Abstract
Purpose: :
A prospective, randomized, double-masked, multi-center study to evaluate 31 patients with Diabetic Macular Edema following implantation of I-vation TA (triamcinolone acetonide).
Methods: :
The I-vation TA implant was designed to provide controlled delivery of steroid to the back of the eye for up to 2 years. In this Phase I study, patients were randomized to either a slow-release or fast-release formulation, each containing 925 µg triamcinolone, and stratified by baseline visual acuity and presence or absence of prior laser treatment. Macular edema was determined by clinically observable macular edema associated with diabetic retinopathy, visual acuity of 20/40 or worse, retinal thickening in the fovea, and angiographic evidence of leakage involving the perifoveal capillary net.
Results: :
At 24 months, 25 of 31 patients remained in the study; 11 patients (11 eyes) in the slow-release group, 14 patients (14 eyes) in the fast-release group. The mean IOP increased from 13.9 mmHg at baseline to 16.6 mmHg in the slow group, and from 14.3 mmHg at baseline to 15.9 mmHg in the fast group. Intraocular pressure in 5 patients was controlled with topical medication, with no filtration procedures required. At 24 months, the proportion of patients demonstrating improved visual acuity (greater than zero ETDRS letter gain from baseline) was 64% in the slow group and 72% in the fast group. 28.6% of patients in the fast group gained greater than 15 letters. The mean macular thickness, measured as the center foveal minimum by OCT, decreased in the slow group from 529 µm at baseline to 328 µm, and in the fast group from 376 µm at baseline to 268 µm. The most commonly reported procedural adverse event (AE) was conjunctival hemorrhage (90.4%). The most commonly reported medication-related AE was lenticular opacities, with 17/18 phakic eyes having had cataract extractions by 24 months. One SAE (endophthalmitis) was reported in a patient two days following a retreatment procedure, which was determined to be a complication of the surgical procedure.
Conclusions: :
Results of the 24 month interim analysis suggest that both formulations of I-vation TA are well tolerated as evaluated by the occurrence of adverse events and IOP changes. Both formulations also appear to be associated with improvements in BCVA and macular thickness. These improvements are consistent with those observed at 6 months, suggesting a sustained therapeutic effect. Additional 30 month data will be presented at the meeting.
Clinical Trial: :
Phase I safety
Keywords: diabetes • edema • drug toxicity/drug effects