The trial included a screening period of up to 28 days. On Day 1, after screening, eligible participants were randomized to one of the treatment arms (1 mg, 4 mg, or 10 mg of MIJ821) or placebo and received study treatment administered as a single subcutaneous injection. Participants remained at the clinic for at least 4 hours after administration of study treatment for safety observation including assessment of local tolerability by visual inspection of the injection area. Post-dose clinic visits occurred 24 hours post dose (Day 2), Days 8, 15, 22 and 29 to evaluate efficacy and safety. Efficacy assessments included the Montgomery-Asberg Depression Scale (MADRS) and other clinical outcome assessments (COAs). Safety assessments included laboratory tests, ECGs, vital signs and physical examinations. In addition, phone calls were conducted 3 days after each on-site clinic visit with the exception of the End-of-study (EOS) visit. EOS visit was completed on site on Day 29. Including screening, participants were in the study for up to 8 weeks (57 days).
