In-situ forming biodegradable implants for sustained Fluocinolone acetonide release to the posterior eye: In-vitro and in-vivo investigations in rabbits

Delivering medication to the posterior segment of the eye presents a significant challenge. Intravitreal injection has emerged as the preferred method for drug delivery to this area. However, current injectable non-biodegradable implants for fluocinolone acetonide (FA) require surgical removal after prolonged drug release, potentially affecting patient compliance. This study aimed to develop an in-situ forming biodegradable implant (ISFBI) optimal formulation containing PLGA504H and PLGA756S (50:50 w/w%) with the additive NMP solvent. The goal was to achieve slow and controlled release of FA over a two-month period with lower burst release, following a single intravitreal injection. Through morphology, rheology, stability and in-vitro release evaluations, the optimal formulation demonstrated low viscosity (0.12-1.25 Pa. s) and sustained release of FA at a rate of 0.36 µg/day from the third day up to two months. Furthermore, histopathology and in-vivo studies were conducted after intravitreal injection of the optimal formulation in rabbits' eye. Pharmacokinetic analysis demonstrated mean residence time (MRT) of 20.02 ± 0.6 days, half-life (t1/2) of 18.80 ± 0.4 days, and clearance (Cl) of 0.29 ± 0.03 ml/h for FA in the vitreous humor, indicating sustained and slow absorption of FA by the targeted retinal tissue from vitrea over the two-month period and eliminating through the anterior section of the eye, as revealed by its presence in the aqueous humor. Additionally, FA exhibited no detection in the blood and no evidence of systemic side effects or damage on the retinal layer and other organs. Based on these findings, it can be concluded that in-situ forming injectable biodegradable PLGA implants can show promise as a long-acting and controlled-release system for intraocular drug delivery.

Ziv-aflibercept for Better Regulating Neovascular Age-Related Macular Degeneration (ZEBRA): A Prospective, Randomized Trial

OBJECTIVE

The purpose of this study is to determine if ziv-aflibercept is a safe and effective maintenance drug for nAMD.

STUDY DESIGN AND METHODS

This is a randomized, prospective, single-blinded trial. Inclusion criteria were active nAMD, prior anti-VEGF treatment, and BCVA ≤20/200. The treatment group received ziv-aflibercept. The control group continued their existing anti-VEGF regimen. The main outcome measures were BCVA, CFT, and safety.

RESULTS

Mean baseline BCVA was 1.58 ± 0.44 logMAR and 1.71 ± 0.39 logMAR in the control (n = 27) and treatment (n = 29) groups, respectively. After 24 months, the mean change in BCVA was 0.11 in the control group (equivalent to a loss of 5 ETDRS letters) and 0.01 logMAR in the treatment group (p = .48). Baseline CFT was 257 ± 33 μm and 247 ± 30 μm in the control and treatment groups, respectively, and after 24 months mean change in CFT was 26 μm and -5 μm (p = .24). There were no ocular or systemic adverse events during the study.

CONCLUSION

Ziv-aflibercept is a safe and effective as a maintenance drug for patients with nAMD. It may represent a cost-effective alternative to aflibercept and second-line therapy for eye resistant bevacizumab or ranibizumab.