Potent suppression of hydrophobic bile acids by aldafermin, an FGF19 analogue, across metabolic and cholestatic liver diseases

Background & Aims

Higher serum bile acid levels are associated with an increased risk of cirrhosis and liver-related morbidity and mortality. Herein, we report secondary analyses of aldafermin, an engineered analogue of the gut hormone fibroblast growth factor 19, on the circulating bile acid profile in prospective, phase II studies in patients with metabolic or cholestatic liver disease.

Methods

One hundred and seventy-six patients with biopsy-confirmed non-alcoholic steatohepatitis (NASH) and fibrosis and elevated liver fat content (≥8% by magnetic resonance imaging-proton density fat fraction) received 0.3 mg (n = 23), 1 mg (n = 49), 3 mg (n = 49), 6 mg (n = 28) aldafermin or placebo (n = 27) for 12 weeks. Sixty-two patients with primary sclerosing cholangitis (PSC) and elevated alkaline phosphatase (>1.5× upper limit of normal) received 1 mg (n = 21), 3 mg (n = 21) aldafermin or placebo (n = 20) for 12 weeks. Serum samples were collected on day 1 and week 12 for determination of bile acid profile and neoepitope-specific N-terminal pro-peptide of type III collagen (Pro-C3), a direct measure of fibrogenesis.

Results

Treatment with aldafermin resulted in significant dose-dependent reductions in serum bile acids. In particular, bile acids with higher hydrophobicity indices, such as deoxycholic acid, lithocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, and glycocholic acid, were markedly lowered by aldafermin in both NASH and PSC populations. Moreover, aldafermin predominantly suppressed the glycine-conjugated bile acids, rather than the taurine-conjugated bile acids. Changes in levels of bile acids correlated with changes in the novel fibrogenesis marker Pro-C3, which detects a neo-epitope of the type III collagen during its formation, in the pooled NASH and PSC populations.

Conclusions

Aldafermin markedly reduced major hydrophobic bile acids that have greater detergent activity and cytotoxicity. Our data provide evidence that bile acids may contribute to sustaining a pro-fibrogenic microenvironment in the liver across metabolic and cholestatic liver diseases.

Lay summary

Aldafermin is an analogue of a gut hormone, which is in development as a treatment for patients with chronic liver disease. Herein, we show that aldafermin can potently and robustly suppress the toxic, hydrophobic bile acids irrespective of disease aetiology. The therapeutic strategy utilising aldafermin may be broadly applicable to other chronic gastrointestinal and liver disorders.

Clinical Trials Registration

The study is registered at Clinicaltrials.govNCT02443116 and NCT02704364.

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Higher serum bile acid levels are associated with an increased risk of liver-related morbidity and mortality.

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Aldafermin produces significant dose-dependent reductions in toxic hydrophobic bile acids in NASH and PSC.

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Changes in bile acids correlate with changes in the novel fibrogenesis marker Pro-C3.

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Bile acids may contribute to a pro-fibrogenic microenvironment in the liver.

NASH-related increases in plasma bile acid levels depend on insulin resistance

Background & Aims

Plasma bile acids (BAs) have been extensively studied as pathophysiological actors in non-alcoholic steatohepatitis (NASH). However, results from clinical studies are often complicated by the association of NASH with type 2 diabetes (T2D), obesity, and insulin resistance (IR). Here, we sought to dissect the relationship between NASH, T2D, and plasma BA levels in a large patient cohort.

Methods

Four groups of patients from the Biological Atlas of Severe Obesity (ABOS) cohort (Clinical Trials number NCT01129297) were included based on the presence or absence of histologically evaluated NASH with or without coincident T2D. Patients were matched for BMI, homeostatic model assessment 2 (HOMA2)-assessed IR, glycated haemoglobin, age, and gender. To study the effect of IR and BMI on the association of plasma BA and NASH, patients from the HEPADIP study were included. In both cohorts, fasting plasma BA concentrations were measured.

