Single-center, randomized, double-blind, placebo-controlled, single ascending dose, safety and tolerability study of TNX-201 capsules in healthy volunteers.

Single-center, randomized, double-blind, placebo-controlled, single ascending dose, safety and tolerability study of TNX-201 capsules in healthy volunteers. Three successive cohorts are planned with doses of TNX-201 capsules, 35 mg, 70 mg, and 140 mg, respectively. Each cohort will consist of 15 subjects, and subjects will be randomly assigned to TNX-201, racemic isometheptene, or placebo capsules.

Inclusion Criteria:

1. Male or female, ≥ 18 and ≤ 55 years of age on the day of randomization. NOTE: At least 6 female subjects need to be randomized in each cohort.
2. Body mass index (BMI) ≥18.5 and ≤33.0
3. Non-tobacco users (no use of tobacco- or nicotine- containing products within 3 months prior to study drug administration)

Exclusion Criteria:

1. Any clinically significant abnormality or clinically significant abnormal laboratory test results found at Screening or Day -1, or a positive test for HBsAg, HCAb, or HIV found at Screening
2. Positive urine drug screen (including alcohol, tetrahydrocannabinol (THC), cocaine, amphetamines, and opiates) or urine cotinine test at Screening or on Day -1
3. Known or suspected hypersensitivity to isometheptene mucate or any excipients used in the formulations.
4. Positive serum pregnancy test at Screening or Day -1
5. Any reason, in the opinion of the Principal Investigator (PI) or the sponsor's Medical Monitor, to prevent the subject from participating in the study
6. Clinically significant ECG abnormalities