Graybug Vision Reports Analysis of Data from the Six-Month Extension Study of the ALTISSIMO Phase 2b Trial in Wet AMD

• 55% of GB-102 1mg patients in Extension Study experienced duration of 12+ months, while maintaining their visual acuity and central retinal thickness
• 73% reduction of injection burden for patients participating in Extension Study
• GB-102 1mg continued to indicate a favorable safety profile and was well-tolerated

BALTIMORE, Sept. 28, 2021 (GLOBE NEWSWIRE) — Graybug Vision, Inc. (Nasdaq: GRAY), a clinical-stage biopharmaceutical company focused on developing transformative medicines for the treatment of diseases of the retina and optic nerve, today provided full-data analysis from the 18-month Phase 2b ALTISSIMO trial of GB-102 for the treatment of wet age-related macular degeneration (wet AMD), Graybug’s proprietary formulation of sunitinib malate injected twice-a-year intravitreally.

The ALTISSIMO trial was a masked and controlled Phase 2b dose-ranging study of two doses of GB-102, 1mg and 2mg, with a single control arm of patients on 2mg aflibercept, conducted across 33 study sites in the United States. The primary endpoint was median time to first supportive therapy with a vascular endothelial growth factor (VEGF) inhibitor, and secondary endpoints were safety and pharmacodynamics, measured as mean change in best-corrected visual acuity (BCVA) and mean change in central subfield thickness (CST) of the retina. As previously reported, the development of GB-102 2mg was terminated in 2020 following an interim safety analysis, and ALTISSIMO was not powered to assess non-inferiority to aflibercept.

ALTISSIMO comprised two phases, the first of which was a 12-month treatment phase, or Core Study, in which GB-102 patients were dosed at Day 1 and Month 6, while a control arm received aflibercept every other month. The second phase of ALTISSIMO was a six-month extended observation phase, or Extension Study, in which patients were monitored without additional treatment to determine the duration of effect measured from their last treatment during the Core Study. Participation in the Extension Study was voluntary, but only patients who completed all study visits, and did not require supportive therapy at their Month 12 visit during the Core Study, were eligible. 58% of the patients who completed the Core Study were eligible and agreed to enter the Extension Study, with 11 patients participating in the GB-102 1mg arm.

By its design, patients could not achieve longer than a six-month duration during the Core Study. The Extension Study provided up to an additional six months for patients to demonstrate longer duration, which resulted in 55% of GB-102 1mg patients experiencing a treatment duration of 12 months or longer, while maintaining visual acuity and central retinal thickness. This is the longest duration ever achieved with an intravitreal injection in a randomized, masked, and controlled clinical trial in wet AMD. In addition, the injection burden was reduced by 73% on an annualized basis for those GB-102 1mg patients who participated in the six-month Extension Study.

As in the Core Study, GB-102 1mg continued to be well-tolerated and maintained a favorable safety profile during the Extension Study. No drug-related adverse events or vision-threatening inflammation were reported.

“The Extension Study gave us our first opportunity to see duration beyond six months in a masked and controlled trial, and we are very excited that the majority of patients volunteering for extended observation achieved a treatment duration of 12 months or longer,” said Parisa Zamiri, MD, PhD, Chief Medical Officer of Graybug. “Furthermore, the significant reduction in injection burden continued throughout the Extension Study and showed that GB-102 1mg has the potential to significantly improve compliance compared to the current standard of care,” Dr. Zamiri concluded.

Graybug continues to optimize its technology platform and is developing additional formulations that have the potential to preserve the durability of GB-102 1mg microparticles while minimizing the risk of dispersion. These new and enhanced formulations, including injectable implants, may also simplify the drug reconstitution process and the injection technique, both of which are sources of variability in clinical outcomes. These innovations have already been incorporated into the development programs of both GB-102 and GB-401. Graybug anticipates that its GB-401 implant program for glaucoma will enter a Phase 1 trial in the second half of 2022. Given the 12-month or longer duration observed with GB-102 in the ALTISSIMO 18-month trial, Graybug decided to stop the further development of GB-103, which was designed to maintain therapeutic drug levels in the retinal tissue for 12 months with a single injection.

“We are encouraged by the Extension Study data that indicate a class-leading durability of GB-102 1mg of 12 months, or longer,” said Fred Guerard, PharmD, Chief Executive Officer, Graybug Vision. “These data further support the significant commercial opportunity that GB-102 1mg could represent. Our search for a partner to fund the further clinical development of GB-102 is ongoing.”

About Graybug

Graybug is a clinical-stage biopharmaceutical company focused on developing transformative medicines for the treatment of diseases of the retina and optic nerve. The company’s proprietary ocular delivery technologies are designed to maintain effective drug levels in ocular tissue for six months and potentially longer, improving disease management, reducing healthcare burdens and ultimately delivering better clinical outcomes. Graybug’s lead product candidate, GB-102, a formulation of the pan-vascular endothelial growth factor (VEGF) inhibitor, sunitinib malate targeting a six-month or longer dosing regimen, inhibits multiple neovascular pathways for the intravitreal treatment of retinal diseases, including wet age-related macular degeneration. Graybug’s other product candidates developed using its proprietary technologies also include GB-401, an injectable sustained release formulation of a beta-adrenergic blocker prodrug, for primary open-angle glaucoma, with a dosing regimen of once every six months or longer. Founded in 2011 on the basis of technology licensed from the Johns Hopkins University School of Medicine, Graybug has offices in Redwood City, California, and in Baltimore, Maryland. For more information, please visit www.graybug.vision.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995 including, but not limited to, statements regarding the company’s clinical pipeline, its ability to timely identify a partner to fund further development of GB-102 for wet AMD on reasonable terms if at all, the timing or outcomes of its interactions with regulatory authorities, its ability to advance GB-102, GB-401, or any future product candidate through preclinical or clinical development, its ability to achieve its anticipated milestones within the timing outlined above or at all, its ability to conduct planned operations within the evolving constraints arising from the COVID-19 pandemic, and the timing, cost, and results of its clinical trials. Forward-looking statements are subject to risks and uncertainties that may cause the company’s actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties described under the heading “Risk Factors” in the company’s annual report on Form 10-K filed for the year ended December 31, 2020, in its subsequent quarterly reports on Form 10-Q, and in the other reports the company files from time to time with the Securities and Exchange Commission. These forward-looking statements speak only as of the date of this press release, and the company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof.