Long-term safety and clinical outcomes of intrathecal heparan-N-sulfatase in patients with Sanfilippo syndrome type A.

INTRODUCTION: Currently, there is no effective therapy for mucopolysaccharidosis IIIA (MPS IIIA). Intravenously-administered enzyme replacement therapies, while effective in other forms of MPS without neurological involvement, have not been successful in patients with MPS IIIA, as they are unable to cross the blood-brain barrier to improve neurological symptoms. We evaluated the long-term safety, tolerability, and clinical outcomes of recombinant human heparan-N-sulfatase (rhHNS) administered intrathecally (IT) in children with MPS IIIA in a phase 1/2 extension study. METHODS: Patients aged ≥3 years with MPS IIIA who had previously completed a phase 1/2 study and received ≥5 of the 6 planned rhHNS infusions via IT administration, were eligible for inclusion. Patients who received 10 mg in the phase 1/2 study had their dose increased to 45 mg. Patients who were treated with 45 mg or 90 mg rhHNS IT in the phase 1/2 study remained on this monthly dose in the extension study. rhHNS was administered via an intrathecal drug delivery device (IDDD). Primary endpoints included the type and severity of adverse events, presence of anti-rhHNS antibodies in the CSF and serum, and changes in laboratory values. Secondary endpoints included standardized neurocognitive assessments and brain magnetic resonance imaging. RESULTS: In the extension study, 12 patients with a mean (SD) age of 9.6 (7.3) years continued treatment with rhHNS IT for a median of 264.4 weeks. Ten of 12 patients completed the extension study. rhHNS IT was generally well-tolerated. All patients experienced at least one treatment-emergent adverse event (TEAE), most being mild or moderate in severity. No serious adverse events (SAEs) were considered related to the study drug, and no deaths occurred. Most SAEs were related to malfunctions of the IDDD. Declines from baseline in Bayley Scales of Infant Development, Third Edition or Kaufman Assessment Battery for Children, Second Edition, Nonverbal Index developmental quotient scores were evident at all rhHNS dosing groups: -17.97%, -18.99%, and -12.12% in the 10/45, 45, and 90 mg groups, respectively, at Month 54. CONCLUSIONS: Overall, rhHNS IT was well tolerated in the extension study. However, rhHNS IT was unable to slow the neurocognitive decline of patients with MPS IIIA. This study was subsequently terminated early because pre-specified efficacy criteria were not met, and the study did not yield clinical proof of concept. (Clinicaltrials.gov Identifier NCT01299727).

Self-buffering capacity of a human sulfatase for central nervous system delivery.

Direct delivery of therapeutic enzymes to the Central Nervous System requires stringent formulation design. Not only should the formulation design consider the delicate balance of existing ions, proteins, and osmolality in the cerebrospinal fluid, it must also provide long term efficacy and stability for the enzyme. One fundamental approach to this predicament is designing formulations with no buffering species. In this study, we report a high concentration, saline-based formulation for a human sulfatase for its delivery into the intrathecal space. A high concentration formulation (≤ 40 mg/mL) was developed through a series of systematic studies that demonstrated the feasibility of a self-buffered formulation for this molecule. The self-buffering capacity phenomenon was found to be a product of both the protein itself and potentially the residual phosphates associated with the protein. To date, the self-buffered formulation for this molecule has been stable for up to 4 years when stored at 5 ± 3 °C, with no changes either in the pH values or other quality attributes of the molecule. The high concentration self-buffered protein formulation was also observed to be stable when exposed to multiple freeze-thaw cycles and was robust during in-use and agitation studies.

Whole Body and CNS Biodistribution of rhHNS in Cynomolgus Monkeys after Intrathecal Lumbar Administration: Treatment Implications for Patients with MPS IIIA.

