The ABC Trial - A Randomised, Double-Masked Phase III Study of the Efficacy and Safety of Avastin® (Bevacizumab) Intravitreal Injections Compared to Standard Therapy in Subjects With Choroidal Neovascularisation (CNV) Secondary to Age-Related Macular Degeneration (AMD)

Abstract

Purpose:: Recent uncontrolled interventional case series indicate a treatment effect of intravitreal bevacizumab in the treatment of neovascular AMD. The ABC trial is a clinical trial designed to evaluate the safety and efficacy of intravitreal bevacizumab in the treatment of subfoveal CNV secondary to AMD. Recruitment is underway and the objectives are to compare the visual and anatomic outcomes and safety data in patients treated with intravitreal bevacizumab compared to standard therapy (either verteporfin photodynamic therapy (PDT), intravitreal Macugen® or sham treatment).

Methods:: This is a 12-month, prospective, randomised, controlled, double-masked study which will enrol 130 patients (trial power of 90% assuming 25% of patients in bevacizumab treated group achieve primary outcome measure of minimum 15 ETDRS letter gain at 12 months compared to 6% in standard therapy group with 5% type I error). Participants are randomly assigned (1:1) to intravitreal bevacizumab (1.25mg in 0.05ml) or to standard therapy (either PDT, Macugen® or sham). Patients randomised to bevacizumab will receive 3 intravitreal injections at 6 weekly intervals with further physician driven retreatment using standardised retreatment criteria every 6 weeks. Inclusion criteria are: age >50 years, study eye best corrected visual acuity 20/40 to 20/320, subfoveal CNV lesion of any type, total lesion size < 12 MPS optic disc areas, area of fibrosis < 25% and blood < 50% of lesion area. Presumed disease progression must be observed in occult with no classic CNV lesions. A data and safety monitoring committee and steering committee are monitoring the conduct of the study.

Results:: Trial recruitment has commenced with demographic data and trial design details to be presented. No interim analyses are planned.

Conclusions:: Here we describe the first randomised controlled trial in AMD to both evaluate the efficacy of intravitreal bevacizumab and to use the novel endpoint of visual gain as the primary outcome measure. The results of the trial will provide nonbiased efficacy and safety data for intravitreal bevacizumab in the treatment of CNV secondary to AMD.

Clinical Trial:: www.ISRCTN.org ISRCTN83325075

Keywords: age-related macular degeneration • choroid: neovascularization