A Study to Assess the Efficacy and Safety of REL-1017 as Adjunctive Treatment for Major Depressive Disorder (MDD)

A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Efficacy and Safety of REL-1017 as Adjunctive Treatment of Major Depressive Disorder (The RELIANCE-I Study)

This is an outpatient, 2-arm, Phase 3, multicenter, randomized, double-blind, placebo-controlled study to assess the efficacy and safety of REL-1017 once daily (QD) as an adjunctive treatment of Major Depressive Disorder. Study participants will continue to take their current antidepressant therapy in addition to the study drug or placebo for the duration of the treatment period.

Inclusion Criteria:

• Adults 18 to 65 years, inclusive.
• Diagnosed with Major Depressive Disorder (MDD) based on structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, DSM-5 (SCID-5) for MDD.
• Current major depressive episode.
• With inadequate response to 1-3 first-line antidepressants administered at an adequate and stable dose

Exclusion Criteria:

• Any current and primary psychiatric disorder other than Major Depressive Disorder.
• Severe alcohol or substance use disorder.
• History of bipolar I and II disorder, psychosis, and/or mania.
• Acute or chronic condition that, in the Investigator's opinion, would limit the subject's ability to complete or participate in this clinical study.
• Prior participation in a ketamine, esketamine, dextromethorphan or any other NMDAR- antagonist study, or received esketamine at any time.