Fig. 1

Overview of idursulfase-IT primary and extension study design [26, 27]. ^a Idursulfase-IT was administered via a surgically implanted IDDD (SOPH-A-PORT Mini S; Sophysa SA, Orsay, France). If the IT space was inaccessible, or in the event of device malfunction, idursulfase-IT could be administered by lumbar puncture. ^b Substudy patients aged > 8–30 months at dosing received an adjusted dose of idursulfase-IT 7.5 mg; patients aged > 30 months–3 years at dosing received idursulfase-IT 10 mg. EOS End of study, IDDD Intrathecal drug delivery device, IT Intrathecal, M Month, W Week