US FDA Grants Orphan Drug Status to Atsena’s XLRS Gene Therapy Candidate

Atsena Therapeutics announced Sept. 17 that ATSN-201, its gene therapy candidate for X-linked retinoschisis (XLRS), had received the US FDA’s orphan drug designation.

The candidate was granted rare pediatric disease designation in August 2024.

XLRS is a monogenic X-linked disease caused by mutations in the RS1 gene that encodes retinoschisin, a protein secreted primarily by photoreceptors. XLRS is characterized by schisis, or abnormal splitting of the layers of the retina, which leads to progressive vision loss.

Atsena says ATSN-201 leverages a novel adeno-associated viral (AAV) capsid that spreads laterally beyond the subretinal injection site to facilitate safe delivery of the functional RS1 gene to photoreceptors in the central retina.

Atsena, of Durham, North Carolina, is developing additional gene therapy candidates for Leber congenital amaurosis 1 (LCA1) and MYO7A-associated Usher syndrome (USH1B). Its LCA1 candidate has also been granted rare pediatric disease status.