Intravitreal Double-Dose Conbercept Injection for the Treatment of Neovascular Age-Related Macular Degeneration: A Pilot Real-Life Clinical Practice Study

Abstract

Purpose: To evaluate the efficacy and safety of conbercept for neovascular age-related macular degeneration (nAMD) when administered at the labeled dose (0.5 mg) and double dose (1.0 mg).

Methods: Patients with nAMD were randomized to either 1.0 mg or 0.5 mg groups. The 1.0 mg group received intravitreal injection of 1.0 mg conbercept once monthly for the first three months, followed by a pro re nata regimen (3+PRN). The 0.5 mg group received 3+PRN regimens of intravitreal 0.5 mg conbercept throughout the treatment period. Changes in best corrected visual acuity (BCVA), central macular thickness (CMT), and maximum pigment epithelial detachment (PED) height from baseline were compared between the two treatment groups at 1-, 3-, 6-, and 12-month follow-ups.

Results: Thirty-three patients completed the study, including 16 in the 0.5 mg group with an average age of 74.00 ± 8.23 years, and 17 in the 1.0 mg group with an average age of 72.29 ± 6.47 years. At 3-month, BCVA improvement in the 1.0 mg group was significantly higher than in the 0.5 mg group (P = 0.0450), though no differences were observed at other time points. There was no statistical difference in CMT reduction at any follow-up points. Regarding PED height reduction, a significant difference was observed at the 1-month follow-up (P = 0.0345), but not at the 3-, 6-, or 12-month follow-ups. After drying the macula, the recurrence interval of fluid in the 1.0 mg group was significantly longer than in the 0.5 mg group (P = 0.0360). No related adverse event was reported in either group.

Conclusion: While the 1.0 mg group showed a transient but significant BCVA improvement at 3 months and a longer recurrence interval, further large-scale trials are needed to validate these preliminary findings.

Trial registration: This study was registered with the Chinese Clinical Trial Registry (http://www.chictr.org.cn/, ChiCTR2000029503). Registration date: 03/02/2020.

Keywords: anti-VEGF treatment; conbercept; high-dose; neovascular age-related macular degeneration.