Duration of Vascular Endothelial Growth Factor Suppression after Intravitreal Injection of Faricimab in Macaque Eyes

<b><i>Purpose:</i></b> To evaluate the duration of vascular endothelial growth factor (VEGF) suppression in the aqueous humor of macaque eyes after intravitreal faricimab (IVF) injection. <b><i>Methods:</i></b> Faricimab (6 mg/50 µL) was injected into the vitreous cavity of the right eye of 6 macaques. Aqueous humor samples (150 μL) were collected from both eyes immediately before injection and on days 1, 3, 7, 14, 21, 28, 42, 56, 84, and 112 after injection. The VEGF concentrations in the aqueous humor were measured using an enzyme-linked immunosorbent assay. <b><i>Results:</i></b> The VEGF was undetectable until 4 weeks after IVF injection in 4 eyes and until 6 weeks in the remaining 2 eyes. The mean duration of complete VEGF suppression was 4.7 weeks (range, 4-6 weeks). The VEGF concentration did not decrease in the aqueous humor of the non-injected fellow eyes. <b><i>Conclusions:</i></b> Faricimab effectively suppressed the VEGF concentrations in the aqueous humor of macaques for an average of 4.7 weeks after a single intravitreal injection. It did not reduce the VEGF concentrations in the aqueous humor of the fellow eyes.