Deerfield Management Company led the series B financing round, which included participation from OrbiMed Advisors, Clarus Ventures, and Hatteras Venture Partners.
Graybug will use the proceeds to further the development of lead drug GB-102 for wet age-related macular degeneration (AMD) through phase 2 clinical trials and to start a clinical program for its glaucoma compound.
GB-102, a dual acting inhibitor of VEGF and PDGF receptors, could be administered twice a year in wet AMD patients.
Graybug Vision is also applying its injectable depot technology to allow twice per year treatment of glaucoma from a subconjunctival injection.
Graybug Vision president and CEO Jeffrey Cleland said: "The significant level of investor interest in our Series B financing is further validation of both the approach and the potential of our lead compound, GB-102, to block both the VEGF and PDGF pathways from a single, twice per year injection."
A six month study in animals for GB-102 has recently been completed, demonstrating the ability of its technology to deliver its small molecule drug that blocks both VEGF and PDGF for more than six months following a single intravitreal injection in rabbits.
Graybug said the technology achieves the six month release profile without inflammation or toxicity after an intravitreal injection.
The US Food and Drug Administration has agreed with the company’s plans for GB-102 IND-enabling studies and for a phase 1/2 study in wet AMD patients to be started in early 2017 for confirming the results in animals.