1. A phase I/II study on intracerebroventricular tralesinidase alfa in patients with Sanfilippo syndrome type B
- Author
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Nicole Muschol, Anja Koehn, Katharina von Cossel, Ilyas Okur, Fatih Ezgu, Paul Harmatz, Maria J. de Castro Lopez, Maria Luz Couce, Shuan-Pei Lin, Spyros Batzios, Maureen Cleary, Martha Solano, Igor Nestrasil, Brian Kaufman, Adam J. Shaywitz, Stephen M. Maricich, Bernice Kuca, Joseph Kovalchin, and Eric Zanelli
- Subjects
Neuroscience ,Medicine - Abstract
Background Sanfilippo type B is a mucopolysaccharidosis (MPS) with a major neuronopathic component characterized by heparan sulfate (HS) accumulation due to mutations in the NAGLU gene encoding alfa-N-acetyl-glucosaminidase. Enzyme replacement therapy for neuronopathic MPS requires efficient enzyme delivery throughout the brain in order to normalize HS levels, prevent brain atrophy, and potentially delay cognitive decline.Methods In this phase I/II open-label study, patients with MPS type IIIB (n = 22) were treated with tralesinidase alfa administered i.c.v. The patients were monitored for drug exposure; total HS and HS nonreducing end (HS-NRE) levels in both cerebrospinal fluid (CSF) and plasma; anti-drug antibody response; brain, spleen, and liver volumes as measured by MRI; and cognitive development as measured by age-equivalent (AEq) scores.Results In the Part 1 dose escalation (30, 100, and 300 mg) phase, a 300 mg dose of tralesinidase alfa was necessary to achieve normalization of HS and HS-NRE levels in the CSF and plasma. In Part 2, 300 mg tralesinidase alfa sustained HS and HS-NRE normalization in the CSF and stabilized cortical gray matter volume (CGMV) over 48 weeks of treatment. Resolution of hepatomegaly and a reduction in spleen volume were observed in most patients. Significant correlations were also established between the change in cognitive AEq score and plasma drug exposure, plasma HS-NRE levels, and CGMV.Conclusion Administration of tralesinidase alfa i.c.v. effectively normalized HS and HS-NRE levels as a prerequisite for clinical efficacy. Peripheral drug exposure data suggest a role for the glymphatic system in altering tralesinidase alfa efficacy.Trial registration Clinicaltrials.gov NCT02754076.FUNDING BioMarin Pharmaceutical Inc. and Allievex Corporation.
- Published
- 2023
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