The study will enroll approximately 165 participants aged 18 to 74 years, inclusive, with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) confirmed primary diagnosis of MDD, a minimum MADRS total score of at least 26 and a CGI-S score of at least 4 at Screening and Baseline without clinically relevant medical or psychiatric history.
The study consists of a 12-week randomized, double-blind, single-dose administration period evaluating DT120 versus placebo, followed by a 40-week Extension Phase (EP) with opportunity for open-label treatment during which participants will be monitored and evaluated for potential retreatment with DT120 based on pre-specified safety and symptom severity criteria.
