Patients with infantile or late infantile NCL have either a reduced amount of, or are missing, the palmitoyl protein thioesterase 1 (PPT1) enzyme or the tripeptidyl peptidase 1 (TPP-I) enzyme. Human central nervous system stem cells (HuCNS-SC) are an investigational product derived from human brain cells. HuCNS-SC have been shown to survive and migrate within the brains of mice. When grown in the laboratory, HuCNS-SC have been shown to produce the PPT1 and TPP-I enzymes. In mice missing the PPT1 enzyme, HuCNS-SC have been shown to increase the amount of this enzyme in the brain, to reduce the amount of abnormal storage material in the brain, and to prevent the death of some neurons (a type of cell) in the brain.

Participation in this study will involve screening assessments, surgery to implant HuCNS-SC, medication to suppress the immune system, and a series of follow-up assessments. The length of time from the start of screening through to the last follow-up visit will be approximately 13 months, with frequent visits to the study center during this time. After completion of this study, patients will be monitored for an additional 4 years under a separate long term follow-up protocol.