Cost-effectiveness and potential value of pharmaceutical treatment of nonalcoholic fatty liver disease

Steatotic Liver Disease: Pathophysiology and Emerging Pharmacotherapies

Steatotic liver disease (SLD) displays a dynamic and complex disease phenotype. Consequently, the metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH) therapeutic pipeline is expanding rapidly and in multiple directions. In parallel, noninvasive tools for diagnosing and monitoring responses to therapeutic interventions are being studied, and clinically feasible findings are being explored as primary outcomes in interventional trials. The realization that distinct subgroups exist under the umbrella of SLD should guide more precise and personalized treatment recommendations and facilitate advancements in pharmacotherapeutics. This review summarizes recent updates of pathophysiology-based nomenclature and outlines both effective pharmacotherapeutics and those in the pipeline for MASLD/MASH, detailing their mode of action and the current status of phase 2 and 3 clinical trials. Of the extensive arsenal of pharmacotherapeutics in the MASLD/MASH pipeline, several have been rejected, whereas other, mainly monotherapy options, have shown only marginal benefits and are now being tested as part of combination therapies, yet others are still in development as monotherapies. Although the Food and Drug Administration (FDA) has recently approved resmetirom, additional therapeutic approaches in development will ideally target MASH and fibrosis while improving cardiometabolic risk factors. Due to the urgent need for the development of novel therapeutic strategies and the potential availability of safety and tolerability data, repurposing existing and approved drugs is an appealing option. Finally, it is essential to highlight that SLD and, by extension, MASLD should be recognized and approached as a systemic disease affecting multiple organs, with the vigorous implementation of interdisciplinary and coordinated action plans. SIGNIFICANCE STATEMENT: Steatotic liver disease (SLD), including metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis, is the most prevalent chronic liver condition, affecting more than one-fourth of the global population. This review aims to provide the most recent information regarding SLD pathophysiology, diagnosis, and management according to the latest advancements in the guidelines and clinical trials. Collectively, it is hoped that the information provided furthers the understanding of the current state of SLD with direct clinical implications and stimulates research initiatives.

The impact of metabolic syndrome severity on racial and ethnic disparities in Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND & AIMS

Previous studies have examined the effects of metabolic syndrome (MetS) rather than its severity on race and ethnic disparities in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD). We used the MetS severity score, a validated sex-race-ethnicity-specific severity measure, to examine the effects of race/ethnicity on the association between MetS severity and MASLD.

METHODS

This study included 10,605 adult participants from the Third National Health and Nutrition Examination Survey. The MASLD diagnosis was based on ultrasound findings in patients without excessive alcohol intake or other liver diseases. MetS severity Z-scores were calculated and stratified into four categories low (1st-50th), moderate (>50th-75th), high (>75th-90th), and very high (>90th+)]. Multivariable adjusted logistic regression models with complex survey methods were used to test the effect of MetS severity on MASLD.

RESULTS

The age-adjusted MASLD prevalence was 17.4%, 25.7%, 42.5, and 54.9% in adults with mild, moderate, high, and very high MetS severities, respectively (P-trend <0.001). MetS severity was significantly higher in patients with MASLD than in those without [mean percentile 60th vs. 44th, P<0.001]. Among patients with MASLD, Mexican-American and Black non-Hispanic females had significantly higher age-adjusted MetS severity (68th and 61st, respectively) than White non-Hispanic females 54th, while Black non-Hispanic males had significantly lower MetS severity (56th) than White non-Hispanic males (70th) (P-Interaction = 0.02). Adults with high and very high MetS severity had 2.27 (95% CI:1.70 to 3.03) and 3.12 (95% CI:2.20 to 4.42), respectively, higher adjusted odds of MASLD than those with mild MetS severity.

CONCLUSIONS

Racial/ethnic disparities in MetS severity play a pivotal role in the risk of MASLD. Our findings highlight the potential clinical utility of the MetS severity score in identifying at-risk individuals, which will help guide targeted prevention and tailoring management strategies to mitigate the MASLD burden.

Cardiovascular outcomes post bariatric surgery in patients with metabolic dysfunction-associated steatotic liver disease - A systematic review and meta-analysis

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is linked with an increased risk of adverse cardiovascular events. Studies have suggested an association between the reduction of incident cardiovascular events in patients with MASLD after bariatric surgery. This systematic review and meta-analysis were performed to assess the influence of bariatric surgery on cardiovascular outcomes in patients with diagnosed MASLD by identifying all available cohort studies and pooling their data.

METHODS

PubMed and Google Scholar databases were searched till July 2023 for published studies that assessed the effect of bariatric surgery on cardiovascular outcomes in MASLD patients. Using a random effects model, hazard ratios (HRs) with 95 % confidence intervals (CIs) were pooled.

RESULTS

The systematic review identified three cohort studies. The analysis of 240,516 MASLD patients found a significantly reduced incidence of cardiovascular events. (HR 0.51; 95 % CI 0.48 to 0.54, P value <0.00001).

