A Phase 2 Trial to Test Safety and Efficacy of ST-100, a Unique Collagen Mimetic Peptide Ophthalmic Solution for Dry Eye Disease.

Objective: Dry eye disease (DED) is a worldwide source of ocular discomfort. This first-in-human phase 2 clinical study determined the efficacy of treating signs and symptoms of DED using an ophthalmic solution of synthesized mimetic of human collagen (ST-100).

Design: This double-masked, randomized, study compared high (60 μg/mL) and low (22 μg/mL) dose ST-100 to vehicle utilizing the Ora, Inc. Controlled Adverse Environment (CAE) during a 28-day period.

Participants: Participants included males and females ≥ 18 years of age with signs and symptoms of DED for ≥ 6 months that worsened during CAE exposure who were not taking any topical prescription therapeutic.

Intervention: Participants applied ST-100 or vehicle placebo topically to both corneas (1 drop) twice daily via a blow-fill-sealed preservative-free container.

Main Outcome Measures: The prespecified primary efficacy sign end point was mean change from baseline (CFB) in total corneal fluorescein staining, and the primary symptom end point was mean CFB in ocular discomfort. A secondary prespecified efficacy end point was CFB in unanesthetized Schirmer's test for tear film production.

Results: Of 160 subjects in the intent-to-treat population (112 female, 48 male, median age 64), 146 completed the study. Total corneal fluorescein staining CFB improved for high-dose ST-100, with superiority over vehicle when both eyes were considered together (2-sample test:  = 0.0394). High-dose ST-100 was superior to vehicle in Schirmer's CFB for the study eye (least squares mean difference [confidence interval] = 2.3 [0.6, 4.0],  = 0.0094). For study eyes, the proportion of Schirmer's test responders (CFB ≥ 10 mm, Schirmer's responder rate) was 12.2% for high-dose ST-100 versus 0.0% for vehicle ( = 0.0266). The CFB for ocular discomfort score improved in study eyes for high- and low-dose ST-100 (paired test,  = 0.0133,  = 0.0151, respectively) but without superiority over vehicle (ANCOVA:  = 0.5696,  = 0.8968, respectively). ST-100 Schirmer's responders also demonstrated total elimination of worsening of corneal fluorescein stain during the stress of CAE sessions.

Conclusions: ST-100 significantly improved tear production and related outcomes in DED and was well-tolerated in reducing symptoms.

Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.