Real-world outcomes of Aflibercept treatment for chronic diabetic macular edema in Bevacizumab non-responders in a Canadian setting

Abstract

Purpose : Off-label use of Bevacizumab, an anti-VEGF agent, has been shown to be effective in treatment of Diabetic macular edema (DME). However, many patients with DME do not respond or demonstrate only a partial response to this agent. Health Canada recently approved Aflibercept as an anti-VEGF agent for treatment of DME, and non-responders to Bevacizumab gained the opportunity to be switched to non-off label anti-VEGFs. We investigated the anatomical and functional vision changes associated with response to Aflibercept in a real-world Canadian setting with DME refractory to Bevacizumab.

Methods : We performed a retrospective chart review of patients with persistent DME refractory to Bevacizumab (after ≥ 6 injections), who were subsequently switched to Aflibercept. Clinical and optical coherence tomography (OCT) anatomical characteristics of patients’ retina at the visit prior to switching to Aflibercept and at the follow-up visit after four Aflibercept injections, were extracted and statistically compared (p<0.05).

Results : 18 eyes had received a minimum of 6 Bevacizumab injections with no response. The mean age was 62 years, with an average of 16 Bevacizumab injections. Switching to Aflibercept significantly decreased central subfield thickness (CST) from 391.5±95.0μm to 308.12±67.5μm (p=0.002), average macular thickness (AMT) from 322.0±50.8μm to 292.7±33.4μm (p=0.002), and average macular volume (AMV) from 11.6±1.8mm³ to 10.5±1.2mm³ (p=0.002). Aflibercept significantly reduced diffused retinal thickening (p=0.016) and intraretinal cystoid size (p=0.021). No significant changes were observed in other OCT measures, including hard exudates, hyper-reflective dots, subretinal fluid, external limiting membrane disruption, ellipsoid zone disruption, and cone outer segment tips. While no significant improvements were observed in best corrected visual acuity (BCVA), median-split analyses revealed significant group interactions (p=0.041) such that in patients with higher baseline CST (>361.5μm), AMT (>312μm), and AMV (>11.25mm³), BCVA improved and in patients with lower baseline values it deteriorated.

Conclusions : Our data evidenced significant anatomical improvements in macula, which did not translate to immediate functional vision improvements. Bevacizumab non-responders with higher CST at baseline might additionally benefit functionally from switching to Aflibercept.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.