Vyznova (Neltependocel) for Bullous Keratopathy: Clinical Outcomes, Regulatory Status, and Industry Impact

What is Bullous Keratopathy? Disease Burden and Treatment Limitations

Corneal Endothelial Cell Physiology and the Absence of In Vivo Regeneration

Bullous keratopathy (BK) is a sight-threatening condition caused by the progressive loss of corneal endothelial cells (CECs).

These cells maintain corneal transparency by actively pumping excess fluid out of the corneal stroma.

Because CECs do not regenerate under physiological conditions, when cell density falls below a critical threshold—typically below 500 cells/mm²—corneal edema and bullae formation progress irreversibly.

Key Etiologies

The primary etiologies of BK include pseudophakic bullous keratopathy, Fuchs endothelial corneal dystrophy (FECD), pseudophakic bullous keratopathy, post-keratoplasty endothelial failure, and bullous keratopathy after glaucoma surgery.

Patients experience blurred vision, decreased night vision, photophobia, and ocular pain, with progression to blindness if left untreated.

Limitations of Current Standard of Care

The current standard treament for BK relies on posterior lamellar keratoplasty—DSAEK or DMEK—both of which require donor corneal tissue.

In Japan, domestic donor supply meets less than 10% of demand, critically limiting access to treatment.

Keratoplasty also carries risks of graft dislocation, primary graft failure, allograft rejection, and irregular astigmatism, and demands considerable surgical expertise.

What is Vyznova (Neltependocel)? Mechanism of Action and Product Overview

Vyznova (INN: neltependocel), developed by Aurion Biotech (Seattle, WA), is the world's first approved allogeneic cell therapy for corneal endothelial disease.

The product received approval from Japan's Pharmaceuticals and Medical Devices Agency (PMDA) in March 2023 (1), representing the first regulatory approval of an allogeneic cell therapy for corneal endothelial disease worldwide.

Manufacturing Process (cHCEC)

Vyznova consists of cultured human corneal endothelial cells (cHCECs) derived from a healthy donor cornea and expanded through a proprietary, multi-step manufacturing process.

The key innovation lies in the propagation of fully differentiated—rather than stem cell-derived—corneal endothelial cells outside the body.

Cultured cells from a single donor can be manufactured into products sufficient to treat more than 100 recipient eyes, fundamentally disrupting the one-to-one donor dependency of current keratoplasty.

Co-administration with the ROCK Inhibitor

Vyznova is co-administered with Y-27632, a Rho-associated, coiled-coil containing kinase (ROCK) inhibitor.

Y-27632 promotes cHCEC adhesion to Descemet's membrane and enhances cell survival, improving engraftment following a single intracameral injection.

Japanese Clinical Data Facilitating PMDA Approval

The PMDA approved Vyznova based on results achieved across three Japanese clinical trials totaling 65 patients.

These comprised a first-in-human clinical research (n=38) (2), a Phase 2 study (dose-ranging trial) (n=15), and a Phase 3 study (confirmatory trial) (n=12).

Primary Efficacy Endpoint Achievement

The primary efficacy endpoint was the proportion of patients achieving a corneal endothelial cell density (ECD) of ≥1,000 cells/mm².

In the first-in-human clinical research, 91% of patients achieved an ECD of ≥1,000 cells/mm² at 24 months post-treatment.

As secondary endpoints, 85% achieved a central corneal thickness (CCT) of less than 630 μm, and 94.1% demonstrated a BCVA improvement of ≥0.2 logMAR.

Five-year follow-up data published in 2021 demonstrated sustained corneal endothelial recovery, supporting the long-term safety profile. (3)

Experience to Date: Post-Launch Real-World Outcomes

Initial Commercial Outcomes at Three Independent Japanese Centers (4)

Between August and October 2024, four eyes of four patients were treated with a commercial lot of Vyznova at three independent Japanese institutions specializing in corneal transplantation.

Underlying conditions included Fuchs endothelial corneal dystrophy (n=2), pseudophakic bullous keratopathy (n=1), and primary angle-closure disease (n=1); all patients received an intracameral injection of 1.0 × 106 cHCECs.

At the 6-month assessment, corneal clarity was restored in the three uncomplicated cases, with mean BCVA improving from 0.20 to 0.55.

Mean CCT decreased from 729 μm to 586 μm, and endothelial cell density—unmeasurable preoperatively—reached a mean of 2,483 cells/mm2 at six months.

One case experienced Descemet's membrane detachment, highlighting the need for careful intraoperative management when adopting the technique at non-developer institutions.

Commercial Scale in Japan

Following the commercial launch in 2024, 25 patients were treated at seven eye institutes, expanding to 180 patients in 2025.

Prof. Kinoshita articulated the long-term vision: achieving permanent corneal endothelial restoration through a single procedure, analogous in durability to cataract surgery.

Cell Therapy vs Standard Corneal Transplant: Clinical Advantages of Vyznova

Vyznova inherently eliminates complications specific to DSAEK and DMEK, including graft dislocation, primary graft failure, allograft rejection, irregular astigmatism, and infection.

Treatment can be performed as a single outpatient injection under topical or local anesthesia, with a face-down positioning requirement of approximately two to three hours post-injection.

Furthermore, the manufacturing scalability—enabling treatment of more than 100 recipients from a single donor—represents a fundamental solution to the global donor cornea shortage.

Regulatory Status and Global Development Outlook

Japan:

Received PMDA approval in March 2023 and has secured national health insurance reimbursement.

United States:

Vyznova has received both FDA Breakthrough Therapy and Regenerative Medicine Advanced Therapy (RMAT) designations, enabling expedited review pathways.

The Phase 1/2 CLARA trial (97 subjects, US and Canada) has completed enrollment and dosing, and Phase 3 development is currently underway.

EU:

Clinical development is currently in the planning stage.

Industry and Market Impact

In 2023, the Bullous Keratopathy market size in Japan was approximately USD 1.2 million, and is expected to grow steadily in the coming years, driven by the clinical application of Vyznova.

Competitive pipeline entrants include Emmecell (EO2002, Phase 3 planned), Trefoil Therapeutics (TTHX1114), and Cellusion (CLS001), but Vyznova maintains a first-mover advantage as the sole globally approved and reimbursed product in this class.

The intellectual property originated with Prof. Kinoshita and Kyoto Prefectural University of Medicine (KPUM) and was out-licensed to Aurion Biotech — a model of university-originated biotechnology commercialization that continues to attract industry attention.

Conclusion: A New Paradigm in Corneal Endothelial Disease Management

Vyznova introduces cell therapy as a transformative alternative to a field constrained for decades by donor shortages and post-surgical complications.

Real-world evidence from Japan's commercial launch supports the feasibility of implementation beyond developer sites, while highlighting the importance of careful intraoperative technique.

With Phase 3 progressing in the United States under FDA RMAT designation, Vyznova is positioned to become a global standard of care in the near future — signaling the dawn of a new era for cell therapy in ophthalmology.

References

• (1) Japan's Pharmaceuticals and Medical Devices Agency (PMDA) https://www.pmda.go.jp/files/000263641.pdf (accessed April 2026)

• (2) Kinoshita S, et al. N Engl J Med. 2018; doi:10.1056/NEJMoa1712770

• (3) Numa K, et al. Ophthalmology. 2021; doi:10.1016/j.ophtha.2020.09.002

• (4) Kobayashi A, et al. Cornea. 2025; doi:10.1097/ICO.0000000000003984

About the Author

Daiki Sakai, MD, PhD

Japanese Board-certified Ophthalmologist

Founder, Ophthoagent Team