AIM: To evaluate the efficacy and safety of HLX04-O, an investigational ophthalmic formulation of HLX04 (bevacizumab biosimilar) for intravitreal injection, as a treatment for wet age-related macular degeneration (wAMD) in a phase 1/2 clinical trial (NCT04993352). METHODS: Eligible patients with wAMD were enrolled to receive HLX04-O intravitreal injections at a dose of 1.25 mg/0.05 mL every four weeks. Efficacy and adverse events were evaluated every month during study visits. RESULTS: A 76-year-old male with wAMD in his left eye participated in the trial and completed six cycles of HLX04-O intravitreal injections. Changes were observed in macular center point thickness (baseline vs last study visit, 437 vs 255 μm) and best-corrected visual acuity letter score (baseline vs last study visit, 36 vs 77) of the affected eye, which indicated an improvement in wAMD over treatment. No adverse events were reported by the data cutoff date. CONCLUSION: HLX04-O at 1.25 mg/0.05 mL every four weeks is well tolerated in this patient, demonstrating promising safety and efficacy in wAMD treatment. Large-scale studies are required to confirm the outcomes.