Results

Plasma BA concentrations were higher in NASH compared with No-NASH patients both in T2D and NoT2D patients from the ABOS cohort. As we previously reported that plasma BA levels were unaltered in NASH patients of the HEPADIP cohort, we assessed the impact of BMI and IR on the association of NASH and BA on the combined BA datasets. Our results revealed that NASH-associated increases in plasma total cholic acid (CA) concentrations depend on the degree of HOMA2-assessed systemic IR, but not on β-cell function nor on BMI.

Conclusions

Plasma BA concentrations are elevated only in those NASH patients exhibiting pronounced IR.

Lay summary

Non-alcoholic steatohepatitis (NASH) is a progressive liver disease that frequently occurs in patients with obesity and type 2 diabetes. Reliable markers for the diagnosis of NASH are needed. Plasma bile acids have been proposed as NASH biomarkers. Herein, we found that plasma bile acids are only elevated in patients with NASH when significant insulin resistance is present, limiting their utility as NASH markers.

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Bile acids have been studied as pathophysiological actors and biomarkers in NASH.

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Plasma BAs have been reported to be higher in NASH vs. No-NASH patients.

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Plasma BAs are altered in patients with T2D, IR, and obesity, risk factors for NASH.

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Thus, the independent association between plasma BA increases and NASH is unclear.

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NASH-associated increases in plasma BA depend on the degree of insulin sensitivity.

Ablation of gut microbiota alleviates obesity-induced hepatic steatosis and glucose intolerance by modulating bile acid metabolism in hamsters

Since metabolic process differs between humans and mice, studies were performed in hamsters, which are generally considered to be a more appropriate animal model for studies of obesity-related metabolic disorders. The modulation of gut microbiota, bile acids and the farnesoid X receptor (FXR) axis is correlated with obesity-induced insulin resistance and hepatic steatosis in mice. However, the interactions among the gut microbiota, bile acids and FXR in metabolic disorders remained largely unexplored in hamsters. In the current study, hamsters fed a 60% high-fat diet (HFD) were administered vehicle or an antibiotic cocktail by gavage twice a week for four weeks. Antibiotic treatment alleviated HFD-induced glucose intolerance, hepatic steatosis and inflammation accompanied with decreased hepatic lipogenesis and elevated thermogenesis in subcutaneous white adipose tissue (sWAT). In the livers of antibiotic-treated hamsters, cytochrome P450 family 7 subfamily B member 1 (CYP7B1) in the alternative bile acid synthesis pathway was upregulated, contributing to a more hydrophilic bile acid profile with increased tauro-β-muricholic acid (TβMCA). The intestinal FXR signaling was suppressed but remained unchanged in the liver. This study is of potential translational significance in determining the role of gut microbiota-mediated bile acid metabolism in modulating diet-induced glucose intolerance and hepatic steatosis in the hamster.

Pharmacometabolomic prediction of individual differences of gastrointestinal toxicity complicating myelosuppression in rats induced by irinotecan

Pharmacometabolomics has been already successfully used in toxicity prediction for one specific adverse effect. However in clinical practice, two or more different toxicities are always accompanied with each other, which puts forward new challenges for pharmacometabolomics. Gastrointestinal toxicity and myelosuppression are two major adverse effects induced by Irinotecan (CPT-11), and often show large individual differences. In the current study, a pharmacometabolomic study was performed to screen the exclusive biomarkers in predose serums which could predict late-onset diarrhea and myelosuppression of CPT-11 simultaneously. The severity and sensitivity differences in gastrointestinal toxicity and myelosuppression were judged by delayed-onset diarrhea symptoms, histopathology examination, relative cytokines and blood cell counts. Mass spectrometry-based non-targeted and targeted metabolomics were conducted in sequence to dissect metabolite signatures in predose serums. Eventually, two groups of metabolites were screened out as predictors for individual differences in late-onset diarrhea and myelosuppression using binary logistic regression, respectively. This result was compared with existing predictors and validated by another independent external validation set. Our study indicates the prediction of toxicity could be possible upon predose metabolic profile. Pharmacometabolomics can be a potentially useful tool for complicating toxicity prediction. Our findings also provide a new insight into CPT-11 precision medicine.