A Phase 3, Randomized, Controlled Trial of Resmetirom in NASH with Liver Fibrosis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a progressive liver disease with no approved treatment. Resmetirom is an oral, liver-directed, thyroid hormone receptor beta-selective agonist in development for the treatment of NASH with liver fibrosis. METHODS: We are conducting an ongoing phase 3 trial involving adults with biopsy-confirmed NASH and a fibrosis stage of F1B, F2, or F3 (stages range from F0 [no fibrosis] to F4 [cirrhosis]). Patients were randomly assigned in a 1:1:1 ratio to receive once-daily resmetirom at a dose of 80 mg or 100 mg or placebo. The two primary end points at week 52 were NASH resolution (including a reduction in the nonalcoholic fatty liver disease [NAFLD] activity score by ≥2 points; scores range from 0 to 8, with higher scores indicating more severe disease) with no worsening of fibrosis, and an improvement (reduction) in fibrosis by at least one stage with no worsening of the NAFLD activity score. RESULTS: Overall, 966 patients formed the primary analysis population (322 in the 80-mg resmetirom group, 323 in the 100-mg resmetirom group, and 321 in the placebo group). NASH resolution with no worsening of fibrosis was achieved in 25.9% of the patients in the 80-mg resmetirom group and 29.9% of those in the 100-mg resmetirom group, as compared with 9.7% of those in the placebo group (P<0.001 for both comparisons with placebo). Fibrosis improvement by at least one stage with no worsening of the NAFLD activity score was achieved in 24.2% of the patients in the 80-mg resmetirom group and 25.9% of those in the 100-mg resmetirom group, as compared with 14.2% of those in the placebo group (P<0.001 for both comparisons with placebo). The change in low-density lipoprotein cholesterol levels from baseline to week 24 was -13.6% in the 80-mg resmetirom group and -16.3% in the 100-mg resmetirom group, as compared with 0.1% in the placebo group (P<0.001 for both comparisons with placebo). Diarrhea and nausea were more frequent with resmetirom than with placebo. The incidence of serious adverse events was similar across trial groups: 10.9% in the 80-mg resmetirom group, 12.7% in the 100-mg resmetirom group, and 11.5% in the placebo group. CONCLUSIONS: Both the 80-mg dose and the 100-mg dose of resmetirom were superior to placebo with respect to NASH resolution and improvement in liver fibrosis by at least one stage. (Funded by Madrigal Pharmaceuticals; MAESTRO-NASH ClinicalTrials.gov number, NCT03900429.).

Fibrosis and steatotic liver disease in US adolescents according to the new nomenclature.

OBJECTIVE: To apply the new nomenclature for steatotic liver diseases (SLD), replacing nonalcoholic fatty liver disease (NAFLD) with metabolic dysfunction-associated steatotic liver disease (MASLD), in adolescents using National Health and Nutrition Examination Survey (NHANES) data. METHODS: Among 1410 adolescents (12-19 years) in NHANES (2017-March, 2020), the controlled attenuation parameter (CAP) of transient elastography (TE) was used to define steatosis and fibrosis (TE ≥ 7.4 kPa). Obesity and alanine aminotransferase (ALT) ≥ 80 U/L were used to identify adolescents qualifying for hepatology referral according to practice guidelines. NAFLD was defined as liver steatosis without a specific exposure; it has no cardiometabolic risk factor requirement, unlike MASLD. RESULTS: Steatosis (yes/no) is the first decision point in the new diagnostic protocol; however, criteria for steatosis are undefined. At the supplier (EchoSens)-recommended CAP threshold of 240 dB/m, 30.5% (95% confidence interval [CI]: 27.1%-34.0%) of adolescents had SLD and about 85% of adolescents with NAFLD met criteria for MASLD. The other 15% would receive an ambiguous diagnosis of either cryptogenic SLD or possible MASLD. At higher CAP thresholds, MASLD/NAFLD concordance increased and approached 100%. Among adolescents with MASLD-fibrosis, only 8.8% (95% CI: 0%-19.3%) had overweight/obese and ALT ≥ 80 U/L. CONCLUSIONS: The new nomenclature highlights the high prevalence of liver steatosis. At the CAP threshold of 240 dB/m, however, approximately 15% of adolescents would receive an ambiguous diagnosis, which could lead to confusion and worry. Fewer than 10% of adolescents with MASLD-fibrosis had overweight/obese and ALT ≥ 80 U/L. Revised guidelines are needed to ensure that the other 90% receive appropriate referral and liver disease care.

