FDA grants RMAT designation to Atsena’s gene therapy for rare eye disease

Durham-based Atsena Therapeutics has received Regenerative Medicine Advanced Therapy (RMAT) designation from the U.S. Food and Drug Administration (FDA) for ATSN-201, its gene therapy product for the treatment of X-linked retinoschisis (XLRS). XLRS is a rare inherited retinal disease with no approved treatments.

ATSN-201 uses AAV. SPR, the company’s novel spreading capsid, delivers the gene therapy directly to the photoreceptors in the central retina, achieving therapeutic levels of gene expression while minimizing surgical risks, such as foveal detachment. ATSN-201 has previously received Fast Track, Rare Pediatric Disease and Orphan Drug Designations from the FDA.

“We’re honored that the FDA has granted Regenerative Medicine Advanced Therapy (RMAT) designation to ATSN-201, further underscoring its potential to address the urgent, unmet need in XLRS,” said Patrick Ritschel, chief executive officer of Atsena Therapeutics. “This regulatory momentum, coupled with the recent close of our oversubscribed $150 million Series C financing, reinforces our commitment to advancing meaningful gene therapies that have the potential to improve vision and quality of life for individuals living with XLRS and other inherited retinal diseases.”

Targeting blindness with gene therapy

XLRS is an X-linked disease caused by mutations in the gene that encodes retinoschisin, a protein secreted primarily by the eye’s photoreceptors. People with XLRS experience schisis, or abnormal splitting of retinal layers, which impairs vision in a way that can’t be corrected with glasses and leads to progressive vision loss and ultimately blindness. 

XLRS is typically diagnosed in early childhood and primarily affects males, with approximately 30,000 males in the U.S. and European Union having the disease.

RMAT designation helps expedite drug development and review processes for promising products, including gene therapies, by providing sponsors with intensive FDA guidance on efficient drug development. This includes the ability to discuss surrogate or intermediate endpoints, potential ways to support accelerated approval, potential ways to satisfy post-approval requirements and potential priority review of the biologics license application.

The safety and tolerability of ATSN-201 is being evaluated in the LIGHTHOUSE study, a Phase I/II, dose-escalation and dose-expansion clinical trial in male patients ages six and older with XLRS caused by mutations in the RS1 gene.