Intravitreal Ziv-Aflibercept versus Bevacizumab for Naïve Central Retinal Vein Occlusion with Macular Edema: An Interim Analysis of a Randomized Non-Inferiority Trial

PURPOSE: To compare the efficacy of intravitreal ziv-aflibercept (IVZ) and bevacizumab (IVB) injections for the treatment of macular edema secondary to central retinal vein occlusion. METHODS: Participants were randomly assigned 1:1 to receive 3 monthly IVZ (1.25 mg/0.05 mL) or IVB (1.25 mg/0.05 mL) followed by the pro-re-nata protocol for persistent or recurrent macular edema. The primary outcomes were best-corrected visual acuity and central subfield thickness. An interim analysis was planned when half of the participants completed the follow-up. RESULTS: Twenty-four participants were recruited. At 6 months, mean best-corrected visual acuity in the IVB and IVZ groups improved from 1.23 ± 0.64 to 0.76 ± 0.56 logMAR (p = 0.003) and from 1.13 ± 0.59 to 0.53 ± 0.26 logMAR (p = 0.003), respectively. The percentage of visual improvement and reduction in central subfield thickness in the IVZ group were insignificantly better than those in the IVB group (44.41 ± 26.72 vs 39.64 ± 24.22%; p = 0.65) and (51.94 ± 20.35 vs 45.78 ± 24.71%; p = 0.51), respectively. Although the mean number of injections was lower in the IVZ group (4.55 ± 1.29 vs 4.82 ±1.33), the difference was not statistically significant (p = 0.68). No ocular or systemic adverse events were observed. CONCLUSION: The interim analysis demonstrated that the visual and anatomical results of IVZ were insignificantly better than those of IVB at 6 months of follow-up. The results also showed that IVZ was non-inferior to IVB for anatomical improvement but inconclusive for visual improvement. CLINICAL TRIAL REGISTRATION: (identifier: TCTR20191205008).