CONCLUSION

Bariatric surgery in MASLD patients significantly reduced the incidence of cardiovascular events, suggesting that bariatric surgery is an effective therapeutic tool among MASLD patients compared to non-surgical interventions.

De Novo Cost-Effectiveness Model Framework for Nonalcoholic Steatohepatitis-Modeling Approach and Validation

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a chronic liver disease associated with hepatic morbidity and mortality and extra-hepatic comorbidities. Published NASH cost-effectiveness models (CEMs) are heterogeneous and consistently omit comorbid conditions that frequently co-exist alongside NASH. We aimed to develop a de novo CEM framework that incorporates extra-hepatic disease states and outcomes alongside hepatic components to enable future estimation of the cost-effectiveness of NASH interventions.

METHODS

Patient-level simulation and cohort-level Markov models were implemented in the same framework. Model inputs included fibrosis progression; late-stage liver disease outcomes; comorbidity outcomes for cardiovascular disease, type 2 diabetes, and obesity; mortality; health-related quality of life; and direct medical costs. The prototype analysis assessed the cost-effectiveness of obeticholic acid versus standard of care from a US payer perspective over a lifetime horizon with costs and effects discounted at 3% per annum. However, the CEM was designed for easy adaptation to other countries, time horizons, and other considerations. Efficacy and adverse event parameters were obtained from the 18-month interim analysis of the REGENERATE trial. Outputs include total and incremental costs, total life years, and quality-adjusted life years.

RESULTS

In this model, total costs, total life years, and quality-adjusted life years were all higher with obeticholic acid compared with standard of care. Cross-validation of this model with the 2016 and 2020 Institute for Clinical and Economic Review models revealed marked differences, mainly driven by mortality inputs, transition probability estimates, and incorporation of the effect of treatment and comorbidities.

CONCLUSION

This is the first CEM in NASH to incorporate the clinical consequences of several comorbidities. The flexible yet standardized framework permits estimation of the cost-effectiveness of NASH interventions in a variety of settings. The model currently includes several assumptions and will be further developed as more relevant data become available.

Physical Activity Protocols in Non-Alcoholic Fatty Liver Disease Management: A Systematic Review of Randomized Clinical Trials and Animal Models

Non-alcoholic fatty liver disease (NAFLD) is closely associated with other metabolic disease and cardiovascular disease. Regular exercise reduces hepatic fat content and could be the first-line treatment in the management of NAFLD. This review aims to summarize the current evidence of the beneficial effects of exercise training and identify the molecular pathways involved in the response to exercise to define their role in the resolution of NAFLD both in animal and human studies. According to the inclusion criteria, 43 animal studies and 14 RCTs were included in this systematic review. Several exercise modalities were demonstrated to have a positive effect on liver function. Physical activity showed a strong association with improvement in inflammation, and reduction in steatohepatitis and fibrosis in experimental models. Furthermore, both aerobic and resistance exercise in human studies were demonstrated to reduce liver fat, and to improve insulin resistance and blood lipids, regardless of weight loss, although aerobic exercises may be more effective. Resistance exercise is more feasible for patients with NAFLD with poor cardiorespiratory fitness. More effort and awareness should be dedicated to encouraging NAFLD patients to adopt an active lifestyle and benefit from it its effects in order to reduce this growing public health problem.

Healthcare and socioeconomic costs of NAFLD: A global framework to navigate the uncertainties

Left unaddressed, non-alcoholic fatty liver disease (NAFLD) will continue to have substantial health, economic and social implications. To address the challenge, a paradigm shift is needed in the way NAFLD is conceptualised. Concerted, collaborative action across medical specialities, industry sectors and governments will be vital in tackling this public health threat. To drive this change, in this review, we present data on the current global healthcare and socioeconomic costs of NAFLD and highlight priority actions. The estimated healthcare costs of patients with NAFLD are nearly twice as high as their age-matched counterparts without the disease and are highest in those with advanced fibrosis and end-stage liver disease. NAFLD is accountable for the highest increase in DALYs (disability-adjusted life years) among all liver diseases globally. NAFLD and non-alcoholic steatohepatitis (NASH)-specific drug therapies are not yet available and there is considerable uncertainty regarding cost, optimal length of treatment, and their impact on liver-related outcomes and mortality. Among the currently available bariatric procedures, sleeve gastrectomy is reported to be the most cost-effective for NASH resolution. Gastric bypass remains very expensive, while data on bariatric endoscopy are limited. Lastly, we propose a global NAFLD/NASH investment framework to guide the development of achievable yet ambitious country-specific targets and strategic actions to optimise resource allocation and reduce the prevalence of NAFLD and NASH. Its focus on high-level inputs will be critical to enabling a political and financial environment that supports clinical-level implementation of NAFLD prevention, treatment and care efforts, across all settings.

