Stuart Therapeutics Shares Phase III ST-100 Results

Stuart Therapeutics has announced initial findings from its Phase III clinical trial evaluating ST-100 (vezocolmitide) ophthalmic solution as a treatment for dry eye disease (DED)—a condition affecting over 30 million adults in the United States.

Trial Design and Primary Endpoint

The 29-day trial was designed as a randomized, double-blind, vehicle-controlled study assessing multiple endpoints. The primary endpoint was the Schirmer’s Responder Rate (SRR), defined as the proportion of patients achieving >10mm improvement from baseline in Schirmer's tear test scores.

While ST-100 outperformed its Phase II SRR result, the difference did not reach statistical significance, as the vehicle group showed better-than-expected performance compared to earlier trials.

Strong Results Across Key Secondary Endpoints

Despite not meeting its primary endpoint, ST-100 demonstrated industry-leading outcomes on several key secondary measures:

• A statistically significant fluorescein staining improvement was observed by week 1 in multiple ocular regions, with clinically meaningful results (>20%) starting on day 4.

• The magnitude of staining improvement vs. vehicle at week 1 exceeded that of any currently approved DED therapy reported to date.

• Significant visual function improvement relative to placebo was achieved as early as day 2, suggesting rapid onset of therapeutic effect.

Clinical Perspective and Therapeutic Implications

“We are very pleased with the outcome of the trial,” said Eric Schlumpf, President and CEO of Stuart Therapeutics. "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 based on collagen mimetic peptides developed through the company’s proprietary PolyCol technology platform. Unlike other DED treatments, ST-100’s mechanism of action targets damaged collagen, which plays a critical role in maintaining tissue integrity and normal cellular signaling on the ocular surface. Repairing this collagen restores homeostatic function, potentially interrupting the inflammatory cycle that drives DED.

Expert Commentary and Future Development

"As a practicing ophthalmologist, I am impressed by the clinical achievements and speed of onset of the therapeutic effects of ST-100 in Stuart's Phase III trial, which suggest rapid ocular surface healing and treatment effects that appear to be considerably greater than those seen with currently approved dry eye disease therapeutics," said Jodi Luchs, MD, Chief Medical Officer at Stuart Therapeutics. "Based on these study results, I believe ST-100 has the potential to greatly enhance the treatment of dry eye disease and has significant promise in treating other debilitating diseases affecting the cornea."

Stuart Therapeutics is currently finalizing plans for an additional clinical trial, informed by these Phase III results. The company also intends to engage with the U.S. FDA to confirm the trial design and regulatory pathway for ST-100’s approval.