Ultragenyx Pharmaceutical Inc. has acquired the global rights to ABO-102 (now UX111), an AAV gene therapy for the treatment of Sanfilippo syndrome type A (MPS IIIA), from Abeona Therapeutics Inc. The agreement grants Ultragenyx exclusive rights to the program, with Abeona eligible for tiered royalties up to 10% on net sales and commercial milestone payments upon regulatory approval. This acquisition strengthens Ultragenyx's portfolio in rare genetic diseases and provides a potential first-in-class treatment for MPS IIIA, a disease with no approved therapies.
Promising Clinical Data from Transpher A Trial
ABO-102 is currently being evaluated in the ongoing pivotal Transpher A trial. Interim results presented at the American Society of Gene & Cell Therapy (ASGCT) showed that children treated before 2 years of age or with a development quotient (DQ) > 60 (n=10) experienced preserved neurocognitive development after treatment with ABO-102 (3x1013 vg/kg). The data also indicated continued or stabilized cognitive function and behavioral progress using standard developmental assessments. Some patients have reached 24 months post-treatment, showing stabilization or an increase in cortical gray matter, total cerebral, and amygdala volumes.
Furthermore, the trial demonstrated statistically significant reductions in liver volume with ABO-102 treatment. Dose-dependent and statistically significant reductions in cerebrospinal fluid and plasma heparan sulfate were observed, indicating replacement of enzyme activity consistent with levels required for disease correction in the central nervous system. These effects have been sustained in treated patients for two years post-treatment. ABO-102 has been well-tolerated, with no treatment-related serious adverse events reported.
Addressing Unmet Needs in MPS IIIA
Sanfilippo syndrome type A (MPS IIIA) is a rare, fatal lysosomal storage disease with no approved treatment, primarily affecting the central nervous system. It is characterized by rapid neurodevelopmental and physical decline, often by age three. The global incidence of MPS IIIA is approximately one in 100,000, with a median life expectancy of 15 years. The disease results from mutations leading to a deficiency in the SGSH enzyme, causing an accumulation of glycosaminoglycans in cells throughout the body.
"MPS IIIA is characterized by severe neurodegeneration with debilitating symptoms for which there is currently no treatment," said Kevin Flanigan, M.D., director of the Center for Gene Therapy at Nationwide Children’s Hospital in Columbus, Ohio, and Transpher A study principal investigator. "The promising results to date suggest a single intravenous dose of ABO-102 AAV-based gene therapy has the potential to help children with MPS IIIA sustain neurocognitive development when they are treated during early stages of their disease."
About ABO-102 / UX111
ABO-102 (UX111) is a novel gene therapy in Phase 1/2 development for Sanfilippo syndrome type A (MPS IIIA). It involves 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 aims to address the underlying SGSH enzyme deficiency, preventing the abnormal accumulation of glycosaminoglycans in the brain and body. The ABO-102 program has received multiple designations, including Regenerative Medicine Advanced Therapy, Fast Track, Rare Pediatric Disease, and Orphan Drug designations in the U.S., and PRIME and Orphan medicinal product designations in the EU.
Transpher A Study Details
The Transpher A Study (ABT-001) is an ongoing, two-year, open-label, dose-escalation, Phase 1/2 global clinical trial assessing ABO-102 for the treatment of patients with Sanfilippo syndrome type A (MPS IIIA). The study includes patients from birth to 2 years of age, or patients older than 2 years with a cognitive developmental quotient of 60% or above. The primary endpoints are neurodevelopment and safety, with secondary endpoints including behavior evaluations, quality of life, enzyme activity in cerebrospinal fluid (CSF) and plasma, heparan sulfate levels in CSF, plasma and urine, and brain and liver volume.
