External Validation of the Core Obesity Model to Assess the Cost-Effectiveness of Weight Management Interventions

Cost-effectiveness of weight-management pharmacotherapies in Canada: a societal perspective

OBJECTIVES

This study aimed to assess the cost-effectiveness of weight-management pharmacotherapies approved by Canada Health, i.e., orlistat, naltrexone 32 mg/bupropion 360 mg (NB-32), liraglutide 3.0 mg and semaglutide 2.4 mg as compared to the current standard of care (SoC).

METHODS

Analyses were conducted using a cohort with a mean starting age 50 years, body mass index (BMI) 37.5 kg/m2, and 27.6% having type 2 diabetes. Using treatment-specific changes in surrogate endpoints from the STEP trials (BMI, glycemic, blood pressure, lipids), besides a network meta-analysis, the occurrence of weight-related complications, costs, and quality-adjusted life-years (QALYs) were projected over lifetime.

RESULTS

From a societal perspective, at a willingness-to-pay (WTP) threshold of CAD 50 000 per QALY, semaglutide 2.4 mg was the most cost-effective treatment, at an incremental cost-utility ratio (ICUR) of CAD 31 243 and CAD 29 014 per QALY gained versus the next best alternative, i.e., orlistat, and SoC, respectively. Semaglutide 2.4 mg extendedly dominated other pharmacotherapies such as NB-32 or liraglutide 3.0 mg and remained cost-effective both under a public and private payer perspective. Results were robust to sensitivity analyses varying post-treatment catch-up rates, longer treatment durations and using real-world cohort characteristics. Semaglutide 2.4 mg was the preferred intervention, with a likelihood of 70% at a WTP threshold of CAD 50 000 per QALY gained. However, when the modeled benefits of weight-loss on cancer, mortality, cardiovascular disease (CVD) or osteoarthritis surgeries were removed simultaneously, orlistat emerged as the best value for money compared with SoC, with an ICUR of CAD 35 723 per QALY gained.

CONCLUSION

Semaglutide 2.4 mg was the most cost-effective treatment alternative compared with D&E or orlistat alone, and extendedly dominated other pharmacotherapies such as NB-32 or liraglutide 3.0 mg. Results were sensitive to the inclusion of the combined benefits of mortality, cancer, CVD, and knee osteoarthritis.

Cost-effectiveness of semaglutide 2.4 mg in chronic weight management in Portugal

BACKGROUND

Obesity and overweight are a significant public health concern. Subcutaneous semaglutide 2.4 mg injection is a glucagon-like peptide-1 (GLP-1) analogue approved by the European Medicines Agency as an adjunct to a reduced calorie diet and increased physical activity (diet and exercise, D&E) for the treatment obesity and overweight in the presence of at least one weight related comorbidity. This study aimed to assess the cost-effectiveness of semaglutide 2.4 mg in combination with D&E compared to D&E alone for the Portuguese setting.

METHODS

Analysis were conducted using the Core Obesity Model (COM) version 18, a Markov state transition cohort model, to predict the health outcomes and costs of weight related complications based on changes in surrogate endpoints. Efficacy and safety data were sourced from the STEP trials (Body Mass Index, systolic blood pressure and glycemic status) from a cohort of adults aged on average 48 years with obesity (BMI ≥ 30 kg/m2) and ≥ 1 obesity-related comorbidities, over a time horizon of 40 years. Costs were estimated from the perspective of the Portuguese National Health Service. Sensitivity analyses were conducted to test the robustness of results across a range of assumptions.

RESULTS

On a patient level, Semaglutide 2.4 mg in addition to D&E compared to D&E alone, improved QALYs by 0.098 and yielded higher costs by 1,325 EUR over a 40-year time horizon, with an ICER of 13,459 EUR per QALY gained and 100% probability of cost-effectiveness at the given WTP. Semaglutide 2.4 mg remained cost-effective across all different scenarios and sensitivity analysis at a WTP of 20,000 EUR per QALY. Among the subpopulations examined, Semaglutide 2.4 mg yielded ICERs of 18,459 EUR for patients with BMI ≥ 30 kg/m2 and of 22,657 EUR for patients with BMI ≥ 35 kg/m2.

