Graybug Vision GB-102 Toxicology/PK Study Presented at ARVO 2016


Redwood City, CA – May 4, 2016 – Graybug Vision, Inc., a venture-stage pharmaceutical company committed to developing potentially transformative therapies for ocular diseases including wet age-related macular degeneration (AMD) and glaucoma, today announced that a second poster with new data from a preclinical study of its lead product, GB-102, a novel injectable depot formulation containing a compound blocking VEGF and PDGF receptors for twice a year treatment of wet AMD, was presented at the Association for Research in Vision and Ophthalmology (ARVO) 2016 Annual Meeting in Seattle, WA.

Graybug Vision researchers Ming Yang, PhD, and Ward M. Peterson, PhD, presented data from an in vivo toxicology/PK study of GB-102 in a poster entitled “GB-102 for Wet AMD: A Novel Injectable Formulation that Safely Delivers Active Levels of Sunitinib to the Retina and RPE/Choroid for Over Four Months.”

The objective of the study was to address the current challenges in therapies for neovascular AMD (nAMD), which are suboptimal due to the need for intravitreal (IVT) dosing every 4-8 weeks as well as the inability to target more than one disease pathway.

The study was designed to evaluate the ocular tolerability, safety and pharmacokinetics (PK) of a single IVT injection (up to 50 µL) of a novel, injectable depot formulation of sunitinib malate (GB-102) for the treatment of nAMD.  Sunitinib malate is a dual VEGF/PDGF inhibitor originally approved in 2006 as an anti-cancer drug.  The results concluded that single dose of GB-102 containing 0.2 or 1.0 mg sunitinib malate was able to deliver pharmacologically active levels of sunitinib to retina and RPE/choroid for up to 6 months and an IVT injection of GB-102 is safe and well tolerated for the entire 6 months following dosing.

“We are very pleased that GB-102 may significantly advance neovascular AMD (nAMD) treatment by blocking both VEGF and PDGF pathways involved in nAMD, and by reducing the number of IVT injections to as few as two per year,” said Jeffrey L. Cleland, PhD, President and Chief Executive Officer, Graybug Vision, Inc.  “Our hope is to provide a more effective and less burdensome treatment for the large number of patients suffering from nAMD.”

Study Methods

Drs. Yang and Petersen and their team at Graybug Vision’s Research Center in Baltimore, MD, engineered biodegradable microparticles (GB-102) containing sunitinib malate with the goal of safely delivering pharmacologically active levels of sunitinib to the retina and RPE/choroid for up to 6 months following a single intravitreal injection.

GB-102 microparticles (containing 0.2 or 1.0 mg sunitinib malate) and placebo microparticles were formulated in hyaluronic acid-containing diluent and dosed as a single IVT injection (10-50 µL) into the inferior vitreous of New Zealand white x red F1 rabbits (27G needle). Ocular slit-lamp and fundus examinations were made immediately following dosing and at regular intervals for up to 6 months. Eyes were enucleated and processed for ocular histopathology or ocular PK at monthly or bi-monthly intervals for up to 6 months post-dose. After injection, GB-102 microparticles coalesce in the inferior vitreous into an immobile, implant-like depot that remains outside of the visual axis.

Toxicology and Pharmacokinetics Results

Five ocular cross-sections per eye were evaluated and analyses were conducted monthly or bi-monthly for 6 months after single IVT dose. No evidence of inflammation or toxicity were seen in any eyes treated with GB-102 or placebo microparticles.  Microparticles were also designed not to adhere to ocular tissues.

With a single injection, sunitinib levels in eyes dosed with the low-dose group were 10-fold (retina) and 1000-fold (RPE/choroid) higher than the well-established target plasma level of free sunitinib (~2 ng/mL) needed for anti-cancer efficacy throughout the 6 month period. Plasma levels of free sunitinib following an IVT injection of GB-102 were >100 fold below the therapeutic effect level and often undetectable.

About Graybug Vision

Graybug Vision, Inc. is developing novel products for the treatment of ocular diseases.  Graybug Vision’s technologies enable the delivery of compounds to the eye up to twice per year and were co-developed by Graybug Vision founder Justin Hanes, PhD, who is the Lewis J. Ort Professor of Ophthalmology at the Wilmer Eye Institute of the Johns Hopkins University, in collaboration with Graybug Vision cofounders, and leading ophthalmology clinician-scientists from the Wilmer Eye Institute Peter A. Campochiaro, MD, and Peter J. McDonnell, MD.  Graybug Vision’s lead product, GB-102, is being developed for twice a year treatment of wet AMD patients.  Graybug Vision’s second product consists of compounds with intraocular pressure lowering and neuroprotection that may be administered to the subconjunctiva twice per year for the treatment of glaucoma.  For more information, please visit www.graybug.com.

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