Abeona Therapeutics Announces Update on AAV Ophthalmology Program

Abeona Therapeutics Inc. (Nasdaq: ABEO) today announced three internally developed investigational preclinical gene therapy product candidates from its ophthalmology program. Abeonas preclinical programs are investigating the use of novel adeno-associated virus (AAV) capsids in therapies for serious genetic eye diseases.

We are excited by the broad potential for treating serious eye diseases with new AAV-based therapies using novel AAV capsids from our in-licensed AIM capsid library and internal research, said Brian Kevany, Ph.D., Chief Technical Officer and Head of Research at Abeona. In 2022, we evaluated the ability of our gene constructs and capsids to deliver and express the recombinant protein in target eye tissues and rescue mutant phenotypes in mouse disease models. Based on encouraging findings from these animal proof of concept experiments, we are looking forward to reporting new data from these programs at a scientific congress in the second quarter of 2023 and gaining alignment with the U.S. FDA on the clinical development plans for these programs.

Preclinical Product Candidate ABO-504 for Stargardt Disease

Abeonas internal research and development team developed ABO-504, which is designed to efficiently reconstitute the full-length ABCA4 gene by implementing a dual AAV vector strategy using the Cre-LoxP recombinase system. In May 2021 at the Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting, Abeona reported preclinical data demonstrating the ability of the dual AAV vector system to produce full length ABCA4 protein in cell culture. Recent proof-of-concept studies have extended these findings by showing expression of ABCA4 mRNA and full-length ABCA4 protein in the retina of subretinally dosed abca4-/- knockout mice, at levels similar to endogenous ABCA4 in wild-type animals.

Preclinical Product Candidate ABO-503 for X-linked Retinoschisis (XLRS)

ABO-503, composed of a functional human RS1 packaged in the novel AIM capsid AAV204, has shown preclinical efficacy following delivery to the retina in a mouse model of XLRS. Preclinical studies have demonstrated robust RS1 expression in the retina, improved cone photoreceptor density and overall photoreceptor cell survival, as well as a restoration of outer retina architecture.

Preclinical Product Candidate ABO-505 for Autosomal Dominant Optic Atrophy (ADOA)

ABO-505 is designed to express a functional copy of human Opa1 in the retina following para-retinal injection. AB0-505 aims to take advantage of the robust optic nerve and retinal ganglion cell (RGC) transduction ability of AAV204 to deliver its genetic payload to the cells most affected by ADOA. Preclinical studies have confirmed expression of Opa1 in both cell culture and the retinas of dosed wild-type and disease model animals. Initial efficacy results suggest an improvement in retinal signaling to the brain, and improved visual acuity in treated mutant mice.

About Stargardt Disease

Autosomal recessive Stargardt disease, the most common form of juvenile macular degeneration with estimated incidence of 1 in 8,000 to 10,000 people1, causes vision loss in children and young adults. The most common form of Stargardt disease is caused by mutations in the ABCA4 gene, which prevent removal of toxic compounds from photoreceptor cells that results in photoreceptor cell death and progressive vision loss. There are currently no FDA approved treatments available, and to date, development of investigational gene modifying therapies has remained challenging in part due to the large size of the ABCA4 gene, which exceeds the encapsidation capacity of a single AAV vector.

About X-linked Retinoschisis (XLRS)

XLRS is a rare, monogenic retinal disease that results in the irreversible loss of photoreceptor cells and severe visual impairment. XLRS is caused by mutations in the RS1 protein, which is normally secreted by retinal photoreceptors and bipolar neurons and functions to mediate cell-cell adhesion. XLRS is characterized by abnormal splitting of the layers of the retina, resulting in poor visual acuity, which can progress to legal blindness. The incidence of XLRS is estimated to be between 1 in 5,000 and 1 in 20,000 in males, with an estimated prevalence of 35,000 in the United States and Europe combined.2,3 There are currently no disease modifying therapies approved for XLRS, but because the genetics of the disease are well understood, early intervention via gene therapy has significant potential to reverse or stabilize disease progression at early stages and prevent vision loss.

About Autosomal Dominant Optic Atrophy (ADOA)

ADOA, a form of hereditary vision loss associated with RGC death, is predominantly caused by mutations in the Opa1 gene. Opa1, a dynamin-related GTPase, acts to stabilize the inner mitochondrial membrane and acts in mitochondrial fusion and inner membrane remodeling. Mutant phenotypes present with a progressive loss of RGCs that results in optic nerve degeneration and legal blindness with a loss of visual acuity, optic disc pallor, and color vision deficits. ADOA affects approximately 1 in 30,000 people worldwide.4 Currently, there is no approved treatment for people living with ADOA.

About Abeona Therapeutics

Abeona Therapeutics Inc. is a clinical-stage biopharmaceutical company developing cell and gene therapies for serious diseases. Abeonas lead clinical program is EB-101, its investigational autologous, engineered cell therapy currently in development for recessive dystrophic epidermolysis bullosa. Abeona is currently in the process of preparing a Biologics License Application (BLA) for submission to the FDA. The Companys development portfolio also features AAV-based gene therapies for ophthalmic diseases with high unmet medical need. Abeonas novel, next-generation AAV capsids are being evaluated to improve tropism profiles for a variety of devastating diseases. Abeonas fully integrated cell and gene therapy cGMP manufacturing facility produced EB-101 for the pivotal Phase 3 VIITAL study and is capable of clinical and potential commercial production of AAV-based gene therapies.