Visual and treatment interval outcomes after switching anti-VEGF therapy in the treatment of nAMD

Abstract

Purpose : To analyze the patterns of drug switching between intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents in the treatment of neovascular age-related macular degeneration (nAMD), and their effects on visual outcomes and treatment intervals in real-world practice.

Methods : This retrospective study of the clinical records of patients undergoing intravitreal therapy for nAMD in 13 practices of 11 retina specialists in Australia was conducted between January 1st, 2000 and November 11th, 2022. All physicians employed a treat-and-extend protocol, with free choice of treatment interval and drug. The patterns of switching behavior (between bevacizumab, aflibercept and ranibizumab) by physicians in real-world practice were examined, looking at timing and direction of switch, and analyzing subsequent changes in visual acuity (VA) and treatment interval, focusing on differences between eyes that had been switched and between the drugs used.

Results : 3791 patients (5731 eyes) were treated with 157,094 injections. Aflibercept’s utilization in these eyes increased from 42 to 64%; ranibizumab (48 to 33%) and bevacizumab (10 to 3%) utilization both decreased by the final visit. Irrespective of when switches occurred (Figure 1), 53% of all switched eyes gained their maximum VA following a drug switch. After a greater initial increase (in weeks) in the retreatment interval following a switch to aflibercept (7.05, SD 8.20) compared to a switch to ranibizumab (5.31, SD 5.85) (p=0.0001), the final interval increases were 1.87 (SD 14.87) and 1.15 wks (SD 7.75), respectively (p=0.70). For those who switched, the final visit (follow-up period) was a mean of 1.72 years (SD 2.52) after switch. A higher proportion of eyes that had undergone a switch than those who had not achieved a VA 50 letters or more after three years of treatment (65% cf. 59%) (Figure 2)

Conclusions : Switching between anti-VEGF agents is common in real-world clinical practice, with visual benefits; the majority of these patients achieve their peak vision after a switch and more remain in higher VA brackets at three years. Although switching to aflibercept initially increased the retreatment interval significantly more than ranibizumab, the final increase achieved by switching was modest and similar for both agents.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Fig 1. Timing of switches, by year of treatment

 

Fig 2. Switching vs. 3-yr vision