Results appear similar at 2 years for diabetic macular edema drugs

Anti-vascular endothelial growth factor (VEGF) agents yielded similar improvements in visual acuity at 2 years in patients with diabetic macular edema, according to a recent study.

Researchers from the Diabetic Retinopathy Clinical Research Network performed a randomized trial of patients with impaired visual acuity due to diabetic macular edema to compare clinical effectiveness of treatment with 3 anti-VEGF drugs. Eyes were assigned to receive 2.0 mg aflibercept, 1.25 mg repackaged (compounded) bevacizumab, or 0.3 mg ranibizumab. (Aflibercept and ranibizumab were provided for the study by manufacturers.) Intravitreous injections were administered up to once per month according to a follow-up and retreatment regimen specified by protocol. If diabetic macular edema persisted after 6 months, patients also received focal/grid laser photocoagulation. Patients visited the physician every 4 weeks in the first year of treatment and at least every 4 months afterward once visual acuity and macular thickness were considered stable. The study's main outcome measures were change in visual acuity, adverse events, and frequency of retreatment. Results were published online Feb. 27 by Ophthalmology.

Six hundred sixty patients were included in the study. The mean age was 61 years, and 47% were women. Ninety percent of the aflibercept group, 85% of the bevacizumab group, and 88% of the ranibizumab group completed the 2-year visit. In year 2, the median numbers of injections were 5 in the aflibercept group and 6 in the bevacizumab and ranibizumab groups; over 2 years, the mean numbers of injections were 15, 16, and 15, respectively. Forty-one percent of the aflibercept group, 64% of the bevacizumab group, and 52% of the ranibizumab group received focal/grid laser photocoagulation (P<0.001 for aflibercept vs. bevacizumab; P=0.04 for aflibercept vs. ranibizumab; P=0.01 for bevacizumab vs. ranibizumab).

Mean visual acuity improved in all 3 groups at 2 years, with treatment group differences varying by visual acuity at baseline. For worse visual acuity at baseline, defined as 20/50 to 20/320, mean improvement was 18.3 letters with aflibercept, 13.3 letters with bevacizumab, and 16.1 letters with ranibizumab (P=0.02 for aflibercept vs. bevacizumab; P=0.18 for aflibercept vs. ranibizumab; P=0.18 for bevacizumab vs. ranibizumab). For better visual acuity at baseline, defined as 20/32 to 20/40, mean improvement was 7.8 letters with aflibercept, 6.8 letters with bevacizumab, and 8.6 letters with ranibizumab (P>0.10 for pairwise comparisons). Adverse events as defined by the Antiplatelet Trialists' Collaboration (i.e., nonfatal myocardial infarction, nonfatal stroke, and vascular death) occurred in 5% of the aflibercept group, 8% of the bevacizumab group, and 12% of the ranibizumab group.

The researchers concluded that all 3 of the anti-VEGF drugs yielded improvement in visual acuity from baseline to 2 years and required fewer injections in the second year of treatment. With better visual acuity at baseline, no statistically significant differences in vision outcomes were seen for any drug at 2 years. With worse visual acuity at baseline, aflibercept appeared to yield better outcomes than ranibizumab at 1 year and to have better 2-year outcomes for visual acuity than bevacizumab; however, superiority of aflibercept over ranibizumab did not persist at 2 years. The authors noted that ranibizumab was associated with higher adverse event rates over 2 years and that this finding should be evaluated further in future trials.