Shire has reported negative top-line results from a Phase II/III clinical trial evaluating SHP609 for the treatment of pediatric patients with Hunter syndrome (mucopolysaccharidosis II or MPS II) and cognitive impairment.
The controlled, randomised, open-label, multi-centre, assessor-blinded study enrolled 48 patients with Hunter syndrome and cognitive impairment who continued to receive and tolerate therapy with intravenous idursulfase.
Neither the primary or key secondary endpoints were achievable in the trial.
The study's primary endpoint was to examine the difference in cognition between the SHP609-treated and control groups, as measured by change from baseline in general conceptual ability (GCA) scores in children with Hunter syndrome after 12 months of treatment.
The key secondary endpoint assessed the difference between the SHP609-treated and control groups as measured by the change from baseline in adaptive behaviour composite (ABC) score.
Shire senior vice-president and R&D (ad-interim) global head Howard Mayer said: “Shire is disappointed that the top-line data from this study did not meet the primary and key secondary endpoints and remains committed to patients and families living with MPS II.”
Hunter syndrome is a severely debilitating rare lysosomal storage disorder (LSD) caused by iduronate-2-sulfatase enzyme deficiency.
The disease is estimated to affect one in 162,000 total live births, and almost exclusively affect males.
Shire is engaged in the development of SHP609 as a formulation of idursulfase that can be administered intrathecally for a new potential indication treatment of pediatric patients with Hunter syndrome and cognitive impairment.
The formulation has yet to receive approval for use from the US Food and Drug Administration, European Medicines Agency, and other regulatory authorities.