Abeona Therapeutics’ AAV Gene Therapy Selected for FDA Rare Disease Endpoint Advancement Pilot Program

CLEVELAND – October 13, 2025 – Abeona Therapeutics Inc. (Nasdaq: ABEO), a commercial-stage biopharmaceutical company, today announced that its investigational gene therapy, ABO-503 for X-linked retinoschisis (XLRS), has been selected for the U.S. Food and Drug Administration (FDA) Rare Disease Endpoint Advancement (RDEA) Pilot Program.

The RDEA program, which accepts a maximum of three proposals per year, facilitates the development and timely approval of rare disease therapies. Participation grants Abeona enhanced communication and collaboration with the FDA, including frequent advice and ad-hoc conversations to accelerate the development and validation of product-specific novel efficacy endpoints for the XLRS program.

Vish Seshadri, Chief Executive Officer of Abeona, noted that XLRS remains an underserved area with a large unmet need. “Participation will meaningfully improve the success rate of our XLRS clinical development efforts, and more broadly, could help facilitate pipeline innovation by using novel efficacy endpoints in new therapy development across other inherited retinal diseases,” Seshadri stated.

The ABO-503 product candidate is an AAV (adeno-associated virus) gene therapy composed of a functional human RS1 gene packaged in the proprietary AIM capsid AAV204. XLRS is a rare, monogenic retinal disease caused by mutations in the RS1 protein that leads to irreversible photoreceptor cell loss and severe visual impairment.

Preclinical data following delivery of ABO-503 to the retina in a mouse model of XLRS demonstrated structural and functional improvements, including improved cone photoreceptor density, restoration of outer retina architecture by eliminating disease-characteristic cysts, and improvements in visual function demonstrated by electroretinogram (ERG). Abeona anticipates completing IND-enabling studies in the second half of 2026.