May 07, 2026 —
Atsena Therapeutics presented new clinical data at the ARVO 2026 Annual Meeting, highlighting progress across two inherited retinal disease gene therapy programs: ATSN-201 for X-linked retinoschisis (XLRS) and ATSN-101 for Leber congenital amaurosis type 1 (LCA1). The company reported 12-month data from Part A of the LIGHTHOUSE Trial for ATSN-201, three-year follow-up data from the Phase 1/2 trial of ATSN-101, and a modified functional vision assessment designed to better capture treatment benefit in inherited retinal diseases.
ATSN-201 is an investigational gene therapy for XLRS, a monogenic X-linked retinal disease caused by mutations in the RS1 gene. XLRS leads to abnormal splitting of retinal layers, impaired visual acuity, progressive vision loss, and potentially blindness. The disease primarily affects males and currently has no approved treatments. ATSN-201 uses AAV.SPR, a laterally spreading AAV capsid designed to efficiently target photoreceptors in the central retina while avoiding the surgical risks associated with foveal detachment.
In Part A of the Phase 1/2/3 LIGHTHOUSE Trial, ATSN-201 demonstrated a favorable safety profile through 12 months across nine adult patients. No drug-related serious adverse events, dose-limiting toxicities, or patient discontinuations were reported. Structural benefit was also durable, with foveal schisis closure maintained in seven of nine treated eyes at 12 months, a finding not observed in untreated eyes. Treated eyes also showed statistically significant improvements in microperimetry, best-corrected visual acuity, and low-luminance visual acuity, supporting both anatomical and functional benefit.
Atsena is now advancing ATSN-201 toward late-stage development. Patient screening is underway for Part C of the LIGHTHOUSE Trial, the pivotal Phase 3 portion of the study. Enrollment is expected to complete by the end of the first quarter of 2027, and the company is targeting a Biologics License Application filing in 2028. ATSN-201 has received multiple regulatory designations, including FDA Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease, and Orphan Drug designations, as well as EMA Orphan Designation.
Atsena also presented three-year data for ATSN-101, a first-in-class investigational subretinal AAV5 gene therapy for LCA1, which is caused by mutations in the GUCY2D gene. LCA1 is one of the most common forms of Leber congenital amaurosis and causes early, severe vision impairment or blindness. There are currently no approved treatments for LCA1.
In the Phase 1/2 trial of ATSN-101, 15 patients were treated, and high-dose participants continued to show clinically meaningful improvements in dark-adapted full-field stimulus testing through at least three years post-treatment. The reported mean improvement was approximately 20 decibels, representing a 100-fold gain in light sensitivity. ATSN-101 was well tolerated, with no drug-related serious adverse events and no patient discontinuations. Atsena expects to initiate a global pivotal Phase 3 trial for ATSN-101 in the second half of 2026.
The company also presented data on a modified Multi-Luminance Mobility Test, or modMLMT, developed to better measure functional vision improvements in patients with retained rod function, such as those with LCA1. According to Atsena, the modified test demonstrated treatment effect in more ATSN-101-treated patients than the standard MLMT, and the company plans to use modMLMT in the pivotal ATSN-101 trial.
Together, the ARVO presentations reinforce Atsena’s position as one of the few gene therapy companies advancing two inherited retinal disease programs toward pivotal trials. The data also highlight several important trends in ocular AAV gene therapy: improved capsid design, durable functional benefit, long-term tolerability, and the growing importance of sensitive clinical endpoints that can capture meaningful changes in vision.