Adherence to pregnancy hepatitis B care guidelines in women and infants in the United States and evaluation of two interventions to improve care: A multicentre hospital-based study.

There has been an increase in hepatitis B (HBV) detection during pregnancy in the United States and an emphasis on measures to decrease mother-to-child transmission of HBV. We performed a multicentre retrospective study (2015-2018) evaluating care among all women with HBV during pregnancy. We determined rates and predictors of adherence to key maternal care measures including: (1) referral to HBV specialty care, (2) assessment of HBV DNA, and (3) initiation of antiviral therapy, and (4) rates of HBIG and HBV vaccine completion in infants. We evaluated two interventions to improve HBV care: (1) clinical decision support with best practice alert and (2) co-location of HBV care in obstetrics department. We identified 372 women with HBV during pregnancy. Patients had a median age of 33 (IQR 29, 36), were mostly of Asian (49%) or Black (36%) race, HBeAg-negative (83%) with HBV DNA ≤2000 IU/mL (65%) and maximum ALT ≤25 (66%). Regarding care measures, 62% were referred to an HBV specialist, 85% had HBV DNA checked during pregnancy and 68% with HBV DNA ≥200,000 were initiated on antiviral therapy. Co-located obstetric-liver diseases clinics appeared to improve adherence to maternal care measures. All infants received HBIG and the first HBV vaccine dose, 106 (81%) received the second, 94 (74%) received the 3rd dose, but fewer at the recommended time intervals. We identified clear gaps in adherence to HBV care measures for both mothers and infants. Co-location of HBV care in the obstetrics department shows promise in improving adherence to maternal care measures.

Resmetirom (MGL-3196) for the treatment of non-alcoholic steatohepatitis: a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is characterised by hepatic steatosis, inflammation, hepatocellular injury, and progressive liver fibrosis. Resmetirom (MGL-3196) is a liver-directed, orally active, selective thyroid hormone receptor-ß agonist designed to improve NASH by increasing hepatic fat metabolism and reducing lipotoxicity. We aimed to assess the safety and efficacy of resmetirom in patients with NASH. METHODS: MGL-3196-05 was a 36-week randomised, double-blind, placebo-controlled study at 25 centres in the USA. Adults with biopsy confirmed NASH (fibrosis stages 1-3) and hepatic fat fraction of at least 10% at baseline when assessed by MRI-proton density fat fraction (MRI-PDFF) were eligible. Patients were randomly assigned 2:1 by a computer-based system to receive resmetirom 80 mg or matching placebo, orally once a day. Serial hepatic fat measurements were obtained at weeks 12 and 36, and a second liver biopsy was obtained at week 36. The primary endpoint was relative change in MRI-PDFF assessed hepatic fat compared with placebo at week 12 in patients who had both a baseline and week 12 MRI-PDFF. This trial is registered with ClinicalTrials.gov, number NCT02912260. FINDINGS: 348 patients were screened and 84 were randomly assigned to resmetirom and 41 to placebo at 18 sites in the USA. Resmetirom-treated patients (n=78) showed a relative reduction of hepatic fat compared with placebo (n=38) at week 12 (-32·9% resmetirom vs -10·4% placebo; least squares mean difference -22·5%, 95% CI -32·9 to -12·2; p<0·0001) and week 36 (-37·3% resmetirom [n=74] vs -8·5 placebo [n=34]; -28·8%, -42·0 to -15·7; p<0·0001). Adverse events were mostly mild or moderate and were balanced between groups, except for a higher incidence of transient mild diarrhoea and nausea with resmetirom. INTERPRETATION: Resmetirom treatment resulted in significant reduction in hepatic fat after 12 weeks and 36 weeks of treatment in patients with NASH. Further studies of resmetirom will allow assessment of safety and effectiveness of resmetirom in a larger number of patients with NASH with the possibility of documenting associations between histological effects and changes in non-invasive markers and imaging. FUNDING: Madrigal Pharmaceuticals.

Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection.

BACKGROUND: Patients who are chronically infected with hepatitis C virus (HCV) and who do not have a sustained virologic response after treatment with regimens containing direct-acting antiviral agents (DAAs) have limited retreatment options. METHODS: We conducted two phase 3 trials involving patients who had been previously treated with a DAA-containing regimen. In POLARIS-1, patients with HCV genotype 1 infection who had previously received a regimen containing an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive either the nucleotide polymerase inhibitor sofosbuvir, the NS5A inhibitor velpatasvir, and the protease inhibitor voxilaprevir (150 patients) or matching placebo (150 patients) once daily for 12 weeks. Patients who were infected with HCV of other genotypes (114 patients) were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. In POLARIS-4, patients with HCV genotype 1, 2, or 3 infection who had previously received a DAA regimen but not an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir-voxilaprevir (163 patients) or sofosbuvir-velpatasvir (151 patients) for 12 weeks. An additional 19 patients with HCV genotype 4 infection were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. RESULTS: In the three active-treatment groups, 46% of the patients had compensated cirrhosis. In POLARIS-1, the rate of sustained virologic response was 96% with sofosbuvir-velpatasvir-voxilaprevir, as compared with 0% with placebo. In POLARIS-4, the rate of response was 98% with sofosbuvir-velpatasvir-voxilaprevir and 90% with sofosbuvir-velpatasvir. The most common adverse events were headache, fatigue, diarrhea, and nausea. In the active-treatment groups in both trials, the percentage of patients who discontinued treatment owing to adverse events was 1% or lower. CONCLUSIONS: Sofosbuvir-velpatasvir-voxilaprevir taken for 12 weeks provided high rates of sustained virologic response among patients across HCV genotypes in whom treatment with a DAA regimen had previously failed. (Funded by Gilead Sciences; POLARIS-1 and POLARIS-4 ClinicalTrials.gov numbers, NCT02607735 and NCT02639247 .).

A Roadmap for Value-Based Payment Models Among Patients With Cirrhosis.

Healthcare reimbursement is shifting from fee-for-service to fee-for-value. Cirrhosis, which costs the U.S. healthcare system as much as heart failure, is a prime target for value-based care. This article describes models in which physician groups or health systems are paid for improving quality and lowering costs for a given population of patients with cirrhosis. If done correctly, we believe that such frameworks, once adopted, could help reduce burnout by freeing physicians of the burden of checking boxes in the electronic medical record so that they can devote their energies to managing populations. Conclusion: Value-based payment models for cirrhosis have the potential to benefit patients, physicians, and healthcare insurers.

Hepatitis C virus double-stranded RNA is the predominant form in human liver and in interferon-treated cells.

