Cost-effectiveness model for neovascular age-related macular degeneration: comparing early and late treatment with pegaptanib sodium based on visual acuity.

Objective: To compare the cost-effectiveness of pegaptanib and usual care within three distinct cohorts of subfoveal neovascular age-related macular degeneration (NV-AMD) patients, that is, those with early, moderate, and late disease, using a comprehensive economic model.

Methods: A Markov framework was used to model lifetime movement of a subfoveal NV-AMD cohort through health states based on visual acuity. The model takes a US payer perspective of patients over the age of 65 years. Clinical efficacy was based on published results for the 0.3 mg pegaptanib and usual care groups. Expert interviews were conducted to determine adverse event treatment patterns and vision rehabilitation resource use. Incidence and costs of comorbidities such as depression and fractures associated with the effects of declining visual acuity were based on our previously published analysis of Medicare data. Transition probabilities were derived from published clinical trial data for each 3-month cycle. Utilities were derived from published sources. Three runs of the model were conducted with cohorts of newly diagnosed patients. Patients were classified as having early, moderate, or late NV-AMD defined as visual acuity in the better-seeing eye of 20/40 to more than 20/80, 20/80 to more than 20/200, and 20/200 to more than 20/400, respectively. Costs and outcomes were discounted 3.0% per annum.

Results: Incremental costs per vision-year gained and per quality-adjusted life-year (QALY) gained for early NV-AMD patients were approximately one-third those of patients with late disease ($15,279 vs. $57,230 and $36,282 vs. $132,381, respectively). On average, patients treated early with either pegaptanib or usual care incurred lower lifetime total direct costs than those treated later. Sensitivity analysis showed that base-case incremental costs per QALY gained for pegaptanib versus usual care were relatively robust.

Conclusions: For patients with subfoveal NV-AMD, treatment with pegaptanib should be started as early as possible to maximize the clinical and economic benefits.