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.).

Expert Panel Recommendations: Practical Clinical Applications for Initiating and Monitoring Resmetirom in Patients with MASH/NASH and Moderate to Noncirrhotic Advanced Fibrosis.

Metabolic dysfunction-associated steatotic liver disease affects 1 in 4 people in the United States and western Europe, with an important proportion developing metabolic dysfunction-associated steatohepatitis (MASH), the progressive subtype of metabolic dysfunction-associated steatotic liver disease. Cirrhosis caused by MASH is a leading indication for liver transplantation and the most common cause of hepatocellular carcinoma. Hitherto, there have been no specific pharmacotherapies for MASH. The recent conditional approval by the Food and Drug Administration of resmetirom for the treatment of moderate or advanced MASH presents a much-anticipated therapeutic option for patients with noncirrhotic advanced MASH. Specifically, the intended population for resmetirom are patients with MASH and fibrosis stages 2 or 3. The approval of resmetirom also presents important challenges, including how to noninvasively identify patients with fibrosis stages 2-3, and how to exclude patients with more advanced disease who should not be treated until further data emerge on the use of resmetirom in this population. Herein we consider the available literature with regard to identifying the intended population for treatment with resmetirom and in proposing criteria for stopping treatment.

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.

Steatotic liver disease and HIV: an agenda for 2030.

People living with HIV are particularly susceptible to developing metabolic disorders, including metabolic dysfunction-associated steatotic liver disease and other forms of SLD. However, people living with HIV have been historically excluded from clinical trials and large cohort studies of SLD. Therefore, our understanding of the risk factors and natural history of SLD in this population is poor. Moreover, relevant knowledge gaps on the epidemiology and barriers for adequate health care, such as stigma, hamper adequate responses to the ongoing HIV and SLD syndemic. This Viewpoint provides a comprehensive perspective on how to tackle SLD in people living with HIV by examining the role of social determinants of health in the development of liver disease and metabolic syndrome comorbidities among this population, emphasising the importance of prioritising SLD management, summarising the most urgent needs in the field, and offering recommendations for advancing research to fill key data gaps and protect liver health of people living with HIV.