A Safety and Efficacy Study of GTX-102 in Subjects With Deletion- or Nondeletion-type Angelman Syndrome (AS)

To join this study, a parent or legal guardian must give their permission. The study is open to both boys and girls with a confirmed diagnosis of Angelman Syndrome. Depending on the specific part of the study, certain genetic types and age ranges are included. Generally, participants need to be at least 1 year old and under 65 years old, and weigh at least 8 kg (about 1 stone 3 pounds).

There are also some medical checks needed, like blood tests, to make sure it's safe to take part. You also need to be able to come to clinic visits and follow the study plan, which includes certain procedures like spinal taps (lumbar punctures) and MRI scans. If you're a female who could have children and are sexually active, you'll need to use reliable contraception. Males will also need to use contraception or avoid sex during and after the study for a certain period.

You might not be able to join if you've recently changed other medicines or diets for Angelman Syndrome, if you have a condition that makes a spinal tap risky, or if you're taking certain other medications at the same time. These rules are in place to help keep everyone safe and make sure the study results are clear.

If you decide to take part, you'll first have a screening visit to check if you're suitable. This will involve medical examinations, blood tests, and other assessments. If you qualify, you'll then enter either a 'loading' period followed by a 'maintenance' period. During these times, you'll receive the study medication (GTX-102) if you're in a treatment group. This will involve regular clinic visits to monitor your health, give the medication, and perform tests like further blood work, spinal taps, and MRI scans to see how you're responding and to check for any side effects. The medication is given via a spinal tap.

For participants in the 'no treatment' group (only in Subprotocol D), you'll have similar visits and tests but won't receive the study drug during that period. Eventually, you'll also have the option to receive GTX-102. The total duration of participation in the main study varies depending on which subprotocol you are in, but after completing it, you'll have the opportunity to continue receiving GTX-102 in a long-term extension study.