Cilofexor in Patients with Compensated Cirrhosis Due to Primary Sclerosing Cholangitis: an Open-label Phase 1B Study.

OBJECTIVES: This proof-of-concept, open-label phase 1b study evaluated the safety and efficacy of cilofexor, a potent selective farnesoid X receptor agonist, in patients with compensated cirrhosis due to primary sclerosing cholangitis (PSC). METHODS: Escalating doses of cilofexor (30 mg [weeks 1-4], 60 mg [weeks 5-8], 100 mg [weeks 9-12]) were administered orally once daily over 12 weeks. The primary endpoint was safety. Exploratory measures included cholestasis and fibrosis markers, and pharmacodynamic biomarkers of bile acid homeostasis. RESULTS: Eleven patients were enrolled (median age: 48 years; 55% men). The most common treatment-emergent adverse events (TEAEs) were pruritus (8/11 [72.7%]), fatigue, headache, nausea, and upper respiratory tract infection (2/11 [18.2%] each). Seven patients experienced a pruritus TEAE (one grade 3) considered drug related. One patient temporarily discontinued cilofexor owing to peripheral edema. There were no deaths, serious TEAEs, or TEAEs leading to permanent discontinuation. Median changes (interquartile ranges) from baseline to week 12 (predose, fasting) were -24.8% (-35.7, -7.4) for alanine transaminase, -13.0% (-21.9, -8.6) for alkaline phosphatase, -43.5% (-52.1, -30.8) for gamma-glutamyl transferase, -12.7% (-25.0, 0.0) for total bilirubin, and -21.2% (-40.0, 0.0) for direct bilirubin. Least-squares mean percentage change (95% confidence interval) from baseline to week 12 at trough was -55.3% (-70.8, -31.6) for C4 and -60.5% (-81.8, -14.2) for cholic acid. Fasting fibroblast growth factor 19 levels transiently increased after cilofexor administration. CONCLUSIONS: Escalating doses of cilofexor over 12 weeks were well tolerated and improved cholestasis markers in patients with compensated cirrhosis due to PSC (NCT04060147).

AI-based histologic scoring enables automated and reproducible assessment of enrollment criteria and endpoints in NASH clinical trials.

Clinical trials in nonalcoholic steatohepatitis (NASH) require histologic scoring for assessment of inclusion criteria and endpoints. However, guidelines for scoring key features have led to variability in interpretation, impacting clinical trial outcomes. We developed an artificial intelligence (AI)-based measurement (AIM) tool for scoring NASH histology (AIM-NASH). AIM-NASH predictions for NASH Clinical Research Network (CRN) grades of necroinflammation and stages of fibrosis aligned with expert consensus scores and were reproducible. Continuous scores produced by AIM-NASH for key histological features of NASH correlated with mean pathologist scores and with noninvasive biomarkers and strongly predicted patient outcomes. In a retrospective analysis of the ATLAS trial, previously unmet pathological endpoints were met when scored by the AIM-NASH algorithm alone. Overall, these results suggest that AIM-NASH may assist pathologists in histologic review of NASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient therapeutic response.

Integration of deep learning-based histopathology and transcriptomics reveals key genes associated with fibrogenesis in patients with advanced NASH.

Nonalcoholic steatohepatitis (NASH) is the most common chronic liver disease globally and a leading cause for liver transplantation in the US. Its pathogenesis remains imprecisely defined. We combined two high-resolution modalities to tissue samples from NASH clinical trials, machine learning (ML)-based quantification of histological features and transcriptomics, to identify genes that are associated with disease progression and clinical events. A histopathology-driven 5-gene expression signature predicted disease progression and clinical events in patients with NASH with F3 (pre-cirrhotic) and F4 (cirrhotic) fibrosis. Notably, the Notch signaling pathway and genes implicated in liver-related diseases were enriched in this expression signature. In a validation cohort where pharmacologic intervention improved disease histology, multiple Notch signaling components were suppressed.