Hepatitis C virus (HCV) is unique among RNA viruses in its ability to establish chronic infection in the majority of exposed adults. HCV persists in the liver despite interferon (IFN)-stimulated gene (ISG) induction; robust induction actually predicts treatment failure and viral persistence. It is unclear which forms of HCV RNA are associated with ISG induction and IFN resistance during natural infections. To thoroughly delineate HCV RNA populations, we developed conditions that fully separate the strands of long double-stranded RNA (dsRNA) and allow the released RNAs to be quantified in reverse transcription/polymerase chain reaction assays. These methods revealed that dsRNA, a pathogen-associated molecular pattern (PAMP), comprised 52% (standard deviation, 28%) of the HCV RNA in the livers of patients with chronic infection. HCV dsRNA was proportionally higher in patients with the unfavorable IL28B TT (rs12979860) genotype. Higher ratios of HCV double-stranded to single-stranded RNA (ssRNA) correlated positively with ISG induction. In Huh-7.5 cells, IFN treatment increased the total amount of HCV dsRNA through a process that required de novo viral RNA synthesis and shifted the ratio of viral dsRNA/ssRNA in favor of dsRNA. This shift was blocked by ribavirin (RBV), an antiviral drug that reduces relapse in HCV patients. Northern blotting established that HCV dsRNA contained genome-length minus strands. CONCLUSION: HCV dsRNA is the predominant form in the HCV-infected liver and has features of both a PAMP and a genomic reservoir. Interferon treatment increased rather than decreased HCV dsRNA. This unexpected finding suggests that HCV produces dsRNA in response to IFN, potentially to antagonize antiviral defenses. (Hepatology 2017;66:357-370).

Estrogen decreases tight junction protein ZO-1 expression in human primary gut tissues.

Females have a higher prevalence of most autoimmune diseases; however, the mechanism is unknown. In this study, we examined the expression of tight junction protein zonula occludens 1 (ZO-1) and estrogen receptor (ER)-α/ß in human primary gut tissues by immunohistochemistry, immunofluorescence and qPCR. The expression of ZO-1 and ER-ß but not ER-α was present in both male and female gut tissues. There was no sex difference in ER-ß expression, but ZO-1 expression was decreased in females compared to males. In vitro, estrogen treatment decreased ZO-1 mRNA and protein expression, ZO-1 promoter activity, IL-6 production, and NF-κB activation in human primary gut tissues or the Caco-2 cells, but increased the ER-ß expression in Caco-2 cells. Consistently, plasma IL-6 levels in females were reduced relative to males in vivo. Our finding indicates that estrogen may play a role in gut tight junction expression and permeability.

Interleukin-15 receptor α on hepatic stellate cells regulates hepatic fibrogenesis in mice.

BACKGROUND & AIMS: Interleukin-15 (IL-15) and its high affinity receptor interleukin-15 receptor alpha (IL-15Rα) are widely expressed in immune cells and hepatic resident cells. IL-15 signaling has important functions in homeostasis of natural killer (NK), natural killer T (NKT) and cytotoxic T (CD8(+) T) cells, and in liver regeneration. We hypothesized that IL-15 has a protective role in liver fibrosis progression by maintaining NK cell homeostasis. METHODS: Fibrosis was induced using two mechanistically distinct models. Congenic bone marrow transplantation was used to evaluate the contribution of IL-15 signaling from various compartments to NK, CD8(+) T and NKT cell homeostasis and fibrogenesis. The gene expression profile of hepatic stellate cell (HSC) from IL-15Rα knockout (IL-15RαKO) mice and wild-type mice were captured using microarray analysis and validated in isolated HSC. Quantitative real-time PCR was used to assess repressors of collagen transcription. RESULTS: IL-15RαKO mice exhibited more fibrosis in both models. IL-15 signaling from specific types of hepatic cells had divergent roles in maintaining liver NK, CD8(+) T and NKT cells, with a direct and protective role on radio-resistant non-parenchymal cells beyond the control of NK homeostasis. HSCs isolated from IL-15RαKO mice demonstrated upregulation of collagen production. Finally, IL-15RαKO HSC with or without transforming growth factor beta (TGF-ß) stimulation exhibited increased expression of fibrosis markers and decreased collagen transcription repressors expression. CONCLUSIONS: IL-15Rα signaling has a direct anti-fibrotic effect independent of preserving NK homeostasis. These findings establish a rationale to further explore the anti-fibrotic potential of enhancing IL-15 signaling in HSCs. LAY SUMMARY: We investigated how a cellular protein, Interleukin-15 (IL-15), decreases the amount of scar tissue that is formed upon liver injury. We found that IL-15 and its receptor decrease the amount of scar tissue that is created by specialized liver cells (called stellate cells) and increase the number of a specific subgroup of immune cells (natural killer cells) that are known to eliminate stellate cells. TRANSCRIPT PROFILING ACCESSION NUMBER: GSE45612, GSE 68001 and GSE 25097.

