use clinically important outcomes such as mortality, health-related quality of life, cirrhosis, decompensated cirrhosis, and liver transplantation. Alternatively, very large groups of participants should be randomised to facilitate shorter trial duration.

Optimal drug regimens for primary biliary cirrhosis: a systematic review and network meta-analysis

Objective

Most comprehensive treatments for PBC include UDCA, combination of methotrexate (MTX), corticosteroids (COT), colchicine (COC) or bezafibrate (BEF), cyclosporin A (CYP), D-penicillamine (DPM), methotrexate (MTX), or azathioprine (AZP). Since the optimum treatment regimen remains inconclusive, we aimed to compare these therapies in terms of patient mortality or liver transplantation (MOLT) and adverse event (AE).

Methods

We searched PubMed, Embase, Scopus and the Cochrane Library for randomized controlled trials until August 2014. We estimated HRs for MOLT and ORs for AE. The sensitivity analysis based on dose of UDCA was also performed.

Results

The search identified 49 studies involving 12 different treatment regimens and 4182 patients. Although no statistical significance can be found in MOLT, COT plus UDCA was ranked highest for efficacy outcome amongst all the treatment regimes. While for AEs, compared with OBS or UDCA, monotherapy with COC (OR 5.6, P < 0.001; OR 5.89, P < 0.001), CYP (OR 3.24, P < 0.001; OR 3.42, P < 0.001), DPM (OR 8.00, P < 0.001; OR 8.45, P < 0.001) and MTX (OR 5.31, P < 0.001; OR 5.61, P < 0.001) were associated with statistically significant increased risk of AEs. No significant differences were found for other combination regimes. Effect estimates from indirect comparisons matched closely to estimates derived from pairwise comparisons. Consistently, in the sensitivity analysis, results closely resembled our primary analysis.

Conclusions

COT plus UDCA was the most efficacious among treatment regimens both for MOLT and AEs.

Systematic review and meta-analysis: bezafibrate in patients with primary biliary cirrhosis

BACKGROUND AND AIM

Ursodeoxycholic acid (UDCA) is the standard treatment for primary biliary cirrhosis (PBC), but not all cases respond well. Evidence has shown that combination therapy of UDCA with bezafibrate significantly improved liver function. A meta-analysis was performed to assess the efficacy and safety of UDCA and bezafibrate combination therapy in the treatment of PBC.

RESULTS

Nine trials, with a total of 269 patients, were included in the analysis. The bias risk of these trials was high. Compared with UDCA alone, the combination with bezafibrate improved the Mayo risk score (mean difference [MD], 0.60; 95% confidence interval [CI], 0.25-0.95; P=0.0008) and liver biochemistry: alkaline phosphatase (MD, -238.21 IU/L; 95% CI, -280.83 to -195.60; P<0.00001); gamma-glutamyltransferase (MD, -38.23 IU/L; 95% CI, -50.16 to -25.85; P<0.00001); immunoglobulin M (MD, -128.63 IU/L; 95% CI, -151.55 to -105.71; P<0.00001); bilirubin (MD, -0.20 mg/dL; 95% CI, -0.33 to -0.07; P=0.002); triglycerides (MD, -26.84 mg/dL; 95% CI, -36.51 to -17.17; P<0.0001); total cholesterol (MD, -21.58 mg/dL; 95% CI, -30.81 to -12.34; P<0.0001), and serum alanine aminotransferase (MD, -10.24 IU/L; 95% CI, -12.65 to -78.5; P<0.00001). However, combination therapy showed no significant differences in the incidence of all-cause mortality or pruritus, and may have resulted in more adverse events (risk ratio [RR], 0.22; 95% CI, 0.07-0.67; P=0.008).

CONCLUSION

Combination therapy improved liver biochemistry and the prognosis of PBC, but did not improve clinical symptoms or incidence of death. Attention should be paid to adverse events when using bezafibrate.

Immunosuppressive therapy in immune-mediated liver disease in the non-transplanted patient

Autoimmune liver disease management goals are primarily slowing disease progression and symptomatic treatment. There are few options for curative medical management other than transplant for a spectrum of autoimmune liver disease that encompasses autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis as well as their overlap syndromes. These diseases are managed primarily with immunosuppressive therapy. Herein, we review the current literature, detailing the promise and pitfalls of the recommended immunosuppressive therapy for these challenging diseases.

Chlorambucil for patients with primary biliary cirrhosis

BACKGROUND

Chlorambucil has been used for patients with primary biliary cirrhosis as it possesses immunosuppressive properties. But it is unknown whether it benefits or harms these patients.

OBJECTIVES

To evaluate the beneficial and any harmful effects of chlorambucil for primary biliary cirrhosis patients.

