Abstract
Purpose::
A prospective, randomized, double-masked, multi-center study is being conducted to evaluate 30 patients with Diabetic Macular Edema following implantation of I-vation TA.
Methods::
The I-vation Sustained Release Drug Delivery System was designed to provide controlled delivery of therapeutics to the back of the eye in a platform that balances minimally invasive implantation, duration, and retrievability. Its unique coiled geometry allows for implantation through a 25 gauge transscleral needlestick, while maximizing the surface area available for drug delivery. The platform is comprised of a metallic backbone and is coated with a polymer/drug matrix. I-vation TA is capable of delivering triamcinolone acetonide into the vitreous for up to 2 years. Patients were randomized to either a slow-release or fast-release formulation, each containing 925 µg triamcinolone. Patients were stratified by baseline visual acuity and presence or absence of prior laser treatment. The implant was anchored against the eye wall without sutures.
Results::
At 6 months, mean IOP increased in the study eye from 13.9 mmHg at screening to 16.1 mmHg in the slow group, and from 14.3 mmHg at screening to 16.4 mmHg in the fast group. In the fellow eye, mean IOP remained unchanged. BCVA improved over the course of the study to the time of the interim analysis. From screening to 6 months, the proportion of subjects with BCVA of at least 70 ETDRS letters with the study eye increased from 14% to 46% in the slow group and from 18% to 41% in the fast group. A gain of more than 15 letters in the study eye by 6 months was reported for 8% of subjects in the slow group and 18% in the fast group. Improvement of any degree at 6 months was reported for 85% and 76% of subjects in the slow group and fast group, respectively. Mean macular thickness in the study eye, as measured as the center foveal minimum by OCT, decreased in the slow group from 529 µm at screening to 364 µm at 6 months, and in the fast group from 376 µm at screening to 230 µm at 6 months. A decrease of at least 50 um at 6 months was reported for 62% of subjects in the slow group and 65% of subjects in the fast group.
Conclusions::
Results of the 6-month interim analysis suggest that both the slow-release and the fast-release formulations of I-vation TA are well tolerated as evaluated by the occurrence of adverse events and IOP. Both formulations also appear to be associated with improvements in BCVA and macular thickness.
Clinical Trial::
n/a - Phase I pharmaceutical trial
Keywords: diabetic retinopathy • corticosteroids • edema