The study will consist of 8 cohorts (Cohorts 1 to 8, 1 cohort per dose level). Each cohort will include 8 subjects (6 subjects receiving a single dose of the study drug NS101 and 2 subjects receiving a single dose of a matching placebo), for a total of 64 subjects planned for evaluation.~For each dose level, the dose to be administered to each subject for a single infusion will be calculated based on subject's body weight, measured on Day 1.~In each cohort, subjects will receive a single infusion of NS101 or matching placebo under fasting conditions over a period of approximately 60 minutes at the target dose level. A total of 21 blood samples will be collected in each cohort for PK analysis and a total of 14 blood samples will be collected in each cohort for PD analysis. A total of 6 immunogenicity blood samples will be collected for ADA and NAbs. For each subject in cohort 5 to 8 only, one single CSF sample will be collected via lumbar puncture over the study, for PK and PD analysis.
Up to 80 healthy adult males, ≥ 18 and ≤ 55 years of age, are planned to be enrolled in the study.~The study will consist of 8 cohorts (Cohorts 1 to 8, 1 cohort per dose level). Each cohort will include 8 subjects (6 subjects receiving a single dose of the study drug NS101 and 2 subjects receiving a single dose of a matching placebo), for a total of 64 subjects planned for evaluation. A total of 21 blood samples will be collected in each cohort for PK analysis and a total of 14 blood samples will be collected in each cohort for PD analysis.