CONCLUSIONS

Semaglutide 2.4 mg was cost-effective compared to D&E alone for patients with obesity (BMI ≥ 30 kg/m2) and weight related comorbidities in Portugal, over a 40-year time horizon.

Cost-effectiveness analysis of five anti-obesity medications from a US payer's perspective

BACKGROUND AND AIMS

To determine the cost-effectiveness of anti-obesity medications (AOM): tirzepatide, semaglutide, liraglutide, phentermine plus topiramate (PpT), and naltrexone plus bupropion (NpB).

METHODS AND RESULTS

From a U.S. perspective we developed a Markov model to simulate weight change over a 40-year time horizon using results from clinical studies. According to the body mass index (BMI), cardiovascular diseases, diabetes and mortality risk were the health states considered in the model, being mutually exclusive. Costs of AOM, adverse events, cardiovascular events, and diabetes were included. We applied a 3% per-year discount rate and calculated the incremental cost-effectiveness ratios (ICERs) of cost per quality-adjusted life-year (QALY) gained. Probabilistic sensitivity analyses incorporated uncertainty in input parameters. A deterministic analysis was conducted to determine the robustness of the model. The model included a cohort of 78.2% females with a mean age of 45 years and BMI of 37.1 (SD 4.9) for females and 36.8 (SD 4.9) for males. NpB and PpT were the least costly medications and, all medications differed no more than 0.5 QALYs. Tirzepatide ICER was $355,616 per QALY. Liraglutide and semaglutide options were dominated by PpT.

CONCLUSION

Compared to other AOM, PpT was lowest cost treatment with nearly identical QALYs with other agents.

Once-Weekly Subcutaneous Semaglutide 2.4 mg Injection is Cost-Effective for Weight Management in the United Kingdom

OBJECTIVES

The objective of the current preliminary study was to present the cost-effectiveness analyses submitted to the National Institute for Health and Care Excellence (NICE) (TA10765) that deemed semaglutide 2.4 mg subcutaneous (s.c.) injection a cost-effective option for weight management in the United Kingdom (UK) alongside diet and exercise (D&E).

METHODS

The study was conducted from the National Health Service (NHS) and Personal Social Services perspective and based on the NICE reference case. The clinical safety and efficacy of semaglutide 2.4 mg s.c. injection were obtained from the Semaglutide Treatment Effect in People with Obesity (STEP) 1 trial. The previously published and validated Core Obesity Model was used to project lifetime occurrence of obesity complications, their costs and quality of life consequences over 40 years. The base case cohort had a mean starting age of 48 years and BMI of 38.7 kg/m². The confidential NHS price for semaglutide 2.4 mg s.c. injection was provided by Novo Nordisk. The incremental cost-effectiveness ratios (ICERs) were expressed as cost/quality-adjusted life-year (QALY). Uncertainty was assessed through sensitivity analyses, including a scenario analysis using clinical data from the STEP 2 trial and a previously published and validated Core Diabetes Model to investigate a cohort with type 2 diabetes at baseline.

RESULTS

Semaglutide 2.4 mg s.c. injection showed higher total costs and health benefits compared with D&E, with an ICER of £14,827/QALY gained. The probabilistic sensitivity analysis showed that semaglutide 2.4 mg s.c. injection was cost-effective in 90% of cases at a willingness-to-pay threshold of £20,000/QALY. The ICER from the scenario analysis for the diabetic population was £16,613/QALY gained, using the Core Diabetes Model.

CONCLUSION

Semaglutide 2.4 mg s.c. injection is a cost-effective therapy compared to D&E alone for patients with obesity and weight-related comorbidities in the UK. Sensitivity and scenario analyses confirm the robustness of the analyses.

