This is a two-part (open-label followed by double-blind) study evaluating the safety, tolerability, pharmacokinetics, and efficacy of KH607 in 120 participants diagnosed with moderate or severe Major Depressive Disorder.
Age: 18 to 65 years old (inclusive), Male or female.
Participant with diagnosis of MDD as diagnosed by Structured Clinical Interview for Diagnostic and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) , with symptoms that have been present for at least a 4-week period
Participant has a Hamilton Rating Scale for Depression (HAM-D) total score ≥24 at screening and Day 1 (prior to dosing).
Participants who is taking antidepressants must have stopped for 7 days or 5 half-lives of the antidepressant prior to Day 1.
Participant is currently at significant risk of suicide, or has attempted suicide associated with the current episode of MDD.
Participant has a history of treatment-resistant depression, defined as persistent depressive symptoms despite treatment with adequate doses of antidepressants from two different classes for an adequate amount of time.
Participant has active psychosis.
Participant had used modified electroconvulsive therapy (MECT), transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), deep brain stimulation (DBS), light therapy, etc. within 1 month prior to Day 1.