Efficacy and safety of a fixed bimonthly ranibizumab treatment regimen in eyes with neovascular age-related macular degeneration: results from the RABIMO trial

Abstract

Purpose: To evaluate prospectively the efficacy and safety of a fixed bimonthly ranibizumab treatment regimen (RABIMO) in eyes with neovascular age-related macular degeneration (nAMD) and to compare these results with a pro re nata (PRN) treatment scheme.

Methods: This was a 12-month, phase IV, single center, randomised, non-inferiority study. Following three initial monthly injections, patients were randomised to receive either ranibizumab bimonthly (RABIMO group) or ranibizumab PRN (PRN group) (n = 20 each). Main outcome measures were best-corrected visual acuity (BCVA), central retinal thickness (CRT), number of injections, and adverse events (AEs).

Results: BCVA [median (interquartile range, IQR)] increased significantly in both groups after 12 months [RABIMO group +8.5 (14); PRN group +6.5 (16) ETDRS letters] when compared to baseline (p < 0.0001; p = 0.0085). At month 12, the RABIMO treatment regimen was non-inferior to the PRN scheme (∆BCVA = 3.5 ETDRS letters; p < 0.0001). CRT was significantly reduced in both groups after the 12-month study period (p < 0.0001 each), with no significant difference between groups (p = 0.6772). Number of overall injections [median (IQR)] was 8 (0) in the RABIMO versus 4 (5) in the PRN group (p = 0.0037). Three patients in the RABIMO group received one additional unscheduled injection. We observed no significant differences between groups in the number of patients with reported SAEs/AEs (RABIMO group n = 6/15; PRN group n = 7/13) (p = 0.7357/p = 0.4902).

Conclusions: We found no evidence of significant functional or anatomical differences between the RABIMO and PRN treatment regimens. However, the RABIMO group's number of injections was twice as high as the PRN group's (protocol-driven). In light of potential side effects, the fixed bimonthly treatment regimen might not be advisable for routine clinical care, but it might be a worthwhile treatment option if monthly monitoring is not possible. Eudra-CT number: 2009-017324-11.

Keywords: AMD; Age-related macular degeneration; Optical coherence tomography; PRN; Ranibizumab; Treatment schedule.