Ranibizumab for AMD: Dose and Frequency

Vaidehi S. Dedania, MD; Sophie J. Bakri, MD


December 17, 2013

In This Article

Twelve-Month Efficacy and Safety of 0.5 mg or 2.0 mg of Ranibizumab in Patients With Subfoveal Neovascular Age-related Macular Degeneration

Busbee BG, Ho AC, Brown DM, et al; HARBOR Study Group
Ophthalmology. 2013;120:1046-1056

The HARBOR Study

Ranibizumab, a monoclonal antibody directed at vascular endothelial growth factor (VEGF)-A, is approved by the US Food and Drug Administration for intravitreal use in the treatment of neovascular age-related macular degeneration (wet AMD).

In this 24-month, phase 3, randomized, multicenter, double-masked, dose-response study in 1097 treatment-naive patients aged ≥ 50 years with subfoveal wet AMD, intravitreal ranibizumab 0.5 mg was compared with ranibizumab 2.0 mg, dosed monthly or on an as-needed (PRN) basis after 3 monthly loading doses.

The rationale for the use of higher doses of ranibizumab in wet AMD is in part derived from the ANCHOR and the MARINA studies,[1,2] which demonstrated a greater improvement in best-corrected visual acuity (BCVA) in patients treated with 0.5 mg vs 0.3 mg ranibizumab. The rationale for PRN dosing of ranibizumab in wet AMD was also derived from the ANCHOR and MARINA studies, as well as from a study of a variable-dosing regimen with intravitreal ranibizumab for neovascular age-related macular degeneration (PrONTO).[3] The safety and tolerability of intravitreal ranibizumab 2.0 mg was assessed in a 10-patient safety run-in assessment before the HARBOR trial and continued throughout the trial.

Patients were randomly assigned to one of the following ranibizumab treatment groups in a 1:1:1:1 ratio:

  • 0.5 mg monthly;

  • 0.5 mg PRN;

  • 2.0 mg monthly; or

  • 2.0 mg PRN.

The primary efficacy endpoint was the mean change in BCVA from baseline to 12 months. Secondary endpoints included the mean number of ranibizumab injections, the mean change from baseline in central foveal thickness, and the proportion of patients who gained ≥ 15 letters of BCVA. Exploratory and post hoc endpoints of the proportion of patients with a Snellen equivalent ≤ 20/200 and the proportion of patients who lost < 15 letters from baseline at 12 months were also examined. Patient examinations were performed on the day of treatment initiation, 1 week after treatment initiation, and at monthly intervals from treatment initiation through 12 months.


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