GrayBug is developing an injectable, long-acting ocular drug delivery technology called GB-102 for treating wet age-related macular degeneration. GB-102 is a dual anti-VEGF/anti-PDGF therapeutic that enables injections every 4-6 months, compared to monthly injections currently required. GrayBug has worldwide rights to the technology from Johns Hopkins University and aims to file an IND for GB-102 in wet AMD in 2016. The company is also exploring applications of its technology for glaucoma and other ocular diseases, with the goal of developing long-acting drugs that improve compliance over daily eye drops.

1. GrayBug OIS Presentation
Jeffrey L. Cleland,PhD
InterimCEO
N o v e m b e r 1 2 , 2 0 1 5

2. 60CONFIDENTIAL AND PROPRIETARY |
CompanyHighlights
Ocular Therapeutics Represents a $10B+ Global and Growing Market
GB-102, a Dual Anti-VEGF/Anti-PDGF Therapeutic, Enables Once Every
4 to 6 Month Intravitreal Injections (2-3 vs ≥ 20 injections per year)
• On track for IND in 2016 for wet AMD indication
GrayBug Technology Solves Key Challenges for Sustained Ocular Delivery
• Injection with small gauge needle – no surgical procedure
• Minimal side-effects, no interference with visual axis
• Tunable approach – release rate and duration
Exclusive Rights for Technology
• Worldwide rights from Wilmer Eye Institute, Johns Hopkins University
• Patent Protection to at least 2030 (additional filings ongoing)
Technology Enables Broad Portfolio of Ocular Products
• Age-related macular degeneration (wet & dry), glaucoma, neuroprotection, etc
• NCEs for glaucoma and neuroprotection as a novel technologies
• Potential for Product Specific Partnerships; Aerie Pharmaceuticals Deal
Experienced and Knowledgeable Team
• Ophthalmology & Drug Delivery Experts

3. 61CONFIDENTIALAND PROPRIETARY |
An Experienced LeadershipTeam
Jeffrey Cleland,PhD
Interim CEO
BoardMember
Former CEO, Co-Founder,Versartis
>20 Years of Drug Development Experience
Team Leader Through Launch of Only FDA Approved
Long-Acting hGH Product; Early development of
Lucentis
Christy Shaffer,PhD
BoardMember Partner, Hatteras Ventures; Former CEO, Inspire
Gerald Cagle,PhD
BoardMember Former CSO, Senior VP R&D, Alcon
Justin Hanes, PhD
Founder, Chair SAB
BoardMember
Lewis J. Ort Professor of Ophthalmology & Director of
the Center for Nanomedicine, Wilmer Eye Institute,
Johns Hopkins School of Medicine
Peter Campochiaro,MD
Founder, SAB Member
Eccles Professor of Ophthalmology and Neuroscience,
Wilmer Eye Institute, Johns Hopkins School of Medicine
Peter McDonnell,MD
Founder, SAB Member
William Holland Wilmer Professor and Chair of
Ophthalmology, Director of the Wilmer Eye Institute,
Johns Hopkins School of Medicine
OPHTHALMOLOGY &
INTRAOCULAR
THERAPY
LONG ACTING
PRODUCTS
VRS-317
ACADEMIC
OPHTHALMOLOGY

4. 62CONFIDENTIAL AND PROPRIETARY |
GrayBug TechnologyAdvantages
• Tunable release profile (up to 6+ months)
• Injection with small gauge needle (27-29 G)
• Minimizes inflammation
• Forms implant outside visual axis
• Ability to deliver compounds with different properties from
small molecules to biologics
• Scalable aseptic manufacturing process
(no terminal sterilization required)
In vivo data to date (rabbits):
>3 month sustained delivery, no inflammation or toxicity

5. 63CONFIDENTIALAND PROPRIETARY |
Injectable High Capacity Reservoirand
Localization of Microparticles
INTRAVITREAL INJECTION
WITH SMALL GAUGE NEEDLE
ENCAPSULATED DRUG
Biodegradability
Biocompatibility
Bioabsorbability
Polymer Modified
to Reduce
Inflammation
FUNDUS PHOTOS, DAY 7
Microparticle
Localization
Designed to Aggregate
and Remain Outside
Visual Axis

6. 64CONFIDENTIALAND PROPRIETARY |
MeanAreaofCNV(mm2)
Control
(PBS)
GB-102
(10ug)
0
0.012
0.008
0.004
0.016
P<0.05
GB-102: Long-Term Suppressionof
Neovascularization
Laser-Induced Model of CNV; P.Campochiaro MD, J.Hanes PhD - Wilmer Eye Institute
SUSTAINED EFFICACY: 5 WEEKS
(Laser at 4 weeks)
SUSTAINED EFFICACY: 9 WEEKS
(Laser at 8 weeks)
P<0.05
MeanAreaofCNV(mm2)
GB-102 Control
(10 ug) (PBS)
0
0.01
0.02
0.03
Control
GB102
Lucentis® lasts only 2 weeks in mouse model
Control
GB102

7. 65CONFIDENTIAL AND PROPRIETARY |
Challenges with Current GlaucomaDrugs
• Current approved glaucoma products require daily or BID topical dosing
• Patients are non-compliant with therapy (72% in controlled setting; 50% or
less in clinical practice; Quigley et al)
• Lack of compliance leads to neurological complications and loss of vision
– No compounds are approved for neuroprotection & trials may be challenging to
prove effects
• Sustained release versions of prostaglandins (PG; e.g. lantanoprost,
travoprost) are in development
• Sustained release of carbonic anhydrase inhibitors (CAIs) complicated by
solubility in aqueous solutions
• Need drugs with IOP lowering and neuroprotection
Library of compounds being synthesized to address these challenges

8. 66CONFIDENTIALAND PROPRIETARY |
GrayBug Pipeline :GB-102 LeadProduct
FORMULATION IN VIVO NON-GLP GLP PROJECTED
INDICATION DEVELOPMENT EFFICACY PK/PD TOXICOLOGY STUDIES IND PHASE1 PHASE2
GrayBug’s Focus on GB-102 Enables Potential for:
- First and Best in Class, Single Dose Dual Inhibitor with 4-6 Month Dose Interval
- Rapid Validation of GrayBug Technology in Humans
- Expansion of Patent Portfolio
- Ability to Leverage GB-102 Experience to Partner Programs
WetAMD GB-102 2016 2016 2018
Glaucoma
IOP Lowering
Neuroprotection
2017
Corneal Graft
Rejection
WetAMD AR13154
+ others

9. Thank You