A Long-term Follow-up Study of Patients With MPS IIIB Treated With ABO-101

A Long-term Follow-up Study of Patients With MPS IIIB From Gene Therapy Clinical Trials Involving the Administration of ABO-101 (rAAV9.CMV.hNAGLU)

This is a multicenter, non-interventional, long-term follow-up (LTFU) study in participants who have been treated with ABO-101 in a prior trial. Eligible participants will undergo clinical evaluations at prespecified intervals for 3 years from the last visit in the prior clinical trial (up to 5 years post-treatment).

This is a multicenter, noninterventional, long-term follow-up study of patients with (Mucopolysaccharidosis IIIB) MPS IIIB who have completed a prior clinical trial involving the administration of ABO-101. This study is designed to provide LTFU in accordance with the FDA and European Medicines Agency (EMA) guidelines for patients treated with gene therapy products. The duration of the current study is 3 years for a total of up to 5 years post-treatment for these participants who rollover from a prior clinical trial of ABO-101. Participants will have a maximum of 5 annual scheduled visits with assessments as specified in the schedule of assessments.

Inclusion Criteria:

• Participants that have completed a prior clinical trial involving the administration of ABO-101
• Parent(s)/legal guardian(s) of participant willing and able to complete the informed consent process and comply with study procedures and visit schedule

Exclusion Criteria:

• Planned or current participation in another clinical trial that may confound the safety and efficacy evaluation of ABO-101 during the duration of this study
• Any other situation that precludes the participant from undergoing procedures required in this study