PRIMIS: design of a pivotal, randomized, phase 3 study evaluating the safety and efficacy of the nonsteroidal farnesoid X receptor agonist cilofexor in noncirrhotic patients with primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic progressive liver disease leading to biliary fibrosis and cirrhosis. Cilofexor is a nonsteroidal farnesoid X receptor agonist that demonstrated significant improvements in liver biochemistry and markers of cholestasis in patients with PSC in a phase 2 study. We describe here the rationale, design, and implementation of the phase 3 PRIMIS trial, the largest placebo-controlled trial in PSC. METHODS: Adults with large-duct PSC without cirrhosis are randomized 2:1 to receive oral cilofexor 100 mg once daily or placebo for up to 96 weeks during the blinded phase. Patients completing the blinded phase are eligible to receive open-label cilofexor 100 mg daily for up to 96 weeks. The primary objective is to evaluate whether cilofexor reduces the risk of fibrosis progression compared with placebo. Liver biopsy is performed at screening and Week 96 of the blinded phase for histologic assessment of fibrosis. The primary endpoint-chosen in conjunction with guidance from the U.S. Food and Drug Administration-is the proportion of patients with ≥ 1-stage increase in fibrosis according to Ludwig histologic classification at week 96. Secondary objectives include evaluation of changes in liver biochemistry, serum bile acids, liver fibrosis assessed by noninvasive methods, health-related quality of life, and safety of cilofexor. CONCLUSION: The phase 3 PRIMIS study is the largest randomized, double-blind, placebo-controlled trial in PSC to date and will allow for robust evaluation of the efficacy and safety of cilofexor in noncirrhotic patients with large-duct PSC. TRIAL REGISTRATION: ClinicalTrials.gov NCT03890120; registered 26/03/2019.

Liver stiffness thresholds to predict disease progression and clinical outcomes in bridging fibrosis and cirrhosis.

OBJECTIVE: In retrospective studies, liver stiffness (LS) by vibration-controlled transient elastography (VCTE) is associated with the risk of liver decompensation in patients with non-alcoholic steatohepatitis (NASH), but prospective data in biopsy-confirmed cohorts with advanced fibrosis are limited. We aimed to establish thresholds for LS by VCTE that predict progression to cirrhosis among patients with bridging fibrosis and hepatic decompensation among patients with cirrhosis due to NASH. DESIGN: We used data from four randomised placebo-controlled trials of selonsertib and simtuzumab in participants with advanced fibrosis (F3-F4). The trials were discontinued due to lack of efficacy. Liver fibrosis was staged centrally at baseline and week 48 (selonsertib study) or week 96 (simtuzumab study). Associations between LS by VCTE with disease progression were determined using Cox proportional hazards regression analysis. RESULTS: Progression to cirrhosis occurred in 16% (103/664) of participants with bridging fibrosis and adjudicated liver-related events occurred in 4% (27/734) of participants with baseline cirrhosis. The optimal baseline LS thresholds were ≥16.6 kPa for predicting progression to cirrhosis, and ≥30.7 kPa for predicting liver-related events. Baseline LS ≥16.6 kPa (adjusted HR 3.99; 95% CI 2.66 to 5.98, p<0.0001) and a ≥5 kPa (and ≥20%) increase (adjusted HR 1.98; 95% CI 1.20 to 3.26, p=0.008) were independent predictors of progression to cirrhosis in participants with bridging fibrosis, while baseline LS ≥30.7 kPa (adjusted HR 10.13, 95% CI 4.38 to 23.41, p<0.0001) predicted liver-related events in participants with cirrhosis. CONCLUSION: The LS thresholds identified in this study may be useful for risk stratification of NASH patients with advanced fibrosis.

Acetyl-CoA carboxylase inhibitor increases LDL-apoB production rate in NASH with cirrhosis: prevention by fenofibrate.

Treatment with acetyl-CoA carboxylase inhibitors (ACCi) in nonalcoholic steatohepatitis (NASH) may increase plasma triglycerides (TGs), with variable changes in apoB concentrations. ACC is rate limiting in de novo lipogenesis and regulates fatty acid oxidation, making it an attractive therapeutic target in NASH. Our objectives were to determine the effects of the ACCi, firsocostat, on production rates of plasma LDL-apoB in NASH and the effects of combined therapy with fenofibrate. Metabolic labeling with heavy water and tandem mass spectrometric analysis of LDL-apoB enrichments was performed in 16 NASH patients treated with firsocostat for 12 weeks and in 29 NASH subjects treated with firsocostat and fenofibrate for 12 weeks. In NASH on firsocostat, plasma TG increased significantly by 17% from baseline to week 12 (P = 0.0056). Significant increases were also observed in LDL-apoB fractional replacement rate (baseline to week 12: 31 ± 20.2 to 46 ± 22.6%/day, P = 0.03) and absolute synthesis rate (ASR) (30.4-45.2 mg/dl/day, P = 0.016) but not plasma apoB concentrations. The effect of firsocostat on LDL-apoB ASR was restricted to patients with cirrhosis (21.0 ± 9.6 at baseline and 44.2 ± 17 mg/dl/day at week 12, P = 0.002, N = 8); noncirrhotic patients did not change (39.8 ± 20.8 and 46.3 ± 14.8 mg/dl/day, respectively, P = 0.51, N = 8). Combination treatment with fenofibrate and firsocostat prevented increases in plasma TG, LDL-apoB fractional replacement rate, and ASR. In summary, in NASH with cirrhosis, ACCi treatment increases LDL-apoB100 production rate and this effect can be prevented by concurrent fenofibrate therapy.

