Aurion Biotech doses first patients in ASTRA phase 3 study

Aurion Biotech has initiated dosing in a pivotal phase 3 clinical trial evaluating AURN001, an investigational corneal endothelial cell therapy, for the treatment of corneal edema secondary to endothelial dysfunction. The ASTRA study represents a late-stage effort to assess whether a single intracameral administration of cultured human corneal endothelial cells, delivered in combination with a rho-kinase (ROCK) inhibitor, can restore corneal clarity and improve visual acuity in patients with conditions such as Fuchs endothelial corneal dystrophy.

The start of patient dosing in the United States marks a key step toward a potential biologics license application (BLA), with the therapy positioned as an alternative to donor tissue–based keratoplasty. If successful, AURN001 could represent a shift from surgical transplantation toward regenerative, cell-based therapy for endothelial disease—a space historically constrained by donor tissue availability and procedural risks.

Trial design and endpoints

The ASTRA trial (NCT07368959) is a randomized, multicenter, phase 3 study expected to enroll participants across approximately 12 US sites.¹ Patients with corneal edema due to endothelial dysfunction are being assigned to receive a single intracameral injection of AURN001, which consists of allogeneic human corneal endothelial cells (neltependocel) combined with the ROCK inhibitor Y-27632.

The primary endpoint is the proportion of patients achieving a ≥15-letter gain (≥3 lines) in best-corrected visual acuity (BCVA) at 6 months. Secondary endpoints include changes in central corneal thickness (CCT) and mean change in BCVA from baseline at the same time point. These endpoints are consistent with prior studies in corneal endothelial disease and reflect both functional and anatomic outcomes relevant to clinical practice.

Safety outcomes have not yet been reported for ASTRA, but prior early-phase studies of similar approaches have focused on intraocular inflammation, endothelial cell density, and graft failure or need for rescue keratoplasty.

Clinical context and unmet need

Corneal endothelial dysfunction, including Fuchs endothelial corneal dystrophy, is a leading indication for corneal transplantation worldwide.² Progressive loss of endothelial cells leads to impaired fluid regulation, stromal edema, and visual decline. Because corneal endothelial cells have limited proliferative capacity in vivo, treatment has historically relied on surgical replacement via endothelial keratoplasty techniques such as Descemet membrane endothelial keratoplasty (DMEK) or Descemet stripping automated endothelial keratoplasty (DSAEK).³

While these procedures have improved outcomes compared with full-thickness penetrating keratoplasty, they remain dependent on donor tissue supply and are associated with risks such as graft detachment, rejection, and prolonged visual recovery.^3,4 Access to surgery also varies globally, highlighting a need for scalable, less invasive approaches.

Mechanism and Prior Evidence

AURN001 combines cultured human corneal endothelial cells with a ROCK inhibitor to enhance cell adhesion, survival, and proliferation after intracameral injection. ROCK inhibition has been shown to promote endothelial cell regeneration and migration, forming the mechanistic basis for this therapeutic strategy.⁵

Clinical proof-of-concept for this approach has been demonstrated in earlier investigator-led studies, particularly in Japan. In a landmark prospective study, injection of cultured endothelial cells with a ROCK inhibitor resulted in sustained corneal clearing and visual improvement in patients with bullous keratopathy, with effects maintained over several years of follow-up.⁶ These findings supported subsequent development programs and regulatory activity in Japan, where conditional approval has been granted for related therapies.

However, differences in study design, patient populations, and manufacturing processes underscore the importance of confirmatory trials such as ASTRA in broader populations.

Interpretation and remaining questions

The initiation of a US phase 3 trial signals increasing maturity in the field of corneal endothelial cell therapy. If efficacy is demonstrated, AURN001 could offer a minimally invasive alternative to keratoplasty, potentially reducing surgical burden and expanding treatment access.

Nevertheless, several uncertainties remain. Long-term durability of cell-based therapy, comparative effectiveness versus DMEK, and reproducibility across diverse patient populations will be critical to assess. Additionally, regulatory considerations for cell-based biologics—including manufacturing consistency and scalability—may influence eventual approval timelines.

Limitations and next steps

At present, no efficacy or safety data from the ASTRA trial are available. As such, clinical impact cannot yet be determined. The study’s 6-month primary endpoint may also limit assessment of long-term endothelial function and durability, which are particularly relevant in a chronic, progressive disease.

Future updates from ASTRA, including detailed safety data and subgroup analyses, will be essential to contextualize the role of AURN001 within existing treatment paradigms.

References

1. ClinicalTrials.gov. Study of AURN001 in subjects with corneal edema due to corneal endothelial dysfunction (ASTRA). Updated 2026. Accessed April 9, 2026. https://clinicaltrials.gov/study/NCT07368959

2. Eye Bank Association of America. 2023 Eye Banking Statistical Report. https://restoresight.org/wp-content/uploads/2024/03/2023-Statistical-Report.pdf

3. Deng SX, Lee WB, Hammersmith KM, et al. Descemet membrane endothelial keratoplasty: safety and outcomes. Ophthalmology. 2018;125(2):295-310. https://doi.org/10.1016/j.ophtha.2017.08.016

4. Stuart AJ, Romano V, Virgili G, Shortt AJ. Descemet’s membrane endothelial keratoplasty (DMEK) versus DSAEK for corneal endothelial failure. Cochrane Database Syst Rev. 2018;6:CD012097. https://doi.org/10.1002/14651858.CD012097.pub2

5. Okumura N, Koizumi N, Ueno M, et al. ROCK inhibitor converts corneal endothelial cells into a phenotype capable of regenerating in vivo endothelium. Am J Pathol. 2012;181(1):268-277. https://doi.org/10.1016/j.ajpath.2012.03.033

6. Kinoshita S, Koizumi N, Ueno M, et al. Injection of cultured cells with a ROCK inhibitor for bullous keratopathy. N Engl J Med. 2018;378(11):995-1003. https://doi.org/10.1056/NEJMoa1712770