Shire has announced top-line results from its Phase II/III clinical trial evaluating SHP609, previously known as HGT-2310. SHP609 is an investigational formulation of idursulfase administered intrathecally for a new potential indication for the treatment of pediatric patients with Hunter syndrome and cognitive impairment.

The study did not meet either its primary or its key secondary endpoint. The primary endpoint evaluated the difference in cognition between the SHP609-treated and control groups, as measured by change from baseline in General Conceptual Ability scores in children with Hunter syndrome after 12 months of treatment. The key secondary endpoint evaluated the difference between the SHP609-treated and control groups as measured by the change from baseline in Adaptive Behavior Composite score.

"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."

Hunter syndrome is a severely debilitating, rare lysosomal storage disorder, causing a range of disease-related signs and symptoms such as hearing loss, declined cardiac function, obstructive airway disease, enlargement of the liver and spleen and decreased range of motion and mobility. Physical manifestations may include distinct facial features, a large head and enlarged abdomen. In many cases the central nervous system may also be affected.