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Study on the Safety and Initial Effects of AAV9-CAG-coh-SGSH in Children with Sanfilippo A Syndrome

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a rare genetic disorder called Mucopolysaccharidosis type IIIA, also known as Sanfilippo A syndrome. This condition affects the body's ability to break down certain sugars, leading to severe neurological symptoms. The study is testing a new treatment called AAV9-hSGSH, which is a type of gene therapy. This treatment uses a harmless virus to deliver a healthy copy of the gene responsible for producing an enzyme called sulfamidase, which is missing or not working properly in patients with Sanfilippo A syndrome.

The purpose of the study is to evaluate the safety and initial effectiveness of this treatment in children with Sanfilippo A syndrome. Participants will receive a single dose of the treatment through a procedure called intracerebroventricular administration, which involves delivering the treatment directly into the brain. The study will monitor the participants over time to assess how well they tolerate the treatment and to observe any changes in their condition.

Throughout the study, various assessments will be conducted, including physical exams, blood tests, and imaging tests like MRI to check brain health. The study will also look at the participants' immune response to the treatment and measure levels of the enzyme sulfamidase in their bodies. Additionally, the study will evaluate the participants' development and quality of life using different scales and tests. The goal is to gather important information that could lead to new treatment options for children with Sanfilippo A syndrome.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    The study begins with an initial assessment to confirm eligibility. This includes a physical examination, blood tests, and a review of medical history.

    Eligibility criteria include being a child aged 2 years or older with confirmed Mucopolysaccharidosis type IIIA (Sanfilippo A syndrome), among other specific conditions.

  2. Step 2

    Administration of investigational product

    The investigational product, AAV9-hSGSH, is administered as a single dose through a procedure called intracerebroventricular (ICV) injection. This involves delivering the product directly into the brain's ventricles.

    The product is a suspension for injection containing a viral vector designed to deliver the human sulfamidase gene.

  3. Step 3

    Monitoring and follow-up

    After administration, regular monitoring is conducted to assess safety and initial efficacy. This includes physical examinations, blood tests, and imaging assessments such as MRI.

    The study also evaluates immune response, including tests for antibodies in the cerebrospinal fluid and blood.

  4. Step 4

    Evaluation of outcomes

    Primary outcomes focus on safety, including monitoring for adverse events and changes in vital signs.

    Secondary outcomes assess the impact on enzyme activity, levels of heparan sulfate, and various developmental and behavioral scales.

  5. Step 5

    Completion of study

    The study is estimated to conclude by November 28, 2025. Final assessments will be conducted to evaluate the long-term effects of the treatment.

Who can join the trial?

10 criteria

  • Children who are 2 years or older, both boys and girls.
  • The family must understand the procedure and agree to it by signing a form called informed consent.
  • Children must have a confirmed diagnosis of Mucopolysaccharidosis type IIIA (MPSIIIA), also known as Sanfilippo A syndrome. This means they have a specific change in their genes and low activity of an enzyme called sulfamidase in their blood cells.
  • The first signs of the condition should have appeared before the child was 6 years old.
  • Children should have a certain level of adaptive behavior, which is how well they can handle daily life activities, measured by a test called the Vineland Adaptive Behaviour Scale.
  • Children should be able to walk and not need a wheelchair.
  • Children should not have severe problems with seeing or hearing, like blindness or needing a hearing aid.
  • Children should have stable treatment for their symptoms for the last 3 months and should not expect changes in their medication.
  • Children should not have any medical reasons that would prevent them from having surgery or anesthesia. If they are taking certain pain relievers called non-steroidal anti-inflammatory drugs (NSAIDs), they should stop using them.
  • Children should be in a stable medical condition to meet the study requirements, including being able to travel and undergo assessments.

Who cannot join the trial?

8 criteria

  • Patients who have a different condition than Mucopolysaccharidosis type IIIA (also known as Sanfilippo A syndrome) cannot participate.
  • Patients who are not within the specified age range for the study cannot participate.
  • Patients who are not able to safely receive the study treatment cannot participate.
  • Patients who have other medical conditions that might interfere with the study cannot participate.
  • Patients who are unable to follow the study procedures cannot participate.
  • Patients who have participated in another clinical trial recently may not be eligible.
  • Patients who are pregnant or breastfeeding cannot participate.
  • Patients who have a known allergy to any component of the study treatment cannot participate.
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Investigated drugs

AAV9-CAG-coh-SGSH is a gene therapy treatment being studied for its safety and initial effectiveness in patients with Mucopolysaccharidosis type IIIA (MPSIIIA), also known as Sanfilippo A syndrome. This therapy uses a viral vector, specifically an adeno-associated virus serotype 9, to deliver a human sulfamidase gene directly into the brain. The goal is to help the body produce the enzyme that patients with this condition lack, potentially improving symptoms or slowing the progression of the disease.

What is already known about the treatment

AAV9-CAG-coh-SGSH – This medication is administered through intracerebroventricular injection, which involves delivering the treatment directly into the brain's ventricles. It is currently being studied in clinical trials to assess its safety, tolerability, and initial effectiveness for treating Mucopolysaccharidosis type IIIA, also known as Sanfilippo A syndrome. The main therapeutic indication is to address the genetic deficiency in patients by delivering a gene that encodes for the enzyme sulfamidase. At the molecular level, the medication uses an adeno-associated viral vector to introduce the human sulfamidase gene into the patient's cells, aiming to restore the enzyme's function. It falls under the pharmacological classification of gene therapy.

Investigated diseases

Mucopolysaccharidosis type IIIA (Sanfilippo A syndrome) – This is a rare genetic disorder that affects the body's ability to break down certain sugar molecules called glycosaminoglycans. It is caused by a deficiency in the enzyme sulfamidase, leading to the accumulation of heparan sulfate in the body. This buildup primarily affects the brain and central nervous system, resulting in progressive neurological decline. Symptoms often begin in early childhood and may include developmental delay, behavioral problems, and sleep disturbances. As the disease progresses, individuals may experience worsening cognitive and motor skills. Over time, the condition can lead to severe intellectual disability and loss of mobility.
Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase I/IITrial ID2024-515835-31-00Protocol codeESTEVE-SANF-201Estimated enrolment9 patientsSponsorEsteve Pharmaceuticals S.A.

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).