Fenofibrate Mitigates Hypertriglyceridemia in Nonalcoholic Steatohepatitis Patients Treated With Cilofexor/Firsocostat.

BACKGROUND & AIMS: Patients with advanced fibrosis due to nonalcoholic steatohepatitis (NASH) are at high risk of morbidity and mortality. We previously found that a combination of the farnesoid X receptor agonist cilofexor (CILO) and the acetyl-CoA carboxylase inhibitor firsocostat (FIR) improved liver histology and biomarkers in NASH with advanced fibrosis but was associated with hypertriglyceridemia. We evaluated the safety and efficacy of icosapent ethyl (Vascepa) and fenofibrate to mitigate triglyceride elevations in patients with NASH treated with CILO and FIR. METHODS: Patients with NASH with elevated triglycerides (≥150 and <500 mg/dL) were randomized to Vascepa 2 g twice daily (n = 33) or fenofibrate 145 mg daily (n = 33) for 2 weeks, followed by the addition of CILO 30 mg and FIR 20 mg daily for 6 weeks. Safety, lipids, and liver biochemistry were monitored. RESULTS: All treatments were well-tolerated; most treatment-emergent adverse events were Grade 1 to 2 severity, and there were no discontinuations due to adverse events. At baseline, median (interquartile range [IQR]) triglycerides were similar in the Vascepa and fenofibrate groups (median, 177 [IQR, 154-205] vs 190 [IQR, 144-258] mg/dL, respectively). Median changes from baseline in triglycerides for Vascepa vs fenofibrate after 2 weeks of pretreatment were -12 mg/dL (IQR, -33 to 7 mg/dL; P = .09) vs -32 mg/dL (IQR, -76 to 6 mg/dL; P = .012) and at 6 weeks were +41 mg/dL (IQR, 16-103 mg/dL; P < .001) vs -2 mg/dL (IQR, -42 to 54 mg/dL; P = .92). In patients with baseline triglycerides <250 mg/dL, fenofibrate was more effective vs Vascepa in mitigating triglyceride increases after 6 weeks of combination treatment (+6 vs +39 mg/dL); similar trends were observed in patients with baseline triglycerides ≥250 mg/d (-61 vs +99 mg/dL). CONCLUSIONS: In patients with NASH with hypertriglyceridemia treated with CILO and FIR, fenofibrate was safe and effectively mitigated increases in triglycerides associated with acetyl-CoA carboxylase inhibition. CLINICALTRIALS: gov, Number: NCT02781584.

IL-31 levels correlate with pruritus in patients with cholestatic and metabolic liver diseases and is farnesoid X receptor responsive in NASH.

BACKGROUND AND AIMS: Pruritus is associated with multiple liver diseases, particularly those with cholestasis, but the mechanism remains incompletely understood. Our aim was to evaluate serum IL-31 as a putative biomarker of pruritus in clinical trials of an farnesoid X receptor (FXR) agonist, cilofexor, in patients with NASH, primary sclerosing cholangitis (PSC), and primary biliary cholangitis (PBC). APPROACH AND RESULTS: Serum IL-31 was measured in clinical studies of cilofexor in NASH, PSC, and PBC. In patients with PSC or PBC, baseline IL-31 was elevated compared to patients with NASH and healthy volunteers (HVs). IL-31 correlated with serum bile acids among patients with NASH, PBC, and PSC. Baseline IL-31 levels in PSC and PBC were positively correlated with Visual Analog Scale for pruritus and 5-D itch scores. In patients with NASH, cilofexor dose-dependently increased IL-31 from Week (W)1 to W24. In patients with NASH receiving cilofexor 100 mg, IL-31 was higher in those with Grade 2-3 pruritus adverse events (AEs) than those with Grade 0-1 pruritus AEs. IL-31 weakly correlated with C4 at baseline in patients with NASH, and among those receiving cilofexor 100 mg, changes in IL-31 and C4 from baseline to W24 were negatively correlated. IL-31 messenger RNA (mRNA) was elevated in hepatocytes from patients with PSC and NASH compared to HVs. In a humanized liver murine model, obeticholic acid increased IL-31 mRNA expression in human hepatocytes and serum levels of human IL-31. CONCLUSIONS: IL-31 levels correlate with pruritus in patients with cholestatic disease and NASH, with FXR agonist therapy resulting in higher serum levels in the latter group. IL-31 appears to derive in part from increased hepatocyte expression. These findings have therapeutic implications for patients with liver disease and pruritus.