Cost-effectiveness analysis of endovascular treatment with or without intravenous thrombolysis in acute ischemic stroke

OBJECTIVE

Intravenous (IV) recombinant tissue plasminogen activator (r-tPA) may not provide additional benefit in terms of functional outcomes in patients with acute ischemic stroke (AIS) who undergo endovascular treatment (EVT). In this context, the cost-effectiveness of EVT alone compared with its application following IV r-tPA has not been evaluated.

METHODS

The authors determined the average rates of death or disability in each of the two treatment groups from four randomized clinical trials that enrolled patients with AIS within 4.5 hours of symptom onset and randomly assigned patients to EVT alone and IV r-tPA and EVT. By using three sources derived from previous studies, the authors determined the cost of IV r-tPA, cost of staff time for administration, cost of the EVT, cost of hospital stay, costs of supported discharge and community care, and cost of posthospitalization care and disability. They then assessed the cost-effectiveness of EVT alone using a decision tree for the 1st year after AIS and a Markov model with a 10-year horizon, including probabilistic assessment by Monte Carlo simulations.

RESULTS

The 1-year cost was higher with IV r-tPA and EVT compared with EVT alone (incremental cost ranging between $3554 and $13,788 per patient). The mean incremental cost-effectiveness ratios (ICERs) were -$1589, -$78,327, and -$15,471 per quality-adjusted life-year gained for cost sources 1, 2, and 3, respectively, for EVT alone compared with IV r-tPA and EVT at 10 years. The ceiling ICER (willingness to pay) for a probability of 100% that EVT alone was more cost-effective ranged between $25,000 and $100,000 in the three models.

CONCLUSIONS

EVT alone appears to be more cost-effective compared with EVT and IV r-tPA for the treatment of AIS patients presenting within 4.5 hours of symptom onset.

Does the Structure Matter? An External Validation and Health Economic Results Comparison of Event Simulation Approaches in Severe Obesity

OBJECTIVES

As obesity-associated events impact long-term survival, health economic (HE) modelling is commonly applied, but modelling approaches are diverse. This research aimed to compare the events simulation and the HE outcomes produced by different obesity modelling approaches.

METHODS

An external validation, using the Swedish obesity subjects (SOS) study, of three main structural event modelling approaches was performed: (1) continuous body mass index (BMI) approach; (2) risk equation approach; and (3) categorical BMI-related approach. Outcomes evaluated were mortality, cardiovascular events, and type 2 diabetes (T2D) for both the surgery and the control arms. Concordance between modelling results and the SOS study were investigated by different state-of-the-art measurements, and categorized by the grade of deviation observed (grades 1-4 expressing mild, moderate, severe, and very severe deviations). Furthermore, the costs per quality-adjusted life-year (QALY) gained of surgery versus controls were compared.

RESULTS

Overall and by study arm, the risk equation approach presented the lowest average grade of deviation (overall grade 2.50; control arm 2.25; surgery arm 2.75), followed by the continuous BMI approach (overall 3.25; control 3.50; surgery 3.00) and by the categorial BMI approach (overall 3.63; control 3.50; surgery 3.75). Considering different confidence interval limits, the costs per QALY gained were fairly comparable between all structural approaches (ranging from £2,055 to £6,206 simulating a lifetime horizon).

CONCLUSION

None of the structural approaches provided perfect external event validation, although the risk equation approach showed the lowest overall deviations. The economic outcomes resulting from the three approaches were fairly comparable.

Cost-effectiveness analysis of semaglutide 2.4 mg for the treatment of adult patients with overweight and obesity in the United States

