This is a Phase 1, randomized, double-blind, placebo-controlled, single ascending dose (SAD), food effect (FE),multiple ascending dose (MAD), drug-drug interaction study, and bioavailability - bio-equivalence study of orally administered NEU-411 in healthy subjects

Up to five (5) single-ascending oral doses will be administered to 40 healthy adult male or female subjects (aged 18-80 years, inclusive). Escalation to the next higher dose level may occur only after evaluation of the safety and PK results of the previous dose level (at least 6 evaluable subjects). Within each cohort, 6 subjects will receive one dose of NEU-411, and 2 subjects will receive one dose of matching placebo. Dose levels may be revised based on available safety and PK data.

Food effect will evaluate approximately 8 subjects in a fasted versus fed state.

Multiple ascending oral doses will be administered up to 24 healthy subjects (aged 18 - 80 years, inclusive) in 3 sequential dosing groups (8 subjects in each dosing group). Six (6) subjects will receive NEU-411 and two (2) subjects will receive matching placebo in each dosing group (cohort) for 7 days. Escalation to the next higher dose level may occur only after evaluation of the safety and PK results of the previous dose level (at least 6 evaluable subjects). Dose levels may be revised based on available safety and PD data.

Multiple oral dosing will be administered in up to 39 healthy subjects in 3 sequential dosing groups (13 subjects across 3 dosing groups) over 28 days.

Inclusion Criteria:

• Subjects for standard cohorts must be 18-80 years, inclusive, at the time of signing the informed consent;
• Subjects who are in good general health with no clinically relevant abnormalities based on the medical history, physical examinations, neurological examinations, clinical laboratory evaluations (hematology and clinical chemistry)
• Subjects who have a body mass index (BMI) of 18-32 kg/m2(inclusive);
• Male subjects are eligible to participate if they are rendered surgically sterile (at least 6 months), or agree to the following during the study and for at least 30 days after the last dose of study drug:
• Refrain from donating sperm;

AND, either:

Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent; OR Agree to use a male condom (contraception/barrier) and should also be advised of the benefit for a female partner to use an acceptable, highly effective method of contraception as a condom may break or leak when having sexual intercourse;

• Female subjects are eligible to participate if they are not pregnant or breastfeeding, subject to one of the following:

• Women of childbearing potential (WOCBP), defined as women physiologically capable of becoming pregnant, must have a negative serum pregnancy test at the Screening visit and a negative urine pregnancy test on Day -1; WOCBP must agree to use an acceptable, highly effective contraceptive method from Screening until 30 days after the last dose of study treatment (see Section 11.3); OR
• Menopausal women must have an elevated serum follicle-stimulating hormone level (FSH) level at Screening; if the FSH is not elevated, they are considered to be of childbearing potential (unless permanently sterile) and must have a negative serum pregnancy test at Screening and a negative urine pregnancy test on Day -1

Exclusion Criteria:

• History of clinically significant hematological, renal, pancreatic, gastrointestinal, hepatic, cardiovascular, metabolic, endocrine, immunological, allergic disease, or other major disorders
• History of clinically significant abnormal chest x-ray
• Clinically significant neurologic disorder
• Contraindications to undergo a lumbar puncture (only for subjects participating in the MAD)