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18-month results from Part A of LIGHTHOUSE Trial reinforce ATSN-201’s favorable safety profile and durable structural and functional benefits in patients with X-linked retinoschisis

Pivotal Part C cohort enrollment expected to complete Q1 2027; topline results anticipated 1H 2028; BLA filing targeted for 2H 2028

DURHAM, N.C., Sept. 30, 2026 (GLOBE NEWSWIRE) -- Atsena Therapeutics, a clinical-stage gene therapy company focused on reversing or preventing blindness from inherited retinal disease, presented 18-month safety and efficacy results from Part A of the Phase 1/2/3 LIGHTHOUSE Trial evaluating ATSN-201 in patients with X-linked retinoschisis (XLRS) at the American Academy of Optometry 2026 Annual Meeting, taking place September 30 – October 3 in Anaheim, CA. The abstract is one of six selected by the Academy Communications Committee for presentation at the Innovations in Vision and Eye Care press conference at the start of the annual meeting.

"We are encouraged by these Part A results, which reinforce ATSN-201’s ability to deliver durable structural and functional improvements for patients with XLRS. Seven of nine treated eyes have demonstrated closure of the foveal schisis alongside notable improvements in visual function, with responses sustained through at least 18 months following treatment,” said Kenji Fujita, MD, Chief Medical Officer of Atsena Therapeutics. “These positive Phase 1/2 efficacy results are complemented by a well-tolerated safety profile, which we believe positions ATSN-201 well to potentially address the significant unmet needs of XLRS patients. With rapid enrollment in the pivotal Part C cohort ongoing, we remain on track for a BLA filing in the second half of 2028.”

18-Month Part A Results:

Laura Pardon, OD, PhD, Associate Director of Clinical Development at Atsena Therapeutics, presented 18-month safety and efficacy results from Part A of the Phase 1/2/3 LIGHTHOUSE Trial. Part A of the study evaluated the tolerability and safety of three different doses of ATSN-201 administered through subretinal injection to one eye per patient, in three patients per cohort, for a total of nine adult patients.

ATSN-201 continued to demonstrate a favorable safety profile across all nine adult patients, with no drug-related serious adverse events, no dose-limiting toxicities, and no patient discontinuations. Foveal schisis closure was maintained in seven of nine treated eyes at 18 months, a result not observed in untreated eyes. Treated eyes also demonstrated statistically significant improvements in central retinal thickness, microperimetry, best-corrected visual acuity (BCVA), and low-luminance visual acuity (LLVA). Six of nine treated eyes achieved ≥7 dB improvement in microperimetry (the same responder threshold that anchors the primary endpoint in the ongoing pivotal Part C cohort) at 18 months, compared to zero of nine untreated eyes. Seven of nine treated eyes demonstrated visual acuity improvements (BCVA or LLVA) ≥ 10 letters at 18 months, compared to one of nine untreated eyes.

Enrollment is ongoing for Part C of the LIGHTHOUSE Trial, the study’s pivotal Phase 3 portion, and is expected to complete by the end of Q1 2027. Topline results are anticipated in the first half of 2028. Data from the Phase 3 cohort are expected to support a Biologics License Application (BLA) filing targeted for the second half of 2028.

About X-linked Retinoschisis (XLRS)

XLRS is a monogenic X-linked disease caused by mutations in the RS1 gene, which encodes retinoschisin (RS1), a protein secreted primarily by photoreceptors. RS1 is localized to the extracellular surface of rods, cones and bipolar cells. XLRS is characterized by schisis, or abnormal splitting of retinal layers, which causes impaired visual acuity that is not correctable with glasses and leads to progressive vision loss and often to blindness. XLRS primarily affects males and is typically diagnosed in early childhood. Approximately 30,000 males in North America and Europe have XLRS, for which there are currently no approved, disease-specific treatments.

About ATSN-201

ATSN-201 is Atsena’s investigational gene therapy leveraging AAV.SPR, a novel, laterally spreading capsid designed to efficiently target photoreceptors in the central retina while avoiding the surgical risks of foveal detachment. It is being evaluated in the LIGHTHOUSE trial, which consists of three parts (A, B and C) across six cohorts. Parts A and B comprised the Phase 1/2 portion of the study, testing different dose concentrations and injection volumes, in both adult and pediatric patients. Part C is the pivotal Phase 3 portion of the study, a randomized, controlled trial of 76 patients ages 5 and older, with microperimetry as the primary endpoint and a 52-week primary readout. The pivotal cohort began dosing in June 2026 and is enrolling ahead of expectations at sites in the U.S. and the United Kingdom, with additional sites in Europe and Canada expected to open later this year. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

In the completed Phase 1/2 portion of the study, ATSN-201 was the first XLRS gene therapy to demonstrate evidence of efficacy and safety, with the majority of patients showing improvements in retinal structure (foveal schisis closure) and meaningful improvements in retinal and visual function as assessed by microperimetry, best-corrected visual acuity and low-luminance visual acuity. ATSN-201 has demonstrated a favorable safety profile and has been well-tolerated, with data now extending out beyond one year in all 15 adult subjects and as long as three years in the earliest treated subject. ATSN-201 has received Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease and Orphan Drug designations from the U.S. Food and Drug Administration and Orphan Designation from the European Medicines Agency.

About AAV.SPR

AAV.SPR, one of Atsena’s novel capsids, spreads laterally beyond the subretinal injection site to enable safe and efficient transduction of the central retina when injected into areas outside the macula. A preclinical study in non-human primates demonstrated that AAV.SPR promotes transgene expression well beyond subretinal injection bleb margins, in contrast to benchmark AAV vectors, which remain confined to the original bleb margins. At clinically relevant doses, AAV.SPR efficiently transduces foveal cones without the need for surgical detachment and has a favorable safety profile relative to benchmark capsids. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

About Atsena Therapeutics

Atsena is a clinical-stage gene therapy company developing best-in-class treatments for the reversal or prevention of blindness from inherited retinal diseases. The company’s lead program is evaluating ATSN-201 in a pivotal Phase 3 clinical trial for X-linked retinoschisis (XLRS), a genetic condition typically diagnosed in childhood that often leads to blindness later in life. Atsena is also developing ATSN-101, an investigational gene therapy for Leber congenital amaurosis type 1 (LCA1), as part of its exclusive strategic collaboration with Nippon Shinyaku Co., Ltd.; ATSN-101 has completed a Phase 1/2 trial and Atsena expects to initiate a global pivotal Phase 3 clinical trial evaluating ATSN-101 in the coming months. Atsena’s pipeline of clinical and preclinical assets, including gene therapies in development for Usher syndrome type 1B and Stargardt disease, is powered by a proprietary adeno-associated virus (AAV) technology platform, featuring its novel laterally spreading AAV.SPR capsid, designed to overcome the challenges presented by inherited retinal disease. For more information, visit atsenatx.com.

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