Background: Age-related macular degeneration (AMD) is a blinding disease placing considerable burden on society due to blindness-associated costs. Intravitreal anti-vascular endothelial growth factors (anti-VEGFs) are effective in reducing the incidence of blindness, but at potentially high costs, depending on the cost of the drug used. Aflibercept has been introduced as an anti-VEGF equally effective to ranibizumab, but less costly. For this new drug, new cost-effectiveness analyses are needed, and AMD models used today give biased results. We investigated the cost-effectiveness of aflibercept compared to bevacizumab, ranibizumab, and no treatment and studied the influence of commonly used model parameters.
Methods: A patient-level, visual acuity-based, 2-eye model was developed. Data on effectiveness were derived from randomized controlled trials evaluating the outcomes of aflibercept, bevacizumab, and ranibizumab. Utility and resource utilization were assessed in interviews with AMD patients. Costs were based on standard health care cost prices. Time horizons were two and five years. A societal perspective was employed.
Results: Over five years, costs associated with aflibercept treatment were <euro>36,030, with 2.15 QALYs. Costs associated with the bevacizumab regimens, ABC study as-needed (PRN); CATT study PRN; and CATT study 1×/month, were <euro>19,367; <euro>26,746; and <euro>30,520, with 2.16; 2.17; and 2.15 QALYs, respectively. Costs associated with ranibizumab PRN and 1×/month were <euro>45,491 and <euro>74,837 with 2.16 and 2.15 QALYs, respectively. 'No treatment' was associated with <euro>9530 and 1.96 QALYs. The incremental cost-effectiveness ratios versus 'no treatment' were: aflibercept-<euro>140,274; bevacizumab-<euro>51,062 (ABC PRN), <euro>83,256 (CATT PRN) and <euro>110,361 (1×/month); ranibizumab-<euro>181,667 (PRN) and <euro>349,773 (1×/month). Results were highly dependent on whether only one or both eyes were included, length of time horizon, and whether the costs of blindness and low-vision were included in the analysis.
Conclusions: Aflibercept is a cost-effective treatment for AMD over ranibizumab. However, aflibercept is not a cost-effective treatment when compared to bevacizumab. Application of inappropriate model assumptions leads to a biased cost-saving estimate of the cost-effectiveness of aflibercept. Therefore, cost-effectiveness analyses should be conducted with appropriate models.