Screening for NAFLD-Current Knowledge and Challenges

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of abnormal liver function tests worldwide, with an estimated prevalence ranging between 19-46% in the general population. Of note, NAFLD is also expected to become a leading cause of end-stage liver disease in the next decades. Given the high prevalence and severity of NAFLD, especially in high-risk populations (i.e., patients with type-2 diabetes mellitus and/or obesity), there is a major interest in early detection of the disease in primary care. Nevertheless, substantial uncertainties still surround the development of a screening policy for NAFLD, such as limitations in currently used non-invasive markers of fibrosis, cost-effectiveness and the absence of a licensed treatment. In this review, we summarise current knowledge and try to identify the limitations surrounding the screening policy for NAFLD in primary care.

Early Cost-Effectiveness and Price Threshold Analyses of Resmetirom: An Investigational Treatment for Management of Nonalcoholic Steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is characterized by inflammation and hepatocellular damage caused by accumulation of fat in the liver. Resmetirom (MGL-3196) is an orally administered, small-molecule, liver-targeted, selective thyroid hormone receptor-β agonist. This early analysis explored the potential cost effectiveness of resmetirom for the treatment of NASH from a US commercial payer perspective.

METHODS

An early economic model was developed to reflect the clinical pathways typically followed by patients with NASH and liver fibrosis. Use of resmetirom, compared with placebo, was assessed. The Markov model structure was informed by a previous modeling study and a randomized, double-blind, placebo-controlled, phase II trial of resmetirom. Costs and outcomes were assessed over a lifetime time horizon with results presented in terms of cost per quality-adjusted life-year (QALY) gained.

RESULTS

Resmetirom treatment resulted in increased costs of US$66,764 per patient, while increasing QALYs by 1.24. The incremental cost-effectiveness ratio was US$53,929 per QALY gained, indicating resmetirom treatment would potentially be cost effective at a willingness-to-pay (WTP) threshold of US$100,000. Results indicated that resmetirom would reduce the lifetime number of cases of decompensated cirrhosis (- 87), hepatocellular carcinoma (- 59), and liver transplants (- 30) per 1,000 patients compared with placebo. Resmetirom treatment remained cost effective at a US$100,000 WTP threshold up to a daily price point of US$72.00.

CONCLUSION

Resmetirom is a potentially cost-effective treatment option for patients with NASH and liver fibrosis based on an analysis performed from a US commercial payer perspective. Future economic analyses of the technology should, however, focus on overcoming the limitations of existing modeling methodology.

Association of Bariatric Surgery With Cardiovascular Outcomes in Adults With Severe Obesity and Nonalcoholic Fatty Liver Disease

Importance

There are no approved treatments for nonalcoholic fatty liver disease (NAFLD) despite its association with obesity and increased risk of cardiovascular disease (CVD).

Objective

To examine the association between bariatric surgery and CVD risk in individuals with severe obesity and NAFLD.

Design, Setting, and Participants

This large, population-based retrospective cohort study obtained data from the MarketScan Commercial Claims and Encounters database from January 1, 2007, to December 31, 2017. Participants included insured adults aged 18 to 64 years with NAFLD and severe obesity (body mass index ≥40) without a history of bariatric surgery or CVD before NAFLD diagnosis. Baseline characteristics were balanced between individuals who underwent surgery (surgical group) and those who did not (nonsurgical group) using inverse probability of treatment weighting. Data were analyzed from March 2020 to April 2021.

Exposures

Bariatric surgery (Roux-en-Y gastric bypass, sleeve gastrectomy, and other bariatric procedures) vs nonsurgical care.

Main Outcomes and Measures

The main outcome was the incidence of cardiovascular events (primary or secondary composite CVD outcomes). The primary composite outcome included myocardial infarction, heart failure, or ischemic stroke, and the secondary composite outcome included secondary ischemic heart events, transient ischemic attack, secondary cerebrovascular events, arterial embolism and thrombosis, or atherosclerosis. Cox proportional hazards regression models with inverse probability treatment weighting were used to examine the associations between bariatric surgery, modeled as time varying, and all outcomes.

Results

The study included 86 964 adults (mean [SD] age, 44.3 [10.9] years; 59 773 women [68.7%]). Of these individuals, 30 300 (34.8%) underwent bariatric surgery and 56 664 (65.2%) received nonsurgical care. All baseline covariates were balanced after applying inverse probability treatment weighting. In the surgical group, 1568 individuals experienced incident cardiovascular events compared with 7215 individuals in the nonsurgical group (incidence rate difference, 4.8 [95% CI, 4.5-5.0] per 100 person-years). At the end of the study, bariatric surgery was associated with a 49% lower risk of CVD (adjusted hazard ratio [aHR], 0.51; 95% CI, 0.48-0.54) compared with nonsurgical care. The risk of primary composite CVD outcomes was reduced by 47% (aHR, 0.53 [95% CI, 0.48-0.59), and the risk of secondary composite CVD outcomes decreased by 50% (aHR, 0.50; 95% CI, 0.46-0.53) in individuals with vs without surgery.

Conclusions and Relevance

Results of this study suggest that, compared with nonsurgical care, bariatric surgery was associated with significant reduction in CVD risk in individuals with severe obesity and NAFLD.