BACKGROUND: The rising prevalence and associated public health burden of obesity has led to advancements in pharmaceuticals for weight management. Semaglutide 2.4 mg, an anti-obesity medication (AOM) recently approved by the US Food and Drug Administration, has demonstrated clinically relevant weight loss in its phase 3 clinical trials. Economic evaluation comparing semaglutide 2.4 mg with other available weight management therapies is essential to inform payers for decision-making. OBJECTIVES: To assess the cost-effectiveness of semaglutide 2.4 mg in the treatment of adult patients with obesity (ie, body mass index [BMI] ≥ 30) and adult patients who are overweight (ie, BMI 27-29.9) with 1 or more weight-related comorbidities from a US third-party payer perspective. METHODS: A cohort Markov model was constructed to compare semaglutide 2.4 mg with the following comparators: no treatment, diet and exercise (D&E), and 3 branded AOMs (liraglutide 3 mg, phentermine-topiramate, and naltrexone-bupropion). All AOMs, including semaglutide 2.4 mg, were assumed to be taken in conjunction with D&E. Changes in BMI, blood pressure, cholesterol level, experience of acute and chronic obesity-related complications, costs, and quality-adjusted life years (QALYs) were simulated over 30 years based on pivotal trials of the AOMs and other relevant literature. Drug and health care prices reflect 2021 standardized values. Cost-effectiveness was examined with a willingness-to-pay (WTP) threshold of $150,000 per QALY gained. Sensitivity analyses were conducted to test the robustness of the cost-effectiveness results to plausible variation in model inputs. RESULTS: In the base-case analysis, treatment with semaglutide 2.4 mg was estimated to improve QALYs by 0.138 to 0.925 and incur higher costs by $3,254 to $25,086 over the 30-year time horizon vs comparators. Semaglutide 2.4 mg is cost-effective against all comparators at the prespecified WTP threshold, with the incremental cost per QALY gained ranging from $23,556 to $144,296 per QALY gained. In the sensitivity analysis, extended maximum treatment duration, types of subsequent treatment following therapy discontinuation, and weight-rebound rates were identified as key drivers for model results. The estimated probability of semaglutide 2.4 mg being cost-effective compared with comparators ranged from 67% to 100% when varying model parameters and assumptions. CONCLUSIONS: As a long-term weight management therapy, semaglutide 2.4 mg was estimated to be cost-effective compared with no treatment, D&E alone, and all other branded AOM comparators under a WTP threshold of $150,000 per QALY gained over a 30-year time horizon. DISCLOSURES: Financial support for this research was provided by Novo Nordisk Inc. The study sponsor was involved in several aspects of the research, including the study design, the interpretation of data, the writing of the manuscript, and the decision to submit the manuscript for publication. Dr Kim and Ms Ramasamy are employees of Novo Nordisk Inc. Ms Kumar and Dr Burudpakdee were employees of Novo Nordisk Inc at the time this study was conducted. Dr Sullivan received research support from Novo Nordisk Inc for this study. Drs Wang, Song, Wu, Ms Xie, and Ms Sun are employees of Analysis Group, Inc, who received consultancy fees from Novo Nordisk Inc in connection with this study.

A novel decision model to predict the impact of weight management interventions: The Core Obesity Model

Aims

Models are needed to quantify the economic implications of obesity in relation to health outcomes and health-related quality of life. This report presents the structure of the Core Obesity Model (COM) and compare its predictions with the UK clinical practice data.

Materials and methods

The COM is a Markov, closed-cohort model, which expands on earlier obesity models by including prediabetes as a risk factor for type 2 diabetes (T2D), and sleep apnea and cancer as health outcomes. Selected outcomes predicted by the COM were compared with observed event rates from the Clinical Practice Research Datalink-Hospital Episode Statistics (CPRD-HES) study. The importance of baseline prediabetes prevalence, a factor not taken into account in previous economic models of obesity, was tested in a scenario analysis using data from the 2011 Health Survey of England.

Results

Cardiovascular (CV) event rates predicted by the COM were well matched with those in the CPRD-HES study (7.8-8.5 per 1000 patient-years across BMI groups) in both base case and scenario analyses (8.0-9.4 and 8.6-9.9, respectively). Rates of T2D were underpredicted in the base case (1.0-7.6 vs. 2.1-22.7) but increased to match those observed in CPRD-HES for some BMI groups when a prospectively collected prediabetes prevalence was used (2.7-13.1). Mortality rates in the CPRD-HES were consistently higher than the COM predictions, especially in higher BMI groups.

Conclusions

The COM predicts the occurrence of CV events and T2D with a good degree of accuracy, particularly when prediabetes is included in the model, indicating the importance of considering this risk factor in economic models of obesity.