This is a Phase 1, single-center, double-blind, randomized, placebo-controlled, 2-part, single ascending dose and multiple dose cohort study of orally administered Norketotifen (NKT) in healthy subjects.

Single Ascending Dose: Three single ascending dose cohorts are planned. A total of 10 subjects will be enrolled in each cohort and will be randomly assigned to receive a single oral dose of NKT (n=8) or a matching placebo (n=2). A Safety Review Team (SRT) will review all available safety data in a blinded manner following the completion of each cohort to determine the next dose level to be evaluated in the next cohort.

Multiple Dose Cohort: A total of 10 subjects will be enrolled and will be randomly assigned to receive multiple oral doses of NKT (n=8) or a matching placebo (n=2) once daily for an adequate number of days to reach steady state (the number of days will be determined based on the half-life of NKT in Part A). The dose of NKT to be evaluated will be determined by the SRT.

Key Inclusion Criteria:

• Body mass index (BMI) of 18 to 30 kg/m^2
• Negative serum pregnancy test (females); females of childbearing potential and males must agree to use acceptable contraception

Key Exclusion Criteria:

• Pregnant or lactating (females)
• Clinically significant past or current medical or surgical history
• Clinically significant illness or abnormality on physical examination, 12-lead ECG, laboratory values
• Participation in an investigational drug or device study within 30 days prior to Screening