Pharmacokinetic Properties of Intravitreal I-124-Aflibercept in a Rabbit Model Using PET/CT

Abstract

Purpose: To determine the anatomic characteristics and pharmacokinetic properties of intravitreally-placed aflibercept in a rabbit model. Materials and methods: Four Dutch-belted rabbits underwent intravitreal injection with I-124-aflibercept. Serial imaging with PET/CT imaging was performed on days 0, 2, 5, 7, 14, 21, 28 and 35. Measured radioactivity emission in becquerels/mL was used to calculate the half-lives for aflibercept. Results: I-124 aflibercept was confined within the vitreous cavity for the duration of the study. I-124 aflibercept could be detected in the vitreous cavity until day 28 and the average retention time with standard error after correction for radioactive decay was 4.58 ± 0.07 days. Conclusions: I-124 aflibercept was only visible in the vitreous cavity by PET/CT imaging following intravitreal injection. The retention properties were found to be comparable to those measured by other reported methods.