A variable-dosing regimen with intravitreal ranibizumab for neovascular age-related macular degeneration: year 2 of the PrONTO Study

Abstract

Purpose: To assess the long-term efficacy of a variable-dosing regimen with ranibizumab in the Prospective Optical Coherence Tomography (OCT) Imaging of Patients with Neovascular Age-Related Macular Degeneration (AMD) Treated with intraOcular Ranibizumab (PrONTO) Study, patients were followed for 2 years.

Design: A 2-year prospective, uncontrolled, variable-dosing regimen with intravitreal ranibizumab based on OCT.

Methods: In this open-label, prospective, single-center, uncontrolled clinical study, AMD patients with neovascularization involving the central fovea and a central retinal thickness (CRT) of at least 300 microm as measured by OCT were enrolled to receive 3 consecutive monthly intravitreal injections of ranibizumab (0.5 mg) [Lucentis; Genentech Inc, South San Francisco, California, USA]. During the first year, retreatment with ranibizumab was performed at each monthly visit if any criterion was fulfilled such as an increase in OCT-CRT of at least 100 microm or a loss of 5 letters or more. During the second year, the retreatment criteria were amended to include retreatment if any qualitative increase in the amount of fluid was detected using OCT.

Results: Forty patients were enrolled and 37 completed the 2-year study. At month 24, the mean visual acuity (VA) improved by 11.1 letters (P < .001) and the OCT-CRT decreased by 212 microm (P < .001). VA improved by 15 letters or more in 43% of patients. These VA and OCT outcomes were achieved with an average of 9.9 injections over 24 months.

Conclusions: The PrONTO Study using an OCT-guided variable-dosing regimen with intravitreal ranibizumab resulted in VA outcomes comparable with the outcomes from the phase III clinical studies, but fewer intravitreal injections were required.

Trial registration: ClinicalTrials.gov NCT00344227.