Mucopolysaccharidosis III type A (MPS IIIA; Sanfilippo syndrome), a genetic lysosomal disorder causing a deficiency of heparan N-sulfatase (HNS), leads to progressive cognitive decline from an early age. An effective enzyme replacement therapy (ERT) for MPS IIIA requires central nervous system (CNS) biodistribution. Recombinant human heparan N-sulfatase (rhHNS), an investigatory ERT for MPS IIIA, has been formulated for intrathecal (IT) administration since intravenous (IV) administration cannot cross the blood brain barrier (BBB) in sufficient amounts to have a therapeutic effect. In this study, systemic and CNS distribution of rhHNS in cynomolgus monkeys following IV and IT administration was evaluated by quantitation of rhHNS in serum, cerebral spinal fluid (CSF) and various tissues, and positron emission tomography (PET) imaging of live animals. Following IV administration, rhHNS levels were low to non-detectable in the CSF, and systemic clearance was rapid (≤2 h). With IT administration, rhHNS was observable in CNS tissues in ≤1 h, with varying Tmax (1-24 h). Appreciable systemic distribution was observed up to 7 days. This provides evidence that in this animal model, intrathecal administration of rhHNS delivers the replacement enzyme to therapeutically relevant tissues for the treatment of Sanfilippo Syndrome type A. Penetration into grey matter and cortex was 3-4 times greater than concentrations in white matter and deeper parenchymal regions, suggesting some limitations of this ERT strategy.

Disease correction by AAV-mediated gene therapy in a new mouse model of mucopolysaccharidosis type IIID.

Gene therapy is a promising therapeutic alternative for Lysosomal Storage Disorders (LSD), as it is not necessary to correct the genetic defect in all cells of an organ to achieve therapeutically significant levels of enzyme in body fluids, from which non-transduced cells can uptake the protein correcting their enzymatic deficiency. Animal models are instrumental in the development of new treatments for LSD. Here we report the generation of the first mouse model of the LSD Muccopolysaccharidosis Type IIID (MPSIIID), also known as Sanfilippo syndrome type D. This autosomic recessive, heparan sulphate storage disease is caused by deficiency in N-acetylglucosamine 6-sulfatase (GNS). Mice deficient in GNS showed lysosomal storage pathology and loss of lysosomal homeostasis in the CNS and peripheral tissues, chronic widespread neuroinflammation, reduced locomotor and exploratory activity and shortened lifespan, a phenotype that closely resembled human MPSIIID. Moreover, treatment of the GNS-deficient animals with GNS-encoding adeno-associated viral (AAV) vectors of serotype 9 delivered to the cerebrospinal fluid completely corrected pathological storage, improved lysosomal functionality in the CNS and somatic tissues, resolved neuroinflammation, restored normal behaviour and extended lifespan of treated mice. Hence, this work represents the first step towards the development of a treatment for MPSIIID.

A phase 1/2 study of intrathecal heparan-N-sulfatase in patients with mucopolysaccharidosis IIIA.

OBJECTIVE: This was an open-label, phase 1/2 dose-escalation, safety trial of intrathecal recombinant human heparan-N-sulfatase (rhHNS) administered via intrathecal drug delivery device (IDDD) for treating mucopolysaccharidosis IIIA (NCT01155778). STUDY DESIGN: Twelve patients received 10, 45, or 90mg of rhHNS via IDDD once monthly for a total of 6 doses. Primary endpoints included adverse events (AEs) and anti-rhHNS antibodies. Secondary endpoints included standardized neurocognitive assessments, cortical gray matter volume, and pharmacokinetic/pharmacodynamic analyses. RESULTS: All patients experienced treatment-emergent AEs; most of mild-to-moderate severity. Seven patients reported a total of 10 serious AEs (SAEs), all but one due to hospitalization to revise a nonfunctioning IDDD. No SAEs were considered related to rhHNS. Anti-rhHNS antibodies were detected in the serum of 6 patients and in the cerebrospinal fluid (CSF) of 2 of these. CSF heparan sulfate levels were elevated at baseline and there were sustained declines in all tested patients following the first rhHNS dose. No impact of anti-rhHNS antibodies on any pharmacodynamic or safety parameters was evident. 4 of 12 patients showed a decline in developmental quotient, 6 were stable, and 2 patients had only a single data point. No dose group showed a clearly different response pattern. CONCLUSIONS: rhHNS administration via IDDD appeared generally safe and well tolerated. Treatment resulted in consistent declines in CSF heparan sulfate, suggesting in vivo activity in the relevant anatomical compartment. Results of this small study should be interpreted with caution. Future studies are required to assess the potential clinical benefits of rhHNS and to test improved IDDD models.

