Glaucoma is a leading cause of irreversible vision loss worldwide, and reduction of elevated intraocular pressure (IOP) is the only proven treatment to slow or halt progression of the disease. A common problem in disease management is low patient adherence to ocular medication administration.

Factors contributing to the lack of compliance include forgetfulness, difficulty with drop self-administration, and difficulty with medication schedule. Lack of adherence has been shown to correlate with the progression of vision loss. A key unmet medical need is the availability of new technology to address low medication adherence.

Graybug is developing a drug-encapsulated microparticle formulation to provide continuous IOP-lowering that is administered by the treating physician every 3 to 6 months using a subconjunctival injection. The goal is to enhance the overall consistency of medical care by placing medication compliance into the hands of the treating physicians rather than the patient.

Graybug has developed a library of over 100 new molecular entities (NME) based upon pro-drugs of approved IOP-lowering agents, rho-kinase receptor inhibitors (ROCK), and other novel IOP-lowering agents. The flexible and unique Graybug platform allows three different approaches (Figure 2) where an inactive proprietary pro-drug is administered and hydrolyzes into active agents as the microparticles undergo bioabsorption.

Figure 2.

 Graybug Vision drug-delivery strategy for primary open-angle glaucoma and ocular hypertension. Subconjunctival administration of a single novel pro-drugs results in single or dual mechanism of action active drugs.