NEW ORLEANS, May 18, 2015 (GLOBE NEWSWIRE) -- Applied Genetic Technologies Corporation (Nasdaq:AGTC), a clinical stage biotechnology company developing adeno-associated virus (AAV)-based gene therapies for the treatment of rare eye diseases, today announced new preclinical data which further supports the safety of the company's AAV vector gene therapies for the treatment of achromatopsia (ACHM) and X-linked retinoschisis (XLRS). Additionally, new safety data were presented on AGTC's proprietary manufacturing process. Study results were presented at the American Society of Gene & Cell Therapy (ASGCT) 18th Annual Meeting, which took place from May 13 – 16, in New Orleans.
"We are encouraged by these study results that further underscore the safety of novel AAV-based gene therapies to treat rare inherited eye diseases with few currently available therapeutic options," said Sue Washer, President and CEO of AGTC. "Furthermore, new data on our proprietary vector manufacturing process suggest that patients receiving rAAV vectors purified in this manner have a very low risk of HSV-related adverse events, and support the continued development of these vectors in the treatment of human disease."
Title: Safety and Biodistribution Study of rAAV2tYF-CB-hRS1 in RS1-deficient Mice
Abstract #: 350775
Presenting Author: Jeffrey D. Chulay, M.D., DTM&H
This study evaluated the toxicology and biodistribution profiles of a recombinant adeno-associated virus (rAAV) vector expressing the human retinoschisin (hRS1) gene at two doses in three groups of male RS1-deficient mice. Results demonstrated that intravitreal injection of rAAV2tYF-CB-hRS1 was well tolerated with minimal ocular inflammatory cells detected by histopathology. RS1 expression, measured by immunohistochemistry, was associated with decreased severity of splitting and disorganization of the inner nuclear layer of the retina at the higher dose level, supporting the use of this vector in patients with XLRS.
Title: Safety and Biodistribution Study of rAAV2tYF-CB-hRS1 in Nonhuman Primates
Abstract #: 350780
Presenting Author: Jeffrey D. Chulay, M.D., DTM&H
This study evaluated the toxicology and biodistribution of an AAV vector expressing retinoschisin in male cynomolgus macaques. Results demonstrated that administration of rAAV2tYF-CB-hRS1 in normal cynomolgus macaques was associated with dose-related anterior and posterior segment inflammatory response that improved over time. Histological examination revealed that mononuclear cell infiltrates of minimal to moderate intensity were more common in the higher dose group and RS1 expression in the retinal ganglion cell ring was demonstrated by immunohistochemistry. These results further support the use of rAAV2tYF-CB-hRS1 in clinical studies of patients with XLRS.
Title: Initial Safety Evaluation of rAAV-hCNGB3 Vectors in Nonhuman Primates
Abstract #: 350277
Presenting Author: Guo-jie Ye, Ph.D.
Previous studies in CNGB3-mutant dogs have shown that subretinal injection of an AAV5 vector expressing a human CNGB3 gene can rescue the ACHM electroretinography (ERG) phenotype, but also showed that at high doses, many of the animals developed chorioretinitis, a toxicity consistent with an immune response to a foreign protein. This study evaluated eight cynomolgus macaques that received subretinal injections of AAV2tYF-hCNGB3 or AAV5-hCNGB3 vectors, followed by ophthalmic examinations, digital fundus photography, scotopic and photopic ERG and visual evoked potentials (VEP) and histological examination. Results showed that both vectors were well tolerated and were associated with dose-related ocular inflammation that was milder than the severe inflammation seen in dogs receiving high dose of AAV5-hCNGB3. No test article-related effects on ERG or VEP were observed. These findings will be helpful for guiding future development of rAAV-CNGB3 gene therapies for humans.
Title: Efficient Clearance of Herpes Simplex Virus Using a GMP-compliant Method for Production of Recombinant Adeno-associated Virus Vectors
Abstract #: 350887
Presenting Author: Guo-jie Ye, Ph.D.
This study evaluated the safety of AGTC's proprietary, herpes simplex virus (HSV) manufacturing process for production of recombinant AAV virus vectors. Results demonstrated that the company's process to produce and purify rAAV vectors for use in patients with XLRS and ACHM effectively inactivates and removes HSV particles during vector production. The study authors concluded that the risk of HSV-related adverse events in patients receiving rAAV vectors purified in this manner is very low.
About AGTC
AGTC is a clinical-stage biotechnology company that uses its proprietary gene therapy platform to develop products designed to transform the lives of patients with severe diseases in ophthalmology. AGTC's lead product candidates focus on X-linked retinoschisis, achromatopsia and X-linked retinitis pigmentosa, which are inherited orphan diseases of the eye, caused by mutations in single genes that significantly affect visual function and currently lack effective medical treatments. AGTC is also using its gene therapy expertise to expand into disease indications with large market opportunity such as wet AMD.
Forward Looking Statements
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