Despite failing its phase 3 primary endpoint, ST-100 (vezocolmitide) ophthalmic solution for the treatment of dry eye disease (DED) maintained other findings that validate its promise and effectiveness, according to developer Stuart Therapeutics. 

Unlike other DED therapeutics, ST-100 is part of a novel drug class of collagen mimetic peptides and works by targeting and repairing damaged collagen, restoring homeostatic function on the ocular surface.  

Evaluating its safety and efficacy, the 29-day randomised, double-blind, vehicle-controlled trial’s primary endpoint was a significant increase in the proportion of patients exhibiting a greater than 10mm improvement from baseline in the Schirmer tear test score. While ST-100's performance exceeded that of its phase 2 outcome, it did not reach statistical significance, since the vehicle performed better than in the phase 2 trial, the Florida-based company said.  

However, on several other key endpoints commonly used to evaluate DED, ST-100 demonstrated industry-leading results, the company said. ST-100 achieved statistically significant week one fluorescein staining improvement in multiple regions of the eyes of trial subjects, with onset and clinically meaningful (>20%) improvement on day four. “The week one magnitude of stain improvement vs. vehicle in this phase 3 trial was greater than any reported result for any approved DED therapeutic or product,” it reported, adding statistically significant visual function improvement relative to placebo was achieved on day two.  

Stuart Therapeutics’ CEO Eric Schlumpf said they are pleased with the outcome of the trial. “While additional study is required, the underlying data and the clinically meaningful results strongly suggest that ST-100 can address the critical unmet needs in dry eye disease: a fast, effective and comfortable dry eye topical drop that gives patients rapid relief they can notice and appreciate.” 

Building on the phase 3 trial findings, Stuart Therapeutics said it is finalising plans for an additional clinical trial while engaging with the FDA about the regulatory path to approval of ST-100.