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

MPS III B Clinical Trial

Official title:

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

Clinical Trial Details — Status: Enrolling by invitation

Administrative data

• NCT number: NCT05492799
• Other study ID #: 250-401
• Status: Enrolling by invitation
• Phase: Phase 4
• Start date: December 2, 2022
• Est. completion date: December 2027

Study information

• Verified date: August 2023
• Source: Allievex Corporation
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Enrolling by invitation
• Enrollment: 15
• Est. completion date: December 2027
• Est. primary completion date: October 2027
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A and older

Eligibility

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

Related Conditions & MeSH terms

• MPS III B
• Mucopolysaccharidosis III

Intervention

Drug:
• AX 250
biweekly infusion by intracerebroventricular (ICV) infusion

Locations

Country	Name	City	State
Colombia	Fundación Cardio Infantil - Instituto de Cardiología	Bogotá,
Germany	University Medical Center Hamburg-Eppendorf	Hamburg
Turkey	Gazi University Faculty of Medicine	Ankara
United Kingdom	Great Ormond Street Hospital For Children, NHS Foundation Trust	London
United States	UCSF Benioff Children's Hospital Oakland	Oakland	California
United States	UPMC Children's Hospital Pittburgh	Pittsburgh	Pennsylvania

Sponsors (1)

Lead Sponsor	Collaborator
Allievex Corporation

Countries where clinical trial is conducted

United States,  Colombia,  Germany,  Turkey,  United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Primary - neurocognition	the rate of change in score from neurocognitive assessment using validated scale	baseline to 144 weeks of treatment