Safety and Sustained Efficacy of the Farnesoid X Receptor (FXR) Agonist Cilofexor Over a 96-Week Open-label Extension in Patients With PSC.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is a major unmet medical need in clinical hepatology. Cilofexor is a nonsteroidal farnesoid X receptor agonist being evaluated for the treatment of PSC. Here, we describe the safety and preliminary efficacy of cilofexor in a 96-week, open-label extension (OLE) of a phase II trial. METHODS: Noncirrhotic subjects with large-duct PSC who completed the 12-week, blinded phase of a phase II study (NCT02943460) were eligible, after a 4-week washout period, for a 96-week OLE with cilofexor 100 mg daily. Safety, liver biochemistry, and serum markers of fibrosis, cellular injury, and pharmacodynamic effects of cilofexor (fibroblast growth factor 19, C4, and bile acids [BAs]) were evaluated. RESULTS: Among 52 subjects enrolled in the phase II study, 47 (90%) continued in the OLE phase (median age, 44 years; 60% male patients, 60% with inflammatory bowel disease, and 45% on ursodeoxycholic acid [UDCA]). At OLE baseline (BL), the median serum alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) were 368 U/L (interquartile range [IQR], 277-468 U/L) and 417 U/L (IQR, 196-801 U/L), respectively. Of the 47 subjects enrolled, 15 (32%) discontinued treatment prematurely (pruritus [n = 5], other adverse events [n = 5], subject decision/investigator discretion [n = 5]). At week 96, reductions in liver biochemistry parameters occurred, including serum ALP (median, -8.3% [IQR, -25.9% to 11.0%]; P = .066), GGT (-29.8% [IQR, -42.3% to -13.9%]; P < .001), alanine aminotransaminase (ALT) (-29.8% [IQR, -43.7% to -6.6%]; P = .002), and aspartate aminotransaminase (AST) (-16.7% [IQR, -35.3% to 1.0%]; P = .010), and rebounded after 4 weeks of untreated follow-up. ALP response (≥20% reduction from BL to week 96) was similar in the presence or absence of UDCA therapy (29% vs 39%; P = .71). At week 96, cilofexor treatment was associated with a significant reduction in serum 7α-hydroxy-4-cholesten-3-one (C4) (-29.8% [IQR, -64.3% to -8.5%]; P = .001). In subjects with detectable serum BAs at BL (n = 40), BAs decreased -23.9% (IQR, -44.4% to -0.6%; P = .006) at week 48 (n = 28) and -25.7% (IQR, -35.9% to 53.7%; P = .91) at week 96 (n = 26). Serum cytokeratin 18 (CK18) M30 and M65 were reduced throughout the OLE; significant reductions were observed at week 72 (CK18 M30, -17.3% [IQR, -39.3% to 8.8%]; P = .018; CK18 M65, -43.5% [IQR, -54.9% to 15.3%]; P = .096). At week 96, a small, but statistically significant absolute increase of 0.15 units in Enhanced Liver Fibrosis score was observed compared with BL (median, 9.34 vs 9.53; P = .028). CONCLUSIONS: In this 96-week OLE of a phase II study of PSC, cilofexor was safe and improved liver biochemistry and biomarkers of cholestasis and cellular injury. CLINICALTRIALS: gov identifier: NCT02943460.

En masse organoid phenotyping informs metabolic-associated genetic susceptibility to NASH.

Genotype-phenotype associations for common diseases are often compounded by pleiotropy and metabolic state. Here, we devised a pooled human organoid-panel of steatohepatitis to investigate the impact of metabolic status on genotype-phenotype association. En masse population-based phenotypic analysis under insulin insensitive conditions predicted key non-alcoholic steatohepatitis (NASH)-genetic factors including the glucokinase regulatory protein (GCKR)-rs1260326:C>T. Analysis of NASH clinical cohorts revealed that GCKR-rs1260326-T allele elevates disease severity only under diabetic state but protects from fibrosis under non-diabetic states. Transcriptomic, metabolomic, and pharmacological analyses indicate significant mitochondrial dysfunction incurred by GCKR-rs1260326, which was not reversed with metformin. Uncoupling oxidative mechanisms mitigated mitochondrial dysfunction and permitted adaptation to increased fatty acid supply while protecting against oxidant stress, forming a basis for future therapeutic approaches for diabetic NASH. Thus, "in-a-dish" genotype-phenotype association strategies disentangle the opposing roles of metabolic-associated gene variant functions and offer a rich mechanistic, diagnostic, and therapeutic inference toolbox toward precision hepatology. VIDEO ABSTRACT.

