ATSN-201

ATSN-201 is an investigational gene therapy developed by Atsena Therapeutics for the treatment of X-linked retinoschisis (XLRS), a rare inherited retinal disease that leads to vision loss and blindness, typically diagnosed in childhood. The therapy utilizes Atsena Therapeutics’ proprietary AAV.SPR, a novel adeno-associated virus (AAV) spreading capsid designed to deliver the functional RS1 gene directly to photoreceptors in the central retina. This approach enables therapeutic levels of gene expression beyond the subretinal injection site without requiring surgical detachment of the fovea, thereby reducing procedural risks. The mechanism involves lateral spread of the vector within retinal tissue, efficiently transducing foveal cones and restoring RS1 protein function lost due to genetic mutations in XLRS patients. ATSN-201 has received Orphan Drug, Rare Pediatric Disease, Fast Track, and Regenerative Medicine Advanced Therapy designations from the US FDA and is currently being evaluated in a Phase I/II clinical trial (the LIGHTHOUSE study) for safety and efficacy in male patients with XLRS.