Glaukos Corporation has received U.S. regulatory approval from the FDA for Epioxa HD (riboflavin 5’-phosphate ophthalmic solution) / Epioxa (riboflavin 5’-phosphate ophthalmic solution) 0.177%, a corneal collagen crosslinking (CXL) iLink therapy.
The long-anticipated announcement is right on schedule after the company’s February 2025 new drug application (NDA) submission.
How exciting! Start with the basics of this.
Epioxa (pronounced E pee ox’ ah) is the latest iteration of Glaukos’s corneal CXL therapy Photrexa (epithelium [epi]-off), a minimally-invasive outpatient procedure that was first FDA-approved in 2016.
From an industry standpoint: iLink was the first and only corneal CXL procedure commercially available in the United States for slowing or halting keratoconus progression.
- See here for how it does this (and click here for four key examples of why using an FDA-approved CXL procedure is so critical).
For greater context: Check out how iLink compares to standard forms of keratoconus treatment.
Next up: Give us the rundown on Epioxa.
What to know about it: The novel, oxygen-enriched topical therapeutic is bioactivated by ultraviolet (UV) light designed as an incision-free alternative to traditional CXL procedures.
Its indication: For use in epi-on corneal collagen CXL for the treatment of keratoconus in adults and pediatric patients aged 13 years and older
But more specifically …
This epi-on (note the difference from Photrexa) utilizes a proprietary novel drug formulation to reduce treatment time and complexity as well as shorten recovery time.
- And as a bonus for patients: It’s intended to eliminate pain typically associated with the epithelium's removal.
What’s the recommended dosage?
Importantly, Epioxa HD and Epioxa are supplied in single-dose syringes (discarded after use) intended for topical ophthalmic use.
Got it. Circle back and talk about that novel formulation.
The formulation is actually a two-in-one composed of Epioxa and Epioxa HD.
And take note: Epioxa uses riboflavin modified to:
- Bolster penetration through the epithelium
- Deliver pulsed UV-A irradiation at increased intensity
- Provide supplemental oxygen (O2n) via “boost goggles”
In other words: Epioxa and Epioxa HD are sequentially administered during the CXL procedure and followed by UV activation in an oxygen-enriched environment, according to Glaukos.
Any contradictions to be aware of?
A few … both Epioxa and Epioxa HD are contraindicated in:
- Patients with known hypersensitivity to benzalkonium chloride (or any ingredients in either therapeutics)
- Aphakic and pseudophakic patients without a UV-blocking intraocular lens
As for potential warnings and precautions: Caution is advised for patients with a history of herpetic keratitis due to the potential for reactivation of herpes keratitis.
And along these lines … how about potential adverse reactions?
There’s definitely a few to be aware of, based on clinical data (which we’ll discuss later).
The following occurred in 5% to 25% of patients during clinical trials:
- Corneal opacity (haze), photophobia, punctate keratitis, eye pain, eye irritation, increased lacrimation, corneal epithelium defect, eyelid oedema, corneal striae, reduced visual acuity, dry eye, and anterior chamber flare.
Now to that supporting clinical data.
We’ve got two prospective, randomized, multicenter, double-masked phase 3 trials to discuss—or rather, the findings from both—that were included in Epioxa’s NDA submission.
These include positive data from a first (NCT03442751) and second study (NCT05759559; a confirmatory pivotal trial) that evaluated Epioxa among 400+ patients’ keratoconus eyes.
Give me specifics.
Both studies met their primary endpoints and demonstrated Epioxa's favorable safety profile.
For example: In the second study—which aimed to reduce the progression of and / or reduce the maximum corneal curvature (Kmax) in keratoconus eyes—Epioxa resulted in a “clinically relevant and statistically significant improvement” in Kmax at Month 12 (from baseline).
- Check out the high percentage of tolerance among Epioxa-treated patients.
- And for data on that first study (which only measured from baseline to Month 6), see here.
Let’s talk big-picture.
The significance of Epioxa’s approval is far reaching.
Glaukos Chairman and CEO Thomas Burns noted that the second-gen iLink therapy represents a new standard-of-care for keratoconus patients as “the first FDA-approved topical drug therapy that does not require removal of the corneal epithelium.
Alrighty, now the big question: When will this be commercially available?
Fairly soon—Q1 2026.
Coupled with Epioxa’s anticipated U.S. launch will be key initiatives to promote patient awareness and treatment access—as well as addressing long-standing challenges of both underdiagnosed and under-treated keratoconus patients).
What kind of initiatives?
- Streamlined patient access support programs
- Launch of a co-pay assistance program (to reduce financial barriers)
- Integration of healthcare provider and patient-focused strategies
- To improve education and engagement
- Launch of broad disease awareness and detection programs
- To encourage earlier and more widespread screenings for/diagnosis of keratoconus