Clinical Study Aimed At Evaluating the Safety and Efficacy of Tear Substitute Formulations in the Treatment of Dry Eye Disease.

A Single-Center, Double- Masked, Randomized Study Evaluating the Safety and Efficacy of PS Therapy (PST) Tear Substitute Formulations in the Treatment of the Signs and Symptoms of Moderate Dry Eye Disease.

This clinical study is aimed at evaluating the safety and effectiveness of 2 test formulations (Rain and Mist), against an approved over-the-counter formulation (Systane Ultra) and a placebo (saline), in the treatment of moderate dry eye disease.

Inclusion Criteria:

Each subject must:

1. Be at least 18 years of age at the Screening Visit;

2. Of either gender and any race;

3. Be willing and able to follow all instructions and attend all study visits;

4. Have ALL of the following in the study eye1 at the Screening Visit:

   1. A corneal fluorescein staining score of ≥ 2 in at least one corneal region OR have a sum of ≥ 4 in all corneal regions
   2. A baseline Schirmer's Test (with topical anesthesia) Score of ≥ 2 millimeters (mm)/ and ≤ 10 mm/5 minutes
   3. A physician's diagnosis of Dry Eye Disease

5. Have normal lid/lash anatomy, blinking function and closure as determined by the Investigator;

6. Be literate and able to complete questionnaires independently;

7. Have sufficient hand strength, in the opinion of the Investigator, to be able to independently administer the study drug;

8. For females capable of becoming pregnant, agree to have urine pregnancy testing performed at screening (must be negative) and exit visits; must not be lactating; and must agree to use a medically acceptable form of birth control throughout the study. Women considered capable of becoming pregnant include all females who have experienced menarche and have not experienced menopause (as defined by amenorrhea for greater than 12 consecutive months), or have not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy).

Exclusion Criteria:

Each subject must not:

1. Have a known hypersensitivity to any of the procedural agents or study drug components, or have previously used the study drug;

2. Have clinically significant corneal epithelial defects at Visit 1, prior to performing Schirmer's Test;

3. Have had any intraocular surgery (such as cataract surgery) or extraocular surgery in either eye within three months, or refractive surgery (e.g., laser-assisted in-situ keratomileusis, laser epithelial keratomileusis, photorefractive keratectomy or corneal implant) within twelve months of Visit 1;

4. Have had blepharoplasty in either eye;

5. Have had a corneal transplant in either eye;

6. Have used Restasis® or Xiidra® in the past 60 days;

7. Be using any ocular medications, other than the study treatment, within 7 days prior to Visit 1 and throughout the study treatment period. This includes both therapeutic and lubricant eye drops that could potentially interfere with the study outcomes, by either exacerbating or alleviating the symptoms of dry eye disease.

8. Have used contact lenses within 7 days prior to Visit 1 or anticipate the use of contact lenses during the study treatment period;

9. Have any form of punctal or intracanalicular occlusion;

10. Have a history or presence of any ocular disorder or condition in either eye that would, in the opinion of the Investigator, likely interfere with the interpretation of the study results or participant safety such as significant corneal or conjunctival scarring; pterygium or nodular pinguecula; current ocular infection, conjunctivitis, or inflammation not associated with dry eye; anterior (epithelial) basement membrane corneal dystrophy or other clinically significant corneal dystrophy or degeneration; ocular herpetic infection; evidence of keratoconus; etc. Blepharitis not requiring treatment and mild meibomian gland disease that are typically associated with DED are allowed;

11. Have a systemic condition or disease not stabilized or judged by the Investigator to be incompatible with participation in the study, or with the lengthier assessments required by the study (e.g., current systemic infection, uncontrolled autoimmune disease, uncontrolled immunodeficiency disease, history of myocardial infarction or heart disease, etc.);

12. Have active or uncontrolled, severe:

    • Systemic allergy
    • Chronic seasonal allergies at risk of being active during the study

13. Have any condition or history that, in the opinion of the Investigator, may interfere with study compliance, outcome measures, safety parameters, and/or the general medical condition of the subject;

14. Be currently enrolled in an investigational drug or device study, or have used an investigational drug or device within 30 days prior to Visit 1 and during the treatment period;

15. Be a female who is currently pregnant, planning a pregnancy or lactating.