Hepatic Deletion of X-Box Binding Protein 1 in FXR Null Mice Leads to Enhanced Liver Injury.

FXR regulates bile acid metabolism, and FXR null (Fxr-/-) mice have elevated bile acid levels and progressive liver injury. The inositol-requiring enzyme 1α/X-box binding protein 1 (XBP1) pathway is a protective unfolded protein response pathway activated in response to endoplasmic reticulum stress. Here, we sought to determine the role of the inositol-requiring enzyme 1α/XBP1 pathway in hepatic bile acid toxicity using the Fxr-/- mouse model. Western blotting and quantitative PCR analysis demonstrated that hepatic XBP1 and other unfolded protein response pathways were activated in 24-week-old Fxr-/- compared with 10-week-old Fxr-/- mice but not in WT mice. To further determine the role of the liver XBP1 activation in older Fxr-/- mice, we generated mice with whole-body FXR and liver-specific XBP1 double KO (DKO, Fxr-/-Xbp1LKO) and Fxr-/-Xbp1fl/fl single KO (SKO) mice and characterized the role of hepatic XBP1 in cholestatic liver injury. Histologic staining demonstrated increased liver injury and fibrosis in DKO compared with SKO mice. RNA sequencing revealed increased gene expression in apoptosis, inflammation, and cell proliferation pathways in DKO mice. The proapoptotic C/EBP-homologous protein pathway and cell cycle marker cyclin D1 were also activated in DKO mice. Furthermore, we found that total hepatic bile acid levels were similar between the two genotypes. At age 60 weeks, all DKO mice and no SKO mice spontaneously developed liver tumors. In conclusion, the hepatic XBP1 pathway is activated in older Fxr-/- mice and has a protective role. The potential interaction between XBP1 and FXR signaling may be important in modulating the hepatocellular cholestatic stress responses.

Elevated de novo lipogenesis, slow liver triglyceride turnover, and clinical correlations in nonalcoholic steatohepatitis patients.

De novo lipogenesis (DNL) converts carbon substrates to lipids. Increased hepatic DNL could contribute to pathogenic liver triglyceride accumulation in nonalcoholic steatohepatitis (NASH) and therefore may be a potential target for pharmacological intervention. Here, we measured hepatic DNL using heavy water in 123 patients with NASH with fibrosis or cirrhosis, calculated the turnover of hepatic triglycerides to allow repeat labeling studies, and determined the associations of hepatic DNL with metabolic, fibrotic, and imaging markers. We found that hepatic DNL was higher in patients with fibrotic NASH [median (IQR), 40.7% contribution to palmitate (32.1, 47.5), n=103] than has been previously reported in healthy volunteers and remained elevated [median (IQR), 36.8% (31.0, 44.5), n=20] in patients with cirrhosis, despite lower liver fat content. We also showed that turnover of intrahepatic triglyceride pools was slow (t½ >10 days). Furthermore, DNL contribution was determined to be independent of liver stiffness by magnetic resonance imaging but was positively associated with the number of large very low density lipoprotein (VLDL) particles, the size of VLDL, the lipoprotein insulin resistance score, and levels of ApoB100, and trended toward negative associations with the fibrosis markers FIB-4, FibroSure, and APRI. Finally, we found treatment with the acetyl-CoA carboxylase inhibitor firsocostat reduced hepatic DNL at 4 and 12 weeks, using a correction model for residual label that accounts for hepatic triglyceride turnover. Taken together, these data support an important pathophysiological role for elevated hepatic DNL in NASH and demonstrate that response to pharmacological agents targeting DNL can be correlated with pretreatment DNL.

A multiancestry genome-wide association study of unexplained chronic ALT elevation as a proxy for nonalcoholic fatty liver disease with histological and radiological validation.

Nonalcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease. Using a proxy NAFLD definition of chronic elevation of alanine aminotransferase (cALT) levels without other liver diseases, we performed a multiancestry genome-wide association study (GWAS) in the Million Veteran Program (MVP) including 90,408 cALT cases and 128,187 controls. Seventy-seven loci exceeded genome-wide significance, including 25 without prior NAFLD or alanine aminotransferase associations, with one additional locus identified in European American-only and two in African American-only analyses (P < 5 × 10-8). External replication in histology-defined NAFLD cohorts (7,397 cases and 56,785 controls) or radiologic imaging cohorts (n = 44,289) replicated 17 single-nucleotide polymorphisms (SNPs) (P < 6.5 × 10-4), of which 9 were new (TRIB1, PPARG, MTTP, SERPINA1, FTO, IL1RN, COBLL1, APOH and IFI30). Pleiotropy analysis showed that 61 of 77 multiancestry and all 17 replicated SNPs were jointly associated with metabolic and/or inflammatory traits, revealing a complex model of genetic architecture. Our approach integrating cALT, histology and imaging reveals new insights into genetic liability to NAFLD.

Cirrhosis regression is associated with improved clinical outcomes in patients with nonalcoholic steatohepatitis.

BACKGROUND AND AIMS: Surrogate endpoints that predict complications are necessary for assessment and approval of NASH therapies. We assessed associations between histologic and noninvasive tests (NITs) of fibrosis with liver-related complications in patients with NASH cirrhosis. APPROACH AND RESULTS: Patients with compensated cirrhosis due to NASH were enrolled in two placebo-controlled trials of simtuzumab and selonsertib. Liver fibrosis at baseline and week 48 (W48) was staged by NASH Clinical Research Network (CRN) and Ishak classifications and a machine learning (ML) approach, hepatic collagen and alpha-smooth muscle actin (α-SMA) expression were quantified by morphometry, liver stiffness (LS) was measured by transient elastography, and serum NITs (enhanced liver fibrosis [ELF], NAFLD fibrosis score [NFS], and Fibrosis-4 index [FIB-4]) were calculated. Cox regression determined associations between these parameters at baseline and their changes over time with adjudicated liver-related clinical events. Among 1,135 patients, 709 (62%) had Ishak stage 6 fibrosis, and median ELF and LS were 10.66 and 21.1 kPa, respectively. During a median follow-up of 16.6 months, 71 (6.3%) had a liver-related event; associated baseline factors included Ishak stage 6 fibrosis, and higher hepatic collagen, α-SMA expression, ML-based fibrosis parameters, LS, ELF, NFS, and FIB-4. Cirrhosis regression observed in 16% (176/1,135) between BL and W48 was associated with a lower risk of events versus nonregression (1.1% [2/176] vs. 7.2% [69/957]; HR, 0.16; 95% CI, 0.04, 0.65 [p = 0.0104]). Conversely, after adjustment for baseline values, increases in hepatic collagen, α-SMA, ML-based fibrosis parameters, NFS, and LS were associated with an increased risk of events. CONCLUSIONS: In patients with compensated cirrhosis due to NASH, regression of fibrosis is associated with a reduction in liver-related complications. These data support the utility of histologic fibrosis regression and NITs as clinical trial endpoints for NASH cirrhosis.

A Machine Learning Approach to Liver Histological Evaluation Predicts Clinically Significant Portal Hypertension in NASH Cirrhosis.

BACKGROUND AND AIMS: The hepatic venous pressure gradient (HVPG) is the standard for estimating portal pressure but requires expertise for interpretation. We hypothesized that HVPG could be extrapolated from liver histology using a machine learning (ML) algorithm. APPROACH AND RESULTS: Patients with NASH with compensated cirrhosis from a phase 2b trial were included. HVPG and biopsies from baseline and weeks 48 and 96 were reviewed centrally, and biopsies evaluated with a convolutional neural network (PathAI, Boston, MA). Using trichrome-stained biopsies in the training set (n = 130), an ML model was developed to recognize fibrosis patterns associated with HVPG, and the resultant ML HVPG score was validated in a held-out test set (n = 88). Associations between the ML HVPG score with measured HVPG and liver-related events, and performance of the ML HVPG score for clinically significant portal hypertension (CSPH) (HVPG ≥ 10 mm Hg), were determined. The ML-HVPG score was more strongly correlated with HVPG than hepatic collagen by morphometry (ρ = 0.47 vs. ρ = 0.28; P < 0.001). The ML HVPG score differentiated patients with normal (0-5 mm Hg) and elevated (5.5-9.5 mm Hg) HVPG and CSPH (median: 1.51 vs. 1.93 vs. 2.60; all P < 0.05). The areas under receiver operating characteristic curve (AUROCs) (95% CI) of the ML-HVPG score for CSPH were 0.85 (0.80, 0.90) and 0.76 (0.68, 0.85) in the training and test sets, respectively. Discrimination of the ML-HVPG score for CSPH improved with the addition of a ML parameter for nodularity, Enhanced Liver Fibrosis, platelets, aspartate aminotransferase (AST), and bilirubin (AUROC in test set: 0.85; 95% CI: 0.78, 0.92). Although baseline ML-HVPG score was not prognostic, changes were predictive of clinical events (HR: 2.13; 95% CI: 1.26, 3.59) and associated with hemodynamic response and fibrosis improvement. CONCLUSIONS: An ML model based on trichrome-stained liver biopsy slides can predict CSPH in patients with NASH with cirrhosis.

