Rare Daily Staff

Abeona Therapeutics reported magnetic resonance imaging data from the phase 1/2 Transpher A clinical study indicating that its gene therapy ABO-102 for the rare lysosomal storage disease Sanfilippo syndrome type A increased grey matter, corpus callosum and amygdala volumes in the brain in three young patients at 24 months as compared to afflicted patients without treatment.

The new data was presented during an oral presentation at the 16th International Symposium on MPS and Related Diseases.

Sanfilippo syndrome type A (MPS IIIA) is a fatal condition with no approved treatment that primarily affects the CNS and is characterized by rapid neurodevelopmental and physical decline. Children with MPS IIIA present with progressive language and cognitive decline and behavioral abnormalities. Other symptoms include sleep problems and frequent ear infections. Additionally, distinctive facial features with thick eyebrows or a unibrow, full lips and excessive body hair for one’s age, and liver/spleen enlargement are also present in early childhood. MPS IIIA is caused by genetic mutations that lead to a deficiency in the SGSH enzyme responsible for breaking down glycosaminoglycans, which accumulate in cells throughout the body resulting in rapid health decline associated with the disorder.

ABO-102 is a novel gene therapy in phase 1/2 development for Sanfilippo syndrome type A.  There are no approved treatments for the condition, which primarily affects the central nervous system (CNS). ABO-102 is dosed in a one-time intravenous infusion using a self-complementary AAV9 vector to deliver a functional copy of the SGSH gene to cells of the CNS and peripheral organs. The therapy is designed to address the underlying SGSH enzyme deficiency responsible for abnormal accumulation of glycosaminoglycans in the brain and throughout the body that results in progressive cell damage and neurodevelopmental and physical decline.

The Transpher A study primary endpoints are neurodevelopment and safety. Secondary endpoints include brain volume, behavior evaluations, quality of life, enzyme activity in cerebrospinal fluid (CSF) and plasma, heparan sulfate levels in CSF, plasma, and urine, and liver volume.

The U.S. Food and Drug Administration has granted Abeona Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease, and Orphan Drug designations for the ABO-102 clinical program. In the European Union, the company holds PRIME and Orphan medicinal product designations.

“Brain volume loss is characteristic in children with MPS IIIA and is associated with long-term cognitive and physical disability. Specifically, grey matter is important for cognitive development, corpus callosum for motor function, and amygdala for fear learning as well as social/emotional development,” said Vishwas Seshadri, head of research and clinical development for Abeona. “The new MRI data shows the potential of ABO-102 to increase brain grey matter, corpus callosum, and amygdala volumes and is consistent with previously reported results of preservation of neurocognitive development in these three young patients in the Transpher A study.”

Photo: Vishwas Seshadri, head of research and clinical development for Abeona

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