On August 14, 2024, Atsena Therapeutics (New Haven, CT, USA), a gene therapy company focused on combating inherited blindness, announced that the U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease (RPD) designation for their gene therapy candidate, ATSN-201. The therapy is being developed to treat X-linked retinoschisis (XLRS), a rare congenital disease leading to vision loss.
ATSN-201 leverages Atsena’s proprietary AAV.SPR technology, a spreading capsid engineered to deliver therapeutic gene expression to photoreceptors in the central retina without the need for invasive surgical procedures. The capsid spreads beyond the injection site, enabling a safe and efficient transduction of the central retina, which is critical for XLRS patients where retinal schisis cavities are prevalent. Preclinical studies in non-human primates have shown that AAV.SPR drives effective transgene expression beyond the subretinal injection bleb margins while avoiding inflammation—a significant improvement compared to benchmark AAV vectors.
“We are pleased to receive the FDA’s Rare Pediatric Disease designation for ATSN-201, which also marks the second RPD designation granted to Atsena this year,” said Patrick Ritschel, CEO of Atsena Therapeutics, in a news release. “Having both of our clinical-stage, ocular gene therapies receive this designation underscores the potential of our technology to address significant unmet needs for patients with inherited retinal diseases.”
The first designation was for ATSN-101, a gene therapy targeting Leber congenital amaurosis type 1 (LCA1), a common cause of childhood blindness.
The FDA grants Rare Pediatric Disease (RPD) designation to therapies aimed at treating serious or life-threatening rare conditions primarily affecting individuals under 18. With this designation, ATSN-201 could qualify for a priority review voucher (PRV) upon approval. This voucher, which can either accelerate the review of another therapy in Atsena’s pipeline or be sold to another company, serves as a significant incentive to encourage the development of treatments for rare pediatric diseases.
The safety and tolerability of ATSN-201 are currently being tested in the LIGHTHOUSE study, a Phase I/II clinical trial involving male patients aged six and older with RS1 gene mutations. Enrollment is ongoing, and more information can be found on ClinicalTrials.gov (Identifier: NCT05878860).
XLRS is a genetic condition caused by mutations in the RS1 gene, which encodes retinoschisin, a protein secreted primarily by photoreceptors. The disease is marked by schisis, or abnormal splitting of retinal layers, leading to impaired visual acuity that cannot be corrected with glasses. Over time this condition causes progressive vision loss and, ultimately, blindness. Affecting around 30,000 males in the United States and Europe, XLRS currently has no approved treatment options.
