Intravitreal Aflibercept Compared to Ranibizumab for Wet Age‐related Macular Degeneration in the US: Cost-effectiveness Analysis

Background

Wet age-related macular degeneration (wAMD) is the leading cause of visual impairment and blindness in the United States (US). Intravitreal aflibercept injection (IAI) and ranibizumab (RBZ) are the two most commonly used anti-vascular endothelial growth factor treatments approved by the US Food and Drug Administration for the treatment of wAMD. Randomized clinical trials in patients with wAMD have shown similar efficacy, safety, and tolerability between IAI administered every 8 weeks after 3 initial monthly injections, IAI monthly, and monthly RBZ. Therefore, associated costs and cost-effectiveness comparisons are key factors to determine which treatment represents a more rational investment of scarce health care resources. This assessment may help address the increasing cost of prescription drugs in the US, a source of concern for patients, prescribers, payers, and policy makers.

Objective

To assess the cost-effectiveness of IAI (2mg every 8 weeks after 3 initial monthly doses [2q8]) vs. RBZ (intravitreal, 0.5mg monthly) and RBZ (intravitreal, 0.5mg as needed [PRN]) for wAMD from a US payer perspective.

Methods

A Markov cohort model was developed to estimate the lifetime quality-adjusted life years (QALYs) and costs of treating patients with wAMD with IAI 2q8, RBZ dosed monthly, and RBZ dosed PRN. The model considered changes in best-corrected visual acuity (BCVA) in the affected and fellow eye over time, and the impact of blindness on mortality. Efficacy data for IAI 2q8 and RBZ dosed monthly, for the first 52 weeks, were from the VIEW 1 and VIEW 2 studies, and from the CATT trial for RBZ dosed PRN. Patients were assumed to be treated for a maximum of 2 years, with BCVA remaining stable between the first and second year in patients remaining on treatment. Natural progression of BCVA loss was applied in patients discontinuing treatment. Background mortality, from US life tables, was adjusted with published hazard ratios for wAMD and blindness. Utilities were from published literature and based on BCVA in the best-seeing eye. Costs (drug acquisition, monitoring, blindness) were from published literature and estimated in 2016 US dollars. Health outcomes and costs were discounted at 3% per annum.

Results

Over a lifetime, IAI 2q8 provided equal health benefits vs. RBZ dosed monthly (5.44 QALYs) at a lower total cost ($33,795 versus $48,031) as a result of fewer injections. IAI yielded incremental health benefits vs. RBZ dosed PRN (5.44 versus 5.40 QALYs) at a higher cost ($33,795 versus $33,652), with an incremental cost per QALY gained of $2,715. Results were sensitive to variations in drug acquisition costs and number of injections of both drugs, and the baseline age of the cohort.

Conclusion

IAI 2q8 can be cost-saving and cost-effective compared with RBZ dosed monthly and RBZ dosed PRN, respectively, for the treatment of wAMD in the US.