More information will come from 4-year results, which will be critical to assess whether there is any long-term benefit to visual acuity using aflibercept.
Early treatment with anti-vascular endothelial growth factor (VEGF) injections slowed the progression of diabetic retinopathy after 2 years but did not significantly slow vision loss more effectively than standard treatment, according to a new study.
The results from the halfway point of a 4-year clinical trial leaves researchers to await its completion to determine whether preventive treatment with anti-VEGF drugs is worth pursuing, the authors said in JAMA Ophthalmology.
The study examined the efficacy of using aflibercept (Eylea) injections in the management of nonproliferative diabetic retinopathy (NPDR)—the condition’s early stages—where changes in the eyes’ blood vessels are visible to clinicians but generally do not affect sight. The study looked at how many patients progressed to proliferative diabetic retinopathy (PDR), where retinal vessels grow abnormally, and/or center-involved diabetic macular edema (CI-DME), where fluid leaks out of the retinal blood vessels and threaten vision loss and blindness.
Among the 328 participants (399 eyes), the rate of vision-threatening complications diminished by more than 2-fold over 2 years. The rate of participants developing PDR was 33.2% in the control group compared with 13.5% in the treatment group, while the rate of developing CI-DME was 14.8% in the control group compared with 4.1% in the treatment group.
However, the mean (SD) change in visual acuity was -0.9 (5.8 letters) with aflibercept and -2.0 (6.1) with the control group (adjusted mean difference, 0.5 letters [97.5% CI, −1.0 to 1.9 letters]; P = .47).
In an accompanying commentary, authors Rajendra S. Apte, MD, PhD, and Christopher K. Hwang, MD, PhD, indicated the results were not promising for use of anti-VEGF injections for diabetic retinopathy.
“Despite substantial differences in the 2 primary endpoints, which were anatomic outcomes, prophylactic aflibercept for eyes with moderate or severe NPDR and good vision may not be cost-effective or practical in the clinical practice setting,” they wrote. They also noted an increased risk of endophthalmitis weighing against use of aflibercept in early treatment.
Anti-VEGF therapy has been demonstrated as an effective first-line treatment for PDR and CI-DME. The study was designed to determine if the therapy has a role in the absence of vision-threatening complications.
Data for the DRCR Retina Network Protocol W randomized clinical trial were collected at 64 US and Canadian sites from 2016 to 2020. Eyes were randomly assigned to 2.0 mg of aflibercept injections, or a sham treatment given at baseline, 1, 2, and 4 months, and then every 4 months through 2 years. Between 2 and 4 years, treatment was deferred if the eye had mild NDPR or better. Aflibercept was administered in both groups if CI-DME with vision loss of high-risk PDR developed.
The authors said the 4-year results will be critical to assess whether there will be any long-term benefit to visual acuity.
Maturi RK, Glassman AR, Josic K, et al. Effect of Intravitreous anti–vascular endothelial growth factor vs sham treatment for prevention of vision-threatening complications of diabetic retinopathy: The Protocol W randomized clinical trial. JAMA Ophthalmol. Published online March 30, 2021. doi:10.1001/jamaophthalmol.2021.0606