Study of Efficacy and Safety of MIJ821 in Addition to Comprehensive Standard of Care on the Rapid Reduction of Symptoms of Major Depressive Disorder in Subjects Who Have Suicidal Ideation With Intent

The main purpose of this study was to support the dose selection for future Phase III clinical trials by evaluating efficacy and safety of four MIJ821 doses (very low, low, high and very high) administered every other week for 6 weeks (3 infusions) by intravenous infusion on top of pharmacological antidepressant treatment, compared with placebo, for the rapid reduction of the symptoms of MDD in participants who have suicidal ideation with intent. In addition, the study explored the effect of single dose administration of very high and high doses to treat MDD in participants who have suicidal ideation with intent. The study consisted of three periods: a Screening Period (up to 48 hrs), a double-blind Core Period (6 weeks) and Extension Period (up to 52 weeks). The Extension Period explored durability of the effect of the study treatment and the effect of MIJ821 on relapse rate, as well as safety of MIJ821 administration. Those patients that responded to treatment at the end of the Core period were followed for up to a 52-week Extension period and were allowed to be retreated due to a relapse once with the same active treatment regimen as in the Core period (participants treated with placebo in the Core period were randomly switched to an MIJ821 regimen).