ST266 Eye Drops for the Treatment of Persistent Corneal Epithelial Defects

Efficacy:

The primary aim of the study is to evaluate the clinical response of ST266 treated subjects
with persistent corneal epithelial defects after 28 days of therapy. The secondary endpoint
is the response rate after 14 days of treatment. Failures are subjects that do not completely
heal during 28 days of therapy. The longest measurement and the measurement perpendicular to
that will be determined and the area calculated. The change in area and perimeter of
epithelial defect from baseline at Day 15 (14 days of treatment) and Day 29 (28 days of
treatment) will be calculated for each subject. The time to complete re-epithelialization is
defined as the time from the start of therapy (Baseline Visit/Day 1) to the Day when no
defect is observed. The number and percent of responders and failures will be summarized at
each visit. Graphical representation of percent of responders and failures will be provided.
The change in area and perimeter of epithelial defect from baseline through Day 15 (14 days
of treatment) and Day 29 (28 days of treatment) will be summarized. Visualization of mean
(Standard Deviation) of the change in area and perimeter will be provided at each time point.
The time to complete re-epithelialization will be summarized and listed.

Safety:

Subject demographics, baseline characteristics and relevant medical history will be
summarized and listed. Data for ST266 administration and concomitant therapies will be
listed.

The number and percent of subjects with treatment emergent adverse events and ST266 related
adverse events will be tabulated by system organ class and preferred terms.

Inclusion Criteria:

- Male and female subjects aged 18 years and over.

- Subjects with a PED persisting for at least 14 days but no longer than 28 days.

- The defect must have a minimum diameter of 2 mm along the greatest axis.

- In the Investigator's opinion, the defect is persistent i.e., the defect has not shown
improvement despite conventional treatment such as tear supplements and bandage
contact lenses.

- The original defect to the cornea must have resulted from corneal epithelial
debridement during diabetic vitrectomy surgery, Herpes Simplex Virus (HSV) keratitis,
Varicella Zoster Virus (VZV) keratitis, acid burns of the cornea, post-photorefractive
keratectomy (PRK), neurotrophic keratopathy, dry eye, or Sjogren's syndrome.

Exclusion Criteria:

- Use of concomitant ocular medications in the screening period that are not specified
in standardized PED treatment regime.

- Likely to require the use of concomitant ocular medications that are not specified in
the standardized PED treatment regime during the study follow-up period.

- Use of anticholinergic drugs, antihistamines, beta-blockers, tricyclic anti-
depressants, doxycycline or azithromycin within the past 30 days.

- Subject has been treated with autologous serum eyedrops within 3 months prior to the
baseline visit.

- Subject has been treated with amniotic membrane or other amnion product within 3
months prior to the baseline visit.

- Subject has had an active lid or ocular infectious process of any sort in the past 30
days.

- History of alkali burns of the cornea.

- The circumference affected by limbal blood vessel ischemia is greater than 75 percent
of the circumference.

- Subjects with severe lid abnormalities contributory to the persistence of the PED such
as inability to close the lids.

- Subjects who have a history of AIDS or HIV.

- Treatment with systemic corticosteroids (equivalent to > 10 mg/day of prednisone) or
immunosuppressive (including Plaquenil) or chemotherapeutic agents within 7 days prior
to Day 1, or likely to receive one of these therapies during study participation.

- Subjects who have participated in a clinical trial within 30 days prior to Day 1.

- Subjects who have more than one distinct PED in the study eye.

- Subjects with bullous keratopathy

- Subjects with corneal perforation or impending corneal perforation.

- Subjects with bilateral PED, if the smaller PED has a longest diameter of > 2 mm.
(Note: if bilateral PED is present and the smaller PED is < 2 mm, the subject is
eligible. In this situation, only the eye with the larger PED should be entered into
the study). The non-study eye will receive standard of care treatment and be observed
throughout the trial.

- Female subjects who are pregnant or breastfeeding. Female subjects who are neither
postmenopausal nor surgically sterile require a negative urine pregnancy test on Day 1
(±1 day) visit.

- Epithelial defect was classified as a progressive corneal melt caused by an
immunological process such as rheumatoid melt or Mooren's ulceration.

- Subjects with recurrent corneal erosion.