An Efficacy and Safety Study of Sirukumab in Participants With Major Depressive Disorder

Inclusion Criteria:

• Participants must have a primary DSM-5 diagnosis of MDD
• Must have a HDRS total score greater than or equal to (>=) 18 at screening and predose at Day 1, as recorded by the remote independent rater and must not demonstrate an improvement of > 25 percent (%) on their HDRS total score from the screening to baseline visit
• Must be medically stable on the basis of physical examination, medical history, vital signs, clinical laboratory tests and 12-lead ECG performed at screening. If there are abnormalities, the participant may be included only if the investigator judges the abnormalities or deviations from normal to be not clinically significant. This determination must be recorded in the subject's source documents and initialed by the investigator
• Participants with hypothyroidism who are on stable treatment for 3 months prior to screening are required to have thyroid stimulating hormone (TSH) and free thyroxine (FT4) obtained. If the TSH value is out of range, but FT4 is normal, such cases should be discussed directly with the medical monitor before the subject is enrolled. If the FT4 value is out of range, the participant is not eligible

Exclusion Criteria:

• Any other current Axis one psychiatric condition, including, but not limited to, MDD with current psychotic features, bipolar disorder (including lifetime diagnosis), obsessive-compulsive disorder, borderline personality disorder, eating disorder (eg, bulimia, anorexia nervosa), or schizophrenia (lifetime). The MINI will be used to screen for comorbid psychiatric diagnoses. As noted above, subjects with a diagnosis of comorbid GAD, Post-Traumatic Stress Disorder, Persistent Depressive Disorder, ADHD, Social Anxiety Disorder, Panic Disorder with or without agoraphobia or Nicotine/Caffeine Dependence may be included, if the investigator considers MDD to be the primary diagnosis
• A history of alcohol or substance use disorder (abuse/dependence) within 6 months prior to screening (nicotine and caffeine dependence are not exclusionary)
• A current or recent (within the past year) history of clinically significant suicidal ideation (corresponding to a score of >= 3 for ideation) or any suicidal behavior within the past year, as validated on the C-SSRS at screening or baseline. Subjects with a prior suicide attempt of any sort, or history of prior serious suicidal ideation/plan should be carefully screened for current suicidal ideation and only included at the discretion of the investigator
• More than 3 failed antidepressant treatments (of adequate dose and duration) in the current episode of depression (verified by the MGH-ATRQ)
• Length of current major depressive episode > 60 months