Stuart Therapeutics announced the initial results of its phase 3 clinical trial evaluating ST-100 (vezocolmitide) ophthalmic solution for the treatment of dry eye disease (DED).

The 29-day randomized, double-blind, vehicle-controlled trial assessed a variety of endpoints, including a primary endpoint of a significant increase in the proportion of patients exhibiting a greater than 10mm improvement from baseline in the Schirmer's tear test score (the Schirmer's Responder Rate, or SRR). According to Stuart, ST-100's SRR performance exceeded that of its phase 2 outcome but did not reach statistical significance, as vehicle performed better than in the phase 2 trial.

ST-100 achieved statistically significant week 1 fluorescein staining improvement in multiple regions of the eyes of trial subjects, with onset and clinically meaningful (>20%) improvement on day 4. The week 1 magnitude of stain improvement vs. vehicle in this phase 3 trial was greater than any reported result for any approved DED therapeutic or product. Statistically significant visual function improvement relative to placebo was achieved on day 2.

"We are very pleased with the outcome of the trial," Stuart Therapeutics president and CEO Eric Schlumpf, said in a company news release. "While additional study is required, the underlying data and the clinically meaningful results from this trial strongly suggest that ST-100, as the first drug candidate in a novel therapeutic class, 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."

ST-100 is part of a novel drug class of collagen mimetic peptides derived from the company's patented and proprietary PolyCol technology platform, which have a unique mechanism of action. Unlike other DED therapeutics, ST-100 works by targeting and repairing damaged collagen. Collagen plays a key role in DED, and collagen damage during the development of DED is part of an inflammatory cycle and loss of tissue integrity that interferes with normal function and cell signaling, particularly in the epithelium of the cornea and conjunctiva. ST-100's ability to repair this ocular collagen restores homeostatic function on the ocular surface, thereby alleviating the effects of DED.

Stuart Therapeutics is finalizing a plan for an additional clinical trial using the results from the present phase 3 trial to help guide the trial design. The company also intends to engage with the FDA to confirm the design of this additional trial, and the regulatory path to approval of ST-100.