Safety, Tolerability and Efficacy of ICV AX 250 Treatment in MPS IIIB -OLE

Open-Label Multicenter Extension Study to Further Evaluate Safety, Tolerability and Efficacy of Intracerebroventricular AX 250 Treatment in Mucopolysaccharidosis Type IIIB (MPS IIIB, Sanfilippo Syndrome Type B) Patients

This is a Phase 3B/4, multicenter, multinational, open label study to further evaluate intracerebroventricular (ICV) delivered AX 250 treatment in MPS IIIB subjects that complete Study 250-202 for up to an additional 3 years (144 weeks) of treatment with AX 250 administered by ICV infusion every other week. Subjects will be evaluated for neurocognitive function, communication, adaptive behavior, quality of life, imaging characteristics and biochemical markers of disease burden. Safety will be assessed by adverse events, clinical labs, and physical exams.

Study Overview

• Status: Enrolling by invitation
• Conditions: MPS III B
• Intervention / Treatment: Drug: AX 250

• Study Type: Interventional
• Enrollment (Estimated): 15
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Study Director; Phone Number: +1978 322-4554; Email: inquiries@alllievex.com

Study Locations

• Colombia
  • Bogotá,, Colombia
    • Fundación Cardio Infantil - Instituto de Cardiología
    • Principal Investigator: Martha Solano, MD
• Germany
  • Hamburg, Germany
    • University Medical Center Hamburg-Eppendorf
    • Principal Investigator: Nicole Muschol, MD
• Turkey
  • Ankara, Turkey
    • Gazi University Faculty of Medicine
    • Principal Investigator: Ilyas Okur, MD
• United Kingdom
  • London, United Kingdom, WC1N 3JH
    • Great Ormond Street Hospital For Children, NHS Foundation Trust
    • Principal Investigator: Spiro Batzios, MD
• United States
  • California
    • Oakland, California, United States, 94609
      • UCSF Benioff Children's Hospital Oakland
      • Contact: Jill Nicholas; Phone Number: 5241 510-428-3885; Email: jinicholas@mail.cho.org
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15224
      • UPMC Children's Hospital Pittburgh

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Must have completed 240 weeks of Study 250-202 and enter 250-401 within 8 weeks of dosing completion.
2. Provides written informed consent from parent or legal guardian and assent from subject, if required
3. Has the ability to comply with protocol requirements in the opinion of the investigator
4. 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:

1. Has (1) a cognitive age equivalent (AEq ) score ≤ 18 months, (2) a development quotient (DQ) score ≤ 20, and (3) no evidence of improvement during the 250-202 study in secondary or exploratory efficacy endpoints
2. Would not benefit from enrolling in the study in the opinion of the investigator
3. Has received stem cell, gene therapy or enzyme replacement therapy (other than AX 250) for MPS IIIB
4. Has a history of poorly controlled seizure disorder
5. Is prone to complications from ICV drug administration including patients with hydrocephalus or ventricular shunts
6. Has received any investigational medication within 30 days prior to the Baseline visit or is scheduled to receive any investigational drug during the course of the study
7. 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: single arm; AX 250 300 mg - open label	Drug: AX 250; biweekly infusion by intracerebroventricular (ICV) infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary - neurocognition	the rate of change in score from neurocognitive assessment using validated scale	baseline to 144 weeks of treatment

Collaborators and Investigators

• Sponsor: Allievex Corporation
• Investigators: Study Director: Medical Director, Allievex Corporation

Study record dates

Study Major Dates

• Study Start (Actual): December 2, 2022
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: August 5, 2022
• First Submitted That Met QC Criteria: August 8, 2022
• First Posted (Actual): August 9, 2022

Study Record Updates

• Last Update Posted (Actual): August 9, 2023
• Last Update Submitted That Met QC Criteria: August 7, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Genetic Diseases, Inborn; Connective Tissue Diseases; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Lysosomal Storage Diseases; Mucinoses; Mucopolysaccharidoses; Mucopolysaccharidosis III
• Other Study ID Numbers: 250-401

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No