Intracerebroventricular Tralesinidase Alfa in Participants With MPS IIIB (Sanfilippo Syndrome Type B)

The primary objectives of this study are to evaluate the effects of Tralesinidase Alfa (TA) on cognition

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Trial opening soon.

Key information

Conditions

MPS IIIB Carbohydrate Metabolism, Inborn Errors Congenital, Hereditary, and Neonatal Diseases and Abnormalities Connective Tissue Diseases Genetic Diseases, Inborn Lysosomal Storage Diseases Metabolic Diseases Metabolism, Inborn Errors Mucinoses Mucopolysaccharidoses Mucopolysaccharidosis III Nutritional and Metabolic Diseases Skin and Connective Tissue Diseases

Age range

1 year–5 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Has a diagnosis of MPS IIIB confirmed by deficient NAGLU enzyme activity during screening.

Has nonattenuated severe MPS IIIB by the Genotype and Clinical Assessment Committee.

Is ≥1 and ≤5 years of age with BSID-III-C raw score of <70. Is male or female as identified at birth.

Exclusion criteria

Genotyped for a known MPS IIIB variant associated with an attenuated phenotype or has a sibling with a known attenuated phenotype.

Has another neurological illness that may have caused cognitive decline (e.g., trauma, meningitis, or hemorrhage) before study entry.

Has received stem cell, gene therapy, or enzyme replacement therapy for MPS IIIB.

Treatment and study plan

Tralesinidase alfa (TA)

Drug

TA study drug is a sterile solution for ICV infusion.

Primary outcomes

Change from Baseline in Bayley Scales of Infant and Toddler Development, Third Edition, Cognition Domain (BSID-III-C) Raw Score

Time frame: Baseline to Week 260 (approximately 5 years)

The BSID-III-C is a standardized tool that evaluates cognitive development in young children, capturing skills such as processing speed, problem solving, and play. Raw scores are used to sensitively measure individual change over time, independent of age. Assessments are administered by a trained, blinded rater and reviewed by a central blinded rater. The endpoint is the difference in mean change from baseline in BSID-III-C raw score between the tralesinidase alfa and control arms at Week 260

Study contacts

Contact information is provided by the study sponsor or research team.

April Freeman

CONTACT

[email protected]

415-343-5986

Sponsors and collaborators

Lead sponsor

Spruce Biosciences

Industry

Registry information

Official study title

A Phase 3, Randomized, Single-blind, Parallel Group, Controlled, Multicenter Study to Evaluate the Safety, Tolerability, and Efficacy of Intracerebroventricular Tralesinidase Alfa Treatment Compared to Standard of Care in Mucopolysaccharidosis Type IIIB (MPS IIIB, Sanfilippo Syndrome Type B)

Acronym: TrAnsform

Important dates

Study start: 2026
Primary completion: 2033
Study completion: 2033
First posted: May 12, 2026
Registry last updated: Jul 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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