Biliary Epithelial Cells Are Not the Predominant Source of Hepatic CXCL12.

Hepatic expression levels of CXCL12, a chemokine important in inflammatory and stem cell recruitment, and its receptor, C-X-C chemokine receptor 4, are increased during all forms of liver injury. CXCL12 is expressed by both parenchymal and nonparenchymal hepatic cells, and on the basis of immunohistochemistry, biliary epithelial cells (BECs) are thought to be a predominant source of hepatic CXCL12, thereby promoting periportal recruitment of C-X-C chemokine receptor 4-expressing lymphocytes. Our study aims to show that BECs may, in fact, not be the predominant source of hepatic CXCL12. We measured CXCL12 secretion and expression from human and murine BECs using enzyme-linked immunosorbent assay and Western blot analysis from cell culture supernatants and whole cell lysates, respectively, whereas CXCL12 expression in murine livers was analyzed in a Cxcl12-Gfp reporter mouse. Cell culture supernatants and whole cell lysates from BECs failed to demonstrate their expression of CXCL12. Furthermore, we confirmed these results with a Cxcl12-Gfp reporter mouse in which green fluorescent protein expression is notably absent from BECs. Interestingly, on the basis of green fluorescent protein expression, we demonstrate a population of CXCL12-expressing cells within the portal tract that are distinct, yet intimately associated with BECs. These findings indicate that BECs are not a predominant source of CXCL12.

Hepatic safety in subjects with HIV-1 and hepatitis C and/or B virus: a randomized, double-blind study of maraviroc versus placebo in combination with antiretroviral agents.

BACKGROUND: One of the more clinically relevant co-morbidities in HIV-infected patients is the development of progressive liver disease due to hepatitis B virus (HBV) or hepatitis C virus (HCV). In addition, hepatotoxicity has been observed with prolonged use of antiretroviral agents. OBJECTIVE: To evaluate the hepatic safety of maraviroc in combination with other antiretroviral agents in HIV-1-infected subjects co-infected with HCV and/or HBV. METHODS: In this 148-week randomized, double-blind, placebo-controlled, multicentre study (NCT01327547), subjects received maraviroc twice daily (n = 70) or placebo (n = 67) in combination with other antiretroviral agents. PRIMARY ENDPOINT: the percentage at week 48 of subjects with Grade 3 and Grade 4 ALT abnormalities, defined as >5 × upper limit of normal (ULN) if baseline ALT ≤ ULN or >3.5 × baseline if baseline ALT>ULN in the maraviroc versus the placebo arm. RESULTS: At week 48, one subject in each group had met the primary endpoint definition. No subjects met protocol-defined liver stopping criteria and there were no cases of Hy's law or treatment-related hepatobiliary serious adverse events. No significant difference in change from baseline in enhanced liver fibrosis or hepatic elastography was observed between groups. Treatment-related hepatobiliary adverse events were reported in one and two subjects receiving maraviroc and placebo, respectively; discontinuations due to treatment-related AEs occurred in four and two subjects receiving maraviroc and placebo, respectively; two deaths were reported in the placebo group. CONCLUSIONS: The use of maraviroc does not increase hepatotoxicity in HIV-1-infected subjects co-infected with HCV and/or HBV through 48 weeks of treatment.

Inhibition of the CXCL12/CXCR4 chemokine axis with AMD3100, a CXCR4 small molecule inhibitor, worsens murine hepatic injury.

