For patients with diabetic macular edema (DME), intravitreal anti-vascular endothelial growth factor (VEGF) agents have become the first-line treatment. There are currently only two VEGF inhibitors approved for use in the United States for the treatment of DME: aflibercept (Eylea, Regeneron) and ranibizumab (Lucentis, Genentech).
Bevacizumab (Avastin, Genentech) is often used off-label, and pegaptanib (Macugen, Bausch + Lomb) has declined in use since the introduction of both aflibercept and ranibizumab. Numerous clinical trials have shown both visual acuity (VA) and anatomic outcomes can be improved with the use of the anti-VEGFs, yet reports of persistent DME remain despite continuous anti-VEGF therapy. Extension studies of RESTORE, RISE and RIDE all show a decline in VA when patients were transitioned to a more flexible treatment after being on a fixed dosing regimen.1,2
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The SWAP-TWO study3 was a prospective, interventional, single-arm study (Cole Eye Institute) that enrolled 20 eyes of 20 patients between December 2015 and August 2017 to evaluate the effects of switching patients with DME to aflibercept after being previously treated with other anti-VEGF agents; the study also placed these patients on a fixed dosing regimen. This initial six-month interim analysis suggests switching agents can substantially improve anatomic outcomes while maintaining vision gains.
In SWAP-TWO,3 eligible participants were aged ≥ 18 years with foveal-involving retinal edema secondary to diabetic retinopathy (DR) based on investigator review of clinical exam and spectral-domain optical coherence tomography (SD-OCT) with central subfield thickness of 325 μm, best corrected visual acuity (BCVA) of 20/25 to 20/400 in the study eye, and history of previous treatment with bevacizumab or ranibizumab with at least four previous injections in the last six months.
Patients were excluded if they had a history of aflibercept use, or if they had used systemic anti-VEGF therapy in the three months prior to enrollment. The average age at screening was 63.7 years, 13 enrolled subjects were female (65%), and the average number of prior injections was 4.25 during the six months prior to study enrollment. Nine of the eyes were considered to have moderate DR severity, and the mean central subfield thickness was 419.7 μm in the study eye.
The majority of patients had been treated with bevacizumab (95%). Patients were administered 2 mg (0.05 mL) of intravitreal aflibercept administered monthly until there was no evidence of fluid as determined by OCT. (For this study, “no evidence of fluid” was considered to include lack of subretinal fluid, a central subfield thickness of < 320 μm, or a foveal cystoid macular edema with focal depression present or with fovea flat.)
1. Boyer DS, Nguyen QD, Brown DM, Basu K, Ehrlich JS: Outcomes with As-Needed Ranibizumab after Initial Monthly Therapy: Long-Term Outcomes of the Phase III RIDE and RISE Trials. Ophthalmology. 2015, 122(12):2504- 2513.e2501.
2. Schmidt-Erfurth U, Lang GE, Holz FG, Schlingemann RO, Lanzetta P, Massin P, Gerstner O, Bouazza AS, Shen H, Osborne A et al: Three-year outcomes of individualized ranibizumab treatment in patients with diabetic macular edema: the RESTORE extension study. Ophthalmology. 2014, 121(5):1045-1053.
3. Babiuch AS, Conti TF, Conti FF, Silva FQ, Rachitskaya A, Yuan A, Singh RP: Diabetic macular edema treated with intravitreal aflibercept injection after treatment with other anti-VEGF agents (SWAP-TWO study): 6-month interim analysis. Int J Retina Vitreous. 2019, 5:17.