A Variable-dosing Regimen with Intravitreal Ranibizumab for Neovascular Age-related Macular Degeneration: Year 2 of the PrONTO Study

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 μm 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 μm 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 μm (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.