Study of Safety, Tolerability and Efficacy of PBGM01 in Pediatric Participants With GM1 Gangliosidosis

To be considered for this study, your child must have a confirmed diagnosis of GM1 gangliosidosis, meaning genetic tests show changes in both copies of the GLB1 gene and laboratory tests confirm a lack of the important beta-galactosidase enzyme.

For children with Type 1 GM1 gangliosidosis: They must be between 1 month and under 12 months old when they join the study. They should also have shown the first signs of GM1 before 6 months of age and still meet certain development milestones.

For children with Type 2a GM1 gangliosidosis: They must be between 6 months and 24 months old when they join. Their first signs of GM1 should have appeared between 6 and 18 months of age, and they must be able to sit up by themselves for at least 10 seconds without help.

Children may not be able to participate if they have other significant brain or thinking problems not related to GM1, have been very unwell and needed to stay in hospital recently, or need help breathing with a machine (like a ventilator or tracheostomy). Children who have had severe, uncontrolled seizures (like status epilepticus) or seizures requiring a hospital visit within the last 30 days also cannot join. However, children who use special vests for breathing or a breathing machine for sleep apnea for less than 12 hours a day might still be eligible.

If your child takes part in this study, they will receive a single dose of the study drug, PBGM01, given as an injection near the brain. The first part of the study will involve different groups of children receiving varying doses to determine the best amount. Over the next two years, your child will have regular visits to the study clinic. During these visits, doctors and nurses will closely monitor your child's health, do physical examinations, take blood samples, and perform other tests to check for any side effects and see how the treatment is working. This might include assessments of their development and other body functions. After the initial two years, there will be a further three years where your child's safety and health will continue to be monitored, though visits might be less frequent. This means the total commitment to the study could be up to five years.