Purpose: To investigate the half-life of aflibercept in aqueous humor after a single intravitreal injection in patients with neovascular age-related macular degeneration.
Methods: Prospective, noncomparative, interventional case series of five eyes with neovascular age-related macular degeneration naive to anti-vascular endothelial growth factor therapy were enrolled and treated with intravitreal aflibercept. At baseline, best-corrected visual acuity, optical coherence tomography imaging, and aqueous humor (treatment eye) and blood/plasma samples were taken. Patients underwent best-corrected visual acuity, optical coherence tomography imaging, and sampling of aqueous humor from the eye and blood/plasma at six additional post-treatment time points of 4 hours and Days 1, 3, 7, 14, and 28. Concentrations of aflibercept were quantified using an enzyme-linked immunosorbent assay.
Results: Median peak concentration (Cmax) of free aflibercept in the aqueous was 122 mg/L. The median half-life of free aflibercept was 11 days in the eye. In plasma, the concentrations of free aflibercept were low and transient, reaching undetectable levels during the first week after injection, and undetectable in all patients at time points beyond 7 days.
Conclusion: The pharmacokinetic profile in the aqueous humor described here together with the previously reported affinity of aflibercept for vascular endothelial growth factor is consistent with and adds to our understanding for the duration of its clinical efficacy.