Efficacy signal substantial enough to move to a larger sturdy

A 1-day, randomized (1:1) controlled, masked, pre-market study. Subjects with moderate to severe Sjögren's related Dry Eye Disease will be evaluated at 0, 5, 30 & 90 minutes post dose of either rhPRG4 (Treatment group) or vehicle (Crossover group). At 90 minutes, Crossover group subjects will be administered rhPRG4, then evaluated 5 & 30 minutes after rhPRG4 instillation (95 & 120 minutes from baseline). All subjects will self-report for the remainder of the day at 4 hours and 8 hours post dose.

Inclusion Criteria:

1. Subjects 18-75 years of age.
2. Subjects previously diagnosed with Sjögren's Syndrome
3. Subjects diagnosed with Sjögren's related Dry Eye Disease for at least 3 months (current use of artificial tears for the treatment of Dry Eye)
4. VAS Eye Dryness (100-point scale) score ≥ 45 mm;
5. Osmolarity ≥ 312 mOsm/L in the worst performing eye;
6. Only subjects who satisfy all Informed Consent requirements may be included in the study.

Exclusion Criteria:

Diagnosis and Main Criteria for Exclusion:

1. Evidence of an active ocular infection in either eye;
2. History or presence of ocular surface disorders not related to dry eye in either eye, including but not limited to significant conjunctivochalasis, SLK, limbal stem cell deficiency, allergic conjunctivitis, GPC, AKC, anterior basement membrane dystrophies, recurrent corneal erosion, neurotrophic keratitis, PCEDs, exposure keratitis and moderate to severe blepharitis;
3. History of any ocular surgery (including laser or refractive surgical procedures) in either eye within 30 days before study enrollment. Ocular surgery will not be allowed during the study treatment period and elective ocular surgery procedures should not be planned during the duration of the follow-up period;
4. Presence or history of any ocular or systemic disorder or condition that might significantly hinder the efficacy of the study treatment or its evaluation, could possibly interfere with the interpretation of study results, or could be judged by the investigator to be incompatible with the study visit schedule or conduct of trial procedures (e.g. ocular trauma, progressive or degenerative corneal conditions, uveitis, systemic infection), or initiation or cessation any systemic drug during the study period that is known to induce dry eye disease;
5. Known hypersensitivity to one of the components of the study or procedural medications;
6. Participation in another clinical study at the same time as the present study or within 14 days of screening/baseline visit;
7. History of drug, medication or alcohol abuse or addiction;
8. Females of childbearing potential (those who are not surgically sterilized or post-menopausal for at least 1 year) are excluded from participation in the study if they meet any one of the following conditions:
9. are currently pregnant or,
10. have a positive result on the urine pregnancy test at the Screening/Baseline Visit or,
11. intend to become pregnant during the entire course of and 30 days after the study treatment periods, or,
12. are breast-feeding or,
13. not willing to use highly effective birth control measures, such as: Hormonal contraceptives - oral, implanted, transdermal, or injected and/or mechanical barrier methods, during the entire course of and 30 days after the study treatment periods.