Transpher A Study


The Transpher A Study: A Phase 1/2 Clinical Trial of ABO-102

Sanfilippo syndrome type A, or MPS IIIA, is a rare, fatal lysosomal storage disease with no approved treatment that primarily affects the central nervous system (CNS) and is characterized by rapid neurodevelopmental and physical decline. MPS IIIA is caused by genetic mutations that lead to a deficiency in the SGSH enzyme responsible for breaking down glycosaminoglycans (toxic sugars), which accumulate in cells throughout the body resulting in cell damage and rapid health decline associated with the disorder. Children with MPS IIIA present with progressive language and cognitive decline and behavioral abnormalities. 

The Transpher A Study is an open-label, dose-escalation global clinical trial assessing one-time gene therapy ABO-102 for patients with MPS IIIA. ABO-102 is dosed in a one-time intravenous infusion using an adeno-associated virus vector (AAV) to deliver a normal copy of the SGSH gene. ABO-102 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.

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Now Enrolling

Can my child participate?

For more information about enrolling in The Transpher A Study, contact us at

Study Sites

Nationwide Children's Hospital
Columbus, Ohio
United States
Kristen Brown:
Tabatha Simmons, PhD:

Children's Hospital of Pittsburgh
Pittsburgh, Pennsylvania
United States
Deepa Rajan, MD:

Women's and Children's Hospital
North Adelaide, South Australia
Louise Jaensch:

Vall d'Hebron Barcelona Hospital Campus
Mireia del Toro, MD:
Lucy Dougherty, MD:

Hospital Clínico Universitario de Santiago
Santiago De Compostela
Maria Luz Couce, MD:
Maria Jose de Castro, MD:

Is my child eligible to participate in the study?

Key criteria for eligible patients include the following, but a full list of inclusion and exclusion criteria are available here.

  • Diagnosis of MPS IIIA
  • Age 6 months to 2 years or children older than 2 years with a minimum cognitive Developmental Quotient (DQ) of 60 or above

What will be required of patients and their families?

  • Up to two screening visits.
  • A treatment visit, once eligibility is confirmed. Patients will be admitted to the hospital for gene transfer and will stay for approximately 48 hours for observation.
  • Patients and their caregiver(s) will be required to stay near the clinical site for 30 days after gene therapy is administered.
  • After gene transfer, a total of nine follow up visits will take place at the clinical site, with the last visit occurring 24 months after gene transfer.
  • Home visits for collection of blood in between the follow-up visits to the clinical site.
  • Additional visits may be required for eligible patients receiving long-term follow-up care.

The safety and efficacy of the investigational use of this product has not been determined. There is no guarantee that the investigational use listed will be filed with and/or approved for marketing by a regulatory agency.