This is a randomized, double-blind, and placebo controlled. 120 HV will be randomized to one
of three ketamine arms, delivered in a bolus dose over one minute: low (0.06 mg/kg), medium
(0.125 mg/kg), and high (0.23 mg/kg).
Within each ketamine arm, subjects will be randomized to 4 days of TS-134 20 mg or placebo in
a 5:3 ratio (25 TS-134:15 placebo). Following an outpatient Screening Period (up to 31 days),
eligible subjects will undergo a 5-day inpatient Treatment Period. During the study, each
subject will undergo a total of two ketamine sessions: a first session during the Screening
Period and a second session on Day 4 of the Treatment Period, conducted at least 7 days
apart. All randomized subjects will be dosed with TS-134 or placebo daily in a fed state for
4 days during the study, titrated to 20 mg over the first 2 days.