Baseline retinal thickness did not adversely impact the ability of aflibercept 8 mg (Eylea HD; Regeneron) to improve vision and anatomy in patients with macular edema secondary to retinal vein occlusion (RVO), according to a post hoc analysis of data from the QUASAR trial. The findings were presented by Ehsan Rahimy, MD, adjunct clinical associate professor of ophthalmology at Stanford University School of Medicine and a surgical and medical vitreoretinal specialist at the Palo Alto Medical Foundation in Palo Alto, California, during Clinical Trials at the Summit in Las Vegas.

Rather than examining outcomes across the overall study population, investigators sought to determine whether disease severity at baseline influenced treatment response. “For the purposes of our study, we were interested to look under the hood and assess the impact of disease severity on these treatment outcomes, and see if there may be a differential effect between 2 mg and 8 mg aflibercept dosing in the thickest retinas,” said Dr. Rahimy, a consultant to Regeneron.

Patients were stratified into tertiles based on baseline central retinal thickness (CRT), creating groups representing the thinnest, middle, and thickest retinas at study entry (Table 1). The highest-thickness tertile included patients with markedly greater edema, particularly among those with central retinal vein occlusion (CRVO) and hemiretinal vein occlusion (HRVO).

Among patients with branch retinal vein occlusion (BRVO), aflibercept 8 mg produced visual gains through week 64 while reducing treatment burden. Across CRT tertiles, patients received approximately 2.5 fewer injections than those treated with aflibercept 2 mg (Eylea; Regeneron). Anatomic outcomes closely tracked visual outcomes. “The anatomy curves mirrored what we saw with vision, as we would expect,” said Dr. Rahimy.

Differences also emerged in treatment intervals. By week 36, fewer patients receiving aflibercept 8 mg required every-4-week dosing compared with those receiving aflibercept 2 mg. However, that gap narrowed over time. “By week 64, the proportion of patients who required every-4-week dosing ended up comparable between the treatment groups,” Dr. Rahimy noted, adding that the 2 mg cohort “eventually caught up with more consistent treatment over time” in BRVO.

The pattern differed in CRVO and HRVO. Visual and anatomic improvements were again maintained through week 64, with patients receiving aflibercept 8 mg requiring approximately 3 fewer injections than those receiving aflibercept 2 mg. Unlike the BRVO cohort, differences in dosing intervals persisted through follow-up, especially in the more severe disease tertiles.

“This is where it gets interesting,” Dr. Rahimy said. At both weeks 36 and 64, substantially fewer patients treated with aflibercept 8 mg required monthly dosing. In the highest CRT tertile at week 64, approximately one-quarter of patients receiving aflibercept 2 mg remained on monthly dosing intervals, whereas no patients receiving aflibercept 8 mg required monthly dosing.

Summarizing the analysis, Dr. Rahimy concluded that aflibercept 8 mg “achieved robust vision and anatomic improvements through week 64” in macular edema secondary to RVO across all baseline CRT tertiles, while requiring fewer injections than aflibercept 2 mg. RP