Sustained-Release Intravitreal Liquid Drug Delivery Using Triamcinolone Acetonide for Cystoid Macular Edema in Retinal Vein Occlusion

Abstract

To investigate side effects seen with this formulation and to search for evidence of effectiveness after a single intravitreal injection of IBI-20089 in eyes with cystoid macular edema (CME) secondary to retinal vein occlusion. Prospective, phase 1 clinical trial. Ten patients with chronic CME resulting from retinal vein occlusion. Patients received a single intravitreal injection of IBI-20089 using a sequential dose escalation schedule. Each cohort consisted of 5 patients who received the intravitreal injection of the sustained liquid drug delivery system containing either 6.9 mg (25 μl) triamcinolone acetonide (TA; cohort 1) or 13.8 mg (50 μl) TA (cohort 2). At each study visit, best-corrected visual acuity testing, slit-lamp biomicroscopy, IOP measurement, dilated ophthalmoscopy, fundus photography and optical coherence tomography (OCT) were performed. Patients also underwent laboratory testing and physical examinations to monitor for any systemic adverse events. Optical coherence tomography central subfield thickness, ocular and systemic adverse events. In cohort 1, mean baseline OCT central subfield thickness (CST) was 477 μm and decreased to 369 μm at day 1 (P<0.06), 387 μm at day 30 (P = 0.18), and 251 μm at day 360 (P = 0.46). In cohort 2, mean baseline OCT CST was 518 μm and decreased to 404 μm at day 1 (P = 0.134), 289 μm at day 30 (P = 0.003), 207 μm at day180 (P = 0.004), and 278 μm at day 360 (P = 0.009). Related adverse events included elevation of IOP in 3 patients, in 2 because of neovascular glaucoma (not related to study drug) and in 1 who required a glaucoma tube shunt. A single intravitreal injection of IBI-20089 resulted in a controlled and sustained delivery of a TA. Side effects included elevated IOP in 3 eyes, 2 of which had neovascular glaucoma.