A Machine Learning Approach Enables Quantitative Measurement of Liver Histology and Disease Monitoring in NASH.

BACKGROUND AND AIMS: Manual histological assessment is currently the accepted standard for diagnosing and monitoring disease progression in NASH, but is limited by variability in interpretation and insensitivity to change. Thus, there is a critical need for improved tools to assess liver pathology in order to risk stratify NASH patients and monitor treatment response. APPROACH AND RESULTS: Here, we describe a machine learning (ML)-based approach to liver histology assessment, which accurately characterizes disease severity and heterogeneity, and sensitively quantifies treatment response in NASH. We use samples from three randomized controlled trials to build and then validate deep convolutional neural networks to measure key histological features in NASH, including steatosis, inflammation, hepatocellular ballooning, and fibrosis. The ML-based predictions showed strong correlations with expert pathologists and were prognostic of progression to cirrhosis and liver-related clinical events. We developed a heterogeneity-sensitive metric of fibrosis response, the Deep Learning Treatment Assessment Liver Fibrosis score, which measured antifibrotic treatment effects that went undetected by manual pathological staging and was concordant with histological disease progression. CONCLUSIONS: Our ML method has shown reproducibility and sensitivity and was prognostic for disease progression, demonstrating the power of ML to advance our understanding of disease heterogeneity in NASH, risk stratify affected patients, and facilitate the development of therapies.

Combination Therapies Including Cilofexor and Firsocostat for Bridging Fibrosis and Cirrhosis Attributable to NASH.

BACKGROUND AND AIMS: Advanced fibrosis attributable to NASH is a leading cause of end-stage liver disease. APPROACH AND RESULTS: In this phase 2b trial, 392 patients with bridging fibrosis or compensated cirrhosis (F3-F4) were randomized to receive placebo, selonsertib 18 mg, cilofexor 30 mg, or firsocostat 20 mg, alone or in two-drug combinations, once-daily for 48 weeks. The primary endpoint was a ≥1-stage improvement in fibrosis without worsening of NASH between baseline and 48 weeks based on central pathologist review. Exploratory endpoints included changes in NAFLD Activity Score (NAS), liver histology assessed using a machine learning (ML) approach, liver biochemistry, and noninvasive markers. The majority had cirrhosis (56%) and NAS ≥5 (83%). The primary endpoint was achieved in 11% of placebo-treated patients versus cilofexor/firsocostat (21%; P = 0.17), cilofexor/selonsertib (19%; P = 0.26), firsocostat/selonsertib (15%; P = 0.62), firsocostat (12%; P = 0.94), and cilofexor (12%; P = 0.96). Changes in hepatic collagen by morphometry were not significant, but cilofexor/firsocostat led to a significant decrease in ML NASH CRN fibrosis score (P = 0.040) and a shift in biopsy area from F3-F4 to ≤F2 fibrosis patterns. Compared to placebo, significantly higher proportions of cilofexor/firsocostat patients had a ≥2-point NAS reduction; reductions in steatosis, lobular inflammation, and ballooning; and significant improvements in alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, bile acids, cytokeratin-18, insulin, estimated glomerular filtration rate, ELF score, and liver stiffness by transient elastography (all P ≤ 0.05). Pruritus occurred in 20%-29% of cilofexor versus 15% of placebo-treated patients. CONCLUSIONS: In patients with bridging fibrosis and cirrhosis, 48 weeks of cilofexor/firsocostat was well tolerated, led to improvements in NASH activity, and may have an antifibrotic effect. This combination offers potential for fibrosis regression with longer-term therapy in patients with advanced fibrosis attributable to NASH.

