Abeona Therapeutics Announces ABO-503 Gene Therapy for X-linked Retinoschisis (XLRS) Selected by FDA for Rare Disease Endpoint Advancement (RDEA) Pilot Program

RDEA Pilot Program provides sponsors enhanced communication and collaboration with FDA to accelerate development of rare disease therapies

CLEVELAND, Oct. 13, 2025 (GLOBE NEWSWIRE) -- Abeona Therapeutics Inc. (Nasdaq: ABEO), a commercial-stage biopharmaceutical company developing cell and gene therapies for serious diseases, today announced that its ABO-503 gene therapy for X-linked retinoschisis (XLRS) has been selected to participate in the U.S. Food and Drug Administration (FDA) Rare Disease Endpoint Advancement (RDEA) Pilot Program. The RDEA program facilitates the development and timely approval of rare disease therapies by supporting the use of novel efficacy endpoints in clinical trials. As part of the RDEA program, Abeona will have opportunities for enhanced communication and collaboration with the FDA, including frequent advice and regular ad-hoc conversations to accelerate the development and validation of product-specific novel efficacy endpoints for Abeona’s XLRS program.

“XLRS is an underserved area with a large unmet need,” said Vish Seshadri, Chief Executive Officer of Abeona. “We are honored that ABO-503 gene therapy for XLRS has been chosen for the FDA’s highly competitive RDEA pilot program. We believe our 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.”

ABO-503 is composed of a functional human RS1 gene packaged in the novel AIM capsid AAV204. ABO-503 has shown preclinical efficacy following delivery to the retina in a mouse model of XLRS. Preclinical studies have demonstrated structural and functional improvements following robust RS1 expression throughout the retina, including improved cone photoreceptor density and overall photoreceptor cell survival, restoration of outer retina architecture by eliminating cysts characteristic of XLRS, and improvements in visual function as demonstrated by electroretinogram (ERG). Abeona anticipates completing IND-enabling studies in the second half of 2026.

The FDA launched the RDEA Pilot Program to support the development of novel efficacy endpoints for rare disease treatments. Under the pilot program, between 2023 and 2027, the FDA will accept up to one RDEA proposal per quarter with a maximum of three proposals per year. To be considered, sponsors must submit a proposal detailing the data they plan to collect, the novelty of the endpoint, and its potential to establish substantial evidence of effectiveness.