Atsena Therapeutics reported positive long-term clinical data for ATSN-201 in X-linked retinoschisis and ATSN-101 in Leber congenital amaurosis type 1 at ARVO 2026, highlighting durable vision improvements and favourable safety profiles as both gene therapies advance toward pivotal Phase 3 studies.
Written By: Dr. Preethi Putti, PharmD
Reviewed By: Pharmacally Editorial Team
Atsena Therapeutics has reported encouraging clinical results from its gene therapy programs for X-linked retinoschisis (XLRS) and Leber congenital amaurosis type 1 (LCA1) during presentations at the ARVO 2026 Annual Meeting, highlighting positive long-term safety and efficacy data for both ATSN-201 and ATSN-101.
XLRS is a rare inherited retinal disorder caused by mutations in the RS1 gene that leads to progressive vision loss, primarily in males, while LCA1 is a severe genetic eye disease linked to GUCY2D mutations that can cause blindness early in life. There are currently no approved treatments for either condition.
Lesley Everett, MD, PhD, Assistant Professor of Ophthalmology at the Casey Eye Institute, presented 12-month results from Part A of the Phase 1/2/3 LIGHTHOUSE Trial (NCT05878860) evaluating ATSN-201 in nine adults with XLRS. The investigational therapy demonstrated a favourable safety profile, with no drug-related serious adverse events, dose-limiting toxicities, or patient discontinuations reported.
Closure of Foveal schisis (abnormal splitting of retinal layers in the central retina) was maintained in seven of nine treated eyes at 12 months, a result not observed in untreated eyes. Patients also showed statistically significant improvements in microperimetry, best-corrected visual acuity, and low-luminance visual acuity.
ATSN-201 uses Atsena’s proprietary AAV.SPR capsid designed to target photoreceptors in the central retina while reducing the surgical risks associated with foveal detachment. The therapy is currently advancing through the LIGHTHOUSE study, with the pivotal Phase 3 portion already underway.
Enrolment is expected to conclude by the end of the first quarter of 2027, with a Biologics License Application planned for 2028. ATSN-201 has received RMAT, Fast Track, Rare Pediatric Disease, and Orphan Drug designations from the U.S. FDA, as well as Orphan Drug designation from the European Medicines Agency. If approved, it could become the first treatment for XLRS.
Separately, Artur Cideciyan, PhD, Research Professor of Ophthalmology at the Scheie Eye Institute, presented three-year results from the Phase 1/2 trial (NCT03920007) evaluating ATSN-101 in 15 patients with LCA1.
High-dose treated patients demonstrated an average improvement of approximately 20 decibels in dark-adapted full-field stimulus testing, representing a 100-fold increase in light sensitivity that remained durable for at least three years. ATSN-101 was well tolerated, with no drug-related serious adverse events or discontinuations reported. Atsena plans to initiate a global pivotal Phase 3 trial in the second half of 2026.
The company also introduced a modified Multi-Luminance Mobility Test (modMLMT), which demonstrated treatment effects in more ATSN-101-treated patients compared with the standard MLMT and is expected to be incorporated into future pivotal studies.
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About the Writer
Dr.Preethi Putti, PharmD (LinkedIn) is a pharmaceutical researcher with experience in healthcare and pharmaceutical market research and competitive intelligence. She specializes in analyzing drug pipelines, clinical data, and industry trends and translating complex scientific data into clear and structured medical content. Strong foundation in clinical research, data interpretation, and evidence-based healthcare analysis. Committed to advancing a global career in clinical research and healthcare innovation.