Epion Phase 3 Milestone Shows What Trial Completion Does and Does Not Mean

Epion Therapeutics said the last patient has completed the final study visit in its Phase 3 program for EpiSmart, an investigational epithelium-on corneal cross-linking system for progressive keratoconus, Optometry Times reported on June 15, 2026, citing a company announcement dated June 12. The program consists of two identical, double-masked, sham-controlled trials that began in October 2023 and enrolled about 800 patients at 26 U.S. sites.

The announcement does not include results. According to Optometry Times, Epion has not released topline efficacy or safety data, and full results are expected after data analysis and before a regulatory submission. The company plans to file a new drug application, subject to the study outcomes.

Announcements like this mark points on a fixed sequence that FDA and federal registry rules define.

What the phases mean

FDA's overview of clinical research describes three phases before approval:

• Phase 1: typically 20 to 80 healthy volunteers or people with the condition, studied for safety and dosage over several months.
• Phase 2: up to several hundred people with the condition, studied for efficacy and side effects. FDA says these studies "aren't large enough to show whether the drug will be beneficial."
• Phase 3: 300 to 3,000 participants over one to four years. FDA says these studies are designed "to demonstrate whether or not a product offers a treatment benefit to a specific population" and are "Sometimes known as pivotal studies."

Phase 4 studies take place after approval, as part of postmarket safety monitoring. FDA estimates that about 25 to 30 percent of drugs move on from Phase 3.

EpiSmart's trials sit at the Phase 3 stage. Both use the same primary endpoint, best spectacle-corrected distance visual acuity at 12 months, according to Optometry Times. FDA granted the product Fast Track designation in October 2025, the publication said.

Completion, topline and full results

A final patient visit, a topline announcement and a published or regulator-reviewed result are separate events. Epion's announcement marks the first: follow-up exams are complete across both trials, and the data still have to be analyzed. Any topline figures that follow would be company-reported until FDA reviews the full application.

Federal rules also set deadlines for public disclosure on ClinicalTrials.gov. Under 42 CFR 11.24, a covered trial must be registered within 21 calendar days after the first participant is enrolled. Under 42 CFR 11.44, results must generally be submitted "no later than 1 year after the primary completion date," which the rule's definitions describe as the date the final subject was examined or received an intervention for the final collection of primary-outcome data.

That deadline can move. When a trial studies a product that was not approved, licensed or cleared for any use before the trial's primary completion date, and the sponsor certifies it is seeking or may seek approval, results are due 30 days after FDA approves the product for a use studied in the trial, or after the application is withdrawn without resubmission for at least 210 days. Optometry Times reported that the NCT registry numbers for the two EpiSmart trials were pending public disclosure.