A Study of Ketamine in Patients With Treatment-resistant Depression

This is a double-blind (patients and study personnel do not know the identity of the
administered treatments), randomized (the drug is assigned by chance), placebo-controlled
(placebo is a substance that appears identical to the treatment and has no active
ingredients), parallel arm study (each group of patients will be treated at the same time).
The study will consist of a screening phase of up to 4 weeks, a 4-week double-blind
treatment phase (Day 1 to Day 29), and a 3-week post treatment (follow up) phase. In the
double-blind phase, patients will receive over 4 weeks either intravenous (IV) infusions of
placebo (2 or 3 times weekly) or IV infusions of ketamine (2 or 3 times weekly). The total
study duration for each patient will be a maximum of 13 weeks.

Inclusion Criteria:

- Be medically stable on the basis of clinical laboratory tests performed at screening

- Meet diagnostic criteria for recurrent major depressive disorder (MDD), without
psychotic features

- Have a history of inadequate response, ie treatment was not successful, to at least 1
antidepressant

- Have an Inventory of Depressive Symptoms-Clinician rated, 30 item (IDS-C30) total
score >= 40 at screening and predose at Day 1

- Inpatient or agreed to be admitted to the clinic on each dosing day

Exclusion Criteria:

- Has uncontrolled hypertension

- Has a history of, or current signs and symptoms of diseases, infections or conditions
that in the opinion of the investigator, would make participation not be in the best
interest (eg, compromise the well-being) of the patient or that could prevent, limit,
or confound the protocol-specified assessments

- Has known allergies, hypersensitivity, or intolerance to ketamine or its excipients

- Is unable to read and understand the consent forms and patient reported outcomes,
complete study-related procedures, and/or communicate with the study staff