A Study to Assess the Electrophysiology, Safety, Tolerability, and Pharmacokinetics of SAGE-718 Using a Ketamine Challenge in Healthy Subjects

Inclusion Criteria:

1. Subject has a body weight ≥50 kg and body mass index ≥18.0 and ≤30.0 kg/m2 at screening.
2. If female, subject is post-menopausal (at least 12 months of spontaneous amenorrhea with confirmatory follicle stimulating hormone \>40 mIU/mL), or surgically sterile (bilateral tubal ligation, bilateral oophorectomy, and/or hysterectomy).
3. Subject is healthy with no history or evidence of clinically relevant medical disorders as determined by the Investigator.

Exclusion Criteria:

1. Subject has a history or presence of any psychiatric disease or condition including suicidal ideation or behavior, has answered YES to any question on the C-SSRS at screening or admission, or is currently at risk of suicide in the opinion of the Investigator.
2. Subject has a history or presence of a neurologic disease or condition, including but not limited to epilepsy, closed head trauma with clinically significant sequelae, or a prior seizure.
3. Subject has a family history of epilepsy.
4. Subject has obstructed venous access and/or has skin disease, rash, acne, or abrasion at venous access site that may affect the ability to obtain a PK sample or affect the ability to receive the ketamine infusions.
5. Subject has had previous exposure to or is known to be allergic to ketamine or any of its excipients.