Graybug Vision presented preclinical study results for GB-401, a novel injectable depot formulation of a proprietary beta-adrenergic antagonist prodrug, as a potential sustained-delivery treatment of up to 6 months for primary open angle glaucoma (POAG), at the American Glaucoma Society annual meeting in Washington, DC.
The study evaluated the in vitro and in vivo performance of GB-401 including pharmacokinetics, ocular safety, and IOP lowering efficacy, and showed that GB-401 achieved sustained ocular drug levels and reduced IOP in experimental animal models after a single intravitreal or subconjunctival injection.
“We are encouraged by these preclinical study results and look forward to evaluating the potential of GB-401 as a new long-term treatment for patients with primary open angle glaucoma in a phase 1/2a first-in-human trial,” Frederic Guerard, CEO of Graybug Vision, said in a company news release.
Primary open angle glaucoma (POAG) is the most common type of glaucoma, a progressive degeneration of the optic nerve and a leading cause of irreversible vision loss, with more than three million people affected in the United States and over 70 million worldwide. Reducing IOP is the only proven treatment to prevent the progression of vision loss associated with POAG. While approved topical eye drops that can lower IOP exist, their effect is often limited due to poor patient compliance and low drug bioavailability/residence time on the corneal surface, according to Graybug Vision. Studies show that significant numbers of glaucoma patients stop taking their medications due to factors including disability, cognitive decline, lack of disease awareness and cost.
Summary of GB-401 preclinical study results
GB-401 achieved high drug loading and encapsulation efficiency of a proprietary beta-adrenergic antagonist prodrug and demonstrated tunable sustained drug release kinetics for approximately 6 months in vitro. The ongoing pharmacokinetic study revealed sustained therapeutic drug levels in the eye from day 1 to over 3 months. A single injection of GB-401 also led to a sustained reduction of IOP in an experimental ocular hypertension animal model, with no signs of ocular toxicity.