Epioxa epi-on cross-linking holds keratoconus gains at 3 years

A single epithelium-on corneal cross-linking treatment with Epioxa (riboflavin 5′-phosphate ophthalmic solution; Glaukos) sustained a 1.9 D improvement in maximum keratometry (Kmax) through three years in patients with keratoconus.¹ Glaukos announced the topline results from the phase 3 extension study GLK-202-03, and reported no serious or treatment-related adverse events.¹

Epi-on cross-linking avoids the epithelial removal required by traditional cross-linking procedures.¹ For optometrists who identify and comanage patients with keratoconus, durability after a single treatment shapes referral conversations and long-term monitoring plans. Epioxa also received a permanent J-code effective summer 2026.²

GLK-202-03 extension study design and three-year Kmax results

GLK-202-03 followed a cohort of patients who completed the phase 3 GLK-202-02 pivotal trial and received cross-linking during the initial study period.¹ Patients were followed for up to three years after treatment, with efficacy assessments focused on changes in corneal curvature and visual acuity.¹ The extension included 38 study eyes from 35 patients, and 92% of eyes completed the year 3 visit.¹

Treated eyes maintained a 1.9 D improvement in Kmax from baseline at three years, with no additional intervention during the extension period.¹ Glaukos described the change as reflecting long-term corneal flattening and stabilization after a single treatment.¹ The announcement did not report P values, confidence intervals, or a comparator arm for the extension.¹

Glaukos describes Epioxa as an oxygen-supplemented topical therapy bioactivated by pulsed UV light. The extension was designed to evaluate safety, durability, and clinical outcomes in this treated cohort. The company says the epi-on approach is designed to reduce the pain associated with epithelial removal, streamline the procedure, and minimize recovery.

Visual acuity and safety outcomes with Epioxa at 3 years

At year 3, 29% of treated eyes had gained 2 or more lines of best-corrected visual acuity (BCVA) from baseline, and 20% had gained three or more lines.¹ The release did not specify how many eyes contributed to each responder rate.¹ Through 3 years, the company reported no serious adverse events, no treatment-related adverse events, and no discontinuations due to adverse events.

In the prescribing information, conjunctival hyperemia was the most common adverse reaction (31%).¹ Other reactions occurring in 5% to 25% of eyes included corneal haze, photophobia, punctate keratitis, eye pain, and corneal epithelial defect.¹ Epioxa is contraindicated in aphakic patients and in pseudophakic patients without a UV-blocking intraocular lens (IOL), and the label advises caution in patients with a history of herpetic keratitis.

"These long-term results further reinforce the potential of Epioxa to provide durable clinical benefits for patients living with keratoconus," Thomas Burns, chairman and chief executive officer of Glaukos, said in a statement.¹

Epioxa HD (0.239%) and Epioxa (0.177%) are indicated for epithelium-on cross-linking in adults and pediatric patients aged 13 years and older with keratoconus, used with the O2n System and Boost Goggles.¹ When identifying candidates, optometrists can confirm lens status and screen for prior herpetic keratitis given the label contraindication and precaution.

The extension data come from a small cohort without a control arm and have not yet appeared in a peer-reviewed publication. Full results will clarify how durability compares across cross-linking approaches and help optometrists set expectations for patients considering epi-on treatment.

Glaukos launched Could it be KC?, a keratoconus awareness campaign aimed at earlier recognition and detection, in September 2026, with expanded activities planned for 2027.³ Epi-on cross-linking is also advancing beyond Glaukos, as Epion Therapeutics completed phase 3 trials of its EpiSmart system in June 2026.⁴

References

1. Glaukos announces positive three-year Epioxa results demonstrating durable clinical outcomes in keratoconus. News release. Glaukos Corporation. October 7, 2026. Accessed October 8, 2026. https://www.businesswire.com/news/home/20261007149511/en/Glaukos-Announces-Positive-Three-Year-Epioxa-Results-Demonstrating-Durable-Clinical-Outcomes-in-Keratoconus

2. Glaukos' Epioxa for keratoconus receives permanent J-code effective summer 2026. Optometry Times. April 21, 2026. https://www.optometrytimes.com/view/glaukos-epioxa-for-keratoconus-receives-permanent-j-code-effective-summer-2026

3. Glaukos partners with NBA champion Stephen Curry to launch "Could it be KC?" campaign to raise awareness of keratoconus. News release. Glaukos Corporation. September 23, 2026. Accessed October 8, 2026. https://www.businesswire.com/news/home/20260923796000/en/Glaukos-Partners-with-NBA-Champion-Stephen-Curry-to-Launch-Could-it-be-KC-Campaign-to-Raise-Awareness-of-Keratoconus

4. Epion Therapeutics completes phase 3 trials of EpiSmart epithelium-on cross-linking for keratoconus. Optometry Times. June 15, 2026. https://www.optometrytimes.com/view/epion-therapeutics-completes-phase-3-trials-of-epismart-epithelium-on-cross-linking-for-keratoconus