Regenerating matrix-based therapy for chronic wound healing: a prospective within-subject pilot study.

The aim of this study was to determine whether a skin-specific bioengineered regenerating agent (RGTA) heparan sulphate mimetic (CACIPLIQ20) improves chronic wound healing. The design of this article is a prospective within-subject study. The setting was an urban hospital. Patients were 16 African-American individuals (mean age 42 years) with 22 wounds (mean duration 2.5 years) because of either pressure, diabetic, vascular or burn wounds. Two participants each were lost to follow-up or removed because of poor compliance, resulting in 18 wounds analysed. Sterile gauze was soaked with CACIPLIQ20 saline solution, placed on the wound for 5 min, then removed twice weekly for 4 weeks. Wounds were otherwise treated according to the standard of care. Twenty-two percent of wounds fully healed during the treatment period. Wounds showed a 15.2-18.1% decrease in wound size as measured by the vision engineering research group (VERG) digital wound measurement system and total PUSH scores, respectively, at 4 weeks (P = 0.014 and P = 0.003). At 8 weeks there was an 18-26% reduction in wound size (P = 0.04) in the remaining patients. Wound-related pain measured by the visual analogue pain scale and the wound pain scale declined 60% (P = 0.024) and 70% (P = 0.001), respectively. Patient and clinician satisfaction remained positive throughout the treatment period. It is concluded that treatment with CACIPLIQ20 significantly improved wound-related pain and may facilitate wound healing. Patient and clinician satisfaction remained high throughout the trial.

Metabolism and pharmacokinetics of anthraquinones in Rheum palmatum in rats and ex vivo antioxidant activity.

Anthraquinones are a major group of polyphenols in the rhizome of Rheum palmatum L. (RP). This study investigated the metabolism and pharmacokinetics of anthraqinones in RP decoction in rats. The concentrations of four anthraquinones including aloe-emodin, rhein, emodin, chrysophanol, and their glycosides in the decoction were quantitated by HPLC before and after acid hydrolysis with the results indicating that the anthraquinones mainly existed as the glycoside form except for rhein. Rats were orally administered RP decoction and blood samples were assayed by HPLC before and after treatments with sulfatase and beta-glucuronidase. It was found that the glucuronides of aloe-emodin, rhein, emodin and chrysophanol were predominant in the blood, whereas their aglycones were not detected except for rhein. In conclusion, the anthraquinones were subject to a rapid and extensive conjugation metabolism in rats and the serum metabolites of RP exhibited a potential free radical scavenging effect on AAPH-induced hemolysis at pharmacologically relevant concentrations.

Administration of iduronate sulfatase by plasma exchange to patients with the Hunter syndrome: a clinical study.

The Hunter syndrome (MPS II) is the only mucopolysaccharidosis in which there is appreciable activity of the deficient enzyme in normal plasma. We performed enzyme-replacement treatment by plasma exchange in five Hunter syndrome children. Carefully monitoring the cardiovascular status, we administered monthly single plasma volume exchanges for a 3 to 8 mo period. The results indicate a substantial gain of enzyme activity, persisting with a t50% = 19 +/- 5 hr. The maximal level and persistence of increased enzyme activity did not change after repeated exchanges, suggesting that immune responses were not elicited. Despite this, no demonstrable clinical benefit was apparent when the study group was compared with an age-matched control group of Hunter syndrome patients.