Shire’s investigational Hunter syndrome therapy SHP609 has failed to meet primary and secondary targets in a mid-stage trial.

SHP609 is an investigational formulation of idursulfase administered intrathecally to treat pediatric patients with Hunter syndrome (mucopolysaccharidosis II or MPS II) and cognitive impairment.

Around two of every three patients with Hunter syndrome are also affected with progressive cognitive decline. SHP609 (previously known as HGT-2310) has been specifically developed to be directly administered via an injection into the cerebrospinal fluid as a means of delivering the drug to the central nervous system.

However, top-line results from a Phase II/III trial show no significant 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 primary endpoint).

The key secondary endpoint assessed the difference between the SHP609-treated and control groups as measured by the change from baseline in Adaptive Behavior Composite (ABC) score, and also found no significant change..

“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,” said Howard Mayer, M.D., Senior Vice President and Global Head of R&D (ad-interim), Shire.

“We are grateful to the children, their families and healthcare providers for participating in this challenging trial and will continue our ongoing dialogue with the community as we conduct an analysis of the full data set. Further analysis of the data will be presented at forthcoming congresses.”