This study is designed as prospective, open-label, ascending dose phase I study. Safety, tolerability, pharmacokinetic, and pharmacodynamic properties of repeat-dose treatment of ICV-administered investigational product will be studied in patients undergoing standard treatments.~Patients will undergo cerebrospinal fluid (CSF) reservoir device implantation surgery on their scalps, and the reservoirs will be used to administer GC1123 to the cerebral ventricles monthly (every 28 days). The planned administering doses are 30 mg and 45 mg. After the 2nd dose on the 6th (last) patient in Group 1, Data and Safety Monitoring Boards (DSMB) will evaluate the safety and tolerability data of GC1123 to determine dose escalation if dose limiting toxicity (DLT) occurs in less than 2 out of 6 patients.
The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of intracerebroventricular GC1123 in patients with MPS Ⅱ who have central nervous system involvement and are receiving treatment with intravenous drug