Inter- and Intra-individual Variation, and Limited Prognostic Utility, of Serum Alkaline Phosphatase in a Trial of Patients With Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: Serum alkaline phosphatase (ALP) and the enhanced liver fibrosis (ELF) score are used as endpoints in trials of patients with primary sclerosing cholangitis (PSC). We aimed to quantify inter- and intra-individual variation in levels of ALP and the ELF score over time, and evaluated their association with fibrosis progression. METHODS: We analyzed data from 234 patients with large-duct PSC enrolled in a 2-year, phase 2b placebo-controlled trial of simtuzumab. Participants were assessed by laboratory tests every 4 weeks, and liver biopsies collected at time of screening, week 48, and week 96. RESULTS: Serum levels of ALP and ELF scores did not differ significantly between simtuzumab and placebo groups, so the data were pooled. Median per-patient variations in ALP between clinic visits were approximately 12% over 12 weeks, 20% over 48 weeks, and 20% over 96 weeks. Reductions, unrelated to study intervention, of more than 40% in ALP were observed in 10.9% of patients with baseline activity greater than 2-fold the upper limit of normal (ULN) and 12.5% of patients with more than 3-fold the ULN at 1 year. At 2 years, reductions of more than 40% in ALP were observed in 15.8% of patients with baseline activity greater than 2-fold the ULN and 17.9% of patients with more than 3-fold the ULN. Among the 209 patients with Ishak fibrosis stage 0-4 at baseline, serum ALP activity did not associate with development of cirrhosis or with a 2-point increase in fibrosis stage at 2 years. In contrast, the median per-patient variation in ELF scores between clinic visits was approximately 3% over 12 weeks, 4% over 48 weeks, and 4% over 96 weeks. Elevated ELF scores at baseline and at weeks 12, 24 and 48, each associated with development of cirrhosis at 2 years (odds ratio >2.75; P < .01 for all timepoints). ELF scores at baseline and weeks 12, 24 and 48, also associated with a 2-point increase in fibrosis stage at 2 years (odds ratios all greater than 2; P < .01 for all timepoints). CONCLUSIONS: In an analysis of data from patients with large-duct PSC enrolled in a prospective trial, we found large interindividual and intraindividual variations in serum ALP activity. Serum ALP activity did not associate with disease progression over a 2-year period. Variations in ELF score were smaller, and scores determined at multiple timepoints associated with fibrosis progression and development of cirrhosis.

A Fibrosis-Independent Hepatic Transcriptomic Signature Identifies Drivers of Disease Progression in Primary Sclerosing Cholangitis.

BACKGROUND AND AIMS: Primary sclerosing cholangitis (PSC) is a heterogeneous cholangiopathy characterized by progressive biliary fibrosis. RNA sequencing of liver tissue from patients with PSC (n = 74) enrolled in a 96-week clinical trial was performed to identify associations between biological pathways that were independent of fibrosis and clinical events. APPROACH AND RESULTS: The effect of fibrosis was subtracted from gene expression using a computational approach. The fibrosis-adjusted gene expression patterns were associated with time to first PSC-related clinical event (e.g., cholangitis, hepatic decompensation), and differential expression based on risk groups and Ingenuity Pathway Analysis were performed. Baseline demographic data were representative of PSC: median age 48 years, 71% male, 49% with inflammatory bowel disease, and 44% with bridging fibrosis or cirrhosis. The first principle component (PC1) of RNA-sequencing data accounted for 18% of variance and correlated with fibrosis stage (ρ = -0.80; P < 0.001). After removing the effect of fibrosis-related genes, the first principle component was not associated with fibrosis (ρ = -0.19; P = 0.11), and a semisupervised clustering approach identified two distinct patient clusters with differential risk of time to first PSC-related event (P < 0.0001). The two groups had similar fibrosis stage, hepatic collagen content, and α-smooth muscle actin expression by morphometry, Enhanced Liver Fibrosis score, and serum liver biochemistry, bile acids, and IL-8 (all P > 0.05). The top pathways identified by Ingenuity Pathway Analysis were eukaryotic translation inhibition factor 2 (eIF2) signaling and regulation of eIF4/p70S6K signaling. Genes involved in the unfolded protein response, activating transcription factor 6 (ATF6) and eIF2, were differentially expressed between the PSC clusters (down-regulated in the high-risk group by log-fold changes of -0.18 [P = 0.02] and -0.16 [P = 0.02], respectively). Clinical events were enriched in the high-risk versus low-risk group (38% [12/32] vs. 2.4% [1/42], P < 0.0001). CONCLUSIONS: Removing the contribution of fibrosis-related pathways uncovered alterations in the unfolded protein response, which were associated with liver-related complications in PSC.