Atsena Therapeutics Receives Orphan Drug Designation for Gene Therapy to Treat X-linked Retinoschisis

Atsena Therapeutics recently announced the US FDA has granted Orphan Drug Designation for ATSN-201 for the treatment of X-linked retinoschisis (XLRS). ATSN-201, a best-in-class gene therapy product candidate, leverages AAV.SPR, the company’s novel spreading capsid, to achieve therapeutic levels of gene expression in photoreceptors of the central retina while avoiding the surgical risks of foveal detachment.

“We are honored to receive the FDA’s Orphan Drug Designation for ATSN-201, which was also recently granted Rare Pediatric Disease designation. These designations mark a significant inflection point for the potential of this ocular gene therapy in an inherited retinal disease that currently has no available treatments,” said Patrick Ritschel, Chief Executive Officer of Atsena Therapeutics. “The Atsena team is passionate and committed to our ongoing work on the XLRS program. We look forward to bringing hope to patients affected by this rare disease and are confident these designations will expedite our path forward.”

The FDA grants Orphan Drug Designation to drugs and biologics that are intended for safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US. Orphan Drug Designation provides certain incentives, such as tax credits toward the cost of clinical trials upon approval and prescription drug user fee waivers. If a product receives Orphan Drug Status from the FDA, that product is entitled to seven years of market exclusivity for the disease in which it has Orphan Drug designation, which is independent from intellectual property protection.

Currently, there are no approved treatments for XLRS, which is typically diagnosed in early childhood and affects approximately 30,000 males in the US and EU. The safety and tolerability of ATSN-201 is currently being evaluated in the LIGHTHOUSE study, a Phase 1/2, open-label, dose-escalation and dose-expansion clinical trial in male patients ages six and older with a clinical diagnosis of XLRS caused by mutations in the RS1 gene. Enrollment for this study is ongoing. For more information, visit ClinicalTrials.gov (Identifier: NCT05878860).

 XLRS is a monogenic X-linked disease caused by mutations in the RS1 gene which encodes retinoschisin, 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 ultimately blindness. XLRS primarily affects males and is typically diagnosed in early childhood. Approximately 30,000 males in the US and EU have XLRS, for which there are currently no approved treatments.

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 (where schisis cavities predominate in XLRS patient retinas) 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. This is in stark 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 does not cause inflammation. For more information about the preclinical study and how AAV.SPR works, visit https://atsenatx.com/our-approach/laterally-spreading-aav/.

Atsena Therapeutics 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 an ongoing Phase 1/2 clinical trial for X-linked retinoschisis (XLRS), a progressive genetic condition affecting boys and men that is typically diagnosed in childhood. Another ongoing Phase 1/2 clinical trial is evaluating ATSN-101 for Leber congenital amaurosis type 1 (LCA1), one of the most common causes of blindness in children. Atsena’s pipeline is powered by novel adeno-associated virus (AAV) technology tailored to overcome the hurdles presented by inherited retinal diseases. Founded by pioneers in ocular gene therapy, Atsena is led by an experienced team dedicated to addressing the needs of patients with vision loss. For more information, visit  https://atsenatx.com/.