SEARCH METHODS

Eligible trials were identified by searching the Cochrane Hepato-Biliary Group Controlled Trials Register (March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2012, Issue 2), MEDLINE (1946 to March 2012), EMBASE (1974 to March 2012), Science Citation Index EXPANDED (1900 to March 2012), The Chinese Biomedical Database (1976 to March 2012), The Chinese Medical Current Contents (1994 to March 2012), The China Hospital Knowledge Database (1994 to March 2012), and a database of ongoing trials (http://www.controlled-trials.com/mrct/) (accessed 6 March 2012). The reference lists of the retrieved publications and review articles were also read through, and pharmaceutical companies known to produce chlorambucil were contacted.

SELECTION CRITERIA

Randomised clinical trials, irrespective of language, year of publication, and publication status, comparing chlorambucil at any dose versus placebo, no intervention, another active drug, or one dose of chlorambucil with another dose.

DATA COLLECTION AND ANALYSIS

We planned to assess continuous data with mean differences (MD), and dichotomous outcomes with relative risk (RR), both with 95% confidence intervals (CI). As we only identified one trial, Fisher's exact tests were employed.

MAIN RESULTS

Only one randomised trial was identified and included in the review. The bias risk in the trial was high. The trial compared chlorambucil versus no intervention in 24 patients with primary biliary cirrhosis. Fisher's exact test did not show a significant reduction of mortality when comparing chlorambucil with no treatment (0/13 (0%) versus (2/11 (18.2%); P = 0.20). There was no significant difference regarding adverse events for chlorambucil compared with no treatment, but all patients receiving chlorambucil experienced adverse events (13/13 (100%) versus (3/11 (27%); P = 0.1). According to the authors of the trial, chlorambucil led to a significant improvement in mean serum levels of bilirubin (P < 0.05), albumin (P < 0.05), immunoglobulin M (P < 0.01), serum aspartate aminotransferase activity (P < 0.01), and hepatic inflammatory infiltrates (P < 0.01).

AUTHORS' CONCLUSIONS

There is not sufficient evidence to support or reject the use of chlorambucil for patients with primary biliary cirrhosis. Chlorambucil may show benefit in some unvalidated surrogate outcome measures (for example, serum bilirubin and immunoglobulin M levels). Chlorambucil is, however, connected with a number of adverse events. Bone marrow suppression should be noted in particular. Further randomised clinical trials are necessary to assess the benefits and harms of chlorambucil in this indication.

Primary biliary cirrhosis and liver transplantation

Primary biliary cirrhosis (PBC) is an immune-mediated chronic progressive inflammatory liver disease, predominantly affecting middle-aged women, characterized by the presence of antimitochondrial antibodies (AMAs), which can lead to liver failure. Genetic contributions, environmental factors including chemical and infectious xenobiotics, autoimmunity and loss of tolerance have been aggressively investigated in the pathogenesis of PBC, however, the actual impact of these factors is still controversial. Survival of PBC patients has been largely improved with the widespread use of ursodeoxycholic acid (UDCA), however, one third of patients still do not respond to the treatment and proceed to liver cirrhosis, requiring liver transplantation as a last resort for cure. The outcome of liver transplantation is excellent with 5- and 10-year survival rates around 80% and 70%, respectively, while along with long survival, the recurrence of the disease has become an important outcome after liver transplantation. Prevalence rates of recurrent PBC rage widely between 1% and 35%, and seem to increase with longer follow-up. Center-specific issues, especially the use of protocol biopsy, affect the variety of incidence, yet, recurrence itself does not affect patient and graft survival at present, and retransplantation due to recurrent disease is extremely rare. With a longer follow-up, recurrent disease could have an impact on patient and graft survival.

Hepatology may have problems with putative surrogate outcome measures

A surrogate outcome measure is a laboratory measurement, a physical sign, or another intermediate substitute that is able to predict an intervention's effect on a clinically meaningful outcome. A clinical outcome detects how a patient feels, functions, or survives. Surrogate outcome measures occur faster or more often, are cheaper, and/or are less invasively achieved than the clinical outcome. In practice, validation is surprisingly often overlooked, especially if a biologic plausible rationale is proposed. Surrogate outcomes must be validated before use. The first step in validation is to demonstrate a correlation between the putative surrogate and the clinical outcome, e.g., the higher the surrogate the shorter time to death. However, a correlation is not sufficient to validate the surrogate. The second step is to establish if the intervention's effect on the surrogate outcome accurately predicts the intervention's effect on the clinical outcome. In hepatology a number of putative surrogate outcomes are used both in clinical research and in clinical practice without having been properly validated. Sustained virological response to interferons and ribavirin in patients with chronic hepatitis C, serum bilirubin concentration following ursodeoxycholic acid or immunosuppressants for patients with primary biliary cirrhosis, and nutritional outcomes following artificial nutrition for liver patients may not be valid surrogates for morbidity or mortality. The challenge is to develop reliable surrogates, both to facilitate the development of new interventions and to ensure our patients and us that these interventions are effective clinically.