A Treatment Extension Study of Mucopolysaccharidosis Type IIIB

• Register: ClinicalTrials.gov
• Last refreshed on: 30 January 2023
• Main ID: NCT03784287
• Date of registration: 30/03/2018
• Prospective Registration: No
• Primary sponsor: Allievex Corporation
• Public title: A Treatment Extension Study of Mucopolysaccharidosis Type IIIB
• Scientific title: A Multicenter, Multinational, Extension Study to Evaluate the Long Term Safety and Efficacy of Intracerebroventricular AX 250 in Patients With Mucopolysaccharidosis Type IIIB (MPS IIIB, Sanfilippo Syndrome Type B)
• Date of first enrolment: February 19, 2018
• Target sample size: 20
• Recruitment status: Active, not recruiting
• URL: https://clinicaltrials.gov/show/NCT03784287
• Study type: Interventional
• Study design: Allocation: N/A. Intervention model: Single Group Assignment. Primary purpose: Treatment. Masking: None (Open Label).
• Phase: Phase 2

Countries of recruitment

Colombia, Germany, Spain, Taiwan, Turkey, United Kingdom, United States

Contacts

• Name: Medical Monitor, MD
• Affiliation: Allievex Corporation

Key inclusion & exclusion criteria

Inclusion Criteria:

- Must have completed 48 weeks in Part 2 of Study 250-201 and enter 250-202 within 8
weeks of study completion

- Written informed consent from parent or legal guardian and assent from subject, if
required

- Has the ability to comply with protocol requirements, in the opinion of the
investigator

- Males and females who are of reproductive age should practice true abstinence, defined
as no sexual activity, during the study and for 6 months after the study has been
completed (or withdrawal from the study). If sexually active and not practicing true
abstinence, males and females of reproductive age must use a highly effective method
of contraception while participating in the study.

- If female with childbearing potential, must have a negative pregnancy test at the
Screening visit and be willing to have additional pregnancy tests during the study.

Exclusion Criteria:

- Has both (1) a cognitive AEq score = 18 months, and (2) a DQ score = 20

- Would not benefit from enrolling in the study in the opinion of the investigator

- Has received stem cell, gene therapy or ERT (other than AX 250) for MPS IIIB

- Has contraindications for neurosurgery (eg, congenital heart disease, severe
respiratory impairment, or clotting abnormalities)

- Has contraindications for MRI scans (eg, cardiac pacemaker, metal fragment or chip in
the eye, or aneurysm clip in the brain)

- Has a history of poorly controlled seizure disorder

- Is prone to complications from intraventricular drug administration, including
patients with hydrocephalus or ventricular shunts

- Has received any investigational medication other than AX 250 within 30 days prior to
the Baseline visit or is scheduled to receive any investigational drug during the
course of the study

- Has a medical condition or extenuating circumstance that, in the opinion of the
investigator, might compromise the subject's ability to comply with protocol
requirements, the subject's well-being or safety, or the interpretability of the
subject's clinical data.

- Is pregnant at any time during the study



Age minimum: 0 Years
Age maximum: 18 Years
Gender: All

Health Condition(s) or Problem(s) studied

Mucopolysaccharidosis Type IIIB

MPS III B

Intervention(s)

Drug: AX 250

Primary Outcome(s)

Evaluate the Long-term safety and tolerability of AX 250 administered in up to 33 subjects with MPS IIIB by assessing the number of participants with abnormal clinical laboratory values and/or Adverse Events related to the treatment [Time Frame: Entire study period, up to 240 weeks]

Evaluating the impact of long-term AX 250 treatment on cognitive function in up to 33 patients with MPS IIIB as assessed by developmental quotient (DQ) [Time Frame: Entire study period, up to 240 weeks]

Secondary Outcome(s)

Evaluate the impact of long-term AX 250 treatment on adaptive function derived from the Vineland Adaptive Behavior Scales, 2nd edition (VABS-II) [Time Frame: Entire study period, up to 240 weeks]

Evaluate the impact of long-term AX 250 treatment on Heparan sulfate (HS) levels in cerebrospinal fluid (CSF), serum and urine. [Time Frame: Entire study period, up to 240 weeks]

Evaluate the impact of long-term AX 250 treatment on cognitive function in up to 33 patients with MPS IIIB as assessed by age equivalent score (AEq) [Time Frame: Entire study period, up to 240 weeks]

Characterize immunogenicity as measured by IgE levels, formation of anti-AX 250, IGF1 and IGF2 antibodies in Cerebrospinal fluid (CSF) and serum. [Time Frame: Entire study period, up to 240 weeks]

Evaluate the impact of long-term AX 250 treatment on brain structure assessed by magnetic resonance imaging (MRI) [Time Frame: Entire study period, up to 240 weeks]

Secondary ID(s)

AX 250-202

Source(s) of Monetary Support

Please refer to primary and secondary sponsors