AIM: Activation of hepatic stellate cells and development of chronic inflammation are two key features in the progression of hepatic fibrosis. We have shown that in vitro activated stellate cells increase their expression of CXCL12 as well as the receptor CXCR4 and that receptor engagement promotes a profibrogenic phenotype. Furthermore, injury promotes increased hepatic expression of CXCL12 and a massive infiltration of CXCR4-expressing leukocytes, granulocytes and myeloid cells. The primary site of inflammatory cell accumulation is around the CXCL12-rich portal tracts and within fibrotic septae, indicating a role for CXCR4 during injury. In order to characterize the relevance of the CXCR4/CXCL12 chemokine axis during hepatic injury we inhibited the axis using AMD3100, a CXCR4 small molecule inhibitor, in models of chronic and acute liver injury. METHODS: Mice were subjected to acute and chronic CCl4 liver injury with and without AMD3100 administration. The degree of liver injury, fibrosis and the composition of the intrahepatic inflammatory response were characterized. RESULTS: Treatment of mice with AMD3100 in the chronic CCl4 model of liver injury led to an increase in hepatic inflammation and fibrosis with a specific increase in intrahepatic neutrophils. Furthermore, in an acute model of CCl4 -induced liver injury, AMD3100 led to an increase in the number of intrahepatic neutrophils and a trend towards worse necrosis. CONCLUSION: Together, this data suggests that inhibition of the CXCR4/CXCL12 chemokine axis is injurious through modulation of the hepatic inflammatory response and that this axis may serve a protective role in liver injury.

Diabetes mellitus and advanced liver fibrosis are risk factors for severe anaemia during telaprevir-based triple therapy.

BACKGROUND & AIMS: Adding telaprevir to pegylated-interferon and ribavirin increased both response rates and side effects of hepatitis C virus (HCV) treatment. We identified variables associated with severe anaemia during telaprevir-based triple therapy. METHODS: An observational study was performed on 142 HCV-infected patients between June 2011 and March 2012. All subjects completed 12 weeks of telaprevir-based triple therapy or discontinued early because of anaemia. Severe anaemia was defined by a haemoglobin≤8.9 g/dl; advanced fibrosis was determined by Fib-4≥3.25. RESULTS: The 47 (33%) patients who developed severe anaemia were similar to those who did not in sex, race, and prior response to dual therapy, but they were more likely to have diabetes (23.4% vs. 6.3%, P<0.01), advanced fibrosis (46.8% vs. 29.5%, P=0.04) and a history of anaemia during previous dual therapy (29.7% vs. 11.4%, P=0.02). Patients developing severe anaemia were older (59 vs. 56 years, P=0.02), had lower baseline platelet counts (134 vs. 163×10(9) /L, P=0.04), haemoglobin (14.0 vs. 15.0 g/dl, P<0.01), estimated glomerular filtration rate (79 vs. 90 ml/min/1.73 m2, P=0.03) and a higher median ribavirin/weight ratio (14.9 vs. 13.2 mg/kg, P<0.01). In multivariable logistic regression, presence of diabetes (OR=5.61, 95% CI: 1.59-19.72), Fib-4≥3.25 (OR=3.09, 95% CI: 1.28-7.46), higher ribavirin/weight ratio (OR=1.31 per mg/kg, 95% CI: 1.13-1.52) and lower baseline haemoglobin (OR=0.57 per g/dl, 95% CI, 0.41-0.80) were independently associated with developing severe anaemia. CONCLUSIONS: Severe anaemia occurred in one-third of patients receiving telaprevir-based triple therapy. Risk was greater in patients with diabetes, advanced liver fibrosis, higher ribavirin/weight ratio and lower baseline haemoglobin.

Pathogenesis of MASLD and MASH - role of insulin resistance and lipotoxicity.

