Short-Term Outcomes of Switching from the Aflibercept Biosimilar SB15 to Ranibizumab Biosimilars

Purpose: To evaluate short-term anatomical outcomes following a switch from the aflibercept biosimilar SB15 to ranibizumab biosimilars in patients with retinal diseases.Methods: This retrospective, single-center study included patients who were switched from SB15 to ranibizumab biosimilars (SB11 or CKD-701) between April and June 2025. Patients who were switched at the first follow-up visit after the last SB15 injection were classified as the immediate-switch group, whereas those who were switched after two or more follow-up visits were classified as the delayed-switch group. Changes in central retinal thickness (CRT) and visual acuity (VA) after SB15 injections were compared with those observed after switching to ranibizumab biosimilars.Results: A total of 46 eyes from 46 patients were included, comprising 22 cases of neovascular age-related macular degeneration, 14 cases of retinal vein occlusion, and 10 cases of diabetic macular edema. In the immediate-switch group (24 eyes), changes in CRT (+17.5 μm after SB15 vs. +27.2 μm after ranibizumab biosimilars; p = 0.432) and VA (p = 1.000) did not differ significantly. Four eyes (16.7%) exhibited a less pronounced CRT reduction (>100 μm less) after switching compared with SB15 treatment. In the delayed-switch group (22 eyes), CRT decreased following both SB15 (−157.7 μm) and ranibizumab biosimilar treatment (−129.4 μm), with no statistically significant difference between treatments (p = 0.201). Changes in VA were likewise not significantly different (p = 1.000).Conclusions: Short-term anatomical and visual outcomes after switching from SB15 to ranibizumab biosimilars were generally comparable to those observed with continued SB15 treatment, although a limited anatomical response was noted in a subset of cases.