Abstract
Purpose :
A “discontinuous” (PRN or fixed quarterly interval) anti-VEGF regimen for neovascular age-related macular degeneration (NAMD) results in less favorable visual outcome than “continuous” (monthly) therapy. Furthermore, patients experiencing a drop in visual acuity (VA) may never recover, despite subsequent implementation of intensive treatment. The purpose of this analysis is to assess visual and anatomic outcomes in subjects experiencing loss of vision in a Phase 2b Study investigating Platelet Derived Growth Factor (PDGF) inhibition in combination with a VEGF inhibitor for NAMD.
Methods :
449 subjects with NAMD were randomized in a prospective, controlled, superiority trial to receive one of the following treatment regimens administered “continuously” for 24 weeks: Fovista® (anti-PDGF agent) 0.3mg in combination with ranibizumab 0.5 mg; Fovista® 1.5 mg in combination with ranibizumab 0.5 mg (“combination therapy”); or sham in combination with ranibizumab 0.5 mg (“monotherapy”). Retrospective analysis of visual outcome and anatomic assessment at 24 weeks was performed in two cohorts comparing combination therapy vs. monotherapy. Cohort 1 included subjects experiencing visual loss at 4 weeks and cohort 2 included subjects experiencing visual loss at 12 weeks.
Results :
In cohort 1, monotherapy after the 4-week timepoint resulted in a gain of +0.6 letters (per protocol) versus +4.6 letters following combination therapy at 24 weeks. In cohort 2 monotherapy after the 12-week timepoint resulted in a gain of +0.1 letters versus +3.9 letters following combination therapy at 24 weeks. 27% vs. 54% of patients with VA loss had increased fibrosis from baseline in the combination and monotherapy arms respectively at 24 weeks.
Conclusions :
During discontinuous anti-VEGF treatment, patients who experience decreased VA may never recover, due to continued growth of the CNV, fibrosis, and/or geographic atrophy. This analysis showed that following early onset of visual loss, anti-VEGF monotherapy results in visual stabilization whereas combination therapy (anti-PDGF/VEGF) results in visual gain. This improvement of VA with combination therapy (anti-PDGF/VEGF) is associated with reduction of fibrosis. A rationale exists to investigate discontinuous combination therapy in a randomized trial.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.