BACKGROUND: Insulin resistance and lipotoxicity are extremely interconnected but fundamental in setting the stage for the development of MASLD/MASH. AIM/METHODS: A comprehensive literature search was performed and key themes were synthesised to provide insight into the underlying molecular mechanisms of insulin resistance and lipotoxicity in the liver, muscle, pancreas and adipose tissue and how organ cross-talk is fundamental to driving disease pathogenesis. RESULTS: Classical thinking postulates that excess FFA load exceeds the storage capacity of adipose tissue, which is predicated upon both genetic and environmental factors. This results in insulin resistance and compensatory hyperinsulinaemia by pancreatic beta cells to overcome target organ insulin resistance. As adipocyte dysfunction worsens, not only are excess FFA delivered to other organs, including skeletal muscle, pancreas and liver but a pro-inflammatory milieu is established with increases in IL-6, TNF-α and changes in adipokine levels (increased leptin and decreased adiponectin). With increased intramuscular lipid accumulation, lipotoxic species decrease insulin signalling, reduce glucose uptake by downregulation of GLUT4 and decrease glycogen synthesis. With this additional reduced capacity, hyperglycaemia is further exacerbated and increased FFA are delivered to the liver. The liver has the largest capacity to oxidise fat and to adapt to these stressors and, therefore, has become the last line of defence for excess lipid storage and utilisation, the capacity of which may be impacted by genetic and environmental factors. However, when the liver can no longer keep up with increasing FFA delivery and DNL, lipotoxic species accumulate with ensuing mitochondrial dysfunction, increased ER stress, oxidant stress and inflammasome activation, all of which drive hepatocyte injury and apoptosis. The resulting wound healing response, marked by stellate cell activation, drives collagen accumulation, progressive fibrosis, and, ultimately, end organ failure and death. This vicious cycle and complex interplay between insulin resistance, hyperinsulinaemia, lipotoxicity and multi-directional cross-talk among different target organs are critical drivers of MASLD/MASH. CONCLUSIONS: Targeting tissue-specific insulin resistance and hyperinsulinaemia while decreasing FFA load (lipotoxicity) through dietary and lifestyle changes remain the best upstream interventions.

Design of the phase 3 MAESTRO clinical program to evaluate resmetirom for the treatment of nonalcoholic steatohepatitis.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease (NAFLD) associated with steatosis, hepatocellular injury, inflammation and fibrosis. In a Phase 2 trial in adults with NASH (NCT02912260), resmetirom, an orally administered, liver-targeted thyroid hormone receptor-ß selective agonist, significantly reduced hepatic fat (via imaging) and resolved NASH without worsening fibrosis (via liver biopsy) in a significant number of patients compared with placebo. AIMS: To present the design of the Phase 3 MAESTRO clinical programme evaluating resmetirom for treatment of NASH (MAESTRO-NAFLD-1 [NCT04197479], MAESTRO-NAFLD-OLE [NCT04951219], MAESTRO-NASH [NCT03900429], MAESTRO-NASH-OUTCOMES [NCT05500222]). METHODS: MAESTRO-NASH is a pivotal serial biopsy trial in up to 2000 adults with biopsy-confirmed at-risk NASH. Patients are randomised to a once-daily oral placebo, 80 mg resmetirom, or 100 mg resmetirom. Liver biopsies are conducted at screening, week 52 and month 54. MAESTRO-NAFLD-1 is a 52-week safety trial in ~1400 adults with NAFLD/presumed NASH (based on non-invasive testing); ~700 patients from MAESTRO-NAFLD-1 are enrolled in MAESTRO-NAFLD-OLE, a 52-week active treatment extension to further evaluate safety. MAESTRO-NASH-OUTCOMES is enrolling 700 adults with well-compensated NASH cirrhosis to evaluate the potential for resmetirom to slow progression to hepatic decompensation events. Non-invasive tests (biomarkers, imaging) are assessed longitudinally throughout, in addition to validated patient-reported outcomes. CONCLUSION: The MAESTRO clinical programme was designed in conjunction with regulatory authorities to support approval of resmetirom for treatment of NASH. The surrogate endpoints, based on week 52 liver biopsy, serum biomarkers and imaging, are confirmed by long-term clinical liver-related outcomes in MAESTRO-NASH (month 54) and MAESTRO-NASH-OUTCOMES (time to event).

