Assessing the Impact of Exagamglogene Autotemcel (Exa-cel) on Health Inequalities in Patients with Sickle Cell Disease in the United Kingdom and Canada
Author(s)
Joshua Soboil, BA, MPH1, Michael Gargano, BS2, Andrea Lopez, MSc2, Chuka Udeze, PharmD2, Gabriela Vega-Hernandez, BSc, MSc2;
1Cogentia Healthcare Consulting, Cambridge, United Kingdom, 2Vertex Pharmaceuticals Incorporated, Boston, MA, USA
1Cogentia Healthcare Consulting, Cambridge, United Kingdom, 2Vertex Pharmaceuticals Incorporated, Boston, MA, USA
Presentation Documents
OBJECTIVES: Exagamglogene autotemcel (exa-cel) is an autologous gene therapy with the potential to provide a functional cure for patients with sickle cell disease (SCD) and recurrent vaso-occlusive crises. In the United Kingdom (UK) and Canada, SCD patients often receive suboptimal health care. We assessed the impact that exa-cel has on health inequalities within the exa-cel-eligible population in the UK and Canada.
METHODS: Distributional Cost-Effectiveness Analysis (DCEA) is a systematic approach to evaluating health inequalities and efficiency in the distribution of healthcare costs and outcomes; traditional cost-effectiveness analysis (CEA) only considers efficiency. We embedded an aggregate DCEA into published Markov models evaluating cost-effectiveness of exa-cel versus standard of care (SOC) in SCD. To assess exa-cel's impact on health inequalities, we applied metrics, such as the Slope Index of Inequality (SII), to estimate pre- and post-intervention health gaps between the most and least deprived population groups within the UK and Canada. We then applied indirect equity weights, calculated using a social welfare function, to CEA outcomes, including costs and quality-adjusted life-years (QALYs). The potential value of reducing health inequalities was assessed by comparing equity-weighted vs. traditional incremental cost-effectiveness ratios (ICERs).
RESULTS: Model projections suggest that, versus SOC, exa-cel may increase survival (mean age at death: UK: +28.4 years, Canada: +24.6 years) and quality-of-life (mean undiscounted QALYs: UK: +28.5, Canada: +27.9), and reduce disease burden (mean undiscounted disease-management costs: UK: -£362k, Canada: -$1.24M). Changes in SII of -72,938 (UK) and -38,934 (Canada) post-exa-cel represent substantial reductions in health inequality. The equity-weighted ICER in both countries is ~30% lower than the ICER for a traditional CEA.
CONCLUSIONS: In the UK and Canada, the DCEA methodology provides a quantitative approach to estimate how exa-cel may significantly lower health inequality, which is an important element for HTA bodies to incorporate into healthcare decision making.
METHODS: Distributional Cost-Effectiveness Analysis (DCEA) is a systematic approach to evaluating health inequalities and efficiency in the distribution of healthcare costs and outcomes; traditional cost-effectiveness analysis (CEA) only considers efficiency. We embedded an aggregate DCEA into published Markov models evaluating cost-effectiveness of exa-cel versus standard of care (SOC) in SCD. To assess exa-cel's impact on health inequalities, we applied metrics, such as the Slope Index of Inequality (SII), to estimate pre- and post-intervention health gaps between the most and least deprived population groups within the UK and Canada. We then applied indirect equity weights, calculated using a social welfare function, to CEA outcomes, including costs and quality-adjusted life-years (QALYs). The potential value of reducing health inequalities was assessed by comparing equity-weighted vs. traditional incremental cost-effectiveness ratios (ICERs).
RESULTS: Model projections suggest that, versus SOC, exa-cel may increase survival (mean age at death: UK: +28.4 years, Canada: +24.6 years) and quality-of-life (mean undiscounted QALYs: UK: +28.5, Canada: +27.9), and reduce disease burden (mean undiscounted disease-management costs: UK: -£362k, Canada: -$1.24M). Changes in SII of -72,938 (UK) and -38,934 (Canada) post-exa-cel represent substantial reductions in health inequality. The equity-weighted ICER in both countries is ~30% lower than the ICER for a traditional CEA.
CONCLUSIONS: In the UK and Canada, the DCEA methodology provides a quantitative approach to estimate how exa-cel may significantly lower health inequality, which is an important element for HTA bodies to incorporate into healthcare decision making.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
EE386
Topic
Economic Evaluation
Topic Subcategory
Novel & Social Elements of Value
Disease
SDC: Rare & Orphan Diseases, SDC: Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)