Treat-And-Extend Versus Pro Re Nata Regimen of Intravitreal Conbercept Injection for Neovascular Age-Related Macular Degeneration: Results from COCOA, a Prospective, Open-Label, Multicenter, Randomized Phase IV Clinical Trial.

Abstract

Purpose: To evaluate and contrast the effectiveness and safety of two conbercept treatment protocols-a three-dose treat-and-extend (3+T&E) regimen and a three-dose pro re nata (3+PRN) regimen-in Chinese patients diagnosed with neovascular age-related macular degeneration (nAMD).

Methods: Eligible patients, who had not undergone anti-VEGF intraocular injections within 3 months prior to enrollment, were randomly assigned to either the 3+T&E or 3+PRN regimen. The 3+T&E group received at least three monthly injections, with subsequent visit intervals extended based on disease activity assessment. The primary endpoint was the mean change in best-corrected visual acuity (BCVA) from baseline to week 48, using a predefined noninferiority threshold.

Results: Among 501 participants (249 in 3+T&E, 252 in 3+PRN), approximately half had prior anti-VEGF treatment. At 48 weeks, both regimens showed significant BCVA improvements (+9.9 for 3+PRN, +8.6 for 3+T&E; p = .208), with comparable rates of ≥15-letter gains (32.12% for 3+PRN, 30.77% for 3+T&E; p = .827). The 3+PRN group received fewer injections (mean 6.4 vs. 6.9 in 3+T&E; p = .028) but had shorter intervals between injections (6.93 weeks vs. 7.46 weeks in 3+T&E; p = .010). Drug-related adverse events occurred in 5% of patients, with ocular events evenly distributed and minimal cardiovascular events reported.

Conclusion: Both 3+T&E and 3+PRN conbercept regimens effectively improved visual and anatomical outcomes in Chinese nAMD patients. The 3+T&E regimen was noninferior to 3+PRN in improving BCVA from baseline to week 48. The 3+T&E regimen enabled longer injection intervals while 3+PRN regimen with less injections is more cost-effective while maintaining a comparable safety profile. Treatment plan tailored to an individual patient's situation appears necessary.