Resmetirom: A Systematic Review of the Revolutionizing Approach to Non-alcoholic Steatohepatitis Treatment Focusing on Efficacy, Safety, Cost-Effectiveness, and Impact on Quality of Life

There has been a rise in the prevalence of non-alcoholic steatohepatitis (NASH), a subset of non-alcoholic fatty liver disease (NAFLD) with an ongoing increase in the prevalence of linked conditions such as obesity, type II diabetes mellitus, and metabolic syndrome. To date, there are no specific drugs that are approved for the treatment of NAFLD/NASH. With the recent discovery of association between subclinical hypothyroidism and NASH, various trials exploring treatment options for NASH using thyroid hormone derivatives led to the discovery of resmetirom (MGL-316) with high affinity to thyroid hormone receptors (THRs) targeting the liver. Following standardized guidelines, a systematic review was performed on the safety, efficacy, and other practical aspects of resmetirom in the treatment of NASH. Advanced search was carried out using the MeSH search strategy and appropriate keywords in major databases using various inclusion and exclusion criteria. The search was narrowed down to seven high-quality articles: four randomized control trials (RCTs), and three reviews to be included in the current study. The online database search yielded 62 articles, out of which six high-quality articles were selected to be included in the current systematic review after deleting duplicates and screening for irrelevant titles, and articles. Out of the three RCTs, two of them assessed the safety and efficacy of resmetirom, while the remaining RCT assessed the impact on health-related quality of life with resmetirom on patients with NASH. resmetirom (MGL-316) is a thyroid hormone derivative with high affinity to THRs targeting the liver and acts by improving mitochondrial oxidation, and lipophagy in the hepatic cell line. All the trials suggested in favor of resmetirom with a decrease in NASH fibrosis score by at least two points, along with reduction in hepatic fat content (minimum relative reduction of 20%), liver volume by 61%, improving secondary outcomes such as low-density lipoprotein-C, apolipoprotein-B, triglycerides, and hepatic enzymes with greater reduction in the study groups treated with higher doses of resmetirom with no significant increase in adverse events. Resmetirom was found to improve patient-reported outcomes, and thereby quality-adjusted life years (QALYs) in 12 weeks while being cost-effective compared to placebo at a willingness-to-pay threshold of US$100,000 up to a daily threshold of US$72.00, and an effective incremental cost-effectiveness ratio of US$53,925 per QALY gained. After carefully analyzing the available data by our team members, it could be concluded that resmetirom holds a strong potential to be implemented as a drug of choice in treating NAFLD/NASH in the coming years with proven efficacy, safety while being cost-effective, and also reducing secondary co-morbidities by improving cardiovascular risk factors. The results can be best achieved when combined with conventional approaches such as weight loss and dietary modifications. Long-term safety and sustainability of the achieved results are yet to be confirmed with large-scale clinical trials. However, resmetirom is still an investigational drug and could be expected to be available for clinical practice in the near future.