The objective of this study is to evaluate the safety and effectiveness of OC-01 Nasal Spray as compared to placebo on signs and symptoms of dry eye disease.

This was a Phase 3, multicenter, randomized, controlled, double-masked (including subjects, Investigators, study site personnel, and Sponsor personnel) study designed to evaluate the safety and efficacy of OC-01 (varenicline) nasal spray 0.6 mg/mL and 1.2 mg/mL in adult participants with DED. The study randomized 758 subjects at least 22 years of age with a physicians' diagnosis of DED and meeting all other study eligibility criteria to receive OC-01 (varenicline) nasal spray or placebo twice daily (BID) for 28 days with three additional long-term follow-up visits at 6 weeks, 6 months, and 12 months. Participants who terminated from the study during the treatment period were asked to complete safety assessments (if the participants agree) prior to study exit. Participants who were terminated early from the study were not replaced

Inclusion Criteria:

- Have used and/or desired to use an artificial tear substitute for dry eye symptoms within 6 months prior to Visit 1

Exclusion Criteria:

• 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.
• 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 dry eye disease are allowed.
• 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.)
• Have a known hypersensitivity to any of the procedural agents or study drug components
• 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.