CXCL12 induces hepatic stellate cell contraction through a calcium-independent pathway.

Liver fibrosis, with subsequent development of cirrhosis and ultimately portal hypertension, results in the death of patients with end-stage liver disease if liver transplantation is not performed. Hepatic stellate cells (HSCs), central mediators of liver fibrosis, resemble tissue pericytes and regulate intrahepatic blood flow by modulating pericapillary resistance. Therefore, HSCs can contribute to portal hypertension in patients with chronic liver disease (CLD). We have previously demonstrated that activated HSCs express functional chemokine receptor, CXCR4, and that receptor engagement by its ligand, CXCL12, which is increased in patients with CLD, leads to further stellate cell activation in a CXCR4-specific manner. We therefore hypothesized that CXCL12 promotes HSC contraction in a CXCR4-dependent manner. Stimulation of HSCs on collagen gel lattices with CXCL12 led to gel contraction and myosin light chain (MLC) phosphorylation, which was blocked by addition of AMD3100, a CXCR4 small molecule inhibitor. These effects were further mediated by the Rho kinase pathway since both Rho kinase knockdown or Y-27632, a Rho kinase inhibitor, blocked CXCL12 induced phosphorylation of MLC and gel contraction. BAPTA-AM, a calcium chelator, had no effect, indicating that this pathway is calcium sensitive but not calcium dependent. In conclusion, CXCL12 promotes stellate cell contractility in a predominantly calcium-independent fashion. Our data demonstrates a novel role of CXCL12 in stellate cell contraction and the availability of small molecule inhibitors of the CXCL12/CXCR4 axis justifies further investigation into its potential as therapeutic target for portal hypertension.

Resmetirom: An Orally Administered, Smallmolecule, Liver-directed, ß-selective THR Agonist for the Treatment of Non-alcoholic Fatty Liver Disease and Non-alcoholic Steatohepatitis.

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of fatty liver disease, including non-alcoholic fatty liver (NAFL) and its more progressive form, non-alcoholic steatohepatitis (NASH). The prevalence of NAFLD/NASH along with type 2 diabetes and obesity is rising worldwide. In those who develop NASH, unlike those with bland steatosis (NAFL), lipotoxic lipids drive hepatocyte injury, inflammation and stellate cell activation leading to progressive accumulation of collagen or fibrosis, ultimately leading to cirrhosis and increased risk of hepatocellular carcinoma. Hypothyroidism is associated with NAFLD/NASH; specifically, intrahepatic hypothyroidism drives lipotoxicty in preclinical models. Agonists of thyroid hormone receptor (THR)-ß, which is primarily found in the liver, can promote lipophagy, mitochondrial biogenesis and mitophagy, stimulating increased hepatic fatty acid ß-oxidation, and thereby decreasing the burden of lipotoxic lipids, while promoting low-density lipoprotein (LDL) uptake and favourable effects on lipid profiles. A number of THR-ß agonists are currently being investigated for NASH. This review focuses on resmetirom, an orally administered, once-daily, small-molecule, liver-directed, ß-selective THR agonist, as it is furthest along in development. Data from completed clincal studies outlined in this review demonstrate that resmetirom is effective in reducing hepatic fat content as measured by magnetic resonance imaging-derived proton density fat fraction, reduces liver enzymes, improves non-i nvasive markers of liver fibrogenesis and decreases liver stiffness, while eliciting a favourable cardiovascular profile with a reduction in serum lipids, including LDL cholesterol. Topline phase III biopsy data showed resolution of NASH and/or fibrosis improvement after 52 weeks of treatment, with more detailed peer-reviewed findings anticipated in order to certify these findings. Longer term clinical outcomes from both MAESTRO-NASH and MAESTRO-NASH OUTCOMES will be a pivotal juncture in the drug's road towards being approved as a NASH therapeutic.