Ongoing Clinical Trials for Mucopolysaccharidosis III
Currently, there are 3 ongoing clinical trials investigating new treatments for Mucopolysaccharidosis III (Also known as: MPS III, Sanfilippo syndrome). These trials are testing gene therapy approaches and enzyme replacement therapies aimed at addressing the underlying genetic causes of this rare disorder. The trials are taking place in Spain and Germany, offering hope for patients and families affected by this progressive neurological condition.
Clinical trial locations
- Germany
- Spain
Long-term safety study of rebisufligene etisparvovec gene therapy in patients previously treated for Mucopolysaccharidosis type IIIA
This trial is designed specifically for patients who have already received the investigational gene therapy treatment ABO-102, also known as rebisufligene etisparvovec or UX111, in a previous clinical study. The main focus is to monitor the long-term safety and effectiveness of this treatment over an extended period.
Who can participate: Eligible participants must be between 2 and 11 years old and have previously been treated with UX111 in an earlier trial. They must have a confirmed diagnosis of Mucopolysaccharidosis type IIIA. Parents or legal guardians need to be able to provide informed consent and commit to attending all scheduled study visits and following the required procedures throughout the monitoring period.
Who cannot participate: Patients who have undergone hematopoietic stem cell transplantation are not eligible. Those who have participated in another clinical trial within 30 days before this study, or who have serious medical conditions that could interfere with the study or pose safety risks, cannot join. Pregnant or breastfeeding individuals are excluded, as are those taking certain prohibited medications or planning major surgery during the study period. Any condition that makes it difficult to comply with study procedures or that the study doctor considers unsafe would also prevent participation.
Study goals: The research team aims to track the long-term effects of the gene therapy by monitoring various health indicators. This includes assessing cognitive development, communication abilities, changes in certain substances in the spinal fluid (particularly heparan sulfate), and brain volume changes. The study will continue until August 2027, providing valuable information about how this treatment affects patients over several years.
Treatment being tested: ABO-102 is a gene therapy product that uses a modified virus to deliver a working copy of the SGSH gene to cells. This aims to help the body produce the enzyme that patients with type IIIA are missing, which is needed to break down complex sugar molecules. The treatment was previously administered through intravenous injection in earlier trials, and this study focuses on monitoring the lasting effects of that treatment.
Study of Weekly Infusions of JR-441 for Patients with Mucopolysaccharidosis Type IIIA
This clinical trial is investigating a different approach to treating type IIIA using a medication called JR-441, which is given through weekly infusions. Unlike gene therapy, this is an enzyme replacement approach designed to supplement the missing enzyme in affected individuals.
Who can participate: Patients between 1 and 18 years old can be considered for this study. They must have a confirmed diagnosis of type IIIA, including laboratory evidence of low SGSH enzyme activity in cells, normal activity of at least one other enzyme to rule out other conditions, and genetic testing showing mutations in the SGSH gene. Patients must weigh at least 10 kilograms and be in stable health. If hearing aids are needed, patients should use them regularly, especially during developmental assessments. Those capable of having children must agree to use reliable birth control methods during the study and for a specified period afterward.
Who cannot participate: While the complete exclusion criteria are based on individual medical assessment, patients must be stable enough to participate without causing excessive difficulty for themselves or their families, including being able to travel for study visits.
Study goals: The primary purpose is to evaluate the safety of JR-441 and explore its effectiveness in managing symptoms. Researchers will monitor for side effects through regular check-ups that include blood tests, vital signs measurements, and heart function assessments. The study will also track changes in cognitive function and adaptive behavior. This trial is expected to run until 2030, providing comprehensive long-term data.
Treatment being tested: JR-441 is a lyophilized (freeze-dried) powder that is prepared for injection and administered through weekly intravenous infusions. At the molecular level, it works by targeting and breaking down the accumulated substances in the body that cause symptoms. This enzyme replacement therapy aims to supplement the deficient enzyme in affected individuals, helping to manage the disease progression.
Study on the Safety and Effectiveness of Rebisufligene Etisparvovec for Patients with Mucopolysaccharidosis Type IIIA
This trial is evaluating the same gene therapy treatment as the first study but for patients who have not necessarily been treated before. It represents an opportunity for newly diagnosed or treatment-naive patients to access this investigational therapy.
Who can participate: Eligible patients must have a confirmed diagnosis through two methods: laboratory testing showing no detectable or very low SGSH enzyme activity in blood, and genetic testing revealing specific mutations in the SGSH gene. Age criteria vary by cohort, with some groups accepting patients from birth to 2 years old, and others from 3 months to 2 years old. In certain cases, patients older than 2 years and up to 5 years with lower cognitive development may be included. For specific groups, vaccination status must be current according to local country guidelines, verified by a primary care doctor.
Who cannot participate: Patients with other serious medical conditions that might interfere with the study are excluded. Those with recent infections, currently taking medications that could interfere with the study treatment, or who have participated in another clinical trial recently cannot join. Individuals with a history of allergic reactions to similar treatments, those unable to comply with study procedures, or anyone with a condition that study doctors believe would make participation unsafe are also excluded.
Study goals: The research aims to evaluate both the safety and effectiveness of UX111 in treating type IIIA. Monitoring includes tracking any adverse effects, particularly treatment-emergent adverse events and serious adverse events. Effectiveness is measured by changes in cerebrospinal fluid components such as heparan sulfate and gangliosides. Developmental assessments using the Bayley Scales of Infant and Toddler Development will help determine changes in cognitive and communication abilities over time. The trial is expected to conclude by July 31, 2027.
Treatment being tested: UX111 (also known as ABO-102) is a gene therapy product administered through intravenous injection. It uses a modified virus to deliver a healthy copy of the SGSH gene to the patient’s cells, enabling the body to produce the missing enzyme. This approach addresses the underlying genetic cause of the condition rather than just managing symptoms, representing a potentially transformative treatment strategy for this progressive neurological disorder.
Summary
The landscape of clinical trials for Mucopolysaccharidosis type IIIA shows concentrated research activity in Spain and Germany, with three distinct trials testing two different therapeutic approaches. Two trials are focusing on the gene therapy treatment rebisufligene etisparvovec (ABO-102/UX111), with one study specifically dedicated to long-term follow-up of previously treated patients and another evaluating the treatment in newly eligible patients. The third trial takes a different approach, investigating JR-441, an enzyme replacement therapy administered through weekly infusions.
These trials reflect the dual strategy being pursued in rare disease research: gene therapy aiming to correct the underlying genetic defect versus enzyme replacement therapy designed to supplement the missing enzyme. The extended timelines of these studies, running through 2027 and 2030 respectively, demonstrate the commitment to understanding both immediate and long-term effects of these novel treatments. Patients and families affected by this condition may find opportunities to participate in these trials by consulting with their healthcare providers and contacting the study centers in Spain and Germany.
