RTA 408 Ophthalmic Suspension for the Prevention of Corneal Endothelial Cell Loss Following Cataract Surgery - GUARD

Many ocular diseases are characterized by oxidative stress and/or inflammation. Oxidative
stress is also known to adversely impact corneal endothelial cells, and may be a factor
resulting in the acute decrease in corneal endothelial cell density following ocular
surgery. While corticosteroids provide potent anti-inflammatory efficacy in a wide range of
acute and chronic inflammatory ocular diseases, their use is limited by their side effect
profile, which includes the potential to elevate IOP and induce cataract formation. In
addition, most available ophthalmic anti-inflammatory treatments, including corticosteroids,
do not directly protect against the underlying oxidative stress component of the disease
process. Consequently, there is a clinical need for agents that protect against oxidative
stress and provide anti-inflammatory efficacy without inducing steroid-like side effects.

This study will assess the safety and efficacy of omaveloxolone (RTA 408) Ophthalmic
Suspension (0.5% or 1%) versus vehicle for the prevention of corneal endothelial cell loss
in patients undergoing cataract surgery.

Inclusion Criteria:

1. Be male or female and ≥18 years of age and ≤80 years of age

2. Plan to undergo cataract extraction by phacoemulsification with the implantation of a
posterior chamber intraocular lens

3. Have the potential, in the opinion of the investigator, to improve best-corrected
visual acuity in the study eye after surgery

4. Have Grade 3, 4, or 5 nuclear cataract in the study eye, according to the LOCS III

5. Have corneal endothelium in the study eye that can be accurately assessed using
specular microscopy

6. Have endothelial cell density of >1800 cells/mm2 in the study eye at the Screening
Visit

7. Have a pinhole visual acuity (VA) of at least 1.0 logarithm of the minimum angle of
resolution (logMAR) in the study eye and fellow eye as measured using an Early
Treatment for Diabetic Retinopathy Study (ETDRS) chart

Exclusion Criteria:

1. Have a score >0 on the ocular pain assessment at the Screening Visit or the
Randomization Visit in the study eye

2. Have an active immunosuppressive disease or an autoimmune disease that, in the
opinion of the investigator, could affect the quality of the ocular surface

3. Have active or chronic/recurrent ocular or systemic disease that is uncontrolled and
will likely affect wound healing

4. Have an intraocular pressure (IOP) ≤5 mmHg in either eye

5. Have had corneal or retinal surgery (laser or incisional) within the past 6 months,
or be planning to have laser or incisional surgery during the study period in the
study eye

6. Have the presence of guttae Stage 2 or greater or other abnormality in the study eye
that does not allow for accurate corneal endothelial cell assessments