The Primary endpoints of the study include:
- Safety and tolerability of velmanase alfa as per Adverse events (AEs, including IRR), vital signs, laboratory parameters (hematology, biochemistry and urinanalysis)
- Detection of anti-velmanase alfa antibodies and neutralizing/inhibitory antibodies
The Secondary endpoints include changes from baseline to 24 months for the following parameters. Efficacy outcomes:
- Serum oligosaccharides
- Functional capacity: Peabody Developmental Motor Scale - 2nd edition (PDMS-2) scores, Mullen's Scale of Early Learning (MSEL) scores, Bruininks-Oseretsky Test Of Motor Proficiency-2nd Edition (BOT-2), when applicable by age (from 4 years) or upon the judgment of the physician
- Endurance: 3-Minute Stair Climb Test (3MSCT) and 6-Minute Walk Test (6MWT) in pediatric patients from 4 years of age, or when applicable according to the judgment of the physician, 2-Minute Walk Test (2MWT) in pediatric patients below 4 years of age, or when applicable according to the judgment of the physician
- Hearing evaluation: Otoacoustic Emissions (OAE) testing, Automatic Auditory Brainstem Response (A-ABR) audiometry
- Immunological profile, when applicable upon the judgment of the physician:
- CSF biomarkers: Tau protein (Tau), Neurofilament Protein Light (NFL), Glial Fibrillary Acidic Protein (GFAp), Oligosaccharides
- Assessment of quality of life via Questionnaire to parents
- Assessment of mannose-rich oligosaccharides in brain tissue, MRI
- Pharmacokinetic parameters